Principles of Surgery
Blood transfusion
Workup



Infections screened for: HBV, HCV, HIV1/2, Syphillis + CMV in
immunocompromised
Adult blood volume = 70mls/kg
Paediatric blood volume = 80mls/kg
Product
Storage / Half-life
Packed red cells 280mls
Stored at 2-6'C
35 days (normal
red cell life is 120
days)
Notes
Additive solutions:
suspend cells
CAPD: citrateadenine-phosphatedextrose
SAMG: salineadenine-mannitolglucose
Dosing: 4ml/kg
raises [Hb] by 1g/dl
Platelets
Stored at room
Platelets are pooled
temperature on
as one donation
agitator (prevents normally contains
clumping)
~55 x109
5-7 day life
Risk of infection
Rhesus sensitisation
Cryoprecipitate Stored at -30'C
Factors V / VII are
/ FFP
12 month shelf-life most labile to
temperature
Dosing: 1015mls/kg
Human
Albumin
4.5% or 20%
solution
Complications of transfusion
1. Immediate
Indications
Anaemia
Restore circulatory volume
Improve tissue oxygen
perfusion (by maintaining
oxygen carrying capacity)
Thrombocytopenia < 50 x
10 9
DIC
Post bypass / dysfunctional
platelets
Reversal of warfarin
Post massive transfusion
DIC / loss of clotting
factors
Ascities / portal
hypertension
Oedema due to
hypoalbuminaemia
Plasma expander
o
Temperature changes - from pyrogens (from dead polymorphs,
endotoxins)
o Immune reactions
1. Type I: Immediate - Anaphylactic reaction
2. Type II: Cytotoxic 3. Type IV: Delayed
o Infection - gram -ve organisms (coliforms, pseudomonas)
o Metabolic - hyperkalaemia (haemolysis); hypocalcaemia (citrate
antocoagulation), acidosis
o Circulatory - hypervolaemia: massive transfusion reaction =
"transfusion equalliny patient's blood volume within 24 hours"
o Bleeding diathesis - deficient in platelets (thrombocytopenia) and
clotting factors
2. Delayed
o Sensitisation to antigens
o Infection from unscreened blood - HBV, HCV, HIV, CMV, syphilis,
malaria
o Fe-overload: heart, pancreas
Or
1. Massive transfusion: Transfusion equallying patients blood volume within 24
hours
o Volume overload - Pulmonary oedema
o Thrombocytopaenia
o Coagulation factor deficiency
o Hypothermia
o Hypocalcaemi: chelation by citrate in additive solution
o Hyperkalaemia: progressive potassium leakage
2. Repeated transfusion
3. Infective complications
o HBV, HCV, HIV
o Syphilis
o Yersinia enterocolitca 4. Immune reactions
o Febrile reactions: white cell antigens, reaction within one hour
o Acute haemolytic reaction: ABO incompatability
o Delayed haemolytic reaction: immunised to foreign red cell antigen
due to previous exposure. Leads to jaundice/haemolysis later
o Post transfusion purpuric reaction
o Graft vs host disease
o Anaphylactic reactions
Management
1. Stop transfusion
2. Resuscitate
3. Repeat G+S
4. Perform direct anti-globulin test (Coomb's test) on post-transfusion sample;
antibodies against surface antigens
5. Check for haemolysis (bili, K); DIC (FDPs, haemoglobinuria)
6. Blood cultures
Acute Limb Ischaemia
Aetiology
1. Embolus: commonest
2. Thrombosis: pre-existing stenosis, aneurysm or occlusion
3. Trauma
Presenting Features
1.
2.
3.
4.
5.
6.
Pale
Pain
Parasthesia
Pulseless
"Perishingly cold"
Paralysed
Management
1. History
o
o
2.
3.
4.
5.
Onset / duration
Risk factors: peripheral vascular disease, cardiac disease
Examination
o Cardiovascular exam
o AAA
o Examine limb - sensation, motor function, pulses; compare with
contralateral limb
Investigations
o Hand-held doppler flow
o Arterial doppler
o (If "threatened" - angiogram)
o Determine source of embolus - cardiac (electrolytes, ECG, echo)
Treatment
o Resuscitation - oxygen, IV fluids, analgesia
o IV heparin - prevent thrombus propagation
o Salvagable: embolectomy, bypass
o Consider thrombolysis (with tPA - tissue plasminogen activator)
o Unsalvagable: amputation
Post-operative
o Continue anticoagulation (1) Heparin (2) Warfarin for 3 months
o Continue resuscitaiton
o Physiotherapy
o Protect limb
Anastamosis
Definition
"Without mouth" - Joining of one viscus/vessel with another to establish continuity of
flow
Types
1. End-to-end
2. End-to-side (differing sizes of lumens)
3. Side-to-side
Uses
Examples
Notes
Gastrointest Colorectal
Two layer technique (classical teaching)
Enterocolost
inal
1. Full-thickness "all coats" continous suture - catches
omy
strong submucosa
2. Seromuscular interrupted suture (Lembert stitch)
- Achieves inversion (low likelihood of anastamotic leakage)
- Inner layers haemostatic but prone to stangulation
Single layer technique (modern teaching)
1. Interrupted seromuscular extramucosal suture on roundbodied needle
- Minimal damage to vascular plexus
- may cause less tissue trauma
Stapled
1. Linear: creates side-to-side anastamosis
o Inserts 4 parallel linear rows and cuts in the
middle
2. Circular:
o Unites bowel end-to-end
- Reduced anastamotic leakage
- Increased strictures
Tissue Glue
Suspection of leakage
1. Unexplained pyrexia
2. Tachycardia
3. Prolonged ileus
4. GI contents in drain
Urology
UreteroUse absorbable sutures (non-absorbable causes stones)
ureterostom
y
Ureteric
bladder reimplantation
Ileal conduit
/ ileal pouch
Vascular / Coronary
Aim:
Cardiothora artery
1. Permanently establish flow
bypass grafts
cics
2. Avoid intimal disruption and turbulence
Fem-pop
o
o
o
bypass
Pass needle within outwards
Smooth intimal suture line
Eversion of anastamosis
Use non-absorbable suture
- Everted anastamosis (provides intact endothelial surface,
low risk of thrombus)
Complications
1. Bleeding / leakage / pseudoaneurysm
2. Stenosis
3. Thrombosis
4. Distal embolism
Transplant
Renal
transplant
Liver
transplant
Plastic
surgery
Microvascula
r
anastamosis
Factors for successful anastamosis
Local
Blood supply
Tension-free
Good approximation
No distal obstruction
Patient
Resuscitated, warm, well perfused
Good nutrition
Surgical
Appropriate sutures
Avoidance of watershed areas
Brainstem death
Definition


Irreversible cessation of all functions of the brain
Loss of capacity for consciousness and for ventilation (brainstem)
Criteria for diagnosis of brainstem death
1. Apnoeic coma of known aetiology - must exclude metabolic (hyglycaemia,
hypothyroid), drug intoxication, hypothermia
2. Absent cranial nerve reflexes - pupillary (II, III), corneal (III, V), vestibulo-ocular,
pharyngeal (IX, X), bronchial (X)
3. Absent motor response to painful stimuli within cranial nerve distribution
4. Absence of spontaneous respiration with permissive hypercapnoea (PaCO2 > 8kPa)
following oxygenation
Tests should be performed on 2 separate occassions by 2 medical practitioners
registered for more than 5 years (and competent in field).
Tests should not be performed by members of the transplant team
(Difficult to perform in brainstem encephalitis, ocular trauma)
Physiological Changes in Brainstem death
1. Loss of pituitary function
o Loss of vasopressin / ADH release - diabetes insipidus, hypernatraemia,
small brain cells; 4ml/kg/hr urine loss - corrected temporarily with IV
dextrose +/- aAVP infusion
o Loss of anterior pituitary hormone production
 TSH loss; hypothyroidis
2. Loss of temperature regulation at hypothalamic level
o Hypothermia, exacerbated by loss of motor/metabolic activity - managed by
warming
o Coagulopathy
3. Disorderd autonomic system
o Initial hypertension - immediate increase in sympathetic activity
o Hypotension from loss of sympathetic vascular tone
Burns
Burn
Coagulative necrosis of tissue result from thermal (heat/cold), electrochemical or
radiation injury





Heat
Cold
Electrical burns
Chemical burns
Radiation burns
Assesment of burns
1. Extent (size)
o % body area: Wallace's rule of 9s
o Hand = 1%
2. Depth
o Superficial - epidermis (painful: erythema, no blistering, heal within 2-5
days)
o Partial thickness - epidermis and variable amounts of dermis (painful:
erythema, blistering)
o Full thickness - all of dermis (painless, white/waxy)
Criteria for referral to Burns unit:
1. Patient
o
Extremes of age
2. Burn
o
o
o
o
Size >15% (10% paediatric)
Location: hands/feet/perineum
Circumferential burns (requiring escharotomy to prevent ischaemia and
necrosis)
Electrical burns (risk of rhabdomyolisis)
Management
1. Airway/Breathing
o Resp distress / high flow oxygen
o Early intubation and support
2. Circulation
o Monitor fluid therapy
ATLS guideline: 2-4mls/kg/%burn in 24 hours: give half in first 8
hours, half over remaining 16 hours (Modified Parkland Formula)
Mount vernon: Weight x%burn/2
o
o
3.
4.
5.
6.
7.
Central venous line
Urinary catheter
Disability
o Assess wound size
o Cover wounds + tetanus prophylaxis
o Renal support
o Analgesia
Exposure
o Warm
o Stress ulcer prophylaxis
Surgery - constricting circumferential thoracic eschars
Nutritional supplementation commenced early
Priority areas for skin grafting - eyelids (prevents ectropion), face, hands, joint
flexures
Complications
1. Respiratory: fire in confined space, soot in mouth/sputum, hoarse voice, >10%
serum carboxyhaemoglobin
o Thermal injury to nose / oropharynx with upper airways oedema
o Smoke inhalation can lead to hypoxia and pulmonary oedema from ARDS
o Toxic gases: carbon monoxide (250 more affinity for Hb), cyanide, sulphur,
nitrogen
2. Shock
o Plasma protein loss (loss of skin cover)
3. Renal failure
o Hypovolaemia from plasma protein loss reduces renal perfusion + ATN
o Myoglobin (from muscle) produces rhabdomyolysis and results in ATN
4. Electrolyte disturbance
o Hypo/hypernatramia
o Hypo/hyperkalaemia
5. Hypothermia
o Loss of skin cover
6. SIRS / Sepsis
7. Gastric ulcers
o Curling's ulcers (cf Cushing's ulcers) as part of stress response
8. Coagulopathy
o Due to DIC
Chemotherapy
Aims of Chemotherapy
1. Cure
2. Prevention (of recurrence)
3. Shrink tumours
Types
1.
2.
3.
4.
Primary
Neoadjuvant - before surgery (eg shrink breast cancer)
Adjuvant - after surgery to gain control of primary disease
Palliative
Considerations
1.
2.
3.
4.
Chemosensitivity
Stage
Grade
Patient's health
Principles of treatment



Adjusted according to weight and height
Body surface area estimated and cycles given at intervals to allow the body normal
tissue to recover
High dose chemotherapy indicated in otherwise fit patients where cure may be
achieved (choriocarcinoma, leukaemia) - but can cause profound toxic effects on
bone marrow [possible to use stem cells support now]
Classification of Cytoxic agents
1. Alkylating agents - impair function of enzymes to form DNA: chlorambucil /
cyclophosphamide
2. Anti-metabolites - irreversibly interrupt DNA: Methotrexate / 5FU
3. Vinca alkaloids - inhibit microtubule function: vincristine / vinblastine
4. Anti-mitotic agents: cause damage by production of free radicals
Clinical Trials / Medical statistics
Scientific method of detecting differences between treatments
Detect merits of specific treatments for patients with specific diseases
Provide evidence of efficacy and safety
Ethics behind clinical trials (declaration of Helsinki 1961)
1. Patients should not be denied effective treatments
2. New treatment must be safe (no patient should suffer as part of a trial)
Pre clinical trials


Assess toxicity / pharmacology of drug
In vitro / in vivo testing
Clinical Trials




Phase I: Normal healthy volunteers - to assess correct pharmacological dosing, route
of administration (<20 patients)
Phase II: Select subpopulation of patients, establish efficacy; resource assessment, if
not helpful would not be ethical to proceed (-100 patients)
Phase III: "Normal patients" (1000s) - establish efficacy and safety
Phase IV: Pos-marketing surveillance
Controlled clinical trial


Active treatment compared with control treatment (may be placebo, current
standard, etc)
Used to determine the best course of treatment
Clinical trial protocol
1.
2.
3.
4.
5.
6.
7.
8.
Introduction
Aims + hypothesis / precise question asked
Materials
Methods: end points
Results
Statistics
Bibliography
+ Financial support, responsibilities of workers, signatures
Error / null hypothesis
Null hypothesis states that there is no difference between two treatment groups
1. Type I:
o
o
null hypothesis rejected despite being true
detecting a difference when one does not really exist
2. Type II:
o
o
null hypothesis accepted when it is false
Failure to detect a difference when one actually does exist
Power


Ability of trial to detect an actual difference
Equal to type II error
Significance level

Statistical probability of a type I error
Confidence interval

Probability of a true population mean lying within a range derived from a sample
mean and it's standard error (standard error = standard deviation/number of
observations)
Sensitivity / Specificity
1. Sensitivity: ability to identify a true positive
2. Specificity: ability to exclude a false negative
Averages / Measures of spread


Mean, median, mode
Standard deviation: - measure of scatter around the mean
Statistical test
Data types
Student t-test
Paired means between two sampls Not for more than two means
Analysis of variance Multiple independent groups
Uses
Chi-squared
Clinical trial designs




Randomised (minises bias)
Case - control
Cross over
Double-blind (useful when trial has subjective endpoints)
Diathermy
Basis of diathermy
1. Electrical current converted to thermal energy
2. Amount of heat is proportional to volume of tissue traversed by current (need for
broad contact with diathermy pad)
Types of diarthermy
1. Monopolar
o Circuit: plate, cable, patient
o Cut (most effective when electrode placed a small distance away from
tissue): continous current discharges across air gap, high temperature sparks
generated, causes cellular water to explode
o Coagulate: intermittent current released: tissue damage occurs by
"fulguration", intermittent bursts of energy generated smaller effects
2. Bipolar
o Current transferred between two electrode (tips)
o Safer but only able to coagulate
Key points





Check position of pad (surgeon's legal responsibility)
Avoid monopolar diathermy if patient has pacemaker; position plates away from
pacemaker
Avoid diathermy on long pedicles (ie, testis, penis, finger) as current with cause
thrombosis of vessel
Check insulation
Avoid use in GI surgery - farting causes explosions
Drains
Indications
1. Drain collections
2. Prevention of collections before they accumulate
Pros:
1. Drainage removes potential sources of infection
2. May be early indicator of anastamotic leakage
3. Leaves a tract for drainage (once removed)
Cons:
1. May increase infections
2. May induce leakage
Classification
1. Active / passive
o Active: Maintained under suction (high or low pressure)
o Passive: No suction (relies on pressure differences between cavities)
2. Open / closed
o Open: Corrugated sheets drains into gauze or bag. May become infected
o Closed: Tubed draining into bag. Less risk of infection
3. Material
o Minimal tissue reaction
o Tissue reaction - eg in biliary surgery
Examples
Chest drains
Abdominal drains
Urinary catheters
VP Shunts / EVDs
Dressings
Optimum environment for wound healing
1.
2.
3.
4.
5.
6.
Moist
Free from infection, with minimal slough
Free of chemicals and foreign bodies
Optimum temperature
Minimal number of dressing changes
Correct pH
Different dressings are appropriate for different stages of the wound healing
Good wound management necessitates flexible approach to election and use of
dressings
Requirements from a dressing
1. Wound
o
o
o
o
Protection from infection and trauma
Debrides, both mechanically and chemically
Absorbent and removes excess exudate, whilst keeping wound moist
Maintains temperature and gaseous exchange
2. Patient
o
o
Comfortable and cosmetically acceptable
Stimulates healing
3. Healthcare provider
o Inexpensive
o Easy to change
Brand
names
Type
Description
Indications
Hydrocolloids
Available as pastes, granules,
wafers
Mixture of
carboxymehtylcellulose, pectins, Granuflex
gelatins, elastomers
Forms gel on contact with wound
secretions, absorbing secretions
Wet sloughly wounds
Hydrofibre
Consists of
carboxymethylcellulose spun into
fibre
Aquacel
Forms gel on contact with wound
secretions, which absorbs
secretions
Heavily exudating
wounds
Hydrogels
Insoluble polymers, water and
propylene glycol
Absorbs large volumes of
exudates and effective at
desloughly/debriding
Desloughing/debriding
Semipermeable
film dressings
Clear polyurethane film coated
adhesive
Not suitable if excessive
exudate
Alignates
Derived from seaweed
Kaltostat,
Absorbs secretions to form gel to
sorbsan
optimise moist wound healing
Foam dressings
Consists of polyurethane /
silicone foam
Very absorbant
Antimicrobial
dressings
Little evidence for benefit
Flat / cavity wounds
Can facilitate cell proliferation,
production of extracellular matrix
Epidermal components Artificial and living
Vivoderm
skin equivalents
Dermal components - Dermagram
Composite grafts (epidermal /
dermal components)
Fracture healing
Stages of fracture healing (HIDOCR)
1. Haematoma formation
o size limited by elastic periosteum and arterial spasm
2. Inflammatory phase
o vascular dilation, exudate, polymorph infiltration
3. Demolition phase
o Macrophages digest clot, fibrin and debris
o Macrophages & osteoclasts remove dead bone fragments
4. Organisation
o Granulation tissue formation with ingrowth of capillary loops from below
the periosteum and from fracture bone ends
5. Early callus/late callus
o Osteoid laid down in haphazard arrangement of fibril
o Mineralise to form woven bone +/- cartilage
o Woven bone absorbed by osteoclasts and osteoblasts which lay down
lamellar bone (with haversian blood systems)
6. Remodelling
o Normal shape of bone is remodelled over many months and marrow cavity
reforms
Abnormalities of fracture healing




Non-union: when foreign material interposed
Delayed-union: (1) sepsis (2) movement (3) FB (4) ischaemia (5) poor nutrition
Malunion
Fibrous union: occurs when there is excessive movement. Cells can differentiate into
synovial cells and results in a pseudoarthrosis
Gunshot wounds / Blast Injury
Classification of Blast Injury
1. Primary: from the shockwave itself
2. Secondary: from flying debris
3. Tertiary: from the body being thrown (becoming a projectile itself)
Informed Consent
The law recognises that it is in the best interest for emergency treatment to go ahead if
it is necessary to save a life or to prevent serious or permanent disability.
Consent






Process where patients understand and agree to treatment
Full discussion of disease, treatment, benefits, risks and alternative treatments
Verbal or written
Patients can change their mind / seek alternative opinions
Children: (1) Child able to consent if judged to be competent (2) otherwise parent or
legal guardian can act on behalf (3) Child cannot refuse treatment
Adult: (1) Only the adult or (2) someone with power of attorney. Relatives should be
involved but cannot consent or withold consent on another individual's behalf.
Who should obtain consent?




Operating surgeon
Suitably qualified person who has knowledge of procedure and understanding of
risks and benefits.
All complications with >1% risk should be discussed
Potentially life-threatening risks should be discussed
Intensive Care (ITU)
Levels of care
1.
2.
3.
4.
Level 0: Ward patient
Level 1: Ward patient needing critical care team input
Level 2: HDU care: single failing organ
Level 3: ITU care: multiple failing organs - 3-4 times more expensive than routine
ward care
Admission criteria
1. Disease treatable / reversible
2. Two or more organs affected
3. Does not breach wishes of patient
Transfer of Critically Ill
1. Primary transfer
o From scene of trauma to hospital
o Managed and organised by pre-hospital team
2. Secondary transfer
o Transfer between hospital (eg to neurosurgical units)
Necessary equipment
1. Support
o
o
o
Oxygen
Ventilator
Suction
2. Monitoring
o ECG
o Sats
3. Emergency treatment
o Fluids
o Defibrillator
o Drugs -
Modes of transportation
1. Ground - Ambulance
2. Air - Helicopters / planes (RFDS)
o Risk of hypoxia (due to altitude)
o Gaseous exansion leads to tension pneumothorax - prophylactic bilateral
chest drains
3. Sea
Nerve Injury
Classification of nerve injury
Pathology
Physiological defect associated
Neuropraxia with ischaemia or focal
demyelination
Axonotmesis
Axonal distruption with
endo/peri neurium intact
Recovery
Example
6-12 week recovery
Nerve compression
injury
Regeneration starts
after 1 month
Growth of 1mm/day
Traction injury to
limb
Stretched nerve in
Prognosis worse with
more proximal lesions
Neurotmesis Axonal transection
Operating list order
Patients who should be first on the list
1.
2.
3.
4.
Diabetics
Major operations*
Poor anaesthetic candidates
Significant allergies
Patients who should be last on the list
1.
2.
3.
4.
High risk infection - HIV, hepatitis, CMV
Septic
MRSA
Contaminated / dirty wound
Paediatrics
Airways



Tongue large
Epiglottis relatively larger
Larynx higher up (C3/4)
Palliative care
Palliative care

Deals with dying
dislocated limb
Poor prognosis without
repair
(Needs diagnosis with Accidentally cut
serial EMGs)
nerve
Exploration and repair
are indicated

Aspects dealt with: social, psychological, medical
Principles
1. Die with dignity
o Patient should be moved to a quiet side room
o Family may wish to be present
o Religious wishes respected
2. Die without suffering
o Investigations / blood tests should be cancelled
o Potentially degrading objects (such as nasogastric tubes) should be removed
3. Die with control of symptoms
o Anti-emetics
o Reduced secretions: hyoscine
o Treat constipation
Patient safety in theatre
Surgeon's duty
1.
2.
3.
4.
5.
6.
Check correct patient, operation, side, consent
Suitably starved
Appropriate antibiotics
Adequate intra-operative DVT prophylaxis
Safe transfer to operating table
Correct positioning
Radiotherapy
Radiotherapy
1. Therapeutic use of radiation in the management of cancer
o Electromagnetic: photons, x-rays, gamma rays
o Particulate: electrons, neutrons
2. Ionizing radiation = amount of energy absorbed per unit mass of tissue (measured in
grays)
3. Delivery: linear accelerator
4. Mechanism of cellular damage
o Damage of DNA - free radical formation leads to chromosomal damage and
cellular death
o Can also induce cellular apoptosis
o Amount of damage is proportional to the dose of radiation
Planning treatment
Factors to consider
1. Radiosensitivity of tumour?
o Highly sensitive: lymphoma, myeloma, seminoma
o
Moderately sensitive: breast, ovarian, teratoma, BCC, Small cell lung
carcinoma
o Moderately resistant: cervical carcinoma, bladder carcinoma, rectal
carcionma, sarcomas
o Highly resistant: melanoma, osteosarcoma, carcinoma of pancreas
2. Extent of tumour
3. Tolerance of normal tissues to radiation
o Damage minimized by 3d imaging to ensure maximum radiation dose is
delivered to tumour itself
o Moulds created (as in head/neck cancers), tattoos of chest wall in breast
cancer (ensure same position each time)
o "Wedge" fields - multiple fields necessary
o + "Shrinking" method to allow margins of treatment to be reduced during
last few weeks of treatment
Complications
1. Acute
o
o
o
o
o
o
o
Fatigue
Anorexia, nausea
Skin irradatioatn- erythema/desquamation
Mucosal irradiation - diarrhoea
Dysphagia
Temporary alopecia
Sterility
2. Late
o
o
o
o
Telangectasia
Loss of saliva production
Pulmonary damage
Bowel strictures
Screening
Screening
Programme to detect unsuspected disease in a population of apparently healthy people
Surveillance
Programme to detect disease in a population already with disease
Important considerations
1. Disease
o
o
o
o
Common
Important
Long premobid latent period
Detectable at early stage
o
Treatable: by defined principles, cost-effective
2. Test
o
o
o
o
o
o
Sensitive (ability to detect)
Specific (ability to exclude others)
Non-invasive
Acceptable to patients
Cost-effective
Does no significant harm to patients
Examples
1. Breast cancer
o All women over 50-64 advised to have mammogram every 3 years.
o Mammographic abnormalities referred to breast specialist for clinical
examination + further investigations
o 5-10% breast cancer familial
o Genetics: BrCA1 (chromosome 17), BrCA(chromosome 13),
p53(chromosome 17), Ataxia telangectasia gene
o Detected cancers: smaller, CIS, well differentiated (ie. all rather good
prognostic factors)
2. Ovarian cancer
o Two or more 1st degree relatives
o BrCA1,BrCA2 genes
3. Cervical cancer
o 3 yearly Papanicolau smears
o CIN 1,2,3
o Treated with cone excision biopsy
4. Colorectal cancer: at risk families, polyps, IBD
o Faecal occult blood-testing kit, plus repeat test
o If positive > colonoscopy or double contrast barium enema
5. Abdominal aortic aneurysms
6. Congenital dislocation of hip
o Ortolani
o Barlow's
7. Prenatal screening
Bias in screening
1. Lead-time bias: Survival measured from detection to death will be longer (cause it's
detected earlier)
2. Selection bias: Individuals who take up screening are more health conscious
3. Length bias: slowly growing tumours more likely to be detected by screening than
rapidly growing tumours between screening intervals
Problems in screening





Increased morbidity with unaffected prognosis
Excessive therapy of doubtful cases
Increased anxiety
Lack of target population co-operation
Costs


Inffective screening tests
False reassurance
Sterilisation & disinfection
Sterilisation

Process which kills all living microorganisms (including viruses, spores - clostridium,
bacillus: rests heat, dehydration, chemical attack, ionising radiation)
Disinfection

Process which kills most living microorganisms (except spores and viruses)
Sterilisation methods
Method
Temperatures Type of equipment


Dressings
Instruments

Moisture sensitive
equipment
Ethylene oxide


Plastics
Sophisticated equipment
Gamma radiation

Plastics and prostheses
Moist heat (autoclave) - steam under 134/3min
pressure
121/15min
Dry heat (hot air)
160/2hours
Disinfection Methods


Skin preparation
Glutaraldehyde treatment of endoscopes
Determining adequacy of sterilisation
Browne'
s tubes
Tubes
contain
heat
sensitive
dyes
Bowie
Dick
tape
Stripes
change
to dark
colour
once
sterilise
d
Lantor
test
Precautions to avoid infection
1. Theatre suites
o Theatres sited away from main hospital traffic
o Clearly designated areas of asepsis etc
o Positive-pressure (plenum) ventilation with 20 air changes/hour / Ultraclean laminar airflow systems with 300 air changes/hour
2. Theatre staff
o Minimum number of individuals necessary in theatre
o Avoidance of excess traffic through clean areas
3. Operating personel
o Gowns - cotton gowns reduce bacterial count by 30%
o Caps / masks
o Scrubbing
4. Patient
o Minimal pre-operative stay
o Pre-operative showering
o Shaving only if required immediately prior to surgery
o Skin preparation - 1% iodine or 0.5% chlorhexidine in 70% alcholol
Universal precautions
Precautions taken to protect theatre staff from infections in all patients
1.
2.
3.
4.
5.
Gowns
Gloves
Masks/visors/goggles
No-touch technique when handling needles
Safe disposal of sharps
Stoma
Stoma

Artificial opening allowing connection between two surfaces
Uses
1. Input
o
o
PEG / gastrostomy / jejunostomy - allow feeding
Tracheostomy - allow air
2. Output
o
o
Ileostomy
Colostomy
3. Diversion
o Nephostomy / urostomy - divert flow of wee
4. Decompression
o Tube thoracostomy
o Laparostomy
Complications of GI Stoma
1. Local
o
o
o
o
Skin irritation
Leakage
Odour
Prolaps
2. Systemic
o Electrolyte imbalances
o Malabsorption
o Short gut syndrome
3. "Surgical"
o Strangulation / ischaemia
o Inadequate diversion and spillage
o Stomal stenosis
o Retraction
o
Stomal ulceration
Formation of End Ileostomy
Indications

Permanent stoma after total colectomy
Terminal ileum has absorptive functions - try to preseve as much as possible
1.
2.
3.
4.
5.
6.
GA + NGT + Antibiotics + DVT
Incise 2cm circle of skin over appropriate area (LIF)
Dissect down to rectus and make cruciate incision
Deliver ileum
Stitch ileal serpsa and mesentry to anterior abdominal wall
6-8 cm protrusion to form spout (ideal spout should be 2-3cm)
Formation of Loop ileostomy
Formation of Loop colostomy
Indications

Defunction distal obstructed colon
1. GA + NGT + DVT + Catheter + supine position
2. Formation of stoma
o Pick up skin, incise 2cm down to rectus sheath
o Cruciate incision
o Dissect down to peritoneum, avoid inferior epigastric artery
o "Rubber sling" the colon with a cather, and draw out into wound
3. Fixation of stoma
o Place colostomy bridge
4. Open bowel longitudinally along taeniae with knife (allow explosive gases to be
release
5. Suture edges of stoma to skin using interrupted sutures
6. Clean skin + apply colostomy appliance
Closure of Loop colostomy
Indications



Restore bowel continuity after temporary diversion
When stoma has "matured" (at least 2-3 months)
Recovered from primary pathological process necessitating stoma
1. NGT + GA + Antibiotics + DVT + catheter
2. Release stoma / free bowel
o Incise around stoma about 0.5cm from the mucocutaneous edge
o Apply traction upwards
o Deepen incision and angle towards colon
3. Close defect
o Excise old stoma
o Close colon with interrupted 2/0 full thickness sutures
4. Close wound in layers
Surgical Audit
Audit



Quality control process
Critical and systematic review of practice against set standard
Aim to improve quality of surgical care
Audit subtypes
1. Structure: - organisation, resources
2. Process: - way in which patient has been managed from admission to discharge
3. Outcome: - outcome of surgical intervention
Stages in Audit process
1.
2.
3.
4.
5.
Define audit topic
Collect data + verification by peer review
Data analysis
Presentation of results + recommendations
Re-audit
Requires honesty, completeness, objectivity
Examples
1. NCEPOD (National Confidential Enquiry into Peri-operative Deaths
o Improve standards of surgical practice
2. ICNARC (Intensive Care National Audit And Research Centre)
3. MINAP (Myocardial Infarction National Audit Project)
Sutures / Needles
Characteristics of an ideal suture
Surgeon
Patient
Easy to handle
Minimal tissue reaction
Minimal trauma
Secure
Predictable tensile strenght
Predictable absorption
Sterile
Healthcare provider
Inexpensive
Easy to produce
Classification of sutures
Absorption
Construction
Absorbable: vicryl, PDS, catgut Monofilament: Nylon,
Non-absorbable: nylon, silk, prolene, PDS
Multifilament: braided
prolene, steel
(vicryl), twisted (silk)
Composition
Natural: Silk, catgut, steel
Synthetic: Nylon, PDS
Classification of needles
Shape
Point
Body
Straight (subcuticular)
Curved
Special: J-shaped,
compound curve
Cutting
Tapered
Blunt (bowel surgery)
Cutting
Reverse cuttinh (reduces
tissue cut out)
Round bodied (bowel
anastamosis)
Abdominal pain differentials
Ureteric Colic
1. Renal:
o
o
o
o
kidney stones
Tumour (clot colic)
Pyelonephritis
Renal infarction
o
o
Stricture
Papillary necrosis
2. Vascular
o AAA
o Bowel infarction
3. Gastrointestinal
o Acute appendicitis
o Diverticulitis
4. Gynae
o Ectopic pregnancy
o Salpingitis
o Torsion ovarian cyst
Theatre design
Theatre design
1. Location
o Close to surgical wards / ITU / Supplies / A&E / Imaging
2. Layout
o Separate clean / dirty areas
o Anaesthetic room adjacent to theatre
o Adequate space for storage
o Staff recreation
3. Enviroment
o Ideal temperature 20-22'C
o Humidity control (hog-hair hygrometer)
o Clear filtered air - enters via ceiling, leaves via door flaps
o Power
o Gas
o Lighting
Tourniquet
Indications



Ensure accurate bloodless field
Prevent systemic toxicity in isolated limb perfusion with cytotoxic drugs
biers block (guanethidine block)
Contraindications



Peripheral vascular disease
Elderly (relative)
Patients at risk of DVT when operating on lower limbs
Procedure
1.
2.
3.
4.
5.
6.
Give agent / iv first - can take up to 5 minutes for systemic circulation
Elevate limb, exsangiunate (with "exsanguinator" / esmarch bandage)
Apply soft padding
Apply tourniquet; inflate to >70-100mmHg systolic
Note tourniquet time
Warm anaesthestist prior to tourniquet release
Lower limb 90-120 minutes
Upper limb
Complications
1. Tourniquet site
o Skin: friction burns / chemical burns if applied to skin
o Nerve: Compression leads to neuropraxia
2. Distal to tourniquet
o Vascular: Ishaemia / thrombosis
o Muscular: reperfusion injury (1) free radials released into hypoxic tissues (2)
3. Systemic
o Haemodynamic changes at time to inflation/deflation
o Tissue hypoxia / cell lysis - raised lactate/acidosis, hyperkalaemia
o Hypercoagulability
o PE
Transplantation
Types of Grafts
Homograft = self
Heterograft = same species
Xenograft = different species
Transplant considerations
1. HLA matching:
o Histocompatibility antigens defined by tissue typing - A, B, C, DP, DQ, DR
(chromosome 6)
o HLA Match essential: renal, pancreas
o HLA Match non-essential: cardiac, hepatic
o ABO blood group essential: renal, pancreatic, cardiac, hepatic (ie, all of
them)
2. Donor considerations
o Established brainstem death
o No sepsis
o
o
o
No maligancy (except primary brain)
No HIV, HBV
Not high risk : IVDU
Graft rejection
1. Hyperacute rejection
o recipient serum antibodies vs donor antigens (very bad news) - thrombosis,
graft infarction within hours
o treat by removal of graft
2. Acute rejection
o cell-mediated CD4 immunocytes (T-helper) within 3 months
o Treated with steroids / immunosuppression
3. Chronic rejection
o Humoral / cell-mediated immune responses occurs months - years
o Not treatable or reversible
Wound healing
Wound healing
1. First intention:
o clean surgical wounds withouth tissue loss that heals with minimal fibrosis
2. Second intention:
o wounds left open that heal to fill gap with extensive fibrosis (granulation
tissue, contraction, epithelisation)
o Used when no possilibity of tension-free approximation (loss tissue,
oedema, infection)
3. Third intention:
o delayed primary closure (wounds with high risk of infection if closed early;
dog bites, contaminated wounds, delayed presentation)
o best left for exploration, debridement and toilet with antibiotics and closure
after 3-10 days
Stages in wound healing
1. Events at epidermis
o Clot formation at site
o Epithelial cells migrate from wound edges (under the clot)
o Integrins on keratinocytes bind to fibronectin
o Proliferation of keratinocytes contributes to the ability to cover wound
2. Events at dermis
o Infiltration of polymorphs, macrophages to remove debris
o Fibroblast activity to restore tensile strenght
o Revascularisation
o Myofibroblast contraction
Growth factors involved





Platelet derived growth factor
Epidermal growth factor
Transforming growth factor
Cytokines
Tumour necrosis factor
Granulation tissue



Vascular: proliferating capillary buds
Fibrous: fibroblasts
Inflammatory cells: Macrophages
Takes part in healing process
Potentially deleterious in joint destruction (rheumatoid arthritis by granulation tissue Pannus)
Tissue is resistant to infection. Not resistant to trauma, chemical agents, radiation
Factors affecting wound healing
1. Patient
o
o
o
o
Old
Obese
Smoking
Systemic diseases- diabetes, cardiac disease, immunosuppression, poor
nutrition
2. Wound
o
o
o
Hypoxia / ischaemia
Infection / contamination
Mobility across wound
3. Surgery
o
o
o
Inadequate debridement
Excess tension
Suture necrosis
Dehiscence
Failure of wound to heal in apposition
Partial / total disruption of surgical wound
Signs of Impending wound dehiscence

Low grade pyrexia



"Pink fluid" sign
Abdominal distension
Abdominal pain