Ward round 9 Apr 2008 - Ischaemic Colitis

The disease of this week is ischaemic colitis. It is sometimes a challenging disease for physicians to make a correct diagnosis and initiate the definitive treatment - yes, is to transfer the patient to the surgeons STAT.
Textbooks describe the classical features of extremely severe abdominal pain out of proportion with physical examination findings. However patient (especially the elderly, long-standing diabetics) may present with vague or atypical symptoms, and may not mount any inflammatory or febrile response (typically raised CRP, fever). Sometimes may be a patient with long-standing atrial fibrillation or vascular disease who suddenly deteriorates.

My first patient was a gentleman who was admitted to cardiology from A&E for preliminary diagnosis of fast atrial fibrillation & acute pulmonary oedema. His past medical history consists of long-standing diabetes mellitus type II complicated by neuropathy & nephropathy, hypertension, hyperlipidaemia, ischaemic heart disease underwent a bypass many years ago, and chronic atrial fibrillation on warfarin treatment but very good INR control. He has been well otherwise & compliant with his medications until the week before admission when he started to complain of increasing fatigue, breathlessness, and reduced appetite due to a vague 'uncomfortable & sinking feeling' down his lower abdomen. He was haemodynamically stable and afebrile, but breathless at rest with respiratory rate 26 per minute, saturatioin 98% breathing 50% oxygen. Abdominal examination found only mild right upper quadrant and epigastric pain.
His haematology & glucose investigations were unremarkable, however his biochemistry revealed unexplained severe high-anion gap metabolic acidosis, renal & liver failure with markedly raised ALT, AST, Bil, CK, Cr, and mildly raised amylase. It is highly unusual to find such abnormal results in patients purely with cardiac or pulmonary diseases, and we must suspect other underlying causes. Indeed, cardiac enzymes in series showed no rising trend. He was given IV maintenance fluids and empirical antibiotics for possible sepsis. The on-call surgeons were informed to evaluate our patient for suspected acute abdomen especially ischaemic colitis. CT with contrast subsequently confirmed the diagnosis of multiple infarcts in the colon and kidneys. He was sent for urgent laparotomy.

Learning points:

• Suspect fatal ischaemic colitis in the differential diagnosis of abdominal pain - especially in the context of patients with high risk factors.
  
• Cardiac or pulmonary diseases frequently present with 'abdominal discomfort' and may be difficult to distinguish from acute abdominal disease processes.
  
• Severe ischaemic colitis may manifest atypically with minimal abdominal findings.
  
• Clinicians should have a low threshold of suspicion for ischaemic bowel in patients with unexplained severe metabolic acidosis.

Further reading:
1. Early diagnosis of ischaemic colitis in a patient with severe metabolic acidosis.
2. Ischaemic colitis on emedicine