Synopsis
Use closed-loop physiology to explain caecal injury and recognise when a patient’s changing symptoms demand intervention despite apparently reassuring measurements.
- A closed loop has obstructed outflow at both ends; a distal colonic lesion and a competent ileocaecal valve can trap the colon between them.
- The caecum can fail remote from a left-sided cancer, so source control must address both the distal obstruction and any proximal necrosis or perforation.
- New focal tenderness, guarding or physiological deterioration overrides a previously reassuring scan, a modest diameter or a normal lactate.
Key red flags
Guarding, hypotension, confusion, oliguria or rising respiratory rate may herald advanced ischaemia, perforation or sepsis. Escalate immediately and communicate the change relative to earlier findings. A patient who was suitable for a bridge two hours ago may no longer be suitable.
Reasoning priorities
Identify the obstruction and inspect bowel both adjacent to and distant from the lesion.
Trace the distal transition, proximal colon and caecum, then assess enhancement, wall thickening, pneumatosis, free fluid and extraluminal gas. Explain whether there is a discrete twist or an obstructed distal segment with trapped proximal colon. The report should indicate which findings raise concern for injury.
Worked reasoning
A 71-year-old initially appears stable with obstruction from a sigmoid cancer.
- CT shows a discrete distal tumour, a caecum measuring 10.6 cm, preserved enhancement and little small-bowel dilatation. The patient is initially comfortable after analgesia, with lactate 1.6 mmol/L. The surgeon recognises that limited proximal decompression may put the caecum at risk and plans close observation while considering relief of the obstruction.
- Within two hours the patient reports persistent right-sided pain and develops caecal tenderness, pulse 118 and falling blood pressure. These are new findings. The team immediately calls the consultant surgeon and anaesthetist, resumes active resuscitation and abandons routine bridging arrangements.
- Guarding and further circulatory deterioration develop. Urgent surgery is organised with intravenous antimicrobial treatment for suspected perforation and sepsis; a repeat scan is not made a prerequisite when the surgical team considers the need for source control already clear.
- At laparotomy there is a perforated necrotic caecum above the obstructing sigmoid tumour. The surgeon removes the damaged proximal colon and the obstructing lesion, using a subtotal colectomy and end ileostomy because shock and contamination make an immediate anastomosis unsafe.
- Following source control and critical-care treatment, perfusion improves and organ support is reduced. The remaining bowel and stoma are reassessed, renal function is followed and nutrition is restored as recovery permits.
- Pathology and completion staging guide subsequent cancer planning. The team explains that the perforation occurred remotely because the trapped proximal colon was under pressure; neither the original 10.6 cm diameter nor the early lactate had guaranteed continued viability.