Lecture 11.
“Surgical infection. Classification. Acute purulent infection.
Osteomyelitis.”
The microorganisms divides on pathogenic and nonpathogenic, but this
division is conditional.
Pathogenicity of a parasite — it is it ability to call infection disease in
organism of the host. Pathogenicity of microorganisms dialectically is connected to
immunity of an macroorganism. Even the agents with expressed pathogenicity not
always can call disease. And on the contrary, at a significant drop of immunity of
an organism under influence of those or other conditions the disease develops at
the expense of a duplication of an agent, nonpathogenic for an organism with
normal immunity.
Modern hospital infection is called in basic just by these last biologicalecological groups of pathogens (nonpathogenic obligate and facultative parasites).
The purulent processes are called by various microorganisms but the most often
reason of their development are Staphylococci, Streptococci, Pneumococci,
Gonococci, Blue pus bacilli, Escherichias etc. Quite often agent of purulent
process happens a symbiosis of several aerobic microorganisms or even their
combination with anaerobic microorganisms. It’s mixed infection.
On clinical current and pathoanatomical to changes in tissues all kinds of
surgical infection are divided on acute and chronic. Acute surgical infection is
divided on acute purulent, acute anaerobic, acute specific – (tetanus, antrax) and
acute putrifactive.
The chronic surgical infection can be nonspecific and specific (tuberculosis,
actinomycosis etc.).
Classification of purulent surgical infection
1. On clinical current is distinguished acute purulent infection — general and local,
and also chronic purulent infection — general and local.
2. On localization of a defeat selects a defeats of a skin, underskin fat; covers of a
skull, its contents; neck, breast, chest wall; pleura, lungs, mediastinum, peritoneum
and organs of abdominal cavity; pelvis and its organs; bones and joints.
3. On aetiology purulent surgical diseases are Staphylococcus, Streptococcus,
Pneumococcus, etc.
4. On aetiology distinguishes also purulent mono- and polyinfection.
SPREAD OF INFECTION
Cellulitis
Cellulitis is inflammation spreading along the subcutaneous or a fascial
plane often as the result of infection with Streptcoccus pyogenes which has entered
the tissue through an accidental wound, graze, or scratch, or following surgical
incision. Unchecked this may lead to septicaemia after a rapid spread within the
tissues. Initially red and itchy at the site of the innoculation, the skin swells and
becomes tender, frequently being shiny. There may be local gangrene. Rest,
elevation of the part, and the appropriate antibiotic should lead to resolution, but
any underlying condition (e.g. diabetes) should be treated.
LOCALLY—Celtulitis
INFECTION
REGIONALLY—Lymphangitis
SPREADS
Lymphadenitis
GENERALLY (systemically)
BLOODSTREAM—Bacteraemia
Septicaemia
TO OTHER
BODY CAVITIES—Peritonitis
PATIENTS
Meningitis
—LYMPHATIC SYSTEM
Cellulitis in special sites
Orbit.—Spreading infection from wounds of the paranasal sinuses will cause
proptosis and impairment of ocular movements. Associated thrombophlebitis can
extend to the meninges and, if the ophthalmic veins are involved, to the cavernous
sinus. Early attention and the use of antibiotics (Penicillin) is vital in reducing
morbidity.
Neck.—Submaxillary cellulitis is often termed 'Ludwig's angina" and the great risk
of infection spreading from tonsils or mastoids to the neck is that the cellulitis will
involve the glottis with concomitant oedema, asphyxia and mediastinitis.
Pelvic cellular inflammation.—The common cause is a lateral tear in the cervix
during parturition. The pelvic inflammation as a result of the trauma incurred
during childbirth may extend along the broad ligament appearing above the
inguinal ligament. Anaerobic infection (actinomycosis) and Chlamydial infection
may arise as secondary infections following the use of intra-uterine contraceptive
devices. They will present as a cause of pelvic pain and the diagnosis requires the
culture of endocervical pus. Metronidazole should be used whilst awaiting the
results of cultures which should also exclude sexually transmitted infections (N.
gonorrhoea or herpes virus infection).
Localised infection will spread by lymphangitis to local or regional lymph nodes
and by bacteraemia to distant organs.
Bacteraemia and Septicaemia (overwhelming bacterial proliferation and toxins in
the blood).—These terms describe the presence of organisms in the blood. The
clinical features include a source of infection, hypotension, pyrexia and often
rigors ('shaking of the bed'). Hepatic involvement and acute cortical necrosis of the
kidneys may be associated with bacteraemia, also peripheral circulatory collapse.
Intra vascular coagulation defects frequently accompany the later stages.
Following at least three blood cultures treatment must be immediate and
aggressive by means of a broad spectrum attack using a p-lactam antibiotic
together with an aminoglycoside and metronidazole, (these should be given
intravenously), with blood transfusions, plasma expanders and hydrocortisone.
Bacteraemia can cause multiple metastatic abscesses in distant organs and these
will require treatment.
Abscess Formation
An abscess is a collection of pus. Bacteria which cause pus (pyogenic bacteria)
reach the infected area by:
(1) Direct infection from without, e.g. penetrating wounds.
(2) Local extension from some adjacent focus of infection.
(3) Lymphatics.
(4) Blood-stream (haematogenous).
Pus is a collection of polymorphonuclear leucocytes from which the
proteolytic enzyme causes liquefaction of the tissues. The tension within an
abscess rises as plasma exudes into it and, unless the abscess is surgically drained,
the pus will discharge eventually along the line of least resistance. The area
immediately around the abscess which is infiltrated with leucocytes and bacteria is
called the pyogenic membrane.
Symptoms depend upon the site, size and tension of the abscess and the virulence
of the bacteria causing it; the patient will suffer generalised illness, and throbbing
pain with swelling.
Signs of Pus—
(a) GENERAL.—The temperature is elevated and bacteraemia with rigors may
occur.
(b) LOCAL.—The five classical local signs of inflammation are due to hyperaemia
and inflammatory exudate : 1. Heat. 2. Redness of the skin over the inflamed area.
3. Tenderness. 4. Swelling. 5.Loss of function.
Prevention.—An abscess can usually be prevented by timely and appropriate
antibiotic treatment.
Treatment. Once pus is diagnosed, the abscess must be incised and dependent
drainage instituted as penetration by antibiotics is poor. In 'high risk' anatomical
areas, as in the neck or axilla, Hilton's method should be used. This consists of
incising the skin and superficial fascia, and opening the abscess by thrusting a pair
of sinus forceps or a haemostat into the cavity. By separating the blades, a
sufficiently large opening can be made to insert, if necessary, a finger in order to
convert loculi into a single cavity, and to insert a drainage tube. Pus should be
cultured in order to isolate and identify the organism and its sensitivity to
antibiotics. The underlying cause needs to be ascertained and appropriate treatment, e.g. surgery, instituted.
Errors in treatment.—If pus is not drained and antibiotics are continued, the
inflammation continues to smoulder and a hard lump forms, called an 'antibioma'.
In certain areas, e.g. the breast, it becomes difficult clinically to decide whether
such a lump is malignant or inflammatory.
Incising an aneurysm in mistake for an abscess. It has been done on many
occasions
IMAGING IN INFECTION
There are four available techniques which allow surgical infections and collections
of pus to be accurately diagnosed and clearly defined:— Conventional radiology,
Isotope scanning. Ultrasound (US), Computed Axial Tomography, (CT). The
clinical indications will usually determine the appropriate technique and the site of
infection will influence the choice of investigation.
Conventional radiology, for example, reveals fluid levels when air or gas is present
as in subphrenic abscess or lung abscess, or pus suggested by an opacity filling a
space (the nasal antrum or the pleural cavity).
Isotope scanning.—Intravenous technetium accumulates at the site of infection and
clearly demonstrates the position of brain abscesses, inflammation such as
osteomyelitis, and hepatic abscesses. Gallium scans may be needed for mediastinal
abscesses, pelvic and perinephric abscesses or subphrenic abscesses, but care in the
interpretation is needed as gallium is taken up by normal breast tissue under certain
circumstances. Ultrasound or CT scans of suspicious areas may show regular
necrotic centres which will help to distinguish abscesses from tumours.
Ultrasound (US) reliability depends upon close contact of the US probe and the
skin. It cannot be used over surgical wounds, colostomy or ileostomy bags. Gas in
the bowel obscures the underlying organs and therefore US is of the greatest use in
liver, spleen and urinary bladder investigations whilst it is of considerable value in
the diagnosis of gallbladder stones or empyema. The demonstration of bacterial
vegetations upon a cardiac valve by echocardiography can be decisively diagnostic
of endocarditis.
Computed tomography (CT) scans are usually necessary for localising brain
lesions and abscesses although isotope scans can demonstrate these also.
PREVENTING INFECTION
Antibiotic Prophylaxis is used to prevent bacteraemia and wound infection when
instrumentation or surgery is performed upon a site with normal flora or where
infection already exists (e.g. cystoscopy when bladder infection is known to be
present). It should be maintained for a short period, seldom using more than three
doses, the maximum duration being 48 hours. Prophylaxis should cover and
control the known or likely pathogens. Prophylaxis may conveniently be given
intravenously as a bolus after induction of anaesthesia or, ifintramuscular
antibiotics are to be used, may be given one hour before surgery. Aminoglycosides
such as gentamicin require that serum levels be monitored if they are used for more
than 36 hours. If renal function is known to be satisfactory three doses only of 80120 mg given at 8 hour intervals may be used for a normal adult.
Metronidazole may be given as one gram per rectum (suppository) with resulting
excellent blood levels; the first suppository should be given 1 1/2 hours
preoperatively. Topical antibiotics should be reserved for use in eye or ear surgery;
skin antibiotics are seldom if ever indicated and can lead to severe antibiotic
resistant infections.
Antibiotic impregnated 'cement' or 'beads' for use in orthopaedic prosthetic
operations are gaining favour; they act as a local reservoir giving slow release to
the site of operation. Alternative regimes are based on single doses of
cephalosporins, e.g. prior to the open reduction of fractures.
Care should be taken with diabetics (superadded Candida and multi-resistant
Gram-negative infections) and patients who are immunodeficient or
immunesuppressed, e.g. receiving steroid therapy or receiving radiotherapy.
Penicillin prophylaxis for up to one week is mandatory for the prevention of
Clostridial gas gangrene at the time of lower limb amputation through the thigh in
those patients who have diabetic or severe peripheral vascular disease.
PREVENTING INFECTION IN SURGICAL PROCEDURES
Abdominal procedures Colorectal surgery
Ampicillin 500 mg I.V. 8
hourly x 3* + Metronidazole
Appendicectomy
Metronidaxole i gram rectally
Peritonitis
Ampicillin 500 mg
Gentamicin 120 mg followed by
80 mg twice at 8 hour intervals
with Metronidazole
Biliary
Ampicillin or a cephalosporin
Urinary tract
Amoxycillin 3 g or single dose of
Instrumentation or
Gentamicin 120 mg if previously
surgery
infected
Obstetric surgery
Vaginal hysterectomy,
Ampicillin 500 mg I.M.
termination of pregnancy
Metronidazole I g rectally
with history of pelvic
once only
inflammatory disease
or abdominal caesarean
Orthopaedic
Compound fractures
Ampicillin 500 mg 8 hourly with
Flucloxacillin 500 mg 6 hourly
(or Erythromycin 500 mg 6 hourly
if Penicillin hypersensitive)
Elective or prosthetic 48 hours only Ampicillin 500 mg
8 hourly surgery
and Flucloxacillin 500 mg 8
hourly
Lower limb amputation Penicillin 2 mega units at
induction and thereafter 4 mega
units daily for 5-7 days
Patients with known
1. Dental surgery
Amoxycillin 3 g orally and
valvular disease,
Probenecid I g, orally (if allergic
prosthetic grafts of the 2. Urethral
to Penicillin, Erythromycin 1-5 g
cardio-vascular system catheterisation orally followed by 0-5 g 6 hours later).
(e.g. aortic or aortic
3. Operations under
If general anaesthesia or
valve), history of
general anaesthesia
gastrointestinal investigation is
rheumatic fever
being performed a single dose
of Gentamicin 1-5 mg per kg of
body weight I.M. must be
added
Preventing Infection at Operation.—The open wound is at risk of contamination
from airborne dust which carries bacteria derived from skin organisms of
attendants and operating room personnel. Positive pressure, filtered ventilation of
the operating theatre prevents bacteria gaining entry with the air. Ultra-clean
ventilation (laminar flow and fine filters) has been shown to reduce wound
infection rate by two-fold. Body exhaust suits carrying away the infected skin
particles of the surgeons and assistants clearly reduces the number of infected
particles near the wound and has been shown to reduce the wound infection rate by
sevenfold.
The patients own skin is a source of infection especially at abdominal operations
and can be treated by pre-operative bathing, and skin preparation with alcoholic
povidone iodine solution or 5% chlorhexidine in 70% alcohol. Povidone iodine
compresses applied to the thigh for one hour prior to hip arthroplasty reduce the
risk of self infection. At the time of operation, the use of a plastic adhesive film
(Opsite®) through which the incision is made helps to prevent contamination
during the operation itself. Surgical hand washing with hexachlorophane,
chlorhexidine, or povidone iodine and the use of gloves, mask and change of
clothes all contribute to reducing the risk of surgeon transmitted infection.
Instruments.—Central hospital and theatre sterile supply departments use high
temperature autoclaves (i32°C) for sterilising instruments, whilst equipment made
of heat sensitive material may be sterilised at 8o°C in sub-atmospheric pressures
('low temperature steam') with or without a formalin injection cycle (e.g. for
cystoscopes). Some endoscopes (e.g. colonoscopes) may require special
procedures for disinfection; liquid gluteraldehyde is often useful for disinfection of
cleaned instruments. Where viral infections (Hepatitis B) are implicated
hypochlorites or steam disinfection are used while in operating theatres the
infection control policy will clearly lay down guidelines for the disinfection of
blood contaminated instruments before cleaning if possible. The exercise of proper
professional care will usually prevent self-inflicted injuries with instruments that
may be at risk of spreading Hepatitis B virus or HIV virus by blood contamination.
Controlling Surgical Infection—Control of Infection Team.—Vigilance,
education and definition of policies for controlling infection in surgical wards is
best placed in the hands of a Control of Infection team consisting of a control of
infection nurse or considerable seniority, a medical microbiologist and a surgeon.
Not only is it necessary to monitor the type of infections and the resistance and
distribution of the bacteria, but the in-service education on the principles of wound
care, catheter toilet, aseptic dressing techniques can best be managed by such a
team. Isolation of high risk patients, modification of antibiotic regimes, and the
prevention of spread of any resistant infections will all require the combined
speciality interest for the advice to be authoritative, acceptable and effective.
Though the tissues do not react to each of the pyogenic bacteria in an exactly
similar way, the typical local effect of pyogenic infection is the formation of a
cavity filled with pus—an abscess—and the general or constitutional effect is the
establishment of fever, leucocytosis and prostration. The constitutional reaction
varies little in kind, though much in degree, whatever the pyogenic microorganism.
The character of the local reaction, on the other hand, is more directly related to
the type of invading bacterium. Frank suppuration, that is, a rapid solution of tissue
and a free outpouring of leucocytes, is habitually excited by staphylococci; and a
diffuse suppurative inflammation, cellulitis or phlegmon, characterized rather by
edema and necrosis than by an abundant formation of pus, is typical of
streptococcal infection. It is the frankly suppurative type of inflammation caused
by the familiar staphylococci of the skin which commonly gives rise to abscess.
The local signs of any suppurative inflammation are heat, redness, swelling
and pain, with which must be included sensitiveness to touch or movement, that is,
tenderness. Moreover, abscesses of sufficient size exhibit, to the practised touch,
fluctuation, a wave-like impulse transmitted through a soft-walled sac of fluid in
response to pressure. The combination of these various signs is unmistakable, but
since any one or more of them may for various reasons be absent, the significance
of each requires investigation. Difficult as it is to assign a relative order to their
importance, pain, heat and fluctuation appear to be of the greatest clinical
significance; redness of the least. They will therefore be considered in that order.
Pain results from the stimulation of sensitive nerve fibers or their endings and may
perhaps be attributed to distension by toxic substances of tissue supplied with such
fibers. The skin is well furnished with sensory nerves; the subcutaneous tissues and
muscles arc not. The periosteum, the serosa of points, the anterior rectus sheath,
the parietal peritoneum and the pleura are potential sources of exquisite pain, but
the abdominal and thoracic viscera are themselves comparatively insensitive,
though when distended by suppuration within, such solid organs as the liver,
spleen, and kidneys may become the seat of pain which must then be attributed to
the rapid stretching of their capsules and, in some instances, tension upon their
(parietal) peritoneal attachments.
The severity of pain is usually proportional to the rapidity in development of the
suppurative process. Thus an abscess which gathers slowly and distends the tissues
gradually, occasions comparatively little subjective sensation while a very active
process may be a source of agony. To some degree also the severity of pain is
influenced by the toughness of the tissue in which the abscess develops. For such
reasons, the minute infection (Paronychia) beneath the edge of the nail is painful
out of all proportion to its extent, and the same is even more true of acute
inflammation within the tough pulp of the finger tip (Felon). Subperiosteal
inflammation, particularly in regions where fibrous tissue is solidly attached to
rough bone, is notably painful. Perhaps the most agonizing of all are the abscesses
within the thick walls of the long bones (Osteomyelitis). On the other hand,
suppuration within yielding tissues may be almost unnoticed until, perhaps, it
reaches and invades one of the sensitive surfaces already mentioned.
Pain, then, is usually the most enlightening of all the symptoms of abscess. It
is increased by pressure or movement. Its character, even in the absence of other
local signs, may suggest the existence of an abscess and indicate its exact position.
The throbbing pain of a felon and the deep agonizing pain of acute osteomyelitis
are examples of this sort. On the surface of the body, pain is a less constant
evidence of abscess than heat, redness and fluctuation, since tension of the
inflamed sensitive skin is readily relieved by softening of the tissues and by even
partial evacuation. Abscesses in the skin are more sore than painful, though they
are often exquisitely tender to the touch.
Heat is due to local hyperemia but may be detected in the absence of any redness
whatever. In infections of the skin, the two signs go together, but beneath the
surface, the hyperemia about an abscess may be evident to the touch when the skin
is quite normal in color. Local heat is a very early and constant sign of even a
relatively deep suppurative process It is to be sought by comparing the suspected
region with a remote symmetrical part. In the presence of an abscess deep in the
thigh, or even within the femur, the surface of the affected leg may be ever so
slightly warmer than that of the other. The two thighs, in that case, or it may be the
hands or arms in another, should be lightly and simultaneously touched by the
sensitive palmar surfaces of the examiner's two hands, and the warmth of the
opposite sides rapidly compared. Local heat and pain are almost pathognomonic of
abscess, even though the suppuration is so situated that fluctuation can not be
elicited, and in the presence of superficial, fluctuating collections of fluid, absence
of heat distinguishes cysts and cold (tuberculous) abscesses from acute pyogenic
infections.
Fluctuation is a rather gross evidence of abscess. Since it merely points to the
presence of the collection of fluid, it’s only valuable when some other sign of
suppuration is detectable. Indeed it is chiefly an aid in confirming other findings
and in marking, for purposes of treatment, the exact position of the lesion.
Recognition of the fluctuant border of a collaction of pus may call attention to the
point at which dependent drainage must be established. Even a collection of fluid
too small to transmit an actual fluid wave may be detected in the midst of a
considerable brawny induration as a crater-like area of softening, and so indicate
beginning suppuration and a favorable location for drainage. Ordinarily, the sense
of fluctuation is sought by placing the palmar surface of the fingers of each hand
on the opposite sides of a swelling, or at a distance from each other upon a flat
surface, when, upon pressing down with one hand, the impression of a fluid wave
is received by the other.
Swelling would appear at first sight to be an indispensable sign of abscess. Indeed
it is usually present, and is quite apparent in such suppurations as are near the
surface of the body as well as in deeper ones of any notable size. In some
instances, however, tissues are destroyed and pus collects without causing any
appreciable swelling. In others, the abscess occurs in unyielding tissues or in
deeply seated organs concealed from sight and touch. Again, so many other
processes—new growths and cysts—are responsible for tumor that other signs of
suppurative inflammation are more reliable.
Redness, or hyperemia, is a very constant part of the response of the tissues to
irritation and is almost invariably present about an abscess. It is only noticeable,
however, when the abscess is near the surface. Then it is the earliest sign of
inflammation and precedes actual suppuration. But deeper abscesses may be
betrayed by the heat of hyperemia before any superficial redness is visible. This is
particularly true of infected operative or accidental wounds of considerable depth,
which may appear on the surface to have healed in a very reactionless way.
The Constitutional Symptoms of abscess become increasingly valuable and
even indispensable to diagnosis when suppuration is remote and inaccessible. A
painful, hot, red, swollen and fluctuant area would be recognized as an abscess
even without the confirmation offered by fever and leucocytosis, but deeply seated
pain, slight local tenderness upon deep pressure, and questionable local heat are
only suggestive of suppuration unless constitutional symptoms are present. In most
instances, the character of these general manifestations can be relied upon
implicitly; it is only in quantity that they vary. Since fever and leucocytosis result
from the reaction of the body to bacterial toxins, the virulence of the toxins is a
prime factor in this response. Naturally, the factor of virulence is influenced by the
degree to which toxic substances are absorbed into the general circulation, that is,
by the nature of the tissue in which the abscess originates. In these respects, the
richness of the blood and lymph supply in any region is a most important
consideration. The tension under which pus is retained is another. Thus a
suppurative process pent up in the vascular but unyielding medullary cavity of a
long bone promptly causes high fever, leucocytosis, and prostration, but an abscess
in the soft, yielding brain, which possesses almost no power of absorption, may for
a long time occasion no constitutional symptoms whatever. An infection within the
palm of the hand is a more potent source of fever than a similar process in the
loose, avascular fat of the thigh or the abdominal wall. Differences of this sort are,
however, matters of degree only. It almost never happens that an abscess of any
consequence fails to cause some rise of temperature, though instances of failure of
leucocytosis in the presence of overwhelming infection are not very rare.
Furuncle. A furuncle, or boil, is a very familiar form of abscess, peculiar to
the skin, and caused almost invariably by the staphylococcus aureus (or albus).
Infection reaches the dermis by way of a hair follicle or sebaceous gland. Bacteria
multiply rapidly at the point of entrance and here their toxins are sufficiently
deadly to provoke, before the protective defenses of the body can be set up, a rapid
necrosis of tissue. This slough is of such tough material as to resist for a time
complete solution. It remains, therefore, as the core of the furuncle. About it,
liquefaction of tissue and outpouring of a highly purulent exudate make pus, and
thus an abscess is formed in and beneath the true skin. About the abscess, new
vessels and young connective tissue keep the infected area surrounded by a layer
of granulation, to which the name pyogenic membrane is given. If the cocci
continue to develop, the pyogenic membrane is dissolved and the furuncle
enlarges. New defenses, however, again are built around it. Should the process be
prolonged, lymphoid and plasma cells begin to replace the polynuclear leucocyte.
Eventually, the invading bacteria are robbed of their virulence or the contents of
the abscess are evacuated, After incision or natural rupture, the cavity closes,
partly by collapse and partly by ingrowth of new tissue. Finally, a scar covered by
epithelium is left.
If the furuncle is observed from its beginning, it will usually be noted that a pustule
first appears about the base of a hair. In a few hours, a circumscribed dark red
swelling surrounds it. Heat, redness and pain are evident. The swelling slowly
increases until, from the fifth to the seventh day, a yellow, softened area appears at
its apex. The furuncle is then said to "point" and there is formed the beginning of
an opening from the abscess to the surface. Under favorable conditions, this
opening enlarges, so that there may be discharged through it by pressure the
sloughing "core" and pus. Sometimes the pus burrows beneath the upper layers of
the epidermis, making a flat, blister-like pustule. This communicates by a narrow
neck with the larger collection beneath. Such a furuncle has, on cross section, the
shape of a collar-button, a name which is often given to it, and the importance of
recognizing the lesion lies in this, that adequately to evacuate the deep portion of
the pus sac something more than the mere exposure of the superficial pocket is
required, ihe tiny opening into the deep pocket must be discovered and enlarged by
incision. From the time the furuncle is evacuated, healing begins. The discharge,
at first purulent, soon becomes serous and then drys up. Skin grows over the
granulations which fill the cavity. The resulting scar is often invisible.
One furuncle may lead to the appearance of many, suggesting, as indeed may be
the case, that a "crop" has been sown by the outpouring upon the skin of countless
virulent bacteria which have escaped from the original lesion. But of course the
same result may arise from a loss of resistance to a particular bacterium widely
distributed in the skin and heretofore held in subjection. The back of the neck is
commonly the seat of this sort of process; the axillary skin is sometimes most
stubbornly infected, the face is often invaded and the buttocks as well. Indeed, any
part of the skin may be affected. When the furuncles are in considerable numbers,
recurrent and spreading, the condition is known as furunculosis. Then the body
appears to have lost, to a greater or less degree, its combative quality. Under these
circumstances, a constitutional reaction in the form of moderate fever may be
present, and instances of considerable debilitation, doubtless partly due to the
annoyance and constant discomfort of the newly developing lesions, are sometimes
observed. That furuncles have long been considered a serious affliction may be
judged from the passage in the Bible wherein it is stated that "Satan went forth
from the presence of the Lord, and smote Job with sore boils from the sole of his
foot unto his crown," the most terrible affliction of which the devil could think,
and one which was intended to try Job's fortitude to the utmost. It is clear in some
instances and quite probable in many others, that furuncles afford entrance for the
staphylococci which so frequently occasion acute infections of bone in children.
Blood-borne staphylococcal infections of a similar source in persons of any age
may invade the lungs, kidneys, and other organs, not infrequently leading to a fatal
outcome.
Treatment: The furuncle should be evacuated in such a way as to render unlikely a
spread of infection into deeper tissues or into neighboring hair follicles. Thus it is
unusual to incise a boil before it has become a pus sac about which a well
organized pyogenic membrane is presumed to exist. And it is unusual even then to
incise until continued enlargement and absence of a necrotic spot upon its surface
indicate that it can not be ruptured by very gentle pressure. After opening, the
furuncle is covered with a sterile absorbent dressing. Sometimes a little piece of
guttapercha tissue is passed into it as a drain. Before evacuation, the skin about it is
kept as clean as possible with soap and water, and is often greased with a bland
ointment to keep the bacteria, as they are discharged from the opened abscess,
from finding new lodgment. A boil may sometimes be aborted by the use of hot
applications or the injection of a drop of pure carbolic acid into its core. The
application of heat, by increasing active hyperemia, hurries on the process to the
destruction of the bacteria or to frank suppuration.
When multiple active furuncles are present, the condition presents considerable
difficulty in treatment. The patient seems at times to lose all resistance and may
develop serious secondary infections. Under these circumstances, vaccines are
sometimes employed and may be useful. Many internal remedies have been tried.
The administration of yeast has sometimes seemed to do good. The salts of tin are
favored by a number of French investigators. On the whole, more reliance is to be
placed on general hygienic measures, in persistence in the most painstaking care of
the skin and in preventing the spread of sepsis from established furuncles to new
regions.
Carbuncle is a suppurative inflammation of the skin and subcutaneous tissue
having the form of a many headed furuncle, and like it, is caused by the
staphylococci. Its peculiar pathologic features and clinical course are due to the
nature of the tissue—the skin of the back of the neck, the back, the hairy dorsal
surface of the hand and fingers, and rarely the upper lip and scalp—in which it
originates. In these regions, the skin is particularly thick and tough, and from the
base of the hair follicles clefts of the true skin filled with fat—the columnae
adiposae of Warren—extend downward for a considerable distance. At their base,
these columns are firmly bound to the underlying fascia. Thus an infection which
does not rapidly reach the surface is likely to follow the fibrous attachments of the
columns downward to the deep fascia, whence it rises again to the skin through
other columns. The process once begun, spreads rapidly by the customary solution
of tissue and pus formation, reaching out continually along the deep fascia and
mounting in new areas. A rather terrifying lesion often several inches in diameter
may result. In its early stages, the carbuncle appears as a raised red area in whose
center pustules are dotted like the holes of a pepper pot. As it extends, its oldest
portion becomes a pussy grayish crater about which cyanotic skin, more tenacious
of life than the deeper tissues, forms an irregularly indented border. Large and
small openings and areas of slough surround the central crater, but in the newer,
growing area the early appearance of yellow pustules scattered or grouped in a
field of angry red is preserved and continued. Still beyond this zone is a region of
brawny edema diminishing in hardness and depth as the normal skin is
approached. The whole back of the neck and head from ear to ear may be occupied
by such a lesion.
Pain and tenderness are variable. Some carbuncles cause great suffering, while
others are painless and remarkably insensitive. When the lesion occupies the back
of the neck, the head is held rigidly bent forward. The patient is often prostrated,
sometimes delirious, and since carbuncles are particularly apt to attack diabetics,
the outcome is occasionally fatal. The small carbuncles which occur on the ulnar
side of the dorsal surface of the hand and upon the back of the proximal phalanges
of the fingers are misleading in appearance, since the many headed appearance of
the typical lesion is sometimes lost. Nor is it always realized that carbuncles occur
in these regions. Nevertheless they are exactly similar to the lesions of larger size
in other localities. Carbuncles of the face and scalp have a remarkable tendency to
invade the venous blood stream, leading to septic processes in the cerebral sinuses
and in the lungs.
Treatment will depend somewhat upon the general condition of the patient.
Careful physical examination with reference to chronic disease of the heart, lungs
or kidneys, and especially, examination of the urine for sugar, should always be
made. If the patient is profoundly septic and the carbuncle is not too large, the
whole may be excised by a circular incision carried down to the deep fascia. This
ends the disease more certainly, perhaps, than the less radical operations of crossed
incisions through the center of the carbuncle, the turning up of the flaps along the
plane of the deep fascia to the outer limit of the suppurative process, and the wide
open packing of the cavity which is usually employed. The anesthesia, should be
as innocuous as possible. Exposure to the x-ray, especially in the earlier stages, is
often curative, least so, unfortunately in diabetics. The carbuncle may soften early
or be "aborted." The sulfonamides and penicillin have been found effective,
particularly if infection is already present in the blood stream.
DIFFUSE SUPPURATIVE INFLAMMATION
This is a common, often severe and occasionally fatal disease. The names,
Phlegmon and Diffuse Cellulitis, are given to those suppurative inflammations in
which necrosis of tissue шау be extensive but pus formation is little marked;
in which the inflammatory reaction is rather in the form of intense widespread
vascularity and outpouring of serum than of local abscess formation; and in which
the streptococcus pyogenes is the usual infectious agent. Lymphangitis is the name
applied to an infection of similar origin confined to lymphatic channels. This may
occur as an independent process or may appear as an extension away from a parent
cellulitis. Almost invariably the superficial lymph vessels are the ones affected.
PHLEGMON, OR DIFFUSE CELLULITIS
Infection reaches the subcutaneous tissues by way of an injury which may be so
small and apparently harmless as to have been unnoticed. Or it may spread from
one of the common punctured, incised wounds of the fingers and toes. It is a
frequent cause, as will appear later, of septic hand. The organism —almost
invariably the streptococcus—causes a local necrosis with exudation. If the
infection is very mild, the exudate is soon absorbed and little loss of substance
occurs. If it is severe, destruction is extensive. When at last it has subsided, much
necrotic tissue remains to be cast off and the area occupied by the septic process is
largely converted into granulation tissue. As the resulting scar contracts, the
overlying skin is likely to become adherent to underlying structures. This sequence
of destruction, induration and shrinkage may impair the function of adjacent
muscle or tendon.
The appearance of such a lesion differs decidedly from that of a furuncle or
carbuncle. Redness and swelling appear about the point of origin. The skin pits on
pressure. The area of infection may extend up a limb or over the body, as the case
may be. Near the starting point of the process, the skin is a deep angry red. At its
advancing edge, which seldom is sharply defined, it is of a lighter color. Everywhere the inflamed tissue has, to the touch, a brawny feeling obscuring all
landmarks. In the older portion of the lesion an area of fluctuation or of crater-like
softening indicates the situation of advanced necrosis and the presence of a
collection of thin pus. Blebs, and even great blisters containing a cloudy fluid,
mark a particularly severe process, as if the tissues had been slightly burned.
Extensive destruction of skin (sloughing) may expose raw skin and a thick, yellow,
gelatinous subcutaneous layer from which a thin, cloudy fluid exudes in
abundance. And if, as resolution of the exudate occurs, such an incision is carefully
observed, it will be noted that larger and smaller bits of grayish tissue are
continually coming from the wound. In the most severe infections, this sloughing
is of great extent, involving large sheets of subcutaneous tissue and more or less of
the skin itself.
THE TREATMENT OF DIFFUSE SUPPURATIVE INFLAMMATION
The General Principles of Treating Established Diffuse Suppurative
Inflammation.—Since the discovery that hemolytic streptococci are susceptible to
the action of sulfanilamide, various other sulfonamides have been found to have a
similar action, some being superior to sulfanilamide in their effect upon certain
bacteria. All tend to sterilize the blood stream, having a bacteriostatic effect on the
organisms, but they do not kill the bacteria in the initial lesion which still requires
surgical drainage. Identification of the causal organism is therefore more than ever
necessary. The sulfonamides are given by mouth (the initial dose often
intravenously) but when sterilized, can be powdered freely into open wounds,
where, especially in fresh ones, they help to overcome infection, without
interfering with healing. For established infection they—and penicillin—are
unpredictably effective.
An example of one of the most familiar types of diffuse cellulitis is an infection
spreading from the tip of the elbow: a small contused wound may have been the
starting point. In the course of a few days the disease will have spread up and
down the arm, perhaps encircling it. Over the olecranon the skin may exhibit a
very small area of necrosis. For several inches in every direction, it will be deep
red and shiny. Swelling will be very great and of a porky firmness. The advancing
borders will show a fainter color and softer edema shading imperceptibly into the
normal tissues. No fluctuation will be discernible, but careful palpation may
disclose a softened area in the center and perhaps other crater-like spots about it.
Tender lymph nodes will probably be palpable in the axilla. Such a lesion can not
possibly be drained in the ordinary sense. Yet if the areas of softening are incised,
a considerable amount of thin pus will escape and perhaps small pieces of
sloughing fascia. Twenty-four hours of immobilization, elevation and hot
poulticing (which here finds its greatest usefulness) will show a marked
improvement. The skin will everywhere be wrinkled, a sure evidence of receding
edema, the redness will have decreased, the lymph nodes in the axilla will have
subsided, and if a blunt instrument is passed into one of the incisions, it will
probably be found that new pockets have become connected with the original
openings. More exactly dependent drainage may then be indicated. The speed of
recovery will depend upon the amount of dead tissue which must be cast off or
absorbed, and upon the persistence of the organisms in scattered areas.
Phlegmonous processes in certain regions, as in the case of the hand or foot, may
penetrate into complicated tissue spaces or tendon sheaths. They may also become
a starting point for lymphangitis. The treatment of this latter condition requires the
nicest judgment, for though it is not of itself a suppurative condition, yet too often
it leads infection to regions which may require drainage. A small area of infection
about the hair follicles on the back of one of the fingers may, without warning,
occasion a sudden extension of lymphangitis which winds up the back of the hand
and arm to the axilla. Chills, high fever, and intense prostration may be present. In
such a case, incision of the long streak or streaks of lymphangitis would certainly
spread rather than restrain infection. Incision of the primary focus might and
probably would be beneficial, but immobilization, elevation and poulticing will
usually (certainly at the beginning) be more helpful. In all probability, there will be
no breaking down of tissue, and unless the infection is of such virulence that death
follows within twenty-four hours, the whole process will probably subside in a few
days, leaving no trace. Indeed, any operative treatment which it requires is called
for only by the lesions with which it is associated or by the complications it causes.
Mastitis of infants is at least as common in the male as in the female. On the
third or fourth day of life, if a breast of an infant is pressed lightly, a drop of
colourless fluid can be expressed; a few days later there is often a slight milky
secretion, which finally disappears during the third week. This is popularly known
as 'witch's milk'. The explanation of this phenomenon is that the hormone which
stimulates the mother's breast reacts also upon the mammary tissue of the foetus.
Thus it is essentially physiological.
Mastitis of puberty is encountered rather frequently, usually in males. The
patient, aged about fourteen, complains of pain and swelling in the breast. In 80%
the condition is unilateral but the opposite breast may be affected later. The breast
is enlarged, tender and slightly indurated. Suppuration never occurs. The
tenderness subsides in fourteen days or so, but induration often persists for several
weeks. In some instances enlarged tender breasts may persist in males for a
prolonged period even up to years. In such circumstances it may be justifiable to
recommend local mastectomy, conserving the nipple.
Mastitis of mumps is usually unilateral, and more common in females.
Mastitis from milk engorgement is liable to occur about weaning time; and
sometimes in the early days of lactation when one of the lactiferous ducts becomes
blocked with epithelial debris. In the latter instance a sector only of the breast
becomes indurated and tender.
Bacterial mastitis, which is by far the most common variety of mastitis, nearly
always commences acutely. Although often referred to as mastitis of lactation, it is
incorrect to assume that acute mastitis in women is necessarily lactational. Of a
hundred consecutive cases of breast abscess, thirty-two occurred in women who
were not lactating; probably some were due to infection of a haematoma. In almost
every case the infecting organism is a staphylococcus. In cases where the infection
is acquired in hospital no less than 90% of the infecting staphylococci are
insensitive to penicillin.
Aetiology.—Mastitis of lactation is seen far less frequently than in former years.
Usually the intermediary is the infant; after the second day of life 50% of infants
harbour staphylococci in the nasopharynx.
'Cleansing the baby's mouth' with a swab is also an aetiological factor. The delicate
buccal mucosa is excoriated by the process; it becomes infected, and organisms in
the infant's saliva are inoculated on to the mother's nipple.
There seems little doubt that in the great majority of cases the precursor of
intramammary mastitis is failure of secretion to escape because one (rarely more)
of the lactiferous ducts becomes blocked with epithelial debris—a hypothesis that
is strengthened by the fact that, whether they are lactating or not, intramammary
mastitis and abscess of the breast are relatively frequent in women with a retracted
nipple. While stasis in some part of the lactiferous tree is a major factor in the
production of this condition, undoubtedly the older hypothesis—ascending
infection from a sore or an infected cracked nipple—must not be spurned. Once
within the ampulla of the duct, staphylococci cause clotting of milk. Within the
clot organisms multiply rapidly.
Clinical Features.—The affected breast, or more usually mainly one part of it,
presents the classical signs of acute inflammation, and what is aptly called 'the
cellulitic stage' of a breast abscess has been reached.
Treatment during the Cellulitic Stage.—The patient should rest in bed and,
pending the results of bacterial culture of her milk, be given an antibiotic
appropriate for a penicillin resistant staphylococcus, e.g. cloxacillin or
flucloxacillin. Support to the breast and local heat will help to relieve the pain and
permit examination of the inflamed breast daily, which is essential.
Unless there is some strong reason to continue breast feeding it is better to wean.
Suppression of lactation usually follows naturally upon the cessation of suckling
but if necessary bromocriptine can be given, 2-5 mg bd for 14 days. Stilboestrol is
no longer used for this purpose. If the mother insists on continuing breast feeding it
is safer to use the unifected breast only and to empty the infected breast of milk,
which may have a high bacierial content, by means of a breast pump. Boiling or
pasteurisation of expressed milk not only destroys its content of antibodies but also
greatly reduces its nutritional value to the infant.
Formation of an 'Antibioma'.—It is absolutely essential that an antibiotic should
not be given in the presence of undrained pus. In such circumstances, if an
antibiotic is given the pus in the abscess frequently becomes sterile and a large
brawny oedematous swelling remains in the breast and takes many weeks to
resolve. Sometimes there is excessive fibrosis and this, with the absence of
tenderness, had led to the mistaken diagnosis of carcinoma. It is better to explore
the mass with a wide-bore aspirating needle than to cause an 'antibioma' with its
attendant pain, chronicity, and ill health. Most 'antibiomas' are due to late,
inadequate, and ineffective antibiotics.
Indications for Operation.—The breast should be incised when, after emptying, an
area of tense induration is felt and/or when oedema of the overlying skin is found.
In contrast to the majority of localised infections, fluctuation is a late sign and
incision must not be delayed until it appears. Usually the area of induration is
sector-shaped, and in early cases about one-quarter of the breast is involved; in
many
later
cases
the
area
is
more
extensive.
Drainage of an Intramammary Abscess.—The usual incision is sited in a radial
direction over the affected segment. One parallel with the cutaneo-areolar margin
has a better cosmetic value and does permit access to the affected area. The
incision passes through the skin and the superficial fascia. A long haemostat is then
inserted into the abscess cavity. Every part of the abscess is palpated against the
point of the haemostat and its jaws are opened. All loculi that can be felt are
entered. Finally, the haemostat having been withdrawn, a finger is introduced and
any remaining septa are disrupted. Unless the abscess cavity is situated at the very
highest sector of the breast a counter-incision should be made at the most
dependent part of the breast and a drainage tube inserted. In this, almost more than
any part in the body, dependent drainage is essential.
Subareolar mastitis is not a true mastitis but results from an
infected (sebaceous) gland of Montgomery, or from a furuncle on or near
the areola. The inflammation develops insidiously, usually without
constitutional symptoms. When the patient presents early, there is often
an area of induration no larger than a pea. No matter how small, if a lump
can be felt, pus is present, and the abscess should be drained without
delay. Spontaneous rupture, if allowed to occur, does not cure the
condition; it merely results in recrudescence or chronicity.
Chronic intramammary abscess which follows inadequate drainage
or injudicious antibiotic treatment is often a very difficult condition to
diagnose: when encapsulated within a thick wall of fibrous tissue, the
condition cannot be distinguished from carcinoma without the
histological evidence from a biopsy.
Chronic Subareolar Abscess (leading to a Mammillary fistula).—A
recurrent subacute or a chronic abscess may occur apart from lactation in
women of the child-bearing age. The condition is a frequent complication
of long-standing retraction of the nipple the infection being restricted to a
single obstructed duct system. The abscess ruptures and subsides, only to
repeat the cycle over and over again at intervals of a few months when it
forms a chronic mammillary fistula. A non-infective inflammation such
as duct ectasia may also result in fistula formation.
Treatment.—Antibiotic therapy followed by incision and drainage is
useless. The fistula must be treated in the same way as a fistula-in-ano,
i.e. the track is laid open and saucerised
Retromammary Abscess.—Here the pus is situated in the cellular
tissues behind the breast, and in the great majority of cases the abscess
has no connection with the breast proper. Usually a retromammary
abscess originates from a tuberculous rib, infected haematoma, or
possibly from a chronic empyema, and treatment must be directed to the
relief of these conditions. A submammary incision allows the breast to be
retracted as necessary from the field of operation.
ERYSIPELAS
Of a character easily distinguishable from other forms of suppurative
inflammation, erysipelas represents the most completely non-suppurative
type of diffuse streptococcal infection. A lesion limited to the skin itself,
it illustrates, apparently, the reaction of a particular tissue to infection,
capable in other situations and in an altered state of virulence, of
producing a very different result. It arises from gross or microscopic
wounds, spreads rapidly, and almost invariably causes chills, high fever,
and such severe constitutional disturbance that delirium is quite common.
Sometimes there is a phlegmonous inflammation at its point of origin and
at other times none. Facial erysipelas spreads over the nose and cheeks in
the shape of a butterfly with outspread wings. In that case the infection
appears to enter from small ulcerations within the nose. This form of
disease may occur at any age, but the very young and old are particularly
subject to it. Rarely it passes over the entire body in a wave or succession
of waves; for though it is ordinarily self-limited, running a course of one
to three weeks, relapses and reinfections are far from uncommon.
Erysipelas appears as an intense blush upon the skin which becomes
glazed and moderately swollen. Its advancing edge is elevated and quite
sharply outlined. The exudate is in the form of an edema, well supplied
with phago-cytic leucocytes, but, since there is little or no solution of
tissue, non-suppurative. Indeed, solution and destruction of the skin is so
little marked that once the infection dies out, repair is rapid and complete.
Streptococci are present in the advancing margin of the lesion and may be
found in the blebs which sometimes appear upon its surface. They
disappear from its center as the disease spreads.
Treatment.—Owing to the rapid progress of erysipelas over considerable
areas, incision, which in any case would be likely to spread the infection
to deeper parts, is out of the question. Indeed, no local treatment has
much of any influence on the disease, though attempts have been made to
limit its spread by establishing a zone of artificial vascularity about the
lesion through painting the surrounding area with tincture of iodine or
crude carbolic acid (and alcohol). Hitherto the greatest progress has been
made by prophylaxis. The cleansing of accidental wounds in soiled skin,
the prompt treatment of seemingly trivial infections have greatly cut
down its incidence. The sulfonamides have revolutionized the treatment
of erysipelas, greati; lowering its mortality in both infants and adults. At
the moment, sulfadiazini is the drug of choice, and should be
administered in full therapeutic dose. Complete bed rest is obligatory;
fluids are forced orally—parenterally if necessary. Hot wet compresses
may be applied to the affected part. Fever usually lessens within 12 to 24
hours, and the lesion often disappear in 5 to 8 days.
Lymphadenitis.— Diffuse suppurative inflammation rapidly involves
those lymph glands placed in the course of the lymphatic vessels which
dram the diseased area. At first slightly swollen and tender, they may
later become ereatly enlarged and inflamed, even at a considerable
distance from the infection Thus a septic process, originating, perhaps, in
an abrasion of the surface of the great toe, may be followed, within a few
hours, or perhaps over night, by the appearance of a red streak which
wanders up the c-uf and thigh toward the groin. Even now, the superficial
group of lymph glands about the saphenous opening may be palpable as a
mass of tender elastic lumps the size of a pea or larger. If the original
focus upon the toe subsides the glands will usually subside as well. But it
is not uncommon to observe enormous enlargement and diffuse
suppuration in the glands of the groin some days or even weeks after the
healing of a local lesion which may,indeed, have appeared insignificant.
In the upper extremity, the cubital and epitrochlear glands may pick_up
infection from a lymphangitis which is spreading toward the axilla. Ihe
axillary group is very commonly involved but usually prevents the
process from advancing further. The cervical glands take up infection
spreading from the mouth, laws, face and scalp. The axillary, inguinal
and cervical groups •ire therefore of great importance as filters, catching
invading micro-organisms on their way to the general circulation,
reacting like other tissues to bacteria and their toxins, and thus affording
the body time and opportunity for defence against virulent and otherwise
overwhelming infection. Considering the fre-auency of their involvmcnt,
lymph nodes seldom undergo abscess formation. They soften reluctantly,
breaking down so gradually that suppuration is exceedingly slow and
incomplete. Treatment.—Should suppuration actually occur, judgment as
to when and how to operate is difficult. Ultimately, a mass of persistently
infected lymph nodes is likely to soften into a single or multilocular
abscess, but all the glands of the axillary or inguinal groups, as the case
may be, seldom undergo abscess formation at one time, or to the same
degree. Incision into such a mass will disclose, if made too early, a little
thin purulent fluid among a group of greatly enlarged glands, some of
which are reduced to necrotic fragments while others are firm or only
partly softened. Drainage is therefore ineffective and the attempt at
complete excision, though occasionally successful, is more apt to spread
the infection. Conservative measures, in the form of poultices or moist
compresses, bring comfort, and result finally in complete breakdown of
the glands or spontaneous healing. The sulfonamides are indicated in
overwhelming infections, but have little effect upon the lesion itself.
LYMPHANGITIS
This very common disease appears in two forms: (1), the reticular, a generalized involvement of the cutaneous mesh of lymph spaces marked by a
diffuse blush, and (2), the tubular, which is actually an infection of the
subcutaneous lymph channels. The visible sign of the second is a red
streak upon ?he kTwiich may advance with remarkable rapidity. If the
local infection from which it takes origin subsides, tho lymphangitis is
quickly resolved, the red streak disappears, and healing occurs leaving no
visible trace. On the other hand if the original focus spreads into the
subcutaneous tissues, the lymphangitis becomes swallowed up in the
more diffuse process which advances along and about it and which then
becomes a cellulitis. Lymphangitis almost necessarily loads to infection
of the lymph nodes in its course. It may convey infection into tendon
sheaths and joints, even into the general circulation. Such complications
occur in only a small percentage of all cases.
ANO-RECTAL ABSCESSES
In 60% of cases the pus from the abscess yields a pure culture of
Esch. coli; in 23% a pure culture of Staphylococcus aureus is obtained. In
diminishing frequency, pure cultures of Bacteroides, a streptococcus, or
B. proteus are found. In many cases the infection is mixed. In a high
percentage of cases—some estimate it as high as 90%—the abscess
commences as an infection of an anal gland. Other causes are penetration
of the rectal wall, e.g. by a fish bone, a blood-borne infection, or an
extension of a cutaneous boil.
A large percentage of anorectal abscesses coincide with a fistula-in-ano.
For this reason, anorectal abscess becomes a highly important subject.
Moreover, as antibiotics cannot reach the contents of an abscess in
adequate concentration, no reliance can be placed on antibiotic therapy
alone. A fistula is much more likely if bacterial culture of the pus
discloses bowel (as opposed to skin) organisms.
Classification of Ano-rectal Abscesses.—A clear understanding of
suppuration in this area is dependent on a concise knowledge of the
anatomy. There are four main varieties—perianal, ischiorectal,
submucous, and pelvirectal.
1. Perianal (60%).—This usually occurs as the result of suppuration in
an anal gland, which spreads superficially to lie in the region of the
subcutaneous portion of the external sphincter. It may also occur as a
result of a thrombosed external pile. If the haematoma is not evacuated, it
may become infected and a perianal abscess results. This is the most
common abscess of the region. Persons of all ages are affected, and the
condition is not uncommon, even in infancy and childhood. The
constitutional symptoms and the pain are less pronounced than in the
ischiorectal abscess because the pus can expand the walls of this part of
the intermuscular space comparatively easily. Early diagnosis is made by
inspecting the anal margin when an acutely tender rounded cystic lump
about the size of a cherry is seen and felt at the anal verge below the
dentate line. Treatment.—No time should be lost in evacuating the pus.
Operation.—Thorough drainage is achieved by making a cruciate
incision over the abscess and excising the skin edges—this completely
removes the 'roof of the abscess. Healing commonly occurs within a few
days.
2. Ischiorectal abscess (30%).—Commonly, this is due to an extension
laterally through the external sphincter of a low intermuscular anal
abscess (fig. IOI2B). Rarely, the infection is either lymphatic or bloodborne. The fat, which fills the ischiorectal fossa, is particularly vulnerable
because it is poorly vascularised; consequently it is not long before the
whole space becomes involved. The ischiorectal fossa communicates
with that of the opposite side via the post-sphincteric space, and if an
ischiorectal abscess is not evacuated early, involvement of the
contralateral fossa is not uncommon. Should an internal opening into the
anal canal ensue, a 'horseshoe' abscess develops enveloping the whole of
the posterior part of the circumference of the anal canal. An ischiorectal
abscess gives rise to a tender, brawny induration palpable on the
corresponding side of the anal canal and the floor of the fossa.
Constitutional symptoms are severe, the temperature often rising to 3839°C. Men are affected more often than women.
Treatment.—Operation should be undertaken early—as soon as it is
certain that an abscess is present in this area—remembering that
antibiotic therapy often masks the general signs.
Operation.—Stage I.—A cruciate incision is made into the abscess. A
portion of skin is sometimes excised but deroofing is not necessary in
every case.
3. Submucous abscess (5%) occurs above the dentate line (fig. i I37C).
When it occurs after the injection of haemorrhoids it always resolves.
Otherwise, it can be opened with sinus forceps when adequately
displayed by a proctoscope.
4. Pelvirectal abscess is situated between the upper surface of the levator
am and the pelvic peritoneum. It is nothing more or less than a pelvic
abscess and as such is usually secondary to appendicitis, salpingitis,
diverticulitis, or parametritis. Abdominal Crohn's disease is an important
cause of pelvic disease that can present as perianal sepsis. A relevant
point to remember is that rarely a supralevator abscess/fistula may be due
to over-enthusiastic attempts to drain an ischiorectal abscess or to display
a fistula, when a probe is forced through the levator ani/rectal wall from
below.
5 Fissure Abscess.—This is the name given to a subcutaneous abscess
lying in immediate association with an anal fissure. Drainage is achieved
at the same time as the fissure is treated by sphincterotomy.
ACUTE OSTEOMYELITIS
Acute osteomyelitis used to be a common and serious, indeed often a
fatal, disease in children. Over recent years there has been a fall in the
incidence of the disease, probably due to an improvement in the general
health of children. At the same time antibiotics have made the disease
less serious: it need never now be fatal and should be curable.
Aetiology.—The bacteria reach the bone by the blood-stream. A primary
focus may be obvious in the form of a boil or an infected graze, but not
uncommonly no obvious source of infection is evident. Rarely the disease
may be secondary to a frank septicaemia or pyaemia. More commonly the
blood-borne infection takes the form of a bacteraemia.
It has been suggested that a lowered general resistance on the part of the
patient, and local trauma, may predispose to this disease, but the evidence
in support of these suggestions is unconvincing.
The usual causative organism is the staphylococcus aureus. Other
organisms which may be responsible include the streptococcus,
pneumococcus, haemophilus influenzae, staphylococcus albus and a
number of other organisms, no one of which is present commonly.
Pathology.—The disease always, or nearly always, begins in the
metaphysis. The infective process progresses through the thickness of the
cortex via the Haversian canals and as it does so causes thrombosis of the
vessels in the bone. As a consequence, by the time the infection reaches
the subperiosteal region of the bone a variable amount of the cortex may
have been infarcted. In the first 24 or 48 hours after the onset of the
infection, an inflammatory exudate forms deep to the periosteum,
elevating the membrane from the bone. Periosteal elevation is painful
and, since the periosteum is inelastic, the inflammatory exudate deep to it
is under tension. As a consequence the patient rapidly develops marked
toxic signs. Approximately 48 hours after the first symptom, frank pus
develops subperiosteally. Partly as a consequence of the resistance of
cartilage to invasion by the septic process, and partly because of the very
firm attachment of the periosteum (more accurately the perichondrium) to
the epiphyseal plate, transgression of the plate itself and consequent
interference with growth is rare. The inflammatory process progresses
along the length of the medulla causing venous and arterial thrombosis as
it does so. Subperiosteally, pus tracks both longitudinally and
circumferentially around the bone, stripping the periosteum and
interrupting the periosteal vessels. Thus progressively larger areas of the
cortex become infarcted and involved in the inflammatory process.
In the absence of treatment pus finally bursts through the periosteum and
tracks through the muscles to present subcutaneously. Eventually the skin
breaks down and pus discharges from a sinus which connects the bone
with the«skin surface.
The bone infarct in acute osteomyelitis is known as a Sequestrum.
Surrounding the sequestrum, the elevated periosteum lays down new
bone which entombs the dead bone within. This ensheathing mass of new
bone is known as the Involucrum. In the places where pus has broken
through the periosteum to form a defect in it, sinuses develop which are
represented in the involucrum by holes known as Cloaca (Latin) = A
drain. The development of such advanced pathology is now rarely seen
since modern treatment if adequate, aborts the disease before pus has
formed, and certainly before a significant amount of bone has died.
Two factors are responsible for the chronicity of this disease: the
presence of dead, infected bone which cannot be resorbed; and the fact
that the intraosseous abscess cavity cannot be obliterated because it has
rigid bony walls. As a consequence of these factors the body's normal
defence mechanisms (leucocytes and antibodies) together with any
antibiotics that may be given therapeutically are unable to reach all the
bacteria in the bone. Accordingly, although the disease process may be
sterilised in the living bone, recurrence is always likely.
Clinical Features.—Pain is the presenting symptom.
It is essential that an accurate history is taken so that the onset of the first
complaint of local pain can be timed exactly. The significance of this
feature of the history is discussed further under Treatment. The pain
gradually increases in severity, and the child becomes increasingly febrile
and toxic, at a rate dependent upon the toxicity and virulence of the
infective organism. It is usual for the mother to seek medical advice
within 48 hours of the onset of the first symptom.
Physical Signs.—The essential physical sign is localised tenderness.
When the doctor first examines the child, the child is likely to be irritable
and to resent examination. It is imperative that the physician should be
patient, and gently palpate the child's limbs until the exact area of
maximum tenderness has been identified. If this tenderness lies over the
metaphysis of a long bone, the diagnosis of acute osteomyelitis should be
presumed until it can be proved otherwise. The adjacent joint may contain
an effusion, raising the differential diagnosis of suppurative arthritis. The
joint itself however is not tender and although the child resists movement
of the limb, with patience it is possible to demonstrate that some
movement of the joint is allowed. This contrasts with acute suppurative
arthritis in which absolutely no movement is permitted. The temperature
is raised, often markedly so, and an associated increase in the pulse rate
occurs. Some days after the onset of the first symptom noticeable
swelling and heat may be detected in addition to tenderness. Finally the
area of the abscess (for such it is by this time) is fluctuant.
It is absolutely essential that blood cultures should be undertaken before
antibiotic treatment is commenced. In order to provide the maximum
possible chance of a positive culture, three separate venipunctures should
be made and from each venipuncture three aliquots' should be cultured
separately. The child's body surface should be searched minutely for
possible primary foci of infection and if these are found they should be
cultured.
Special Investigations.—Other investigations are of no diagnostic value
early in the disease. The E.S.R. and white cell count are usually raised but
this is entirely non-specific.
X-ray.—There are no abnormal radiological features in the first few days
of the infection. As time goes by, new bone can be seen deposited by the
elevated periosteum, but this sign does not appear until more than 10 days
after the onset of the disease and will then be demonstrable whether or
not the disease has been sterilised: it depends entirely upon the presence
or absence ofperiosteal elevation. Some rarefaction in the bone due to
local hyperaemia will also occur after 2 or 3 weeks but again does not
distinguish continuing osteomyelitis from the sterilised disease. The
radiological appearances of chronic osteomyelitis are dealt with
elsewhere.
Treatment.—The child is admitted to hospital and the limb is splinted,
but in such a way that easy access to the tender area is retained. The
outline of the tender area is marked on the skin.
If the patient is first seen within 48 hours of the appearance of the first
symptoms, antibiotic treatment is begun immediately after appropriate
samples have been taken for blood culture. Acute osteomyelitis is one of
the few diseases in which it is justifiable to begin antibiotic treatment
without waiting for bacterial sensitivity, a peculiarity which stems from
the fact that if the disease can be sterilised within the first 48 hours,
complete resolution can be guaranteed. If sterilisation fails or is not
attempted in this time, the disease may become chronic, so generating
life-long disability and a possible cause of death. The great majority
(about 80%) of the isolates from osteomyelitis are Staphylococcus aureus
and cloxacillin should be administered at a dosage of 100-200 mg/kg
body weight in divided doses intravenously until the child is clinically
well, has no fever and the local signs have decreased. Oral therapy, with
flucloxacillin can then be given. In addition, benzyl penicillin should be
given intravenously (0.25-1.0 million units every six hours). For
penicillin-hypersensitive patients a cephalosporin may be given
intravenously. In children under three Haemophilus influemae may be a
responsible organism and especially affects the small bones of the hands
and feet. At the present time ampicillin 250 mg q.d.s. intravenously is
recommended. Unfortunately antibiotic resistance amongst organisms
causing osteomyelitis creates problems. The staphylococci are usually
resistant to benzyl penicillin and ampicillin and therefore require a
penicillinase-stable penicillin. Most strains of Haemophilus influemae are
currently susceptible to ampicillin but if failure to respond is thought to
be due to a resistant organism, chloramphenicol should be substituted.
Other antibiotics may be substituted if they are dictated by the sensitivity
tests.
If the patient is first seen 48 hours or more after the onset of the first
symptom, the possibility arises that pus is present. If pus is present, it may
be sterilised by antibiotics, but the general surgical principle applies to
bone as to other tissues that an abscess requires surgical evacuation. The
presence of pus may be difficult or impossible to detect with certainty
since fluctuation is late to develop. Fluctuation cannot be demonstrated in
the early stages of abscess formation because the periosteal membrane is
tense, the involved bone is often deep to muscle, and the area is too
tender to palpate firmly. Therefore the surgeon has to rely upon his
general impression as to the severity of the disease and his knowledge of
its duration in deciding either to treat the patient initially with antibiotics,
or to combine this therapy with incision of the tender area.
If it is decided to rely on antibiotic therapy alone in the belief that no pus
is present, antibiotics should be given and the effect of this treatment
upon the toxic signs and upon local tenderness should be watched very
closely. If the antibiotic is controlling the disease, and if no pus is present,
the temperature will subside to become normal within 2 or 3 days and
tenderness will progressively disappear. If, on the other hand, the
antibiotics are inappropriate to the sensitivities of the organism or pus is
present, the temperature is likely to settle but not to normality: spikes up
to 38°C will continue. If this occurs, the tender area must be explored
surgically with a view to evacuating pus if any is present and to obtaining
the organism for culture and sensitivity.
Operation.—Operation is carried out under general anaesthesia and is
preceded by exsanguination of the limb by elevation and the use of an
inflatable tourniquet. An incision is made over the tender area and carried
down to the bone where pus is usually found deep to the periosteum. The
abscess cavity is fully opened and the pus evacuated. A swab is taken for
culture and sensitivity at this stage. There is controversy as to whether or
not this procedure should be followed by drilling the cortex in order to
enable any pus that may be present in the medullary cavity to drain to the
surface. The wound is then closed with interrupted sutures over a closed
sterile suction drain. Antibiotics and local splintage are continued postoperatively.
Complications.—These may be divided into two types, general and
local. The general complications are septicaemia and pyaemia which may
give rise to metastatic abscesses. Either complication, if uncontrolled,
may prove fatal. Amyloid disease may develop as a complication of
chronic osteomyelitis.
The local complications include: (1) secondary involvement of the joint if
the epiphyseal line is intra-articular, e.g. the hip joint in association with
osteomyelitis of the proximal femur; (2) spontaneous fracture which is
rare provided the limb is splinted and the disease adequately treated, (3)
deformity which, surprisingly, is rare, and (4) chronic osteomyelitis.
Acute Traumatic Osteomyelitis
This condition arises as a result of infected wounds, for example
compound fractures, and operations on bones. The constitutional
disturbances are less severe than in acute (infective) osteomyelitis, as the
causative wound provides some measure of drainage. Treatment consists
of more extensive opening of the wound, removal of dead bone, and
antibiotics. The prevention of this condition depends upon the adequate
initial treatment of compound fractures and upon sterile operating
conditions.
CHRONIC OSTEOMYELITIS
Pathology.—Acute haematogenous osteomyelitis may pass into chronic
osteomyelitis if early treatment is not available, or is inadequate so that
infected bone dies to form a sequestrum. The disease may take two forms.
The pathology of the more common variety in which a large volume of
bone is involved has been described under acute osteomyelitis. The
incidence of this condition has been greatly reduced by the modern treatment of the acute infection, but some cases remain as a legacy of the preantibiotic era, and more will probably occur in the future if the acute
infection is inadequately treated. The second variety is known as Brodie's
abscess. The infection in this form of the disease is closely contained so
as to create a chronic abscess within the bone composed of pus or jellylike granulation tissue surrounded by sclerotic bone. The lesion may be
the sequel to a pyogenic septicaemia from which the patient has
recovered, leaving a bone abscess which may remain dormant for years.
On the other hand, it may be found in a patient who is known to have had
osteomyelitis (but not septicaemia) affecting a bone other than the one in
which the Brodie's abscess is discovered.
Clinical Features.—Chronic osteomyelitis may remain quiescent for
months or years, but from time to time acute or sub-acute exacerbations
occur. An exacerbation is ushered in with constitutional upset and local
evidence of inflammation, which may culminate in a discharge of pus,
often from a preexisting sinus. An x-ray sometimes reveals a sequestrum
which has separated from the surface of the bone or which lies in a
cavity. Tomographs may help to demonstrate a sequestrum and a
sinogram may delineate an abscess cavity in the bone.
A Brodie's abscess causes intermittent local pain and occasionally
transitory effusions in the adjacent joint during an exacerbation.
Examination may reveal tenderness and thickening of the bone. A
radiograph is diagnostic. The amount of bony sclerosis is variable,
ranging from dense sclerosis extending a considerable distance round the
cavity to, more commonly, a faint line of sclerosis at the junction of the
abscess with the cancellous bone.
The chronicity of a Brodie's abscess is the result of the physical
characteristics of bone, because the abscess can never close by collapse of
the walls as happens in soft tissues. Moreover, the infection kills the hard,
bony walls of the abscess and provokes new bone deposition, thus
preventing leucocytes, antibodies and antibiotics from reaching the
contents of the cavity.
Treatment of exacerbations in chronic osteomyelitis consists of
immobilization of the limb and the administration of antibiotics. On this
regime the exacerbation often subsides, but only to recur again later in
life.
Surgical intervention in chronic osteomyelitis has as its objective the
removal of dead bone and the elimination of dead space. Dead bone in the
form of a sequestrum may be detected by probing a sinus or by x-ray.
Seams of dead bone dispersed within living bone cannot be detected with
certainty but may be suspected if an x-ray shows an area of sclerosis. An
appropriate antibiotic (which is chosen in the light of the sensitivity of the
causative organism) is administered for some days prior to operation.
Access to the bone is usually gained through a previous scar. The soft
tissues are stripped from the bone, and the involucrum is removed to
reach the sequestrum. If a cavity is present, the over-hanging walls are
removed with an osteotome, until it is 'saucerised'. Sclerotic bone is
removed en bloc if this is practicable. The wound is drained and closed in
such a way as to eliminate dead space as far as possible. Modern
approaches to this problem include insertion of gentamycin-impregnated
beads following debridement of the affected area. These are removed 14
days later and the dead space obliterated by packing the cavity with
cancellous bone chips, or filling it with a local muscle flap.
So difficult is it to guarantee that an operation will cure chronic
osteomyelitis affecting a large volume of bone, that operative intervention
is not be be considered lightly unless a sequestrum is known to be
present. If, however, a sequestrum is present and is removed, sinuses will
often close and the disease may be cured. If only a cavity or sclerosis is
present in the bone without a sequestrum, the attempt to 'saucerise' may
fail and still leave a sinus. There are many patients for whom, if the
discharge is slight and easily controlled by a dressing, it is preferable to
retain the sinus and dressings permanently. Amyloid disease need be
feared only when a copious discharge of pus has persisted for some years.
Amputation may be advisable if exacerbations are frequent or prolonged,
in order to rid the patient of recurring periods of painful disability, and to
forestall the onset of amyloid disease.
A Brodie's abscess should be treated by surgical evacuation and curettage
of the cavity under antibiotic cover followed, if the cavity is of moderate
size, by packing with cancellous bone chips.
ACUTE SUPPURATIVE ARTHRITIS
Like acute osteomyelitis, this used to be a common disease especially in
children, but is now rare. Acute infection of a joint occurs as a result of:
/. Direct infection, as by a penetrating wound or a compound fracture
which involves the joint.
2. Local extension, from some neighbouring focus, such as acute arthritis
of the hip joint from osteomyelitis of the femoral neck.
3. Blood-home infection, the usual organisms being the streptococcus,
staphylococcus, and pneumococcus, and less commonly the gonococcus
and B. typhosus.
The knee joint, owing to its large size and exposed position, is the
commonest joint to be involved by penetrating wounds, while suppurative
arthritis from blood-borne infections is the more common cause in other
joints.
Clinical Features.—The patient complains of steadily increasing pain,
inability to move the joint and malaise. On examination the patient is
often severely toxic with a raised temperature and pulse rate. The joint is
held in the position of its greatest capacity (the 'position of ease') and, if
subcutaneous, it can be seen to be swollen. Palpation reveals increased
heat, tenderness and an effusion. Movements are prevented absolutely by
muscular spasm, and attempts at either active or passive movement cause
severe pain. On this regime the exacerbation of the limb and the
administration of antibiotics. On this regime the exacerbation often
subsides, but only to recur again later in life.
Treatment.— 1.Immobilisation.—The joint must be immobilised until
the infection has been cured. As any case of suppurative arthritis may be
followed by ankylosis, it is the duty of the surgeon to anticipate this
possibility by immobilising the joint in the best position for ankylosis (i.e.
the position of optimum function), as indicated in the table below. The
limb is supported and fixed by a suitable splint or appliance in the correct
position, an anaesthetic being administered if necessary. Traction is used
in cases of septic arthritis of the hip to prevent dislocation.
2. Antibiotics are administered systemically as in acute osteomyelitis.
3. Aspiration is useful for both diagnostic and therapeutic reasons. The
nature of the fluid can be ascertained, and the organism cultured to obtain
its antibiotic sensitivity.
Aspiration reduces the tension within the joint, thereby relieving pain,
and limiting the stretching of ligaments and capsule. It has the
disadvantage that a previously uninfected 'sympathetic' effusion may be
infected if the needle traverses a septic focus on its way into the joint. On
balance, the advantages outweigh this disadvantage. If frank pus is
aspirated, the joint is opened.
4. Aspiration and Injection.—After fluid has been aspirated, antibiotics
may be injected into the joint. Repeated injections of antibiotic into a
joint are unnecessary, since systemic administration is adequate.
5. Arthrotomy and Drainage is only done if the joint is found on
aspiration to contain frank pus, or if bone destruction has involved the
articular surfaces so that some degree of ankylosis is all that can be
expected when healing has occurred. The joint is opened, washed out, and
closed suction drains are placed down to the sy no vial cavity. This technique is nowadays less often needed, because the disease, if diagnosed
early, can be treated by antibiotics and aspiration.
Extra-articular abscesses sometimes require to be opened and drained. In
the case of the knee joint, pus is particularly liable to track upwards
beneath the quadriceps, where its presence may be overlooked.
6. Excision.—Nowadays this too is rarely required, but if the condition of
the patient deteriorates in spite of treatment, or if suppuration is
prolonged, drastic surgical ablation of the diseased bone is necessary.
Complications.—Early complications include destruction of articular
cartilage, pathological dislocation, and necrosis of the epiphysis resulting
from damage to the blood supply (especially in the case of the proximal
femoral epiphysis). Late complications include secondary degenerative
osteoarthritis, joint stiffness and fibrous or, particularly, bony ankylosis.