Intraoperative hypotension
The main objective of anesthesiologist is maintenance of patient''s homeostasis during surgery. Among all the physiological parameters, only arterial pressure has such significant amplitude of oscillations, still the association between postoperative complications and blood pressure fluctuations is often unobvious. Furthermore, blood pressure is a modifiable parameter and can be easily regulated by fluids, vasopressor and inotropic agents in most cases. Intraoperative decrease of blood pressure may occur due to the action of anesthetics, hypotensive drugs, nonphysiological positioning of the patient on the operating table, artificial ventilation, surgical procedures, cardiopulmonary bypass, hypovolemia, acid-base and electrolyte disorders, acute heart failure, arrhythmias, anaphylaxis and others factors. The lack of consensus about the definition of hypotension makes difficulties in evaluation of its effect on human organism. More than 140 different absolute and relative values are used as hypotension thresholds. Nevertheless, the data accumulated over the past few years lead us to the conclusion that intraoperative decrease of blood pressure is associated with the development of various nervous, cardiovascular and renal complications, what ultimately leads to increased morbidity and mortality. Severity of adverse effects is a function of range and duration of blood pressure fall. Every patient has an individual set of genetic, physiological and pathophysiological features that determine the optimal blood pressure level. Thus, another promising direction may be development of the strategy for individualized blood pressure management.