Core Topics in General & Emergency Surgery: Companion to Specialist Surgical Practice (84 page)

Although effective management of patients with severe sepsis may entail complex investigations and procedures, the results of these manoeuvres are often suboptimal or even lethal without adequate prior resuscitation. A systematic approach such as that described in the
Care of the Critically Ill Surgical Patient
(CCrISP) course
¹⁸
has much to recommend it, as it provides a common management structure for problems of any type or severity (
Fig. 18.1
). Having a structured approach in times of crisis facilitates speed and may also be important in reducing the likelihood of management errors. It certainly provides a common language and transparency that lets other health professionals understand interventions more easily. With complex abdominal sepsis, a team approach is required: firstly, because help will often be needed from radiology, anaesthesia and intensive care; and secondly, because the illness will often run a prolonged time course of days or weeks and hence many doctors will be involved.

Patients with abdominal sepsis will present with some degree of instability and CCrISP advocates rapid
immediate management
following ABC principles of assessment with simultaneous correction of life-threatening conditions and initiation of high-flow oxygen therapy, fluid resuscitation and basic monitoring as required. Although some patients will deteriorate catastrophically and require immediate intensive care support, simple resuscitation will more commonly buy sufficient time for a more thorough
full assessment
to be carried out. This aims to determine the cause and severity of any problem and to exclude other conditions that would prove deleterious if left untreated. It also includes a thorough appraisal of the patient's notes and charts.

As the clinical manifestations of abdominal sepsis can be subtle and varied (
Box 18.3
), a high index of suspicion, combined with anticipation of potential complications, is essential. Complications can usually be anticipated from the surgical condition in question, any operation recently carried out and knowledge of comorbid conditions. Frequently, the range of possible diagnoses is large (
Box 18.4
) and the initial diagnostic net must be cast wide before drawing it in rapidly with the assistance of selective investigations. Reaching a provisional diagnosis and management plan rapidly is important as outcome worsens with delay and deterioration.

Patients should improve after clinical interventions. Failure to progress, or signs of deterioration, suggest a new problem or an unresolved one. The same systematic CCrISP approach forms the basis of ongoing assessment of the critically ill or at-risk patient on the critical care unit or ward. As repeated complications and setbacks are likely in complex cases, the surgeon must be prepared for a long campaign as compared to a single battle, and be prepared to take a leading role in ongoing management.

Definitive management of sepsis requires eradication of the source of infection. However, the role of antimicrobial therapy is also vital.
¹⁹
When sepsis is suspected, blood cultures, urine, wound swabs and sputum should be submitted for urgent Gram staining and culture, with all sources of sepsis considered. Cultures from the main source of sepsis are several times more likely to be positive (75% vs. 18%)
²⁰
than blood cultures, but both are important in the critically ill patient. Once cultures are taken, best-guess antibiotic therapy should begin immediately as delay may influence outcome.
¹⁷
The role of cultures is to enable the antibiotics to be changed successfully if the patient fails to respond. The choice of antibiotic will be influenced by the clinical circumstances to cover the expected range of infecting organisms. Early combination antibiotic therapy yields significantly improved survival compared with single-agent use in septic shock.
²¹
The route of administration must ensure adequate plasma levels and the drugs should penetrate adequately into the tissues. Intravenous infusion is usually necessary. Whenever there is doubt concerning the optimal choice of antibiotics, the advice of a medical microbiologist should be urgently sought. For most abdominal sepsis, coverage of Gram-negative and anaerobic bacteria will be necessary. With biliary sepsis, approximately 15% of cases will involve streptococci species that are resistant to cephalosporins, so the addition of a modern penicillin is a common approach. With postoperative hospital acquired infection, cover against a broader and more resistant spectrum of organisms will be needed.
¹⁹
Fungal infection (usually
Candida
species) is not uncommon in complex abdominal sepsis requiring ICU care and often antifungal therapy will be required.

Various imaging techniques may be employed to localise an infective focus (see also
Chapter 5
). Computed tomography (CT), usually with gastrointestinal and/or intravenous contrast enhancement, can provide excellent information in thoracic, abdominal and pelvic sepsis. Most surgical patients can be stabilised sufficiently for safe scanning to take place and the assistance that CT gives in terms of accurate diagnosis and selective therapeutic intervention should not be underestimated. CT is excellent at primary diagnosis and at least as useful in the complex or postoperative patient where clinical examination is more difficult.
²²
Contrast can be usefully inserted up drains or down stomas when needed. Comparison with previous scans is important and the input of a senior, specialist radiologist will increase the accuracy of the report. In emergency cases, the surgeon should ideally be present at the scan so that decisions about any interventional radiological procedure can be made jointly.

It should not be considered that CT or any other diagnostic test is perfect. Interference from infusions, drains and metallic prostheses may reduce image quality. Intravenous contrast use is often contraindicated in acute renal failure, although gastrointestinal contrast can still be used to advantage. Even in expert hands, there is a small but significant rate of missed diagnoses. When emergency scans are interpreted by trainees, the rate is probably higher.

The chest radiograph remains an integral part of patient assessment and ultrasound has the advantages of being portable, harmless and repeatable. The greatest utility of ultrasound probably lies with the assessment of biliary and renal pathology and the monitoring of identified collections. However, it is limited by operator dependency, and a negative scan will offer little reassurance when the clinical picture is concerning. When a focus of subacute sepsis cannot be identified radiologically, isotopic methods such as labelled white cell scanning using indium-111 may help.

Source control describes the physical measures taken to control an infective focus. This includes the drainage of collections, debridement of necrotic tissue and definitive surgical procedures to correct the anatomical abnormality. Whilst it is intuitive that early source control will improve outcomes in abdominal sepsis, there is a relative paucity of data to support this, and obvious ethical considerations in performing prospective randomised trials. Delay to source control significantly increases mortality in septic shock,
²³
and there are clear advantages of expedient source control before progression to septic shock occurs.
^17
,
24

In a complex system such as a hospital, it is all too easy for multiple small delays to add up. Managing the multidisciplinary team to achieve prompt and timely intervention is a considerable skill, which requires active and continued leadership from the surgeon. The Royal College of Surgeons of England and the Department of Health have issued timelines regarding the urgency of source control in sepsis (
Box 18.5
), which are advocated as a standard of care.