Cover the protruding viscera with sterile saline-soaked packs and prepare for urgent theatre. This patient has suffered acute abdominal wound dehiscence with evisceration ('burst abdomen'), classically presenting on postoperative day 6 to 8 with profuse serosanguinous ('salmon-pink') wound discharge following increased intra-abdominal pressure (such as coughing or straining). The immediate emergency management is to reassure the patient, position them supine with knees flexed to minimize abdominal wall tension, and cover the exteriorized bowel immediately with sterile saline-soaked packs or towels to maintain moisture, warmth, and prevent desiccation and bacterial contamination. The patient must be kept strictly nil by mouth, given intravenous analgesia and fluids, and transferred urgently to the operating theatre for formal emergency re-laparotomy and mass closure under general anaesthesia. Attempting to reduce the bowel into the abdominal cavity at the bedside is strictly contraindicated because it causes excruciating pain, tears delicate mesentery, risks bowel perforation, and introduces contamination into the peritoneal cavity. Circumferential binders or bedside stapling without formal fascial inspection risk trapping, strangulating, or perforating bowel loops.

Q: A 65-year-old male who underwent an open low anterior resection for rectal carcinoma 18 hours ago has had a total urine output of 35 mL over the past three hours through his indwelling Foley catheter. He weighs 75 kg. His temperature is 37.4°C, pulse rate is 84 beats per minute, blood pressure is 128/76 mmHg, and oxygen saturation is 98% on room air. Abdominal examination reveals a soft, non-distended abdomen with expected localized incisional tenderness. Review of his fluid balance chart shows 1500 mL of intravenous Hartmann's solution infused over the last 24 hours, with estimated intraoperative blood loss of 250 mL. Which of the following is the most appropriate first-line action?

Inspect the drainage tubing and flush the Foley catheter with sterile saline under aseptic technique. The patient has postoperative oliguria (defined as urine output under 0.5 mL/kg/h for two or more consecutive hours; for a 75 kg patient, output should be greater than 37.5 mL/h, but he has produced under 12 mL/h). The fundamental first step in the systematic evaluation of postoperative oliguria in a catheterized patient is to exclude a simple mechanical problem: inspecting the drainage tubing for kinks, loops, or dependency, and gently flushing the catheter with 20 to 30 mL of sterile saline using aseptic technique to confirm patency and clear any obstructing blood clot or mucous plug. If the catheter flushes and aspirates easily without obstruction, the next step is assessing intravascular volume and administering a fluid challenge (e.g., 250 to 500 mL of balanced crystalloid) if hypovolaemia is suspected. Administering a loop diuretic like furosemide without assessing catheter patency or intravascular volume is dangerous and can precipitate acute tubular necrosis if the patient is hypovolaemic. While laboratory investigations and imaging may eventually be required if oliguria persists despite confirmed patency and fluid resuscitation, mechanical clearance is the immediate first action.

Q: A stable patient on postoperative day two has fever and reduced breath sounds at the bases. There is no wound inflammation or hypotension. What is the most appropriate initial approach?

Assess for pulmonary and other causes, using targeted imaging and supporting analgesia and mobilisation. Postoperative timing does not establish a cause. Assess respiratory symptoms, oxygenation, examination, devices, medicines and other possible sources, with targeted imaging if warranted. Atelectasis is not an established explanation for fever. Adequate analgesia and mobilisation support lung expansion while infection or deterioration requires its own treatment.

Key Takeaways

Postoperative tachycardia can be an early warning sign of bleeding, sepsis or PE.
Assess anastomotic leak when recovery deteriorates or abdominal signs appear.
Mobilisation and thromboprophylaxis should be matched to bleeding risk and clinical condition.

Last updated: October 2026

Postoperative fever

The day of onset helps organise assessment but cannot diagnose the cause. Early fever may reflect inflammation, drug reactions, transfusion reactions or infection. Atelectasis is not an established cause of postoperative fever, so the traditional five-W timetable should not be used as a diagnostic rule.

Review the operation, devices, medicines, symptoms and observations. Examine the wound, lungs, abdomen, urine/retention and thrombosis signs; use cultures or imaging when the clinical findings warrant them. Shock, hypoxia, confusion, peritonism or disproportionate wound pain requires immediate escalation. Pulmonary complications are prevented and treated with suitable analgesia, mobilisation, physiotherapy and targeted respiratory care, while antibiotics address suspected infection rather than a timetable.

Surgical Site Infections & Abdominal Wound Dehiscence

Surgical Site Infections (SSI)

Classified into three tiers according to depth:

Superficial Incisional: Involves skin and subcutaneous fat only. Managed by removing sutures, opening the wound, evacuating hematoma or seroma, and applying moist saline dressings. Systemic antibiotics are unnecessary unless surrounding spreading cellulitis or systemic toxicity is present.
Deep Incisional: Involves deep fascia and muscle. Requires surgical debridement in the operating theatre and systemic intravenous antibiotics.
Organ / Space: Involves any anatomical cavity manipulated during the procedure (e.g., subphrenic abscess, pelvic collection, anastomotic leak). Evaluated with contrast-enhanced CT of the abdomen and pelvis; managed via percutaneous image-guided drainage or surgical re-exploration plus broad-spectrum antimicrobials.

Wound Dehiscence & Burst Abdomen (Evisceration)

Wound dehiscence represents separation of the structural layers of an abdominal incision. Complete dehiscence with protrusion of abdominal contents (small bowel or omentum) through the wound is termed burst abdomen or evisceration.

Timing & Pathognomonic Presentation: Characteristically occurs on postoperative day 6 to 8. The hallmark sign is a sudden, copious discharge of "salmon-pink" serosanguinous fluid soaking abdominal dressings, frequently preceded by an episode of coughing, vomiting, or straining. Patients often describe a sensation of "something giving way" or tearing.
Risk Factors: Patient factors (malnutrition, hypoalbuminaemia, obesity, advanced age, diabetes, chronic steroids, ascites, chronic coughing) and surgical factors (wound infection, inadequate bite size during closure, broken sutures, excessive tension).
Immediate Emergency Management Protocol:
1. Position the patient supine with hips and knees flexed to relax the abdominal wall musculature and minimize intra-abdominal pressure.
2. Cover the exposed viscera immediately with sterile saline-soaked gauze or towels to maintain moisture, preserve warmth, and protect against desiccation and contamination.
3. Never attempt to force or push the protruding viscera back into the abdominal cavity at the bedside; this causes bowel perforation, mesenteric tearing, and severe peritonitis.
4. Make the patient strictly nil by mouth (NPO), secure large-bore IV access, administer intravenous balanced fluids, analgesia, and broad-spectrum intravenous antibiotics.
5. Mobilize the surgical team and operating theatre immediately for emergency re-laparotomy and formal mass abdominal wall closure using heavy, non-absorbable or slowly absorbable continuous monofilament sutures (e.g., No. 1 polydioxanone [PDS] or nylon) taking large tissue bites ( $> 1\text{ cm}$ from the fascial edge with $1\text{ cm}$ spacing).

Postoperative Oliguria & VTE Prophylaxis

Postoperative Oliguria

Defined as urine output $< 0.5\text{ mL/kg/hour}$ for two or more consecutive hours in an adult.

Systematic Diagnostic Approach

Rule out mechanical catheter obstruction first: Inspect drainage tubing for kinks, loops, or air-locks. Flush the catheter with $20\text{ to }30\text{ mL}$ of sterile normal saline using strict aseptic technique. Inability to instill or aspirate fluid confirms catheter lumen obstruction, mandating immediate catheter replacement.
Assess for pre-renal hypovolaemia: Review intraoperative blood loss, fluid balance charts, third-space fluid sequestration, and clinical volume status (postural vitals, peripheral perfusion, jugular venous pressure). If hypovolaemia is suspected, administer an intravenous fluid challenge ( $250\text{ to }500\text{ mL}$ of balanced crystalloid) over 15 to 30 minutes and observe urine response.
Evaluate for intrinsic renal injury (Acute Tubular Necrosis): Caused by prolonged intraoperative hypotension or nephrotoxins (NSAIDs, aminoglycosides, IV iodinated contrast). Check serum creatinine, urea, and urine microscopy.
Evaluate for post-renal obstruction: Accidental surgical ureteric ligation or transection during deep pelvic surgery. Exclude with bedside renal ultrasound if oliguria persists despite confirmed catheter patency and fluid resuscitation.

Venous Thromboembolism (VTE) Prophylaxis

Mechanical Prophylaxis: Graduated compression stockings (GCS) and Intermittent Pneumatic Compression (IPC) devices should be fitted preoperatively and maintained until the patient is fully mobile.
Pharmacological Prophylaxis: Low-molecular-weight heparin (enoxaparin 20 mg to 40 mg SC daily) commenced 6 to 12 hours postoperatively once surgical haemostasis is assured.
Neuraxial Anaesthesia Timing (ANZCA Guidelines): To avoid catastrophic spinal/epidural haematomas, ensure a minimum of 12 hours between a prophylactic LMWH dose and spinal needle placement or epidural catheter manipulation/removal; delay the subsequent LMWH dose for at least 4 hours following catheter removal.

Primary references (checked 7 October 2026): Australian 2025 GLP1/GIP perioperative recommendations.

Test Your Knowledge

A 68-year-old woman is recovering on the surgical ward on postoperative day 7 following an open emergency Hartmann procedure for perforated diverticulitis. While walking to the bathroom, she experiences a vigorous bout of coughing followed by a sensation of something 'tearing and giving way' in her lower abdomen. A nurse notices that her abdominal dressing is saturated with profuse, salmon-pink, watery fluid. On removing the dressing, loops of viable small bowel are visible protruding through the lower half of the midline laparotomy wound. Which of the following is the most appropriate immediate action?

Gently manipulate the exteriorized bowel loops back into the peritoneal cavity at the bedside

Cover the protruding viscera with sterile saline-soaked packs and prepare for urgent theatre

Apply a firm circumferential abdominal binder and administer oral paracetamol for discomfort

Approximate the wound edges immediately using bedside sterile surgical staplers under local anaesthesia

Test Your Knowledge

A 65-year-old male who underwent an open low anterior resection for rectal carcinoma 18 hours ago has had a total urine output of 35 mL over the past three hours through his indwelling Foley catheter. He weighs 75 kg. His temperature is 37.4°C, pulse rate is 84 beats per minute, blood pressure is 128/76 mmHg, and oxygen saturation is 98% on room air. Abdominal examination reveals a soft, non-distended abdomen with expected localized incisional tenderness. Review of his fluid balance chart shows 1500 mL of intravenous Hartmann's solution infused over the last 24 hours, with estimated intraoperative blood loss of 250 mL. Which of the following is the most appropriate first-line action?

Administer a 20 mg intravenous bolus of furosemide to stimulate renal tubular diuresis

Request an urgent renal ultrasound to assess for bilateral ureteric obstruction or transection

Inspect the drainage tubing and flush the Foley catheter with sterile saline under aseptic technique

Send blood immediately for urgent serum creatinine, urea, and fractional excretion of sodium

Test Your Knowledge

A stable patient on postoperative day two has fever and reduced breath sounds at the bases. There is no wound inflammation or hypotension. What is the most appropriate initial approach?

Diagnose atelectasis as the cause solely from the postoperative day

Start broad antibiotics without examining the patient

Ignore the fever until postoperative day five

Assess for pulmonary and other causes, using targeted imaging and supporting analgesia and mobilisation

Sections you finish are checked off in the contents.

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