Postoperative sepsis — POD-5 fever after anterior resection: leak hunt, CRP timing, and the urgent source-control clock

Model answer

(A) Working diagnosis: anastomotic leak with early postoperative sepsis (3 marks). New fever on day 5 passes both day-cutoffs: continuing fever beyond day 3 raises strong suspicion of a new complication, and first fever after day 2 carries a sixfold odds of infectious complication — with temperature above 38.6 C and a rising trajectory as co-predictors.^[12][15] The CRP clinches the hunt: a POD-3 value of 148 mg/L carries 95% sensitivity and specificity for colorectal leak, and here 165 mg/L on a steep rise from day 2 fits the diverging-leak pattern exactly.^[23] Tachycardia with localized (not generalized) peritonitis places her in leak-with-sepsis rather than established septic shock — resuscitate and hunt simultaneously.

(B) Investigations in sequence (3 marks). First, blood cultures plus lactate, full blood count, renal function and venous blood gas with the qSOFA scored at the bedside (here 1: tachypnoea absent, mentation intact, pressure held — ward-level sepsis, not ICU physiology yet).^[39] Second, procalcitonin alongside the CRP trend — both are early leak predictors from day 2 to 3.^[24] Third, contrast-enhanced abdominal-pelvic CT without delaying antibiotics: the gold standard, hunting extraluminal contrast extravasation, fluid collection, pneumoperitoneum or abscess — then integrate markers with imaging rather than trusting either alone.^[24][26]

(C) Resuscitate, shorten, control — with the stoma modifying the knife (4 marks). Antibiotics inside the first hour — mortality rises steadily after 1 hour across 17,990 analysed patients.^[39] Norepinephrine-first if pressure fails, to MAP 65 mmHg or more (number needed to treat 9 over dopamine).^[57][1] Antibiotics stop at 4 days once control is adequate: STOP-IT's fixed 4-day course matched 8 days (21.8% versus 22.3%).^[49] Source control in the urgent 2-to-6-hour window — half the mortality odds of crashing inside 2 hours — and here the diverting stoma is decisive: with diversion already in place, reoperation for sepsis control is rarely necessary, especially for extraperitoneal anastomoses, so percutaneous drainage of any collection plus washout only if generalized contamination declares itself.^[44][24] Non-resolution at reassessment means re-look, never another week of drugs.^[44]