Synopsis
Recognise diffuse peritonitis and septic physiology from free diverticular perforation, resuscitate while obtaining rapid CT when safe, and choose damage control, resection and reconstruction according to contamination and patient reserve.
- Free diverticular perforation causes diffuse purulent or faecal contamination, generalised peritonitis and potentially septic shock.
- Resuscitation, intravenous antibiotics, anaesthetic preparation and operative source-control planning must proceed in parallel.
- Contrast CT helps locate perforation and alternative pathology when transfer is safe; obvious peritonitis and instability must not wait for avoidable imaging delay.
Key red flags
Generalised involuntary guarding or rigidity indicates diffuse peritoneal contamination rather than a contained microperforation.
Hypotension, confusion, oliguria, acidosis or rising lactate indicates organ hypoperfusion and increases both operative urgency and anastomotic risk.
Progressive abdominal distension, respiratory compromise or worsening vasopressor need signals advanced sepsis requiring immediate senior coordination.
Investigation priorities
quantify organ dysfunction and prepare transfusion or critical care.
Management branches
A 76-year-old has a rigid abdomen, confusion, blood pressure 86/54 mmHg and lactate 5.1 mmol/L. CT obtained during immediate resuscitation shows perforated sigmoid colon, free gas and widespread faecal fluid.
- Activate colorectal, anaesthetic and critical-care teams, give co-amoxiclav 1.2 g intravenously every 8 hours as one NICE national-table option after checking allergy and current renal function, obtain cultures and blood-bank samples, start warmed fluid and catheterise to measure urine output; adapt coverage to local resistance and sepsis policy.
- Use vasopressor support after initial fluid with anaesthetic oversight, correct hypothermia and major electrolyte disturbance, and proceed to theatre without waiting for lactate normalisation.
A 55-year-old has generalised peritonitis but blood pressure 124/72 mmHg, lactate 1.8 mmol/L and no major comorbidity; CT shows a free sigmoid perforation with purulent fluid.