SCE Surgery: Mastering Acute Abdomen Diagnosis & Management

As medical students and future clinicians, mastering the complexities of acute abdomen is paramount, especially when preparing for high-stakes exams like the Specialty Certificate Examination (SCE). The acute abdomen, a clinical syndrome presenting with severe abdominal pain of recent onset, demands prompt and accurate diagnosis and management. It's a frequently tested area in medical exams due to its breadth of causes, diagnostic challenges, and potential for severe outcomes if mishandled.

Why is Acute Abdomen So Important for SCE?

The SCE assesses a broad range of medical specialties, and surgical emergencies often present to general medical wards or require collaborative management. Understanding the acute abdomen not only tests your diagnostic acumen but also your ability to formulate a management plan, recognize red flags, and understand the indications for surgical referral. It's a testament to your foundational clinical skills.

Understanding the Spectrum: Causes of Acute Abdomen

When faced with a patient presenting with acute abdominal pain, your differential diagnosis should be structured. Think in categories:

1. Inflammatory: Appendicitis, Diverticulitis, Cholecystitis, Pancreatitis, Mesenteric Adenitis.

2. Obstructive: Small bowel obstruction (adhesions, hernia, tumour), Large bowel obstruction (colorectal cancer, diverticular stricture, volvulus), Biliary obstruction.

3. Perforative: Perforated peptic ulcer, perforated diverticulitis, perforated appendicitis.

4. Vascular: Mesenteric ischaemia, Aortic Aneurysm rupture.

5. Gynaecological/Urological: Ectopic pregnancy, Ovarian torsion, Pelvic Inflammatory Disease (PID), Renal colic, Pyelonephritis.

The Diagnostic Approach: A Systematic Review

Your approach should be systematic, combining history, examination, and targeted investigations.

1. History Taking: The Cornerstone

• Pain Characteristics: Use SOCRATES (Site, Onset, Character, Radiation, Associated symptoms, Timing, Exacerbating/Relieving factors, Severity). Crucial details include onset (sudden vs. gradual), character (colicky, constant, burning), and radiation.

• Associated Symptoms: Nausea, vomiting, changes in bowel habits, fever, chills, urinary symptoms (dysuria, haematuria), gynaecological symptoms (vaginal bleeding, discharge).

• Past Medical History: Previous surgeries (adhesions), inflammatory bowel disease, cardiovascular disease, gallstones, diverticular disease, medication history (NSAIDs, anticoagulants).

• Social History: Alcohol intake (pancreatitis), travel history (infectious causes).

2. Clinical Examination: The Hands-On Assessment

• General Appearance: Look for signs of distress, peritonism, shock, jaundice.

• Abdominal Examination:

  • Inspection: Distension, scars, visible peristalsis.

  • Palpation: Tenderness (localised vs. generalized), guarding, rigidity (peritonitis), rebound tenderness, palpable masses, organomegaly.

  • Percussion: Tympany (obstruction), dullness (ascites, masses).

  • Auscultation: Bowel sounds (absent in ileus, tinkling in obstruction).

• Rectal Examination: Essential for lower abdominal pain; assess for tenderness, masses, blood.

• Pelvic Examination (in women): Rule out gynaecological causes (adnexal tenderness, cervical motion tenderness).

3. Investigations: Confirming Your Suspicions

• Blood Tests:

  • FBC: Leukocytosis (inflammation, infection).

  • U&Es: Hydration status, renal function.

  • LFTs: Biliary pathology, pancreatitis (amylase/lipase).

  • CRP/ESR: Inflammatory markers.

  • Coagulation Profile: Pre-surgical assessment.

  • Lactate: Indication of ischaemia or sepsis.

  • Blood Cultures: If suspicion of sepsis.

• Urine Tests: Urinalysis (UTI, renal stones), Urine HCG (rule out pregnancy in females of childbearing age).

• Imaging:

  • Plain Abdominal X-ray: Limited utility but can show dilated bowel loops (obstruction), air under diaphragm (perforation), calcification (pancreatitis, renal stones).

  • Ultrasound Scan (USS): Excellent for gallstones, cholecystitis, appendicitis (especially in children/pregnant women), gynaecological pathology, abdominal aortic aneurysm.

  • Computed Tomography (CT) Scan: Gold standard for most acute abdominal pathologies (diverticulitis, appendicitis, bowel obstruction, pancreatitis, vascular issues, trauma). Essential for differentiating causes and guiding management.

Management Principles: Act Swiftly, But Thoughtfully

Initial management for almost any acute abdomen involves:

1. Resuscitation: ABCDE approach. Ensure patent airway, adequate breathing, and circulation (IV fluids, consider inotropes if hypotensive).

2. Analgesia: Important for patient comfort, but should not delay diagnosis. IV opioids are commonly used.

3. Anti-emetics: For nausea and vomiting.

4. Nil by Mouth (NBM): In anticipation of potential surgery.

5. IV Antibiotics: If infection is suspected or confirmed.

Specific Management: This is dictated by the definitive diagnosis. Surgical causes require timely surgical intervention, while medical causes are managed conservatively (e.g., pancreatitis, pyelonephritis).

High-Yield Tips for SCE Success

• Differential Diagnosis is Key: Be able to list the top 3-5 differentials for any given presentation (e.g., right iliac fossa pain, epigastric pain radiating to back).

• Red Flags: Recognize signs of peritonitis, shock, severe sepsis, or impending rupture (e.g., rigid abdomen, absent bowel sounds, hypotension, tachycardia). These demand urgent surgical review.

• Appropriate Investigations: Know which investigation is first-line for suspected conditions (e.g., USS for suspected cholecystitis, CT for suspected diverticulitis).

• Initial Management Principles: Always prioritize stabilization before definitive diagnosis. Remember ABCDE and early resuscitation.

• Communication: Even in an exam setting, think about how you'd communicate with the patient, explain findings, and involve surgeons early when appropriate.

Mastering acute abdomen for the SCE is about more than just memorizing facts; it's about developing a structured, logical approach to a common and critical clinical scenario. Practice applying this framework to various cases, and you'll be well-prepared to ace this essential topic.