Overview
This lecture covers the urgent assessment, causes, diagnosis, and initial management of acute abdominal pain (acute abdomen), focusing on identifying life-threatening conditions.
Definitions & Urgent Causes
- Abdominal pain is common, but acute abdomen is rapid, severe pain indicating possible life-threatening causes.
- Generalized peritonitis is inflammation of the peritoneum affecting most of the abdomen; can quickly lead to hypovolemic or septic shock.
- Most common cause of peritonitis is perforation of abdominal organs (e.g., bowel obstruction, peptic ulcer, diverticular disease).
- Bleeding causes include ruptured abdominal aortic aneurysm, ruptured ectopic pregnancy, trauma, or bleeding peptic ulcer.
- Ischemic bowel presents with severe pain out of proportion to exam findings; also an emergency.
Other Major Categories of Causes
- Inflammatory: acute cholecystitis, pancreatitis, appendicitis.
- Gynecological: ruptured ovarian cyst, ovarian torsion, ectopic pregnancy.
- Infections: intra-abdominal abscess (risk of peritonitis).
- Urological: pyelonephritis, renal stones, testicular torsion.
- Other: sickle cell vaso-occlusive crisis, diabetic ketoacidosis.
History & Pain Assessment (SOCRATES)
- Site: location can suggest specific causes (e.g. RUQ—gallstones; RLQ—appendicitis/gynecological; periumbilical—AAA, early appendicitis).
- Onset: acute worsening may suggest peptic ulcer, history of similar pain—gallstones/diverticulitis.
- Character: colicky pain suggests obstruction, sharp pain suggests vascular causes.
- Radiation: e.g., to back in pancreatitis, shoulder in gallstones.
- Associated symptoms: nausea, vomiting, fever, rigors, bowel habit changes, shortness of breath.
- Timing: relation to food may indicate gallstones or ulcers.
- Exacerbating/Relieving: peritonitis—stillness; renal colic—restlessness.
- Severity: pain score out of 10, note fluctuation.
Physical Exam
- General inspection for distress, color, breathing, scars, distension, bruising.
- Auscultation: abnormal or absent bowel sounds (perforation or late obstruction).
- Palpation: diffuse tenderness, guarding, or rebound (peritonitis); Murphy’s sign (cholecystitis); lumps (hernias).
- Percussion: pain suggests peritoneal inflammation; dullness (fluid), tympanic (air).
- Vital signs: hypotension and tachycardia may indicate shock or sepsis.
Investigations
- Labs: hemoglobin, WBC, electrolytes, CRP, amylase, blood gas (lactate for perfusion).
- Imaging: plain abdominal X-ray (obstruction), erect chest X-ray (free air), CT (generalized pain), ultrasound (gallbladder, FAST scan, gynecological causes).
Management Principles
- Monitor vitals, give oxygen and IV fluids (cautiously in bleeding/aneurysm).
- Fluid balance and broad antibiotics for infection/perforation suspicion.
- Pregnancy test for women of childbearing age.
- Analgesia and antiemetics.
- Keep patient nil by mouth pending surgery.
- Early surgical review if acute abdomen suspected.
Key Terms & Definitions
- Acute abdomen — sudden severe abdominal pain, often requiring urgent intervention.
- Peritonitis — inflammation of the peritoneal lining, often due to perforation.
- Ischemic bowel — loss of blood supply to intestines, causing severe pain.
- SOCRATES — mnemonic for pain assessment: Site, Onset, Character, Radiation, Associated symptoms, Timing, Exacerbating/relieving, Severity.
- Murphy’s sign — pain on liver palpation during inspiration, indicating cholecystitis.
Action Items / Next Steps
- Practice taking abdominal pain histories using SOCRATES.
- Review causes of acute abdomen by quadrant.
- Read up on imaging findings for common abdominal emergencies.