General Surgery
Final Professional MBBS — General Surgery. Explanation-first answers that teach the reasoning behind every fact, with classifications, comparison tables, drug doses, clinical pearls and key-point recaps from Bailey & Love and SRB's Manual.
THE CONCEPT
Preoperative assessment is the systematic evaluation and optimisation of a patient before surgery, with the aim of minimising the risk of the operation and anaesthetic. It brings together assessing the patient's fitness, identifying and improving any medical conditions, stratifying risk, obtaining informed consent, and preparing the patient physically for theatre. A good preoperative work-up prevents avoidable complications and cancellations.
AIMS
The aims are to assess fitness for surgery and anaesthesia, identify and optimise comorbidities, stratify operative risk, obtain informed consent, and plan the perioperative care (fasting, prophylaxis, anaesthetic technique).
HISTORY & EXAMINATION
The assessment covers comorbidities (cardiac, respiratory, diabetes, renal, hepatic disease), current medications (especially anticoagulants, antiplatelets and steroids), allergies, previous anaesthetic and surgical history, functional capacity (exercise tolerance), and smoking and alcohol use, together with an airway assessment for anaesthesia.
RISK ASSESSMENT & INVESTIGATIONS
Risk is stratified using the ASA physical status classification, functional capacity and cardiac risk indices. Investigations are chosen according to the patient and the surgery, and may include full blood count, urea and electrolytes, blood glucose/HbA1c, coagulation, group-and-save or crossmatch, an ECG, and a chest X-ray, with further tests (liver/thyroid function, echocardiography, pulmonary function) as indicated.
OPTIMISATION & MEDICATION MANAGEMENT
Modifiable factors are optimised before surgery: good glycaemic control in diabetes, correction of anaemia, optimisation of cardiac and respiratory disease, and smoking cessation. Medications need careful management — anticoagulants and antiplatelets may need to be stopped or bridged, long-term steroids need perioperative stress dosing, the combined pill/HRT raises VTE risk, and drugs such as metformin need a plan for the day of surgery.
PREPARATION FOR THEATRE
Final preparation includes fasting (typically nil-by-mouth for 6 hours for food and 2 hours for clear fluids), informed consent, VTE prophylaxis, antibiotic prophylaxis where indicated, correct site marking, and completion of the WHO Surgical Safety Checklist (and bowel preparation for certain operations).
💡CLINICAL PEARL: A simple framework: preoperative care = assess fitness + optimise comorbidities + stratify risk (ASA) + consent + prepare. Remember the fasting rule (6 hours for food, 2 hours for clear fluids), the need to manage anticoagulants and diabetes, and the routine use of VTE and antibiotic prophylaxis plus the WHO Surgical Safety Checklist.MANAGING THE ANTICOAGULATED PATIENT
A frequently-examined practical area is the perioperative management of anticoagulants and antiplatelets, which balances bleeding risk against thrombotic risk. Warfarin is usually stopped several days before surgery (and the patient 'bridged' with LMWH if the thrombotic risk is high, e.g. a metal heart valve); DOACs are stopped a defined number of days before according to renal function; and decisions about aspirin/clopidogrel depend on why they are being taken (e.g. recent coronary stents are high-risk). Getting this balance right avoids both catastrophic bleeding and dangerous thrombosis.
THE DIABETIC PATIENT & STEROID COVER
Two specific groups need particular planning. Diabetic patients are ideally placed first on the list, with a clear plan for their medication on the day (often omitting/adjusting oral agents and insulin, sometimes using a variable-rate insulin infusion) and close glucose monitoring, since both hyper- and hypoglycaemia are harmful. Patients on long-term steroids may have a suppressed adrenal axis and need perioperative 'steroid cover' (stress-dose steroids) to prevent an Addisonian crisis under the stress of surgery. Anticipating these needs is a key part of optimisation.
A NOTE ON CONSENT & THE WHO CHECKLIST
Two safety pillars complete preparation. Informed consent is a process, not just a signature: the patient must understand the nature of the operation, its benefits, material risks, and the alternatives (including doing nothing), and consent voluntarily with capacity. Immediately before surgery, the WHO Surgical Safety Checklist is performed at three points — 'sign in' (before anaesthesia), 'time out' (before incision) and 'sign out' (before leaving theatre) — confirming patient identity, site, procedure, allergies, equipment and counts. Together these have been shown to reduce errors and improve surgical safety.
A NOTE ON FUNCTIONAL CAPACITY & CARDIAC RISK
A practical measure used throughout preoperative assessment is functional capacity, often expressed in metabolic equivalents (METs): a patient who can climb two flights of stairs or walk up a hill (roughly ≥4 METs) without symptoms generally has adequate cardiorespiratory reserve for major surgery, whereas poor exercise tolerance flags higher risk and may prompt further cardiac assessment (ECG, echocardiography, or specialist referral). Combined with the ASA class and any cardiac risk index, this simple question about exercise tolerance is one of the most informative parts of the whole assessment.
💊KEY POINTS / NUMBERS (viva)- Fasting: 6 hours for food/solids, 2 hours for clear fluids.
- Risk stratification with the ASA classification; investigations tailored to patient + surgery.
- Manage anticoagulants (stop/bridge), steroids (stress dose), diabetes; give VTE + antibiotic prophylaxis; WHO Surgical Safety Checklist.
🔑KEY POINTS TO REMEMBER- Preoperative assessment = evaluate fitness, optimise comorbidities, stratify risk, obtain consent, prepare for theatre.
- Assess comorbidities, medications (anticoagulants, steroids), allergies, previous anaesthesia, functional capacity, airway.
- Investigations tailored to patient/surgery: FBC, U&E, glucose/HbA1c, coagulation, group-and-save, ECG, CXR as indicated; risk by ASA class.
- Optimise: glycaemic control, anaemia, cardiorespiratory disease, stop smoking; manage anticoagulants/steroids/OCP/metformin.
- Fasting (6 h food/2 h clear fluids), consent, VTE + antibiotic prophylaxis, site marking, WHO Surgical Safety Checklist.
📚SOURCES: Bailey & Love's Short Practice of Surgery; SRB's Manual of Surgery.THE CONCEPT
Postoperative complications are the adverse events that follow surgery. The best way to master them is to have a classification — by timing (immediate, early, late) and by system — so that they can be anticipated, recognised early and managed promptly. Many are preventable, which is why prophylaxis and vigilant monitoring are emphasised.
CLASSIFICATION BY TIMING
- Immediate (within 24 hours) — primary and reactionary haemorrhage, and anaesthetic complications.
- Early (days to weeks) — atelectasis and chest infection, wound and urinary infection, DVT/PE, paralytic ileus, wound dehiscence, secondary haemorrhage, anastomotic leak, and acute kidney injury.
- Late (weeks to months) — incisional hernia, adhesions with bowel obstruction, strictures, and disease recurrence.
A NOTE ON HAEMORRHAGE
Post-operative bleeding is classified by timing into three types: primary (during surgery), reactionary (within 24 hours — as blood pressure recovers and a ligature slips or a vessel opens), and secondary (after 7–10 days — usually due to infection eroding a vessel).
CLASSIFICATION BY SYSTEM
Alternatively, complications are grouped by system: respiratory (atelectasis, pneumonia), cardiovascular (myocardial infarction, arrhythmia, DVT/PE), wound (infection, dehiscence, hernia), gastrointestinal (ileus, obstruction, anastomotic leak), urinary (retention, UTI, AKI), and general (sepsis, haemorrhage). It is also useful to separate general complications (which can follow any operation) from those specific to the particular procedure.
PREVENTION & MANAGEMENT
Prevention runs through good surgical technique, appropriate prophylaxis (VTE and antibiotic), early mobilisation, chest physiotherapy, adequate analgesia, and careful fluid management. Management depends on early recognition — regular monitoring and early warning scores detect deterioration — followed by identifying and treating the specific cause.
💡CLINICAL PEARL: Organise the answer around timing (immediate/early/late) or system. Know the three types of haemorrhage — primary, reactionary (within 24 h) and secondary (7–10 days, from infection). The common early complications to quote are atelectasis, infection, DVT and ileus; prevention rests on prophylaxis and early mobilisation, and management on early recognition.A NOTE ON THE ANASTOMOTIC LEAK
One of the most serious specific complications is the anastomotic leak — breakdown of a surgical join in the bowel — which typically presents around day 5–7 with fever, tachycardia, abdominal pain, ileus and signs of sepsis (and sometimes faeculent or purulent drain fluid). It is dangerous because it causes peritonitis and sepsis, and any deterioration after bowel surgery should raise this suspicion. Management ranges from antibiotics and drainage of a contained leak to re-operation for generalised peritonitis, underlining the value of early recognition.
A NOTE ON PARALYTIC ILEUS
Paralytic ileus — a temporary failure of bowel peristalsis after (especially abdominal) surgery — is a common early complication worth understanding. It presents with abdominal distension, absent bowel sounds, vomiting and failure to pass flatus/stool, and is aggravated by handling of the bowel, electrolyte disturbance (low potassium), opioids and immobility. Management is supportive — 'drip and suck' (IV fluids and nasogastric decompression), correcting electrolytes, and minimising opioids — while distinguishing it from a mechanical obstruction, which may need surgery.
A NOTE ON THE CLAVIEN-DINDO CLASSIFICATION
A widely-used way to grade the severity of a surgical complication (rather than just its type or timing) is the Clavien-Dindo classification, which ranks complications by the treatment they require — from Grade I (a deviation needing no specific intervention), through Grade II (needing drug treatment or transfusion) and Grade III (needing surgical, endoscopic or radiological intervention), to Grade IV (life-threatening, needing intensive care) and Grade V (death). This standardised grading allows outcomes to be compared objectively between surgeons and units, and is increasingly used in audit and research.
A NOTE ON POSTOPERATIVE URINARY RETENTION & CHEST INFECTION
Two very common, everyday complications round out the picture. Postoperative urinary retention — an inability to void with a painful distended bladder — is frequent after pelvic, anorectal and hernia surgery and under spinal anaesthesia, and is managed by catheterisation while treating contributory factors (pain, drugs, immobility). Chest infection commonly follows atelectasis, particularly in smokers and after upper-abdominal surgery, and is reduced by physiotherapy, analgesia and early mobilisation. Both illustrate the general theme that many complications are anticipated and preventable with good basic care.
A NOTE ON ADHESIONS & LATE OBSTRUCTION
The commonest late complication of abdominal surgery is the formation of intra-abdominal adhesions — fibrous bands that form as part of healing after peritoneal handling. Although often silent, adhesions are the leading cause of small-bowel obstruction in the developed world, sometimes years after the original operation, and can also cause chronic pain and complicate future surgery. This underlies the modern emphasis on gentle tissue handling and minimally invasive (laparoscopic) techniques, which provoke fewer adhesions, and it is a key example of a complication whose effects appear long after the patient has left hospital.
💊KEY POINTS / NUMBERS (viva)- Timing: immediate (<24 h — haemorrhage), early (days–weeks — atelectasis, infection, DVT, ileus, dehiscence, leak), late (hernia, adhesions).
- Haemorrhage: primary (intra-op), reactionary (<24 h, ligature slips), secondary (7–10 days, infection erodes vessel).
- Prevent with prophylaxis (VTE/antibiotic), early mobilisation, physiotherapy, analgesia; recognise early with monitoring/early warning scores.
🔑KEY POINTS TO REMEMBER- Classify postoperative complications by timing (immediate/early/late) or by system; separate general from procedure-specific.
- Immediate: primary/reactionary haemorrhage, anaesthetic issues; early: atelectasis, infection, DVT/PE, ileus, dehiscence, anastomotic leak.
- Late: incisional hernia, adhesions/obstruction, strictures, recurrence.
- Haemorrhage: primary (intra-op), reactionary (<24 h), secondary (7–10 days, infection).
- Prevent with prophylaxis + early mobilisation + physiotherapy + analgesia; recognise early with monitoring/early warning scores.
📚SOURCES: Bailey & Love's Short Practice of Surgery; SRB's Manual of Surgery.THE CONCEPT
Postoperative fever is common, and the key to diagnosing its cause is timing — when after the operation the fever appears strongly suggests its source. A classic and highly examinable aid is the mnemonic of the '5 Ws', each linked to a typical postoperative day, which gives a structured approach to a very common clinical problem.
THE '5 Ws'
'W' Cause Typical day Wind Atelectasis / chest infection Day 1–2 Water Urinary tract infection Day 3–5 Walking DVT / thromboembolism Day 4–6 Wound Surgical site infection Day 5–7 Wonder drugs / What did we do Drug reaction, IV lines/cannulae, transfusion Any time TIMELINE IN MORE DETAIL
- Immediate (0–24 h) — the inflammatory response to surgical tissue trauma, a transfusion reaction, a pre-existing infection, or (rarely) malignant hyperthermia.
- Early (day 1–2) — atelectasis is the classic cause (basal collapse from shallow breathing/retained secretions).
- Day 3–5 — urinary tract infection (often catheter-related), chest infection, and cannula-site thrombophlebitis.
- Day 5–7 (and later) — wound infection, DVT, an anastomotic leak, or a collection/abscess.
ASSESSMENT & MANAGEMENT
Assessment is a focused history and examination directed at the likely sources — the chest, wound, legs, intravenous lines and abdomen — supported by investigations: full blood count, and cultures of blood, urine, sputum and wound as appropriate, a chest X-ray, and imaging (ultrasound/CT) to look for a collection. Management is to identify and treat the specific cause — chest physiotherapy for atelectasis, removing or changing infected lines/catheters, draining collections, and antibiotics for confirmed infection.
💡CLINICAL PEARL: Use the '5 Ws' with their timing — Wind (atelectasis, day 1–2), Water (UTI, day 3–5), Walking (DVT, day 4–6), Wound (infection, day 5–7), and Wonder drugs/lines (any time). As a rule of thumb, early fever is often atelectasis, whereas a later, swinging fever should make you think of a collection, abscess or anastomotic leak.WHY ATELECTASIS CAUSES EARLY FEVER
It is worth understanding why atelectasis is the classic cause of day 1–2 fever. After surgery — particularly abdominal or thoracic — shallow breathing (from pain), reduced coughing and retained secretions cause the small airways and alveoli at the lung bases to collapse. This collapsed, poorly-ventilated lung both mounts an inflammatory (febrile) response and predisposes to infection. This is precisely why early mobilisation, good analgesia, deep-breathing exercises and chest physiotherapy are emphasised — they re-expand the lung and both prevent and treat this early fever.
A STRUCTURED APPROACH TO THE FEBRILE PATIENT
In practice, a structured approach to the postoperative fever combines the timing (the '5 Ws') with a focused clinical search: examine the chest (atelectasis/pneumonia), the wound (infection), the calves (DVT), the intravenous and urinary lines (phlebitis, catheter UTI), and the abdomen (collection/leak). Investigations are then directed by the findings — cultures, chest X-ray, and cross-sectional imaging for a suspected deep collection. This disciplined approach avoids blindly starting antibiotics and instead finds and treats the actual source.
A NOTE ON SEPSIS RECOGNITION
Whatever the source, the crucial skill is recognising when a postoperative fever signifies developing sepsis rather than a benign cause. Warning features include a rising or swinging fever with tachycardia, hypotension, a rising respiratory rate, confusion, reduced urine output and a rising lactate — captured by early warning scores. Suspected sepsis triggers the 'sepsis six' (oxygen, blood cultures, IV antibiotics, IV fluids, lactate measurement and monitoring urine output) alongside urgent source control (e.g. draining a collection). Treating the fever as a potential early sign of sepsis, not merely a nuisance, can be life-saving.
A NOTE ON NON-INFECTIVE CAUSES
It is important not to assume every postoperative fever is infective. Non-infective causes include the normal inflammatory (cytokine) response to surgical trauma (typical in the first 24–48 hours), a transfusion reaction, drug fever, a haematoma resorbing, and — importantly — venous thromboembolism (DVT/PE), which is itself a non-infective cause of fever. Recognising these prevents the reflex, and sometimes harmful, prescription of antibiotics for every temperature, and directs attention instead to the true cause identified by timing and a focused clinical assessment.
💊KEY POINTS / NUMBERS (viva)- '5 Ws': Wind (atelectasis, d1–2), Water (UTI, d3–5), Walking (DVT, d4–6), Wound (infection, d5–7), Wonder drugs/lines (any time).
- Immediate fever (0–24 h) often the inflammatory response to surgery or a transfusion reaction.
- Later/swinging fever (day 5–7+) → think collection/abscess or anastomotic leak; culture and image.
🔑KEY POINTS TO REMEMBER- Postoperative fever: timing suggests the cause — remember the '5 Ws'.
- Wind (atelectasis/chest, day 1–2), Water (UTI, day 3–5), Walking (DVT, day 4–6), Wound (infection, day 5–7), Wonder drugs/lines (any time).
- Immediate fever (0–24 h): inflammatory response to surgery, transfusion reaction, pre-existing infection.
- Assess chest, wound, legs, lines, abdomen; investigate with FBC, cultures (blood/urine/sputum/wound), CXR, imaging for collections.
- Early fever often atelectasis; later/swinging fever → collection, abscess or anastomotic leak; treat the cause.
📚SOURCES: Bailey & Love's Short Practice of Surgery; SRB's Manual of Surgery.THE CONCEPT
Splenectomy is the surgical removal of the spleen. Its importance in exams centres on knowing the indications and, above all, the serious lifelong complication of overwhelming post-splenectomy infection (OPSI) — because the spleen has a crucial role in defending the body against encapsulated bacteria, its loss leaves the patient vulnerable to fulminant sepsis.
FUNCTIONS OF THE SPLEEN
Understanding OPSI requires knowing the spleen's roles: it acts as a filter (removing aged red cells and 'pitting' out inclusions), an immune organ (producing antibody and opsonins, and clearing encapsulated bacteria), a site of fetal haematopoiesis, and a blood reservoir. It is the loss of the immune/filtering role against encapsulated organisms that underlies OPSI.
INDICATIONS
- Trauma — splenic rupture (the commonest emergency indication), though conservative and spleen-preserving management is now preferred where possible.
- Haematological disease — hereditary spherocytosis, refractory immune thrombocytopenia (ITP), hypersplenism, and some lymphomas/thalassaemias.
- Other — splenic tumour, cyst or abscess, or as part of another operation.
EFFECTS & COMPLICATIONS
Early complications include haemorrhage, injury to adjacent structures (tail of pancreas, stomach), and left basal atelectasis. Haematological changes are characteristic: a reactive thrombocytosis (with thrombosis risk), leucocytosis, and red-cell changes such as Howell–Jolly bodies. The most feared complication is OPSI.
OPSI & ITS PREVENTION
Overwhelming post-splenectomy infection (OPSI) is a fulminant, rapidly fatal sepsis caused by encapsulated organisms — Streptococcus pneumoniae (commonest), Haemophilus influenzae and Neisseria meningitidis. The risk is lifelong but highest in the first two years and in children. Prevention is essential:
- Vaccination against pneumococcus, Haemophilus influenzae type b and meningococcus — ideally 2 weeks before elective surgery (or after recovery in emergencies), with an annual influenza vaccine.
- Prophylactic antibiotics (penicillin), particularly in children and during the high-risk first two years.
- Patient education — a medical-alert card/bracelet and prompt treatment of any infection.
💡CLINICAL PEARL: Two things must be known: the indications (trauma, hereditary spherocytosis, ITP) and OPSI. OPSI is overwhelming sepsis from encapsulated organisms (pneumococcus commonest), prevented by vaccination (pneumococcal, Hib, meningococcal) + prophylactic penicillin + patient education. The blood film after splenectomy shows Howell–Jolly bodies and thrombocytosis.A NOTE ON THE TREND TOWARD SPLENIC CONSERVATION
An important modern principle is the shift away from routine splenectomy toward splenic conservation, driven precisely by awareness of OPSI. In splenic trauma, a haemodynamically stable patient is now often managed non-operatively (observation, or angioembolisation), or with spleen-preserving surgery (splenorrhaphy, partial splenectomy) rather than removing the whole organ. Preserving even part of the spleen retains immune function and reduces the lifelong infection risk — a good example of how understanding a complication has changed surgical practice.
A NOTE ON POST-SPLENECTOMY THROMBOSIS
Besides infection, the reactive thrombocytosis that follows splenectomy deserves attention: the platelet count can rise markedly (sometimes above 1000 ×10⁹/L), creating a risk of venous thrombosis, including portal and mesenteric vein thrombosis. This is why post-splenectomy patients receive thromboprophylaxis and are monitored, and why persistent thrombocytosis may prompt antiplatelet therapy. Together with OPSI, this makes clear that the consequences of removing the spleen are both infective and thrombotic.
A NOTE ON THE POST-SPLENECTOMY BLOOD FILM
The peripheral blood film after splenectomy shows characteristic changes that reflect the lost filtering function, and these are a favourite viva topic. Because the spleen no longer removes red-cell inclusions, the film shows Howell-Jolly bodies (nuclear remnants), Pappenheimer bodies, target cells and occasional nucleated red cells, along with the reactive thrombocytosis and leucocytosis. The presence of Howell-Jolly bodies in a patient's film can even be the clue that alerts a clinician to previous splenectomy or functional hyposplenism — a neat illustration of the spleen's normal role.
A NOTE ON THE APPROACH TO SPLENIC TRAUMA
Splenic injury is worth expanding as the commonest reason the topic arises. It is graded (I–V) by the extent of injury on CT in the stable patient. Management follows haemodynamic status: an unstable patient with intra-abdominal bleeding needs emergency laparotomy (and often splenectomy), whereas a stable patient is increasingly managed non-operatively — with close monitoring, and often splenic artery angioembolisation to control bleeding while preserving the organ. A late risk after splenic trauma is delayed rupture, so monitoring and clear safety advice are important even when initial management is conservative.
💊KEY POINTS / NUMBERS (viva)- Indications: trauma (splenic rupture — now often conserved), hereditary spherocytosis, refractory ITP, hypersplenism.
- OPSI = overwhelming sepsis from encapsulated organisms — S. pneumoniae (commonest), H. influenzae, N. meningitidis; highest risk first 2 years/children.
- Prevent: vaccinate (pneumococcal/Hib/meningococcal, ~2 weeks pre-op) + prophylactic penicillin + education; film shows Howell–Jolly bodies + thrombocytosis.
🔑KEY POINTS TO REMEMBER- Splenectomy indications: trauma (rupture — now often managed conservatively/spleen-preserving), haematological (hereditary spherocytosis, refractory ITP, hypersplenism), tumour/cyst/abscess.
- Spleen functions: filtration, immune (antibody/opsonisation, clears encapsulated bacteria), fetal haematopoiesis, reservoir.
- Post-splenectomy: thrombocytosis (thrombosis risk), leucocytosis, Howell–Jolly bodies; early — haemorrhage, pancreatic tail injury, left basal atelectasis.
- OPSI = fulminant sepsis from encapsulated organisms (S. pneumoniae commonest); lifelong risk, highest first 2 years/children.
- Prevent OPSI: vaccination (pneumococcal/Hib/meningococcal ~2 weeks pre-op) + prophylactic penicillin + patient education/medical alert.
📚SOURCES: Bailey & Love's Short Practice of Surgery; SRB's Manual of Surgery.THE CONCEPT
Nutritional support is a vital but often-neglected part of surgical care. Malnutrition impairs wound healing and immunity and worsens outcomes, while the metabolic stress of surgery increases catabolism and nutritional requirements. The guiding principle of nutritional support is captured in a simple phrase: 'if the gut works, use it' — enteral feeding is preferred over parenteral wherever possible.
WHY NUTRITION MATTERS
Malnutrition leads to poor wound healing, impaired immunity and more infections, muscle wasting and weakness, a longer hospital stay, and higher mortality. Surgical patients are especially at risk because illness reduces intake while the stress response increases demand, so identifying and correcting malnutrition is an important part of perioperative care.
ASSESSMENT
Nutritional status is assessed from the history (weight loss, poor intake), examination (BMI, muscle wasting), and screening tools such as the MUST score; biochemical markers like albumin are unreliable acutely (they fall with the inflammatory response rather than purely with nutrition).
ROUTES OF SUPPORT
- Oral (normal diet with supplements) — always preferred if the patient can eat.
- Enteral (tube feeding) — via a nasogastric or nasojejunal tube, or a gastrostomy (PEG)/jejunostomy; used when the patient cannot eat but the gut works. It is preferred over parenteral nutrition because it is more physiological, maintains gut mucosal integrity (preventing bacterial translocation), has fewer complications and is cheaper.
- Parenteral (intravenous, TPN) — via a central line, reserved for when the gut cannot be used (obstruction, prolonged ileus, short bowel, a high-output fistula, or a non-functioning gut).
COMPLICATIONS & REFEEDING SYNDROME
Enteral feeding can cause tube problems, aspiration and diarrhoea; parenteral nutrition carries the major risk of line sepsis, plus metabolic disturbance (hyperglycaemia, electrolyte shifts) and liver dysfunction. A critical hazard in the malnourished patient is refeeding syndrome: feeding too rapidly causes dangerous falls in phosphate, potassium and magnesium (hypophosphataemia in particular), risking cardiac and neurological complications. It is prevented by feeding slowly, monitoring and replacing electrolytes, and giving thiamine.
💡CLINICAL PEARL: The mantra is 'if the gut works, use it' — enteral nutrition is preferred over parenteral because it is safer, cheaper and maintains gut integrity. Reserve TPN for a non-functioning gut (its main danger being line sepsis), and always beware refeeding syndrome (hypophosphataemia) in the malnourished — feed slowly and give thiamine.A NOTE ON WHO IS AT RISK & PERIOPERATIVE OPTIMISATION
Recognising the at-risk patient is the first step. Those with significant recent weight loss, a low BMI, prolonged poor intake, or high-output losses (fistula, malabsorption) are nutritionally at risk and benefit from support before as well as after surgery. Correcting malnutrition preoperatively (with oral supplements or, if needed, a period of enteral/parenteral feeding) improves wound healing and reduces complications, which is why nutritional screening is now a routine part of preoperative assessment rather than an afterthought once problems arise.
A NOTE ON DAILY REQUIREMENTS & MONITORING
Effective nutritional support requires attention to requirements and monitoring. The patient needs an appropriate provision of energy, protein (nitrogen), fluid, electrolytes, vitamins and trace elements, tailored to their weight and clinical state. Feeding is monitored — including glucose, electrolytes (especially phosphate, potassium and magnesium), fluid balance and, over time, weight and nutritional markers — both to ensure adequacy and to detect complications early. This monitoring is what makes the difference between safe, effective feeding and harm such as refeeding syndrome or line sepsis.
A NOTE ON IMMUNONUTRITION & THE ROLE OF THE DIETITIAN
Modern surgical nutrition increasingly involves the wider team and specific strategies. A dietitian is central to assessing requirements, choosing the route and monitoring support. Interest has also grown in 'immunonutrition' — feeds supplemented with substrates such as glutamine, arginine and omega-3 fatty acids — which may modulate the immune response and improve outcomes in selected major surgical (especially upper-GI cancer) patients. Whatever the specifics, the principles remain: identify malnutrition early, use the gut whenever possible, feed safely, and involve the multidisciplinary team.
💊KEY POINTS / NUMBERS (viva)- 'If the gut works, use it': oral → enteral (NG/NJ/PEG/jejunostomy) → parenteral (TPN) only for a non-functioning gut.
- Enteral preferred: physiological, maintains gut mucosa/prevents bacterial translocation, fewer complications, cheaper; TPN main risk = line sepsis.
- Refeeding syndrome: hypophosphataemia (also low K+/Mg2+) in the malnourished fed too fast → feed slowly, monitor electrolytes, give thiamine.
🔑KEY POINTS TO REMEMBER- Malnutrition impairs healing/immunity and worsens outcomes; surgery increases catabolism — assess (history, BMI, MUST) and support nutrition.
- 'If the gut works, use it': prefer oral, then enteral tube feeding (NG/NJ/PEG/jejunostomy).
- Enteral preferred over parenteral: physiological, maintains gut mucosa (prevents bacterial translocation), fewer complications, cheaper.
- Parenteral (TPN) reserved for a non-functioning gut (obstruction, ileus, short bowel, high-output fistula); main risk = line sepsis.
- Beware refeeding syndrome (hypophosphataemia, low K+/Mg2+) in the malnourished — feed slowly, monitor electrolytes, give thiamine.
📚SOURCES: Bailey & Love's Short Practice of Surgery; SRB's Manual of Surgery.THE CONCEPT
A suture is a material used to hold tissues together (approximate them) until healing occurs, or to ligate blood vessels. Choosing the right suture is a basic surgical skill, and the choices are best understood through a few key classifications that determine which suture suits which tissue.
CLASSIFICATION
- Absorbable vs non-absorbable — absorbable sutures (e.g. polyglactin/Vicryl, Monocryl, PDS, catgut) are broken down over time and used for deep tissues and mucosa; non-absorbable sutures (e.g. silk, nylon, polypropylene/Prolene, steel) persist and are used for skin, tendon and vascular anastomoses.
- Monofilament vs multifilament (braided) — monofilament (Prolene, Monocryl) is smooth and harbours less infection but handles/knots less easily; braided (silk, Vicryl) handles well but can harbour bacteria.
- Natural vs synthetic.
SIZING & SELECTION
Suture size is expressed by a number of zeros — the more zeros, the finer the suture (e.g. 3-0 is finer than 2-0). Selection matches the tissue: fine sutures for the face, stronger sutures for the abdominal wall, absorbable for deep layers, non-absorbable for skin and tendons. Sutures come mounted on needles (cutting for tough skin, round-bodied for delicate tissue/bowel).
IDEAL SUTURE & PRACTICAL SELECTION
The properties of an ideal suture help explain the choices: it should have adequate tensile strength, good knot security, minimal tissue reaction, and predictable handling and absorption — no single material is ideal for everything. In practice a surgeon chooses by tissue and purpose: a slowly-absorbed strong suture (e.g. PDS) for the abdominal wall, a fine monofilament for the face, an absorbable braided suture (Vicryl) for deep layers and bowel, and a non-absorbable monofilament (Prolene) for a vascular anastomosis — matching the classification to the job.
THE BOTTOM LINE
Sutures approximate tissue until healing; the choice follows a few classifications (absorbable vs non-absorbable, monofilament vs braided, size by number of zeros), matched to the tissue and purpose.
A NOTE ON WOUND CLOSURE METHODS
Sutures are only one way to close a wound, and knowing the alternatives adds context. Skin staples (clips) are quick and useful for long incisions; adhesive skin strips (Steri-Strips) and tissue glue (cyanoacrylate) suit small, low-tension wounds (and are handy in children); and subcuticular absorbable sutures give a good cosmetic result. The method is chosen for the site, tension, cosmetic importance and infection risk — for example, glue or a fine subcuticular suture for the face, and staples for a long laparotomy wound.
🔑KEY POINTS TO REMEMBER- Suture = material to approximate tissues until healing (or to ligate vessels).
- Absorbable (Vicryl, Monocryl, PDS, catgut — deep/mucosa) vs non-absorbable (silk, nylon, Prolene, steel — skin, tendon, vessels).
- Monofilament (Prolene, Monocryl — less infection, smooth) vs braided (silk, Vicryl — better handling but harbours bacteria).
- Size = number of zeros (more zeros = finer); choose by tissue; needles cutting (skin) vs round-bodied (bowel/delicate).
📚SOURCES: Bailey & Love's Short Practice of Surgery.THE CONCEPT
A surgical drain is a tube or conduit placed to allow fluid, blood, pus or air to escape from a cavity or wound. Drains are used either to treat an existing collection or to prevent one from forming, and understanding this distinction (therapeutic vs prophylactic) explains why and when they are used.
PURPOSES & TYPES
A drain may be therapeutic (draining an existing collection — an abscess or a pleural effusion) or prophylactic (placed after surgery to evacuate any anticipated blood or serum, or to warn of a leak). They are classified as:
- Open vs closed — open drains (corrugated, Penrose) drain passively onto a dressing; closed drains lead into a sealed bag/bottle and carry a lower infection risk (e.g. chest drain).
- Active vs passive — active drains use suction (e.g. a Redivac); passive drains rely on gravity or capillary action.
COMPLICATIONS & REMOVAL
Complications include retrograde infection, blockage, erosion of adjacent tissue/vessels, the drain being retained or breaking, and patient discomfort. A drain is removed once it has served its purpose — when the output falls to a low level or the risk it guarded against has passed.
THE DEBATE ABOUT PROPHYLACTIC DRAINS
A point of ongoing surgical debate is the value of prophylactic drains. While they can evacuate blood/serum and warn of a leak, drains are not harmless — they can introduce infection, erode tissue, and give false reassurance (a drain can block and fail to signal a leak). Consequently, evidence has moved against the routine use of drains in many operations, and they are used selectively where there is a genuine indication rather than as a reflex. This reflects the general principle of using a drain only when its benefit clearly outweighs its risks.
THE BOTTOM LINE
A surgical drain lets fluid, pus or air escape from a cavity or wound, used therapeutically or prophylactically, classified as open/closed and active/passive, and removed once its purpose is served — increasingly used selectively rather than routinely.
A NOTE ON THE CHEST DRAIN
The chest (intercostal) drain is a specific closed drain worth knowing as a distinct topic. It is used to evacuate air (pneumothorax), fluid (effusion), blood (haemothorax) or pus (empyema) from the pleural space and to allow the lung to re-expand. It is connected to an underwater seal that acts as a one-way valve — allowing air/fluid out on expiration while preventing air being drawn back into the chest on inspiration — with the fluid level 'swinging' with respiration confirming a patent, correctly-placed drain. This makes it a good example of the closed-drain principle.
🔑KEY POINTS TO REMEMBER- Surgical drain = conduit to let fluid/blood/pus/air escape from a cavity or wound.
- Therapeutic (drain an existing collection) vs prophylactic (prevent/warn of a collection or leak).
- Open (corrugated/Penrose, passive) vs closed (to a bag, lower infection risk); active (suction, e.g. Redivac) vs passive (gravity/capillary).
- Complications: retrograde infection, blockage, erosion, retention, discomfort; remove when output falls/purpose served.
📚SOURCES: Bailey & Love's Short Practice of Surgery.THE CONCEPT
Wound dehiscence is the partial or complete separation of the layers of a surgical wound. When an abdominal wound disrupts completely and the abdominal contents protrude, it is called a 'burst abdomen' — a dramatic and serious complication, typically occurring around the fifth to tenth postoperative day.
HERALD SIGN & CAUSES
A characteristic warning sign is the discharge of serosanguinous ('pink', salmon-coloured) fluid from the wound a day or two before it bursts. The causes combine patient factors — malnutrition, obesity, diabetes, steroids, malignancy, jaundice, old age, and raised intra-abdominal pressure (chronic cough, distension) — and local factors (wound infection), together with technical factors (poor closure technique).
MANAGEMENT
A burst abdomen is a surgical emergency: the exposed viscera are covered with sterile saline-soaked gauze, the patient is reassured and given analgesia, IV fluids and antibiotics, and arrangements are made to return to theatre for resuturing (a mass closure of the abdominal wall). Even after successful repair, these patients are at increased risk of a later incisional hernia.
💡CLINICAL PEARL: Recognise the salmon-pink serosanguinous discharge as the herald of an impending burst abdomen around day 5–10. Immediate management is to cover the wound with saline-soaked gauze and arrange urgent return to theatre for resuturing; the risk factors to quote are infection, malnutrition, obesity, steroids and raised intra-abdominal pressure.PREVENTION & THE ROLE OF MASS CLOSURE
Because a burst abdomen is serious, prevention is emphasised, and it centres on sound closure and patient optimisation. A mass closure technique (taking large bites of the whole musculo-aponeurotic layer with a suture length at least four times the wound length) distributes tension and reduces dehiscence, as does preventing wound infection and optimising the patient (nutrition, diabetic control, treating a chronic cough). When dehiscence does occur, prompt recognition of the herald pink discharge and urgent resuturing give the best outcome and reduce the later incisional-hernia burden.
THE BOTTOM LINE
Wound dehiscence, and its extreme form the burst abdomen, is heralded by a serosanguinous discharge around day 5–10 and is an emergency requiring saline-gauze cover and urgent resuturing, with infection and poor closure the key causes.
A NOTE ON PARTIAL VS COMPLETE DEHISCENCE
It is useful to distinguish the degrees of dehiscence. A partial (incomplete) dehiscence separates the superficial layers while the deep musculo-aponeurotic layer holds, so the viscera remain covered — this may present later as an incisional hernia. A complete dehiscence disrupts all layers, producing the burst abdomen with protruding viscera that is the emergency. Recognising that a superficial breakdown, though less dramatic, still signals a weak repair helps anticipate the later hernia and informs follow-up.
🔑KEY POINTS TO REMEMBER- Wound dehiscence = separation of the layers of a surgical wound; 'burst abdomen' = complete disruption with protrusion of viscera (usually day 5–10).
- Herald sign: serosanguinous ('pink'/salmon) discharge before it bursts.
- Causes: patient factors (malnutrition, obesity, diabetes, steroids, malignancy, jaundice, raised intra-abdominal pressure) + infection + poor technique.
- Emergency: cover viscera with saline-soaked gauze, IV fluids/analgesia/antibiotics, urgent return to theatre for resuturing (mass closure); later incisional hernia risk.
📚SOURCES: Bailey & Love's Short Practice of Surgery.THE CONCEPT
A surgical site infection (SSI) is an infection of the operative wound, occurring within 30 days of surgery (or up to 90 days if an implant is present). It is one of the commonest healthcare-associated infections and an important cause of postoperative morbidity, so its prevention is a major focus of surgical care.
CLASSIFICATION & RISK
SSIs are classified by depth as superficial incisional, deep incisional, or organ/space. The risk is strongly predicted by the wound classification — clean, clean-contaminated, contaminated, or dirty (infection risk rising across these). Additional risk comes from patient factors (diabetes, obesity, smoking, immunosuppression, malnutrition) and operative factors (degree of contamination, long operating time, poor technique).
PRESENTATION, PREVENTION & MANAGEMENT
An SSI presents with pain, erythema, swelling, warmth and purulent discharge, often with fever (typically around day 5–7). Prevention is key: appropriate antibiotic prophylaxis, aseptic technique, skin preparation, maintaining normothermia and glycaemic control, and good surgical technique. Management is to open and drain the wound, send a swab, give antibiotics if there is spreading infection, and provide appropriate dressings.
THE TIMING OF ANTIBIOTIC PROPHYLAXIS
A key practical detail in preventing SSI is the correct timing of antibiotic prophylaxis: a single dose is given within about 60 minutes before the skin incision, so that adequate tissue levels are present during the operation, with a repeat dose for very long procedures or major blood loss. Giving it too early or too late reduces its effectiveness. This, combined with good skin preparation, asepsis, normothermia and glycaemic control, forms an evidence-based bundle that measurably reduces surgical site infection rates.
THE BOTTOM LINE
A surgical site infection is a wound infection within 30 days (90 with an implant), its risk predicted by wound class and patient factors, prevented by prophylaxis and asepsis and treated by drainage and antibiotics.
A NOTE ON THE WOUND CLASSES IN PRACTICE
The four wound classes translate directly into expected infection rates and prophylaxis decisions. A clean wound (e.g. a hernia repair, no viscus opened) has a very low infection rate; a clean-contaminated wound (a controlled entry into the GI/respiratory/urinary tract) a moderate rate; a contaminated wound (gross spillage, or acute inflammation) a higher rate; and a dirty wound (established infection or perforation, e.g. faecal peritonitis) the highest. This gradation guides whether prophylactic antibiotics suffice or a full therapeutic course is needed, and whether the skin is closed primarily or left open to heal by secondary intention.
🔑KEY POINTS TO REMEMBER- Surgical site infection (SSI) = wound infection within 30 days of surgery (90 days with an implant); common and important.
- Depth: superficial incisional, deep incisional, organ/space; risk predicted by wound class (clean → clean-contaminated → contaminated → dirty).
- Risk factors: diabetes, obesity, smoking, immunosuppression, malnutrition; contamination, operative duration, technique.
- Prevent: antibiotic prophylaxis, asepsis, skin prep, normothermia, glycaemic control; treat by opening/draining, swab, antibiotics, dressings.
📚SOURCES: Bailey & Love's Short Practice of Surgery.THE CONCEPT
Venous thromboembolism (VTE) prophylaxis means the measures taken to prevent deep vein thrombosis and pulmonary embolism in surgical patients. It is one of the most important routines in surgery because VTE is a major, largely preventable cause of postoperative death, and every surgical patient should be assessed for it.
RISK ASSESSMENT
Prophylaxis is guided by a risk assessment weighing the type of surgery (major, pelvic or orthopaedic surgery being high-risk) against patient factors — increasing age, malignancy, immobility, previous VTE, obesity, thrombophilia — and the patient's bleeding risk.
METHODS
- Mechanical — graduated compression stockings and intermittent pneumatic compression devices (used for most patients, and especially where drugs are contraindicated).
- Pharmacological — low-molecular-weight heparin (e.g. enoxaparin) or a DOAC.
- General — early mobilisation and adequate hydration.
The choice balances thrombosis risk against bleeding risk, and prophylaxis may be extended after discharge for high-risk surgery (major cancer or major orthopaedic operations).
MECHANICAL VS PHARMACOLOGICAL & BALANCING BLEEDING RISK
The interplay of the two arms of prophylaxis is worth spelling out. Mechanical methods (stockings, intermittent pneumatic compression) carry no bleeding risk and are used when pharmacological prophylaxis is contraindicated (e.g. active bleeding, or immediately around neurosurgery/spinal anaesthesia). Pharmacological prophylaxis (LMWH) is more effective but must be timed to avoid bleeding around surgery and neuraxial blocks. Combining the two in high-risk patients, while individualising the plan to the bleeding risk, is the essence of good VTE prevention.
THE BOTTOM LINE
VTE prophylaxis prevents a major cause of postoperative death by combining risk assessment with mechanical and pharmacological measures and early mobilisation, balanced against bleeding risk.
A NOTE ON EARLY MOBILISATION
Beyond stockings and heparin, the simplest and most universally applicable measure is early mobilisation: getting the patient up and walking soon after surgery activates the calf muscle pump, which promotes venous return and directly counters the stasis limb of Virchow's triad. Combined with adequate hydration (avoiding the haemoconcentration that predisposes to clot), early mobilisation is a cornerstone of VTE prevention that costs nothing, benefits recovery generally, and complements the mechanical and pharmacological methods.
🔑KEY POINTS TO REMEMBER- VTE prophylaxis prevents DVT/PE — a major preventable cause of postoperative death; assess every surgical patient.
- Risk assessment: surgery type (major/pelvic/orthopaedic) + patient factors (age, malignancy, immobility, previous VTE, obesity) vs bleeding risk.
- Mechanical (compression stockings, intermittent pneumatic compression) + pharmacological (LMWH/DOAC) + early mobilisation + hydration.
- Balance thrombosis vs bleeding risk; extend prophylaxis after major cancer/orthopaedic surgery.
📚SOURCES: Bailey & Love's Short Practice of Surgery.THE CONCEPT
Day case (ambulatory) surgery is surgery in which the patient is admitted, operated on and discharged home on the same day, without an overnight hospital stay. It has become a large and growing part of elective surgery because it is efficient and beneficial for both patients and the health service, made possible by advances in minimally invasive techniques and short-acting anaesthesia.
BENEFITS
Its advantages are that it is cost-effective and efficient, reduces the risk of hospital-acquired infection, is often preferred by patients (recovering at home), and frees inpatient beds for those who need them.
PATIENT & PROCEDURE SELECTION & DISCHARGE
Success depends on careful selection. The procedure should be relatively short, with low complication rates, minimal blood loss and manageable postoperative pain. The patient should be reasonably fit (ASA I–II or stable III), with adequate social support, transport home and a responsible adult, living within reasonable distance. Before discharge, patients must meet discharge criteria — stable observations, controlled pain and nausea, tolerating fluids, having passed urine, and accompanied by an escort — with clear instructions and follow-up arranged.
ENHANCED RECOVERY & THE ROLE OF MINIMALLY INVASIVE SURGERY
Day surgery is part of a wider shift toward enhanced recovery after surgery (ERAS) and minimally invasive techniques. Laparoscopic and regional/short-acting anaesthetic techniques reduce pain, nausea and recovery time, allowing more procedures to be done as day cases and enabling faster discharge even after larger operations. Good preoperative counselling, multimodal (opioid-sparing) analgesia, early mobilisation and early feeding all contribute — so day surgery is best seen not in isolation but as one expression of modern, recovery-focused perioperative care.
THE BOTTOM LINE
Day case surgery admits, operates on and discharges a patient the same day, offering efficiency and lower infection risk, and depends on careful patient/procedure selection and meeting discharge criteria.
A NOTE ON UNPLANNED ADMISSION & SAFETY-NETTING
An important safety aspect of day surgery is planning for the minority who cannot be discharged as intended — because of uncontrolled pain or nausea, urinary retention, bleeding, an unexpectedly extensive operation, or a lack of a suitable escort/home circumstances. Robust day-surgery services therefore have clear pathways for unplanned overnight admission, and every patient is discharged with written instructions, analgesia, warning signs and contact details ('safety-netting') so they know when and how to seek help. This planning is what makes same-day discharge safe rather than merely convenient.
🔑KEY POINTS TO REMEMBER- Day case surgery = admission, operation and discharge on the same day (no overnight stay).
- Benefits: cost-effective, efficient, less hospital-acquired infection, patient preference, frees beds.
- Selection: suitable procedure (short, low complications, minimal blood loss, manageable pain) + suitable patient (ASA I–II/stable III, social support, transport, escort).
- Discharge criteria: stable observations, controlled pain/nausea, tolerating fluids, passed urine, responsible escort + instructions.
📚SOURCES: Bailey & Love's Short Practice of Surgery.THE CONCEPT
The ASA physical status classification (of the American Society of Anesthesiologists) is a simple grading of a patient's overall physical/health status before anaesthesia, used to communicate risk and help predict perioperative morbidity and mortality. It is a quick, universally understood shorthand for how fit a patient is for surgery.
THE GRADES
Class Description I A normal healthy patient II Mild systemic disease (e.g. controlled hypertension, smoker) III Severe systemic disease (limiting but not incapacitating — e.g. poorly-controlled diabetes, stable angina) IV Severe systemic disease that is a constant threat to life (e.g. recent MI, severe heart failure) V Moribund; not expected to survive without the operation VI Brain-dead patient (organ donor) USE
The suffix 'E' is added for an emergency operation (which carries higher risk). In general, a higher ASA class correlates with higher perioperative risk and mortality, so it is a useful part of preoperative risk assessment — though it grades the patient's overall health, not the difficulty of the surgery itself.
STRENGTHS & LIMITATIONS
The ASA classification's strength is its simplicity and universal use as a quick communication of a patient's fitness, and it does correlate with outcome. Its limitations are that it is somewhat subjective (assignment can vary between assessors), and — importantly — it grades the patient's health, not the magnitude or urgency of the surgery (hence the separate 'E' modifier for emergencies). For this reason it is used alongside other tools (functional capacity, cardiac risk indices, frailty scores) rather than as a sole measure of operative risk.
THE BOTTOM LINE
The ASA classification is a simple, widely used grading of a patient's physical status (I–VI, with an 'E' for emergencies) that predicts perioperative risk but grades the patient's health rather than the surgery itself.
A NOTE ON ITS PLACE IN RISK ASSESSMENT
In everyday practice the ASA class is recorded for every patient and used as a common language between surgeons, anaesthetists and the wider team to flag those needing extra caution — for example, an ASA III or IV patient may require higher-level postoperative care, more thorough optimisation, or reconsideration of whether elective surgery is in their best interests. It also feeds into day-surgery selection (favouring ASA I–II and stable III) and into audit and outcome comparison. Its enduring popularity rests on being quick to apply yet genuinely predictive of perioperative risk.
🔑KEY POINTS TO REMEMBER- ASA classification = grading of a patient's physical status before anaesthesia to predict perioperative risk.
- I normal healthy; II mild systemic disease; III severe (limiting) systemic disease; IV severe disease, constant threat to life; V moribund; VI brain-dead (donor).
- 'E' suffix = emergency (higher risk).
- Higher ASA class = higher perioperative morbidity/mortality; grades patient health, not operative difficulty.
📚SOURCES: Bailey & Love's Short Practice of Surgery.