Introduction to the postanaesthetic care unit

High-risk, noncardiac surgery represents only 12.5% of surgical procedures, but 83.3% of deaths. The postanaesthetic care unit (PACU) addresses the need for an improved level of care for these patients by providing postoperative high-dependency or intensive care (Level 2 or 3). The PACU aims to improve the structure of care provision for high-risk surgical patients. By maintaining 24-hour cover at the same staffing level, the risk of poorer 'out-of- hours' care is reduced. In a PACU, whose remit is solely postoperative care, evidence-based protocols can be established to standardize the care given. The aim is to provide 24 hours of postoperative optimized care, thus targeting the period when these patients are most vulnerable, to reduce the risk of complications developing and identify complications promptly, should they occur. The PACU is set up to facilitate certain processes to aid optimized care in the postoperative period. These include invasive and noninvasive ventilation, goal-directed haemodynamic management, invasive monitoring and optimal pain management. Identification of high-risk patients who might benefit from PACU care is not always straightforward. However, tools are available to aid the clinician, supplementing clinical assessment and basic investigations. These include clinical prediction rules and cardiopulmonary exercise testing. Both the setting up and the running of a PACU clearly have cost implications. However, the reduction in postoperative morbidity, and thus patients' length of stay, should, overall, reduce costs. The benefits of a PACU should therefore be seen in terms of improved surgical outcomes, reducing postoperative morbidity and mortality, and cost savings.