What is the differential diagnosis?

What investigations are required at this stage – and why?

What treatment is required at this stage?

What does the image show and what should be done?

A.1 The most likely diagnosis is a pelvic collection or abscess. Other conditions to consider include a wound infection, urinary or chest infection. A pneumonia is unlikely given this clinical picture.

A.2 Her laboratory studies should include a full blood count (a leucocytosis would support the diagnosis of infection), C-reactive protein (inflammatory response) and electrolytes (dehydration). She is likely to have a septicaemia and blood cultures may help identify the organism(s) and help target antibiotic therapy. A chest X-ray and urinalysis are also required to exclude the respiratory and renal tracts as sources of sepsis. As the most likely source of sepsis is within the abdomino-pelvic cavity some form of imaging is required and a CT scan would be most appropriate.

As the patient is septic she may be coagulopathic and her clotting profile should be established.

A.3 Oral fluids must be withheld in case some procedure or operative intervention is required. Intravenous fluids should be started (see Problem 1) and broad-spectrum antibiotics given on a empirical basis. These should cover Gram-positive cocci and rods and Gram-negative rods and anaerobes. Possible combinations of antibiotics might include ceftriaxone and metronidazole or amoxicillin, gentamicin and metronidazole.

A.4 There are several collections of fluid in the pelvis and specifically in Morrison’s pouch. There is also a small collection of fluid in the subcutaneous tissues in the region of the skin incision. The wound needs to be opened. Percutaneous drainage of the pelvic collections needs to be considered. If not feasible, the patient may require open drainage. The antibiotics must be continued and adjusted if need be, depending on the sensitivities of any organisms grown.

Fever is generally defined as a core body temperature of >38°C. It is a relatively common complication following surgery, with the incidence quoted as being 18–70%. When investigating the cause of a postoperative fever, both infective and non-infective causes must be considered. Common causes include the following:

The time of onset of fever in relation to the surgery can be a useful guide in assessment and determining the underlying cause (Figure 2.2).

Figure 2.2

When assessing a patient with a postoperative fever it is important to consider the surgery that has been performed, as the risk of complications is directly related to the nature of the surgical procedure and this may guide the investigations. The risk of infection depends on the bacterial load related to the operation (Box 2.1). Similarly, other causes of postoperative fever are more common following certain operations, for example venous thrombo-embolic events are high risks following orthopaedic operations.

When assessing a patient who has a postoperative fever a complete history of symptoms must be taken. These include:

The examination should cover the major sources of postoperative fever listed above and if the patient has had abdominal surgery, a careful rectal examination may be useful to identify a pelvic collection. The standard investigations are those discussed in the case and will often also involve imaging of the operative site, the CT scan being favoured for potential intra-abdominal sepsis. The principles of treatment include tailored antibiotic therapy, drainage of any localized collection and removal of infected foreign materials (e.g. skin sutures, intravenous cannulae or an indwelling urinary catheter). The indications for antibiotics include:

Adhering to the principle that prevention is better than cure, all reasonable measures should be taken to reduce the risks of postoperative complications, particularly infection and venous thromboembolism. These include:

Antibiotics should be used on a prophylactic basis for those at increased risk of infection through the type of procedure to be performed (contaminated and dirty procedures – see Box 2.1). Two other groups of patients likely to require prophylactic antibiotics, no matter what the type of procedure, are (i) those who might be immunocompromised (diabetes, steroids, cytotoxic therapy) and (ii) those who have prostheses (e.g. heart valves) in whom any infection could have disastrous consequences. Other patients at increased risk of infection include the obese, those who are malnourished, the anaemic and those who suffer with alcoholism.

In the postoperative period attention must be paid to appropriate analgesia to facilitate early mobilization, deep breathing and coughing and so reduce the chance of chest infection and venous thrombo-embolic problems. Any indwelling device (intravenous cannulae, bladder catheters) should be removed as early as possible.