*6 CE credits
AANA Journal Course
1
Respiratory
System
I
Preoperative evaluation and physical
assessment of the patient
NANCY J. WITTSTOCK, CRNA, MS
Detroit, Michigan
Traditionally,the physical examination and
assessment of the patient has been exclusively
in the physician'sdomain. Recent expansion
of the role of the nurse in critical care and
the evolvement of the nurse practitionerhas
necessitated the development of expertise in
physical assessment. It is equally important
that nurse anesthetists develop these skills in
order to provide optimum anesthesia care in
the pre-, intra-,and post-operative periods.
While it is true that physical assessment
is now included in the majority of nurse
anesthesiacurriculums, this did not occur
until approximately the mid-1970's or even
later, depending on the area. The purpose of
this article, the first in the "Preoperative
PhysicalAssessment of the Patient"series,
is to provide not only the "how to" of
physical assessment, but also to discuss the
implicationsof abnormalphysical findings
and their impact on planning the anesthesia
care plan.
Objectives:
1. Describe the technique of inspection, palpation, percussion and auscultation of the lungs and
thorax.
2. Discuss several significant findings in the preoperative evaluation of the respiratory system.
3. Discuss the key points in the intraoperative
management of the patient with obstructive lung
disease.
A thorough history and physical are the foundation of the patient's preoperative evaluation. If
pulmonary dysfunction is suspected a more complete evaluation is indicated including pulmonary
function tests, chest x-ray, ECG and arterial blood
gases. Three basic goals should be kept in mind
when evaluating the patient: (1) determination of
the severity of disease; (2) formation of a plan to
optimally prepare the patient for surgery and (3)
application of appropriate prophylactic measures
in the preoperative period so as to minimize or
eliminate postoperative complications.
*As part of the AANA Continuing Education Program, this course has prior approval for continuing education credit. The course will
consist of six successive articles, each with a self-test and sources for additional reading.At the conclusion of the six-part series, a final
examination will be printed in the AANA Journal. Successful completion of the examination will yield the participant 6 CE Credits.
April/1981
History
In reviewing the pulmonary history, it is important to look for dyspnea, cough, sputum production, color of sputum, past history of pulmonary disease, occupational exposure to airborn
irritants (coal dust, paint fumes, silicone dust, and
the like) and the patient's smoking history. Cigarette smoking, if excessive, and sputum production
greater than 2 ounces per day are associated with
increased risk of postoperative complications.
Physical assessment of the lungs and thorax
The four basic methods of physical assessment
are inspection, palpation, percussion and auscultation, commonly referred to as IPPA. The examination should proceed in an orderly fashion, working
from the top of the chest toward the bottom.
The patient should be seated comfortably and
undressed to the waist for the first part of the
examination. Proper lighting is important for
visual inspection. Physiological variations are not
only common from one patient to the next, but can
be present on an individual basis as well. Thus, it
is useful to compare one side to the other during
the examination; in this way, the patient can serve
as his or her own control. The posterior chest
should be examined first while the patient is sitting. Then, he or she can lie down for examination of the anterior chest.
Like any new skill, physical assessment examining techniques require knowledge and consider-
able practice in order for the anesthetist to become
adept at them. Until these skills are developed, it
is important to have someone already experienced
in physical examination check on your performance and the accuracy of your findings.
Localization of findings is accomplished by
using important landmarks such as the suprasternal
notch or Angle of Louis. First, palpate the suprasternal notch at the top of the manubrium, then
"walk" your fingers down a few centimeters until
you feel a bony ridge which joins the manubrium
to the body of the sternum (Figure 1). The second
rib attaches to the sternum at the Angle of Louis
and the second intercostal space lies directly below.
As you proceed downward, the ribs and interspaces
can be palpated down to the tenth rib.
Anatomical lines are also useful for reference
points and, when used in conjunction with a particular rib or interspace, can be used to localize
abnormal findings.
Inspection. During the physical examination,
a general impression of the patient's respiratory
status should be ascertained. The patient should
be observed for the work of breathing, use of accessory muscles, posture, facial expression, nasal
flaring, and respiratory rate and pattern. Extrathoracic signs indicative of chronic hypoxemia such
as digital clubbing and cyanosis should also be
noted. The thorax is visually observed both posteriorly and anteriorly for any number of ab-
Journal of the American Asscauat on of Nurse Aneathetsuu
chial structures transmit vibration. Decreased vocal
fremitus may occur with bronchiole obstruction
or if there is an abnormal accumulation of air or
fluid in the pleural space.
normalities that could be a sign of pulmonary
distress (Table I).
Palpation. The chest is manually palpated to
identify areas of tenderness and to assess any abnormalities that were observed during the inspection stage. Palpation. further assesses respiratory
excursion and elicits vocal or tactile fremitus. Vocalization causes a vibration of air in the tracheobronchial tree which can be felt by the anesthetist
when palpating the chest wall. This vibration can
be palpated and is called vocal fremitus. It can be
elicited when the patient is instructed to say
"ninety-nine" at each area of palpation.
During this phase of the examination, the
anesthetist should place the palmar bases of the
fingers of one hand on the patient's chest, com-
Percussion. Percussion of the chest produces
motion in the chest wall and underlying lung
which causes audible sounds and palpable vibrations. Different sounds are elicited depending on
the density of the underlying tissue. Percussion
helps the anesthetist to determine whether the underlying tissue is air filled (as in the normal lung),
fluid filled or solid. Since percussion usually penetrates less than 7 cm, it is not useful in detecting
dec,
lesions. With practice, you should learn to
distinguish five percussive notes, each differentiated
by variances in intensity, pitch and duration
(Table II). Start at the lung apex and percuss the
entire lung field, working progressively from top
to bottom.
The technique of percussion involves pressing
the distal phalanx of the middle finger on the
paring each region that is palpated. For example,
compare the left apex to the right, the left middle
lung region to the right, and so forth. Vocal fremitus is normally increased in the parasternal area
near the second right interspace where major bron__
Table I
Visual observations of the thorax
Examplee of abnormalktiea
1'. Thoracic deformities
Kyphoscollosls, pectus carinatum (pigeon chest), pectus
excavatum (funnel chest), barrel chest (Increase AP diameteremphysema)
2. Slope of the ribs
More horizontal-emphysema
3. RetractIon or bulging of the interspaces
Obstruction-asthma, COPD
4.
Impaired respiratory movement
Obesity, neuromuscular weakness, COPD
5.
Rate and pattern of breathing
Tachypnea, COPD, prolonged expiration, shortness of breath
6. Use of accessory muscles:
Inspiration-neck muscles
Expiration-abdominal muscles
Asthma, emphysema, COPD
Table II
Slgnificance of percussive notes
Intensity
Pitch
Duration
Location
Abnormality
Flatness
soft
high
short
thigh
fluid in pleural space
Dullness
medium
medium
medium
liver
atelectasis
Resonance
loud
low
long
normal lung
Hyperresonance
very loud
low
longer
emphysematous lung
Tympany
loud
gastric air bubble
I
*pri/1981
pneumothorax
,
-
-
199
chest. Avoid contact with any other part of the
hand as this would damp the vibrations. With the
middle finger of the other hand, strike a sharp
blow on the distal phalanx making sure the wrist
is relaxed (Figure 2). The action involves a
rhythmic flexing of the wrist using short, staccato
blows.
Auscultation. The last part of the physical
assessment examination is auscultation of the lung
fields, usually done with the diaphragm of the
stethoscope. Auscultation aids in both determining
air flow through the tracheobronchial tree and
lung parenchyma and the presence of secretions or
obstruction resulting in abnormal or absent breath
sounds. The patient should breath deeply through
his mouth as each area is auscultated. Care should
be taken in the pacing of the examination so that
the patient does not become dizzy from hyperventilating. Listen for the quality and intensity of
breath sounds and the presence of adventitious or
abnormal sounds (Table III).
Figure 2
Finger positioning for palpation
1
The lungs are also auscultated for voice sounds
which are useful in detecting atelectasis, pleural
effusion and consolidation. Surprisingly enough,
in the presence of these abnormalities, voice
sounds are actually transmitted more clearly. This
phenomenon is called bronchophony. Whispered
pectoriloquy is an exaggeration of bronchophony
and indicates a very clear transmission of whispered
words heard with the stethoscope. Egophony is
present if the spoken "EE" sounds more like "AY".
Additional considerations
during the examination
Adventitious sounds. There are a number of
adventitious or abnormal sounds, important for
the anesthetist to observe, which can be categorized
into friction rubs, rhonchi and rales. A pleural
friction rub, a coarse, grating sound, is generally
heard in late inspiration and early expiration, and
is associated with an inflamed pleura. Friction
rubs often clear when fluid accumulates in the
pleural space. Rhonchi are sounds produced in the
airways from an accumulation of secretions. They
produce a deep rumbling sound from turbulent
air flow and will generally clear with coughing.
A wheeze is a particular type of rhonchi that
has a musical quality and is heard primarily during
expiration when bronchoconstriction is present.
Rales sound somewhat like the crinkling of
cellophane and occur when there is an accumulation of fluid in the alveoli, as in pulmonary edema,
congestive heart failure or pneumonia.
In emphysema, a marked decrease in the intensity of breath sounds is the chief and single most
reliable physical symptom. Other signs, in decreasing order of reliability are: prolonged exhalation,
decreased lung expansion, use of accessory muscles,
decreased diaphragmatic activity, pursed-lip breathing and barrel chest (increased A-P diameter). The
patient with chronic bronchitis presents different
physical findings although both emphysema and
bronchitis are manifested in marked expiratory
obstruction to airflow.
The classic picture of chronic obstructive
Table III
Auscultation interpretations
Normal breath
Insp:Exp
Expiratory
Expiratory
sounds
duration
pitch
Intensity
Location
Vesicular
Insp. > Exp.
low
soft
majority of lungs
Broncho-vesicular
Insp. = Exp.
medium
medium
near the main stem bronchi
Bronchial
Exp. > Insp.
high
usually loud
over the trachea
Journal of the American Association of Nurse Anesthetists
pulmonary disease (COPD) generally involves a
mixture of the symptoms of chronic bronchitis and
emphysema. The bronchitic patient frequently has
rhonchi and wheezing, and "noisy breathing" can
often be heard without the aid of a stethoscope. A
simple test for retained secretions common in
chronic bronchitis is to ask the patient to take a
deep breath and forcibly exhale a few times. This
usually results in an attack of paroxysmal coughing and wheezing.
Chest x-ray
Examination of the chest is incomplete without a chest x-ray. Normal lung parenchyma appears black on film, whereas atelectasis or an accumulation of fluid in the alveoli appears as a
whitish density. Acute changes noted on the chest
film should be treated and surgery postponed until
improvement is evident both clinically and on
repeat film. A very important point to remember
is that significant pulmonary dysfunction may be
present even though the chest x-ray appears perfectly normal.
ECG
An electrocardiogram (ECG) is included in
the evaluation procedure, with attention directed
to right atrial hypertrophy or right ventricular
strain pattern. Electrocardiographic changes are a
late sign of pulmonary disease and usually do not
develop until the patient has pulmonary hypertension (which may lead to right heart failure or cor
pulmonale).
Arterial blood gas measurements
The ease with which arterial blood gases can
be obtained and measured is one of the outstanding developments in respiratory care in the last
decade. Many hospitals that have a large surgical
schedule now have a blood gas machine in the
recovery room where it is readily available for use
in evaluating patients postoperatively. Even the
smallest hospital should be equipped with at least
one blood gas machine; the valuable information
it gives far out-weighs the purchase price.
The primary function of the lungs, exchange
of oxygen and carbon dioxide, is easily assessed by
measuring blood gases (Table IV).
The PaO2 is often less than 80 torr with advancing age (patients older than 60 years), due to
progressive ventilation perfusion inequality that is
a normal part of the aging process. A PaOs less
than 70 torr on room air should always be investigated. While blood gases are not routinely
drawn preoperatively, they should be drawn and
April/1981
evaluated if the patient has significant clinical
symptoms of pulmonary dysfunction and/or grossly
abnormal pulmonary function tests.
Pulmonary function tests
Pulmonary function tests are vital in documenting the existence of and assessing the degree
of dysfunction. Frequently, physical examination
and chest x-ray fail to reveal significant airway obstruction in patients with obstructive lung disease.
The spirometer functions as an extension of the
stethoscope and should be used routinely in patients with pulmonary disease, just as the ECG is
used in patients with heart disease.
Abnormal spirometric studies are generally
categorized as restrictive or obstructive. A restrictive abnormality indicates inspiratory obstruction
to airflow and is reflected in a decreased vital capacity in the presence of normal expiratory flow
rates. An obstructive abnormality indicates expiratory obstruction to airflow and is reflected in a
decreased forced expiratory volume in one second
(FEV1), peak flow rate (PFR), mean forced expiratory flow (FEF 25-75%) and forced vital capacity
(FVC). Currently utilized spirometry varies from
simple bedside tests, such as the vital capacity and
peak flow rate, to sophisticated computerized programs that provide complete spirometric evaluation.
The volume of air exhaled during the first
second of the FVC is the FEV1. It is a standard
means of evaluating large airway (greater than 2
mm in diameter) obstruction. When expressed as
a percent of FVC, less than 80% indicates obstructive disease and greater than 80% indicates
restrictive disease. (Figure 3).
FEF 25-75%. This test measures the maximum mid-expiratory flow rate during the middlehalf of the FVC. A decrease is indicative of early
Table IV
Arterial blood gas interpretations
Arterial
Normal
blood gases
rage
?MeaWsre
PaCO 2
35-45 torr
Adequacy of ventilation
(respiratory parameter)
PaO 2
80-100 torr
Adequacy of
oxygenation
pH
7.35-7.45
HCO 3
22-25 meq/L Metabolic parameter
Base excess
+2 -2
Acid-base status
Metabolic parameter
small airway disease (less than 2 mm in diameter).
This important prognostic test is indicated for
asymptomatic smokers because it detects small airway disease, the earliest manifestation of chronic
bronchitis.
Closing volumes. The closing volume is a
measurement of the lung volume at which airways
begin to close in the dependent areas of the lung.
This test is also a sensitive indicator of early small
airway disease. When abnormal, this test provides
a valuable prognostic sign of probable development of obstructive lung disease.
Simple bedside screening tests. These tests encompass (1) tidal volume and minute volume,
(2) forced vital capacity, (3) negative inspiratory
force, and (4) peak flow rate.
Simple spirometry-like tidal volume, minute
volume and forced vital capacity can be directly
measured at the bedside with a hand-held respirometer attached to an anesthesia face mask. The
patient can hold the mask on his or her face and
breathe through it one full minute while the
respiratory rate is counted. At the end of the
minute, the face mask is removed and the minute
ventilation volume can be read directly off the face
of the respirometer. The average tidal volume is
calculated by dividing the minute ventilation in
milliliters
by the respiratory rate. Normal values
for tidal volume are 6-7 ml/kg. For minute ventilation, the values are 58 liters.
Forced vital capacity (FVC) is measured by
instructing the patient to hold the mask onz his
or her face, take a maximal inspiration, and then
exhale as rapidly as possible through the mask. At
this point, the mask is removed, and the FVC is
read directly off the face of the respirometer.
Patient cooperation is essential to correctly perform this maneuver; since errors are common, it
is a good idea to repeat the maneuver three times,
recording the best of three readings.
The FVC is a rough measurement of the
patient's ventilatory reserve. It has been deter-
mined that a minimum of 15 mI/kg is essential in
order to have sufficient mechanical ability to take
a deep enough breath to generate an effective
cough. For this reason, patients are generally not
extubated until their FVC is at least 15 mI /kg. If
less, the endotracheal tube is left in place and used
as a route for tracheobronchial suctioning.
The negative inspiratoryforce (NIF) is an alternate means of assessing ventilatory reserve and
is especially useful in the uncooperative or obtunded patient who is unable to perform a forced
vital capacity. A manometer that registers negative
pressure is adapted to a face mask or artificial airway. The manometer is occluded for 15-20 seconds
during which time the patient inspires against an
occluded airway. This creates a negative pressure
reading on the manometer.
The normal NIF is as much as -80 cm H 2 0
pressure in a patient with normal ventilatory
mechanics. It has been determined that a min-
imum of - 20 cm H 2 0 pressure is necessary to
have muscle power sufficient to generate an effec-
tive cough. Therefore, patients should not be
extubated unless this minimal value is attained.
Peak flow rate (PFR). The PR is the fastest,
easiest and most sensitive single breath pulmonary
function test available. An example of the instru-
Figur. 3
mentation available is the Wright's peak flowmeter. Such a flowmeter is inexpensive and port-
Normal, obstructive, and restrictive patterns of a
forced expiration.
able so it may be used at the patient's bedside to
Norm#al
Obstructive
Restrictive
measure the expiratory flow rate. Since maximal
flow rates occur at the beginning of expiration, a
complete
exhalation
spirogram
is not
(which may
FI
£
FEV
used
-- ::
FEV=4.Q
FVC-5.O
:Fvra:
1
FVC
PVC
FVC:~:
.I
FEV=1.3
FVC-3.1
%_O%42
(Adapted with permlslon franm W~rt.12 )
FEV:
is not necessary. Because a
used,
initial
breath
holding
be difficult
for the dyspneic patient) is
unnecessary. The patient is instructed to take a
deep breath then exhale as rapidly as possible
through the mouthpiece. The expiratory flow rate
is read directly on the face of the peak flowmeter.
used
This is a valuable, pulmonary screening tool
that can be used not only for preoperative evalua-
FEV-2.8
FVC-3.1
tion, but also for postoperative follow up. Decreases in flow rate associated with obstructive lung
%,mg0
disease can be demonstrated earlier in the peak
flow rate than with any other single breath
maneuver.
Journal o/ sta Aeri*.n Ae.fsku ej
o Nunt.
An~ahkoide
Preoperative management
Since COPD is undoubtedly the most common type of pulmonary dysfunction the anesthetist
faces in everyday practice, the remainder of this
article will focus on pre-, intra- and post-operative
management considerations in the patient with
obstructive lung disease.
The identification of risk factors associated
with pulmonary complications is a key part of preoperative anesthetic management. Of all the risk
factors, bronchospasm, retained secretions and infection are the most amenable to therapy.
A thorough evaluation of the patient provides
sufficient information to formulate an effective
plan of therapy designed to optimize lung function
before surgery. Numerous studies have indicated
that appropriate therapy before surgery decreases
morbidity and mortality. A statistically significant
decrease in postoperative complications was reported by Gracey and colleagues, who recommend
a systematic approach to preoperative preparation
using a standard protocol that can be understood
and followed by the nursing staff and other health
care professionals.
Preoperative mobilization of secretions from
the airways may be the main beneficial result of
such intensive preparations for surgery, thus preventing or minimizing retention and consequent
infection and atelectasis. After identifying the
patient's needs, various therapeutic modalities may
be indicated. It is desirable for the patient to stop
smoking three to four weeks prior to elective surgery. Unfortunately, this is not always a realistic
goal; and it is difficult to improve bronchial
hygiene if the patient continues to smoke.
Bronchial hygiene therapy
Systemic hydration. Adequate systemic hydration is the most important method of decreasing
the vicosity of thick secretions to promote expectoratio. Patients should be encouraged to drink
at least two quarts of water a day. Supplemental
parenteral fluids may be indicated in the aged and
debilitated. Some authorities feel that aerosol
therapy is no more than an adjunct to good systemic hydration and can never be as effective alone.
Aerosol Therapy. Bland mist aerosols such as
saline, sodium bicarbonate, or propylene glycol
solutions may be useful in hydrating the airway
and liquefying secretions. Many fail to realize that
10.15 min aerosol treatments probably deposit very
little moisture in the airways. The length of
therapy depends on the patient's problem and may
range from 30 min treatments four times a day to
April/1981
virtually continuous inhalation to aid in evacuation of secretions.
Mobilization of secretions. Once secretions are
adequately hydrated, mobilization and expectoration should not present a problem if the patient
has an adequate cough mechanism. Patients with
significant decreases in expiratory flow rates may
not be able to generate an effective cough and will
have to be assisted with percussion, vibration,
postural drainage, and tracheobronchial suctioning
to clear the airways.
Infection. Acute infection must be eliminated
with the appropriate antibiotics, as determined by
culture and sensitivity of the sputum. It is sometimes difficult to distinguish between acute and
chronic infection. Purulent sputum usually indicates the need for antibiotics.
Chest physiotherapy-postural drainage. The
patient with limited ability to cough may require
chest physiotherapy maneuvers such as percussion,
vibration and clapping to aid in mucociliary
clearance. Various positions are indicated to clear
specific bronchopulmonary segments. Frequent
turning from side to side is very important to
prevent increasing ventilation-perfusion inequality
in the immobilized patient.
Bronchospasm. Various bronchodilators are
available to alleviate bronchial spasm. Isoproterenol, at one time very popular when administered
as an aerosol, has declined in clinical use in favor
of beta, agonists such as terbutaline. Undesirable
side effects of tachycardia and palpitations occur
less often with these betas agonists. On occasion,
the physician may have to try more than one bronchodilator to find one that is effective for a particular patient.
Steroids may be useful if the patient does not
respond or responds poorly to bronchodilators.
Though prednisolone has been frequently used,
beclomethasone, a new inhalant steroid, is becoming increasingly popular because it does not have
the untoward side effects of systemic steroids such
as sodium and water retention, hypokalemia, and
psychological disturbances. It is important to appreciate that beclomethasone and another relatively
new inhalant drug, cromolyn sodium, are only
useful to prevent bronchospasm and are ineffective
during an acute attack.
In addition to routine laboratory tests, the
patient should have electrolytes and baseline
arterial blood gases to assess the adequacy of
oxygenation, ventilation and acid base status. Ventilation-perfusion inequality due to shunting and
increased physiologic dead space is the primary
cause of hypoxemia in COPD. The degree of hypo-
xemia can be accurately determined only by direct
measurement of arterial blood gases.
An abnormal chest x-ray can be a reliable predictor of the presence of moderate to severe emphysema. A normal film does not exclude the
presence of emphysema and no single finding or
combination of findings has been described which
serves especially well to detect early asymptomatic
disease. Typical findings in long-standing disease
include: low, flat diaphragms; hyperinflation; increased anterior-posterior diameter and increased
lung markings. Roentgenographic abnormalities,
considered by some authorities to be due to bronchitis, include over-inflation, parallel lines, "tram
tracks" which may represent thickened bronchial
walls and an increase in lung markings.
Electrocardiographic abnormalities commonly
associated with COPD include tall, peaked P waves,
right axis deviation and right ventricular hypertrophy. Generally, these abnormalities appear to be
secondary to increased pulmonary vascular resistance and are seen only in relatively advanced
disease. Atrial and ventricular arrhythmias attributable to hypoxemia are common and have been
found to occur in a large number of patients on
routine electrocardiograms. Monitoring for 72
hours demonstrates that arrhythmias occur in the
majority of hospitalized patients with moderate to
severe COPD.
Prior to surgery, the patient should be counseled
as to the importance of deep breathing and coughing after surgery. One of the most valuable respiratory maneuvers designed to prevent atelectasis and
maintain optimal lung function is the sustained
inspiratory maneuver or voluntary maximal inhalation. Deep-breathing exercises with emphasis
on sustained inspiration to total lung capacity have
been consistently effective in expanding alveoli
and preventing pulmonary complications.
A device called the incentive spirometer is
becoming increasingly popular in helping the
patient to perform sustained inspiratory maneuvers. Utilizing such devices, the patient is able
to observe his or her own progress and is stimulated to improve. Incentive spirometry is goal
oriented and often has a positive psychological
effect because patients feel they are personally contributing to their recovery from surgery.
Intraoperative management
The COPD patient should arrive in the operating room only after receiving thorough preoperative preparation designed to optimize lung function. Preoperative medication should be sufficiently
light to avoid respiratory depression. If the patient
is not in pain, a mild tranquilizer such as hydroxyzine or oral diazepam is usually sufficient. A
small dose (25 mg) of intravenous lidocaine will
prevent the burning sensation that often occurs
with the injection of diazepam into a superficial
vein.
Since it interferes least with ventilatory
mechanics, regional anesthesia is desirable for
surgery on the extremities. Spinal anesthesia may
interfere with the patient's ability to contract abdominal musculature and should be used with
caution in patients with advanced COPD who
must use their abdominal muscles to effectively
exhale.
If general anesthesia is required, several factors must be kept in mind for safe, successful management. The induction of general anesthesia is
associated with the development of a 10-15% increase in right to left intrapulmonary shunting
which can be attributable to a variety of factors.
Functional residual capacity (FRC) decreases between 15-30% whether ventilation is spontaneous
or controlled. This appears to be a constant occurrence during anesthesia although the exact
mechanism is unknown.
As FRC falls below critical alveolar volume,
airway closure occurs, particularly in dependent
parts of the lungs. These factors lead to increasing
ventilation perfusion inequality and impaired oxygen transport; therefore, it is advisable to administer at least 40% oxygen when anesthetizing patients with known pulmonary dysfunction.
A patient with normal lung function can be
denitrogenated by inhaling 100% oxygen within
approximately five minutes. The COPD patient
may require 15-30 minutes to denitrogenate because of an increase in physiologic dead space
which is most common in emphysema. Physiologic
dead space is defined as that portion of the total
ventilation that does not exchange with pulmonary
capillary blood and is thus "wasted ventilation."
Preoxygenation should begin as soon as possible to
attain an optimal PaO2 prior to induction of anesthesia. A patient with severe hypoxemia and
hypercarbia, whose primary stimulus to breathe is
through the "hypoxic drive," must be observed
carefully during preoxygenation since respiratory
depression may develop.
The choice of halothane, enflurane or a bal.
anced technique (nitrous oxide, narcotic, relaxant)
is probably not as critical as the technique and
skill with which the anesthesia is administered.
The key points of management are: awareness of
the underlying problems associated with the disease
process and assuring adequacy of oxygenation, ven-
Journal of the American Association of Nwrse Aaesthetist
tilation and acid base balance. Halothane, a bronchodilator, is advantageous in the COPD patient
who has bronchospasm. A recent study by Rodriquez and Gold suggests that enflurane is equally
satisfactory for general anesthesia. In addition, an
inhalation agent facilitates the use of high oxygen
concentrations.
While changes in PaCOa and PaO 2 are relatively predictable in patients with normal lung
function, the COPD patient does not respond predictably to changes in ventilation and fractional
inspired oxygen concentrations (F10O). Therefore,
it is necessary to monitor arterial blood gases. If
the patient had compensated respiratory acidosis
preoperatively, as evidenced by an elevated PaCO2
and HCO3 and normal pH, excessive ventilation
could result in a severe alkalosis. Various hazards
have been attributed to alkalosis, including cardiac
arrhythmias, hypokalemia, shift of the O,-Hb dissociation curve to the left resulting in both increased
Hb-O affinity and decreased tissue oxygenation,
and decreased cerebral blood flow.
Whether ventilation is assisted or controlled,
an appropriate I:E (inspiration to expiration) ratio is important to facilitate adequate distribution
of ventilation and assure sufficient time for exhalation. A two second inspiration and four second exhalation is usually satisfactory, although
some patients with marked obstruction may require longer to completely exhale. If air trapping
is to be avoided, exhalation should be allowed to
continue until no further breath sounds are
audible via esophageal or precordial stethoscope.
Many emphysematous patients have blebs or
surface bullae which may rupture during positive
pressure ventilation. All lung fields should be
auscultated as frequently as possible. Peak inspiratory pressures should be monitored to help in the
recognition of a tension pneumothorax, which, if
present, requires immediate insertion of a thoran tpmy tube.
Postoperative mana ament
Several factors impact on the immediate postanesthetic care of the patient: type and duration
of surgery, severity of pulmonary disease and condition of the patient at the time of surgery. A
patient with a preoperative forced expiratory flow
in one second (FEVi) of less than 2 L and a forced
vital capacity (FVC)of less than 15 ml/kg is a high
risk for development of postopetative respiratory
falure and should receive elective mechanical
ventilation. An intermittent mandatory ventilation
(IMV) mode is advantageous because it allows s
patient to maintain spontaneous ventilation during
April/1981
which gas is primarily distributed to the dependent
areas of the lung. IMV offers several advantages in
that it: (1) minimizes respiratory muscle asynchrony, (2) minimizes deleterious hemodynamic
effects, (3) minimizes sedation requirements, and
(4) simplifies weaning.
In contrast, controlled ventilation tends to
deliver a larger portion of the tidal volume to nondependent areas of the lung where perfusion is
less, thus causing an increase in the ratio of dead
space to tidal volume (VD/VT). IMV maximizes
any spontaneous ventilatory activity the patient
may have. The decrease in intrapleural pressure
that occurs with each spontaneous breath enhances
venous return and aids in maintaining hemodynamic stability.
The same sophisticated monitoring that was
utilized intraoperatively should be continued in
the immediate postoperative period until the patient is fully recovered from the effects of anesthesia. Meticulous clinical assessment of the patient's
ability to maintain adequate spontaneous ventilation should be utilized prior to extubation, along
with objective measurable criteria such as forced
vital capacity (FVC) and negative inspiratory force.
Should it be necessary for the patient to remain
intubated for tracheobronchial toilet, a small
amount of positive end expiratory pressure (PEEP)
is currently recommended to prevent the fall in
PaO that often occurs in intubated patients. The
oxygen deficit is usually reversed when 3-5 cm HiO
PEEP is applied. Extubation should occur as soon
as feasible since the presence of an endotracheal
tube prevents glottic closure and interferes with
the ability to cough effectively.
Controlled oxygen therapy which is sufficient
to maintain a normal PaO2 should be monitored
with serial arterial blood gases. Deep breathing
exercises and sustained maximal inspirations (SMI)
should be instituted as soon as possible to prevent
atelectasis. Narcotics should be given judiciously
to avoid respiratory depression yet control pain
sufficiently to enable the patient to take deep
breaths. Post-thoracotomy, intercostal nerve blocks
will facilitate deep breathing and help prevent
atelectasis.
Conclulson
This article has outlined the key points in
evaluating and preparing the patient with pulmonary dysfunction for surgery. These points represent the ideals for which to strive. Unfortunately,
conditions are not always optimum and occasionally, in an emergency situation, one is forced to
anesthetize a patient with severe pulmonary dys-
function who has not had the benefit of
preoperative
extensive
evaluation and preparaion.
In such caines, it is safest to anticipate pro emus
gical
procedure,
because alarming degrees of hypounder 'anesthesia in the patient
xemia may occur
with undocumented pulmonary disease. Serious
consideration should be given to postoperative
mechanical ventilation until a more thorough
evaluation of the patient's pulmonary status is
I which is the tN~~,
Wit;
A4I L OWLWGEMENT
Flue au~thor wishes to expresa her gratitude to Rosmary
Iscretarl! of the ~Iey Ford Ho0ptal Universty of
ur * ~ e Pro resui for her patdmuce anal aadt
lie p r a ,o this areids.
tgla Cum Laude
t Nursin in Dervt WMin She
"RNA, KS, ,la
4tast
cool.-of Anaduesa, ))etroit. In
r. Uatb*~s ad Master's degree. in
ate Uniesty Colleg of Phuiquay
hii pra tcedI clinical ass
anmbser of years. In lW s
nw the Waybw ate Utulverulty PI
als held various academic ap-,
fteCu~c
%l ri ator at the
iAe
sd 44usty of Detroit,
Mt'She
&
els br Re.rougot the
a speer at
uember of the
-pat Sea
r
The Johns Hopkins University
School of Medicine presents
A LOOK AT
ANESTHESIA TODAY
MAY 9-10, 1981
NURSE
ANESTHETIST
CERTIFIED-REGISTERED
Progressive extremely modern 470-bed university affiliated teaching hospital noted for
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required. The hospital is easily commutable
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For Further Information:
Program Coordinator
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Room 22
720 Rutland Avenue
Baltimore, Maryland 21205
(301) 955-5880
Call us about our NEW SALARY RATES
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STATEN ISLAND
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475 Seaview Ave.
Staten Island, N. Y. 10305
an equal opportunity
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I
CHARLES C THOMAS
New!
COMMUNICATION AND COMPLIANCE IN
A HOSPITAL SETTING edited by David J. Withersty,
West Virginia Univ. School of Medicine, Morgantown. (13
Contributors) Contributors from the disciplines of medicine, physical therapy, social work, and mental health define the problem of patient noncompliance, explore its
probable causes, and offer solutions. A sampling of chapter
topics includes noncompliance as a diagnostic issue, environmental influences upon compliance, practical aspects of
communications research, and educating students and
housestaff regarding compliance and other psychosocial
issues. '80, 208 pp., 11 il., 4 tables, $18.50
SPUBLISHER
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DIMENSIONAL ANALYSIS IN THE BIOMEDICAL SCIENCES by Bernard Schepartz, Jefferson
Medical College, Philadelphia.The author herein employs
a pragmatic, instrumental approach to explain the application of dimensional analysis to the biomedical sciences. By
operating largely on the level of algebra, he facilitates the
nonmathematician's understanding of these processes. Beginning with an explication of the basic concepts of dimensional analysis, the author then shows how dimensional
analysis can help to solve complex problems related to the
biomechanics of solids and fluids; surface phenomena, diffusion, and membranes; energy and work; enzymes and metabolism; and allometry and scaling. '80, 184 pp., 9 il.,
$19.75
SYNOPSIS OF PATHOLOGY FOR THE ALLIED
HEALTH PROFESSIONS by Alvin F. Gardner, Food and
Drug Administration, Washington, D.C. This text explains
the latest concepts in general pathology while providing the
reader with a thorough understanding of the local and
systemic basis of disease. Specific areas of pathology covered include, among others, congenital anomalies and
hereditary diseases, repair and regeneration, heart and blood
vessels, the respiratory system, blood and bone marrow, the
skin, and the nervous system. Numerous appendices feature
laboratory values, chemical compounds, and a wealth of
other valuable data. '79, 480 pp., $34.50
A PICTORIAL HISTORY OF MEDICINE (5th Ptg.) by
Otto L. Bettmann, Bettmann Archive, New York City. Foreword by Philip S. Hench. This profusely illustrated volume depicts the great physicians, the key inventions, and
the crucial discoveries of medicine. Each medical landmark
is presented in a compact pictorial unit that delineates the
technical perspective and relates the healing arts to their
concurrent cultural movements. A review in Surgery, Gynecology and Obstetrics stated, "Perhaps nowhere else can one
obtain so clearly and quickly a broad grasp of medical
history." '79, 336 pp. (8 1/2 x 11), 1000 il., $16.00, paper
MONITORING SURGICAL PATIENTS IN THE OPERATING ROOM edited by J. S.sGravenstein, Case Western
Reserve Univ., Cleveland, Ohio; Ronald S. Newbower, Harvard Univ., Cambridge, Massachusetts; Allen K. Ream,
Stanford Univ., Stanford, California; and N. Ty Smith,
Univ. of California, San Diego. (34 Contributors) Clinical
aspects, developing trends, and new concepts are reviewed
in this volume on cardiovascular, respiratory, and central
nervous system monitoring. Specific topics include monitoring neuromuscular functions, systolic time intervals,
ventilation, anesthesia management systems, and anesthesia
keyboard systems. '79, 288 pp., 78 il., 19 tables, $25.75
REGIONAL BLOCKS FOR NURSE ANESTHETISTS: A
Technical Manual by Phyllis Adams Roberts, Des Moines,
Iowa. This text describes methods for administering spinal,
axillary block, and intravenous regional anesthesia. The
author discusses the most commonly used drugs, premedication drugs, and dosage calculation. The section on spinal
anesthesia includes information on positions, methods of
holding the needle, prevention of hypotension, and techniques for puncturing the subarachnoid space when difficulties arise. The patient's anesthetic record, the basic
mid-line decubitis approach, a variation of that method
using the lateral approach to the mid-line, and the Taylor
approach are also detailed. '78, 128 pp., 26 il., 1 table,
$11.75
A MANUAL OF THORACIC SURGERY by Arndt von
Hippel, Private Practice, Anchorage, Alaska. Foreword by
Alfred Tector. The author brings together useful old and
new approaches and concepts for mediastinal and pericardial drainage; he expands upon simple and clinically
proven practices; he clearly and definitively identifies and
analyzes the hazards inherent in many currently marketed
chest drainage devices. The approaches and techniques outlined in this carefully organized and eminently practical
book will improve patient care and expedite recovery in any
thoracic surgical service. '78, 264 pp., 9 il., cloth-$18.75,
paper-$11.50
RESPIRATORY INTENSIVE CARE edited by Robert M.
Rogers, Univ. of Oklahoma Health Sciences Center, Oklahoma City. (38 Contributors) Contributors provide selections on diagnosis and clinical presentation of respiratory
failure, the logistics of establishing a respiratory intensive
care unit or service, acid-base balance as it relates to respiratory failure, gas exchange in chronic obstructive lung diseases, oxygen transport, oxygen therapy and nonventilatory
therapy of respiratory failure, and the principles of mechanical ventilation. '77, 448 pp., 138 il. (3 in color), 36 tables,
$37.50
THE PHARMACOLOGY OF ANESTHETIC DRUGS: A
Syllabus for Students and Clinicians (5th Ed., 3rd Ptg.) by
John Adriani, Tulane Univ. School of Medicine, New Orleans, Louisiana. The format of this volume is one of succinct statements describing the effect of a particular
anesthetic or combination of anesthetics on a specific organ
system. Sections are included on uptake and distribution of
anesthetics, which summarizes present day concepts; on the
new inhalation anesthetics such as halothane, fluoroxene,
and vinyl ethyl ether; on adjunctive drugs; and on premedication, hyperthermic and hypotensive anesthesia, and
carbon dioxide absorption. '77, 320 pp. (9 x 12), 128 il.,
$30.00
PHYSICS FOR ANAESTHETISTS by James Duffin, Univ.
of Toronto, Toronto, Ontario, Canada. Foreword by R. A.
Gordon. Using the necessary basics - mathematics, mechanics, and units of measurement - this text examines the
elementary behavior of atoms, heat, gases, vapors, and
fluids. Essential aspects of fluid flow and electricity are
given careful and thorough consideration. Overall concepts
of patient monitoring and commonly used methods of gas
analysis also are examined. An underlying philosophy of
problem solving forms the basis for this introductory text.
'76, 296 pp., 109 il., 19 tables, $22.25
Orders with remittance sent, on approval, postpaid * Catalog of 2924 titles sent on request
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