Chapter 139. Surgical Critical Care

1. Which surgical patients require admission to the intensive care unit?

2. How should postoperative bleeding be best managed?

3. What contributes to postoperative pulmonary insufficiency, and how should it be managed?

4. What is damage control surgery?

5. What are the indications for open abdomen and delayed abdominal closure?

Invasive Monitoring

Several measurements can be obtained in the intensive care unit (ICU) to guide management. Central venous monitoring is used to measure central venous pressure, a marker of volume status and right atrial pressure. The central oxygen venous saturation, obtained from the distal port of a multilumen catheter, can be measured as a surrogate for mixed venous oxygen saturation instead of using a pulmonary artery catheter (PAC). The central venous oxygen saturation is usually 10% lower than the mixed venous oxygen saturation from the PAC, but this measure can vary due to multiple factors such as anemia or sepsis. Arterial vascular access monitors blood pressure and measures arterial blood gases (ABG). The base deficit in the ABG is a particularly useful aggregated index for determining tissue perfusion. The arterial base deficit is the amount of additional base that must be added to raise one litre of whole blood pH as predicted by the arterial partial pressure of carbon dioxide (PaCO2). Base deficit, which is used as a surrogate marker of metabolic acidosis, is a calculated value; can be classified as mild (2–5 mmol/L), moderate (6–14 mmol/L), and severe (>15 mmol/L); and is used as a surrogate marker of metabolic acidosis. Serial measurements are useful in guiding resuscitation and have been shown to predict hospital mortality, length of stay, severity of sepsis, and organ failure in both medical and surgical ICU patients. The PAC can be used to monitor ventricular filling pressures, cardiac output and index, vascular resistance, and venous oxygen saturation. The routine use of PACs in postoperative patients is controversial. A large meta-analysis and randomized trials in medical and surgical patients have not demonstrated any benefit in PAC use. However, a recent study using 53,000 trauma patients showed a survival benefit with the use of PACs in severely injured, elderly patients with high base deficits. The results of invasive monitoring should not be used as isolated values. Rather, they should be trended and used in the broader context of the clinical exam.

Criteria for Admission to the ICU

Patients may be admitted to the ICU preoperatively, immediately postoperatively, or postoperatively after initial admission to the ward. Preoperative admission may be required for resuscitation in the event of preoperative respiratory failure, cardiogenic shock, or sepsis. ICU admission may also be required for patients who need invasive monitoring for blood pressure management in the setting of severe cardiovascular disease, such as a stroke or acute myocardial infarction.

Postoperatively, patients may be admitted to the ICU for respiratory failure, hemodynamic instability, or close monitoring for complications such as bleeding or physiologic alterations. ...