⚠️ Chapter 75: Acute Abdomen

Appendicitis · Intussusception · Volvulus · Bowel Obstruction · Peritonitis · HSP · Acute Intermittent Porphyria

⚠️ Acute Abdomen: Surgical Emergency Requiring Prompt Recognition

📊 Definition
Clinical syndrome of signs/symptoms of intra-abdominal disease usually requiring operative treatment. Common causes by age: infant (intussusception, volvulus, incarcerated hernia), preschool/school age (appendicitis, Meckel's), adolescent (appendicitis, testicular/ovarian torsion, ectopic pregnancy).
🩸 Key Surgical Emergencies
• Appendicitis: most common surgical abdomen
• Intussusception: 6 months-3 years, red currant jelly stools
• Malrotation with volvulus: bilious vomiting, sick infant
• Incarcerated hernia: irreducible, tender
• Bowel obstruction: abdominal distension, vomiting, obstipation
⚠️ Red Flags for Surgery
• Bilious vomiting (obstruction until proven otherwise)
• Abdominal distension with tenderness
• Peritoneal signs (rebound, guarding, rigidity)
• Absent bowel sounds
• Haematochezia with abdominal pain (intussusception)
🩺 Non-Surgical Causes
• HSP (Henoch-Schönlein purpura): palpable purpura + abdominal pain
• DKA, porphyria, sickle cell crisis
• Pneumonia (lower lobe), pharyngitis (mesenteric adenitis)
• Constipation, gastroenteritis
🩻 Diagnostic Imaging
• Ultrasound: first-line for appendicitis, intussusception, torsion
• CT abdomen: when diagnosis unclear, stable patient
• Abdominal X-ray: obstruction, perforation, volvulus (double bubble)
⚙️ Management Principles
• Resuscitate first (fluids, electrolytes, NG tube)
• Surgical consultation early
• Broad-spectrum antibiotics if peritonitis/sepsis
• Urgent laparotomy for perforation, volvulus, non-reducible hernia
⚠️ Surgical Abdomen Red Flags: Bilious vomiting, abdominal distension, peritonitis, irreducible hernia, septic shock. Do NOT delay surgery for extensive imaging if patient is unstable.

🩺 Step-by-Step: Acute Abdomen Management

1
Initial assessment — ABCs & resuscitation
Assess airway, breathing, circulation. Hypotension/shock requires fluid resuscitation. Do not delay resuscitation for imaging. NG tube for distension/vomiting.
2
History — key red flags
Bilious vomiting = obstruction until proven otherwise. Location of pain (RLQ = appendicitis). Duration, progression. Associated symptoms: fever, vomiting, diarrhoea, bloody stools. Past surgical history.
3
Physical examination
Inspect for distension, scars, hernias. Auscultate bowel sounds. Palpate for tenderness, guarding, rebound, rigidity. Peritoneal signs indicate surgical abdomen. Rectal exam for tenderness, mass, occult blood.
4
Diagnostic studies based on suspicion
• Ultrasound: appendicitis, intussusception, torsion, cholecystitis
• Abdominal X-ray: obstruction (air-fluid levels), volvulus (double bubble), perforation (free air)
• CT: when diagnosis unclear, stable patient
• Labs: CBC, CRP, electrolytes, LFTs, amylase/lipase, UA
5
Surgical consultation — early
Involve paediatric surgeon early. Do not give opioids before surgical evaluation (may mask signs).
6
Specific conditions management
• Appendicitis: appendectomy + antibiotics
• Intussusception: air or contrast enema reduction (if no peritonitis/perforation)
• Malrotation with volvulus: urgent laparotomy (Ladd's procedure)
• Incarcerated hernia: manual reduction → elective repair
• Bowel obstruction: NG decompression, IV fluids, surgery if complete
7
Non-surgical abdomen management
• HSP: supportive care, steroids for severe abdominal pain
• DKA: insulin, fluids (pain resolves with acidosis correction)
• Sickle cell crisis: hydration, analgesia
• Constipation: disimpaction, laxatives