Regulation of cerebrovascular resistance below the lower limit of cerebral autoregulation during induced hypotension: an observational study.

Background: To maintain adequate perfusion, cerebral blood flow (CBF) is preserved by changes in cerebrovascular resistance (CVR) inversely related to fluctuations in mean arterial blood pressure (MAP). It has been hypothesised that during progressive hypotension, a lower limit of cerebral autoregulation (LLCA) is reached beyond which cerebrovascular dilation becomes exhausted and CBF starts to decrease together with BP. We tested this hypothesis by assessing CVR above and below the LLCA.

Cerebral hemodynamics during sustained intraoperative hypotension.

Static cerebral autoregulation (CA) maintains cerebral blood flow (CBF) relatively constant above a mean arterial blood pressure (BP) of 60-65 mmHg. Below this lower limit of CA (LLCA), CBF declines along with BP. Data are lacking in describing how CA reacts to sustained hypotension since hypotension is usually avoided.

Malignant Hyperthermia During Cardiac Surgery Successfully Treated by Deep Hypothermia Using Cardiopulmonary Bypass: A Case Report.

Malignant hyperthermia (MH) is a life-threatening hypermetabolic disorder triggered by volatile anesthetics and/or succinylcholine. We report a case of a 58-year-old patient with a type-A aortic dissection. After induction of general anesthesia, a hypermetabolic reaction was successfully treated by deep hypothermia using cardiopulmonary bypass.