Intra-abdominal sepsis--epidemiology, aetiology and management.

Peritonitis is a progressive disease leading inexorably from local peritoneal irritation to overwhelming sepsis and death unless this trajectory is interrupted by timely and effective therapy. In children peritonitis is usually secondary to intraperitoneal disease, the nature of which varies around the world. In rich countries, appendicitis is the principal cause whilst in poor countries diseases such as typhoid must be considered in the differential diagnosis. Where resources are limited, the clinical diagnosis of peritonitis mandates laparotomy for diagnosis and source control. In regions with unlimited resources, radiological investigation, ultrasound, CT scan or MRI may be used to select patients for non-operative management. For patients with appendicitis, laparoscopic surgery has achieved results comparable to open operation; however, in many centres open operation remains the standard. In complicated peritonitis "damage control surgery" may be appropriate wherein source control is undertaken as an emergency with definitive repair or reconstruction awaiting improvement in the patient's general condition. Awareness of abdominal compartment syndrome is essential. Primary peritonitis in rich countries is seen in high-risk groups, such as steroid-dependent nephrotic syndrome patients, whilst in poor countries the at-risk population is less well defined and the diagnosis is often made at surgery.