Acute Abdomen Definition: Sudden severe abdominal pain of acute onset requiring urgent clinical evaluation and often emergency surgical intervention. It represents a spectrum from life-threatening perforation to medical mimics.
Waxes and wanes with visceral smooth muscle contraction. Diagnoses: renal/ureteric colic, bowel obstruction, biliary colic. Patient cannot lie still.
Sudden catastrophic onset. Diagnoses: hollow viscus perforation, mesenteric infarction, ruptured AAA.
Diffuse, lower abdominal. Diagnoses: gastroenteritis, IBD flare, IBS.
Tearing retroperitoneal character. Diagnoses: aortic dissection, acute pancreatitis — both can be life-threatening.
Peritonism = surgical emergency until proven otherwise. Call senior immediately.
GCC context: Acute cholecystitis and biliary colic are highly prevalent due to high-fat diet patterns. Appendicitis peaks in young adults. Untreated peptic ulcer (often due to H. pylori) carries significant perforation risk across the region.
Inferior STEMI (right coronary territory) presents as epigastric pain and vomiting. Always perform 12-lead ECG in ALL acute abdominal pain presentations.
DKA presents with abdominal pain and vomiting — a known mimic. GCC has one of the world's highest T2DM prevalences. Check glucose and ketones in all acute abdomen.
Ectopic pregnancy causes haemoperitoneum and haemodynamic collapse. Mandatory urine or serum beta-HCG in ALL women of reproductive age with acute abdominal pain.
All patients with suspected surgical emergency: IV access × 2 (16G minimum), NBM, analgesia (do NOT withhold), bloods including group and save, senior surgical review immediately.
Acute appendicitis is the most common surgical emergency globally. Peak incidence in adolescents and young adults. GCC: high incidence in expatriate worker populations.
Low probability appendicitis. Observe, repeat bloods/USS, consider discharge with safety netting.
Equivocal. Admit for observation, CT/USS, repeat examination. Serial WBC.
High probability. Surgical review for laparoscopic appendicectomy. Score ≥7 = high probability (sensitivity ~80%).
Rovsing's sign: palpating LIF causes pain in RIF — highly specific for appendicitis. Also check psoas sign (hip extension) and obturator sign (internal hip rotation).
GCC context: Very common given high dietary fat intake. Biliary colic (obstruction without infection) presents with colicky RUQ pain but no fever — distinguish from cholecystitis.
Erect CXR: Free air under diaphragm (pneumoperitoneum) — present in ~70% of perforations. Absence does NOT exclude perforation — proceed to CT.
Adhesions (most common in adults with previous surgery) > hernias > Crohn's. Central cramping pain, vomiting bilious early.
Malignancy (most common) > volvulus > diverticular stricture. Absolute constipation (no flatus), marked distension.
Obstruction + vascular compromise = surgical emergency. Do NOT attempt manual reduction in A&E — risk of reducing non-viable bowel into abdomen. Features: irreducible lump + pain + obstructive symptoms + local erythema/tenderness. Emergency surgery.
Haemoperitoneum → haemorrhagic shock. Clinical: missed period, acute unilateral pelvic pain, shoulder tip pain (diaphragm irritation by blood), haemodynamic collapse. Investigations: beta-HCG positive + USS (no intrauterine pregnancy + free fluid). Emergency surgery — laparoscopic salpingectomy.
"Pain out of proportion to examination" — classical teaching. Risk factors: AF (embolic), atherosclerosis, heart failure. CT mesenteric angiography is diagnostic. Mortality >50% if diagnosis delayed. Emergency surgical/IR intervention.
Elderly, institutionalised, or chronically constipated patients. Massive sigmoid loop on AXR ("coffee bean" or "omega" sign). First-line: rigid sigmoidoscopy / endoscopic decompression and deflation. If ischaemia/perforation suspected: emergency surgery.
Key principle: Many causes of acute abdomen are medical, not surgical. Misdiagnosis leads to unnecessary laparotomy — or worse, missed medical emergency. Always consider the full differential before committing to surgical pathway.
Epigastric pain radiating to the back, worse lying flat, improved leaning forward. Nausea, vomiting, fever. Serum amylase or lipase >3× upper limit of normal is diagnostic.
Monitor for SIRS — fever >38°C, HR >90, RR >20, WBC >12. Persistent SIRS beyond 48h indicates severe disease requiring HDU/ICU.
Septic shock risk: Elderly patients and diabetics (GCC — very high prevalence) can deteriorate rapidly to urosepsis. Apply Sepsis 6 protocol if septic criteria met.
Occurs in cirrhotic patients with ascites. May be subtly presenting — easy to miss.
PMN (polymorphonuclear cells) >250 cells/mm³ in ascitic fluid = diagnosis of SBP. Begin cefotaxime IV empirically while awaiting culture results.
Right coronary artery territory infarction → epigastric pain, nausea, vomiting. May lack classic chest pain. ECG shows ST elevation in II, III, aVF.
Do ECG in ALL acute abdomen.
Abdominal pain + vomiting in DKA is common. Mechanism unclear (gastric paresis, mesenteric ischaemia). Can be severe enough to mislead towards surgical diagnosis.
Check BM and urinary/blood ketones. GCC: T2DM prevalence 20–30%.
Right lower lobe pneumonia irritates the diaphragm → referred pain to RUQ or epigastrium. Can mimic cholecystitis or appendicitis. Listen for reduced breath sounds, crepitations. CXR is diagnostic.
Pre-operative nursing preparation is a critical patient safety function. Errors in preparation — missed blood group, late antibiotics, inadequate resuscitation — directly worsen surgical outcomes.
Evidence-based: Withholding analgesia does NOT improve diagnostic accuracy and significantly increases patient distress. The Cochrane review (2011) and NICE guidelines confirm analgesia should NOT be withheld pending surgical review.
Recommended options in acute abdomen pre-operatively:
Must be given within 60 minutes of knife to skin. Re-dose for prolonged surgery (>4h) or major blood loss.
Check local hospital antibiogram. GCC hospitals with high ESBL prevalence may use carbapenem as first line for peritonitis.
Avoid fluid overload — associated with delayed GI recovery, wound complications, pulmonary oedema. Use goal-directed fluid therapy. If urine output drops — reassess fluid status before giving bolus blindly. Target urine output >0.5 mL/kg/hr post-operatively.
Normal after abdominal surgery — bowel sounds typically return day 2–4. Features: absent bowel sounds, abdominal distension, no flatus, nausea. Management: NBM, IV fluids, NGT if vomiting, early ambulation accelerates resolution. Distinguish from early mechanical obstruction (adhesion) which tends to occur day 3–5.
High mortality complication — peaks day 3–7 post-op.
Warning signs: rising CRP and WBC, increasing pain (especially around stoma or wound), tachycardia, fever, change in drain output character (faeculent or purulent), patient "not progressing as expected." Escalate immediately to surgical team. CT scan with contrast is diagnostic.
Risk factors: obesity, malnutrition, diabetes, steroids, immunosuppression, infection. Partial dehiscence: cover with moist saline dressings, tissue viability review. Burst abdomen (evisceration): cover bowel with moist sterile packs, call surgical team — emergency return to theatre.
| Drain Output | Normal | Concern |
|---|---|---|
| Colour | Serous/serosanguinous | Faeculent, bile-stained, heavy blood |
| Volume | <100 mL/day reducing | Sudden large output or increasing |
| Character | Clear, thin fluid | Purulent, cloudy, opaque |
Non-opioid: Paracetamol, NSAIDs (ibuprofen, diclofenac, ketorolac)
Mild opioid: Codeine, tramadol, dihydrocodeine
Strong opioid: Morphine, oxycodone, fentanyl — regular + breakthrough
GCC Exam Focus: DHA (Dubai Health Authority), DOH (Department of Health Abu Dhabi), SCFHS (Saudi Commission for Health Specialties), and QCHP (Qatar Council for Healthcare Practitioners) nursing exams regularly test acute abdominal assessment, surgical scoring tools, and emergency recognition.
| Feature | Points |
|---|---|
| Migration of pain to RIF | 1 |
| Anorexia or acetonuria | 1 |
| Nausea or vomiting | 1 |
| RIF tenderness on palpation | 2 |
| Rebound tenderness in RIF | 1 |
| Elevated temperature (>37.3°C) | 1 |
| Leukocytosis (WBC >10×10⁹/L) | 2 |
| TOTAL | 10 |
| Criterion | Threshold |
|---|---|
| Age | >55 years |
| WBC | >16 × 10⁹/L |
| Blood glucose | >11 mmol/L |
| LDH | >350 IU/L |
| AST | >250 IU/L |
| Criterion | Threshold |
|---|---|
| Haematocrit fall | >10% |
| BUN rise | >1.8 mmol/L |
| Serum calcium | <2 mmol/L |
| PaO₂ | <8 kPa |
| Base deficit | >4 mEq/L |
| Fluid sequestration | >6 L required |
| Region | Common Diagnoses | Key Signs |
|---|---|---|
| RUQ (Right Upper Quadrant) | Acute cholecystitis, biliary colic, hepatitis, hepatic abscess, right lower lobe pneumonia | Murphy's sign, jaundice, fever |
| RIF (Right Iliac Fossa) | Appendicitis, ovarian cyst/torsion (female), ectopic pregnancy, Crohn's, Meckel's diverticulum, psoas abscess | McBurney's, Rovsing's, Psoas sign |
| LIF (Left Iliac Fossa) | Diverticulitis, sigmoid volvulus, constipation, ovarian pathology, LIF hernia | Localised guarding LIF, mass |
| Epigastric | Peptic ulcer / perforation, acute pancreatitis, inferior STEMI, GORD, gastritis, aortic dissection | Board rigidity (perf), ECG changes (STEMI) |
| Central / Periumbilical | Early appendicitis (pain migrates), small bowel obstruction, mesenteric ischaemia, AAA | Colicky (SBO), "pain out of proportion" (mesen. ischaemia) |
| LUQ (Left Upper Quadrant) | Splenic pathology (rupture, infarct), pancreatitis (tail), gastric volvulus, left lower lobe pneumonia | Kehr's sign (shoulder tip — splenic) |
| Generalised / Diffuse | Peritonitis (any cause), perforated viscus, mesenteric ischaemia, SBP | Board-like rigidity, rebound, absent bowel sounds |
A: Acute cholecystitis. Positive when patient catches breath on deep inspiration during RUQ palpation — gallbladder descends onto palpating fingers, causing pain and halting inspiration. Most specific clinical sign for cholecystitis.
A: "Coffee bean" sign — a massively dilated sigmoid loop appearing as an inverted U or omega shape, often extending to the right upper quadrant. The apex points to the right side. Immediate endoscopic decompression is first-line management.
A: Score ≥7 indicates high probability of appendicitis and requires immediate surgical review. Score 5–6 is equivocal — admit for observation, USS/CT. Score 1–4 is low probability — consider safe discharge with safety netting instructions.
A: Adhesions (from previous abdominal surgery) — account for approximately 60–70% of small bowel obstruction cases in adults. Second most common: external hernia. For large bowel obstruction: colorectal carcinoma is most common.
A: PMN (polymorphonuclear neutrophil) count >250 cells/mm³ on diagnostic paracentesis in a cirrhotic patient with ascites. Treatment: cefotaxime IV empirically. Culture may be negative — do not wait for culture results to treat.
A: Cochrane review evidence confirms that giving analgesia in acute abdomen does NOT impair diagnostic accuracy and significantly reduces patient suffering. The historical teaching to withhold was based on opinion, not evidence. Current NICE and surgical society guidelines recommend prompt analgesia.
A: Palpation of the left iliac fossa (LIF) causes pain to be felt in the right iliac fossa (RIF). Positive Rovsing's sign is associated with appendicitis. The mechanism is thought to involve shifting of peritoneal contents and gas toward the inflamed appendix.
A: Classic description of mesenteric ischaemia — patient reports extreme pain but the abdomen may be soft with minimal peritoneal signs early on. This is because visceral (gut) ischaemia causes severe pain before transmural necrosis and peritonitis develop. This is a time-critical emergency with mortality >50% if delayed.