Perforated peptic ulcer

Overview

A surgical emergency where a peptic ulcer erodes through all layers of the gastric or duodenal wall, releasing contents into the peritoneum - causing chemical then bacterial peritonitis. Duodenal ulcers are the most common site. Mortality 10-40%, rising sharply with delay to surgery.

Risk Factors

Key risk factors
H. pylori infection - disrupts mucus barrier
NSAIDs - inhibit COX → reduced prostaglandins → loss of mucosal defence
Elderly patients - especially NSAID use
Male sex
Smoking
Corticosteroids (with NSAIDs)
Previous peptic ulcer disease
Physiological stress (ITU, major illness)

Presentation

•Sudden severe epigastric pain - instantaneous onset ('thunderclap/stab'), worst pain of patient's life; the defining feature
•Pain rapidly generalises across whole abdomen as contents spread; may radiate to right iliac fossa (fluid tracking down paracolic gutter)
•Board-like rigidity - involuntary guarding; most specific examination finding
•Generalised tenderness + rebound - peritoneal irritation
•Absent bowel sounds - paralytic ileus from peritoneal irritation
•Referred shoulder tip pain - diaphragmatic irritation by free gas/fluid (phrenic nerve C3/4/5)
•Tachycardia, hypotension, fever - as peritonitis and systemic response develop
⚠️
A brief 'lucid interval' of apparent improvement can occur hours after perforation as chemical peritonitis is diluted by peritoneal fluid. Do not be reassured - bacterial peritonitis follows.

Investigations

🥇 First-line

•Erect chest X-ray - free air under diaphragm (pneumoperitoneum) in ~70-80% of perforations
•Bloods: FBC, U&E, LFTs, amylase, CRP, lactate, coagulation, group and save - baseline and exclude pancreatitis
•ABG: assess metabolic acidosis and lactate (severity marker)

🏆 Gold standard

•CT abdomen/pelvis with IV contrast - confirms perforation site, free gas and fluid, detects contained perforations, guides surgical planning; perform in all haemodynamically stable patients
🎯
Free air under the diaphragm is absent in up to 20-30% of perforations - a normal erect CXR does NOT exclude a perforated peptic ulcer. If clinical suspicion is high, proceed to CT.

Management

Step 1 · Immediate resuscitation
  1. 1Nil by mouth
  2. 2IV fluid resuscitation
  3. 3Nasogastric tube insertion (gastric decompression)
  4. 4IV broad-spectrum antibiotics (e.g. co-amoxiclav + metronidazole)
  5. 5IV PPI (e.g. pantoprazole)
  6. 6Analgesia, catheter, senior surgical review
Step 2 · Confirm diagnosis
  1. 1CT abdomen/pelvis with IV contrast in stable patients
  2. 2Erect CXR if CT not immediately available
Step 3 · Definitive surgical repair
  1. 1Emergency laparoscopic (or open) Graham patch repair with peritoneal lavage - first-line definitive treatment
  2. 2Team: emergency surgery, anaesthetics, ITU

Follow-up

•H. pylori testing (urea breath test or stool antigen) at least 4 weeks after completing antibiotic therapy
•H. pylori eradication (7-day triple therapy) if positive - significantly reduces recurrence
•Ongoing PPI post-operatively until follow-up endoscopy confirms healing
•Repeat OGD at 6-8 weeks for gastric ulcers - confirm healing and exclude malignancy
•Review NSAIDs/aspirin - stop or use lowest dose with PPI; smoking cessation and reduce alcohol

Prognosis

•Overall 30-day mortality ~10% (low risk) to >40% (high-risk elderly, delayed presentation)
•Boey score - pre-operative risk stratification: (1) pre-operative shock (systolic BP <100 mmHg), (2) perforation duration >24 hours, (3) significant medical comorbidity; all three = substantially higher operative mortality
🚨
Mortality increases significantly with every hour of delay to surgery. Time to theatre is the single most important modifiable determinant of outcome.