Perioperative hypotension and myocardial ischemia: diagnostic and therapeutic approaches

Although perioperative hypotension is a common problem, its true incidence is largely unknown. There is evidence that postoperative outcome, including the incidence of myocardial adverse events, may be linked to the prolonged episodes of perioperative hypotension. Despite this, there are very few comprehensive resources available in the literature regarding diagnosis and management of these not so uncommon clinical occurrences, especially during non-cardiac surgery. Most anesthesia providers consider intraoperative hypotension to be caused by systemic vasodilatation and relative hypovolemia and so treat it empirically. The introduction of new monitoring devices including transesophageal echocardiography and arterial pressure waveform based stroke volume measurement have provided additional tools to narrow the differential diagnoses and initiate optimal treatment measures. Understanding the basic pathophysiology of hypotension and myocardial ischemia can further assist in providing goal directed management. This article serves as a comprehensive guide for anesthesiologists to diagnose and treat hypotension and myocardial ischemia. A summary of available techniques to monitor perioperative myocardial ischemia and their limitations are also discussed.