Spinal hypotension during elective cesarean delivery: closer to a solution.

摘要

Hypotension during spinal anesthesia for cesarean delivery should be minimized, both for maternal safety and comfort, and fetal wellbeing. Traditional teaching is that aortocaval compression predisposes the parturient to decreased venous return and hence cardiac output and blood pressure during spinal anesthesia for cesarean delivery. However, a variety of measures to improve venous return, including lateral tilt and numerous fluid administra-tion regimens, have failed to eliminate hypotension. Recent studies focusing on the arterial circulation as a source for hypotension suggest that in the fluid-replete parturient undergoing elective cesarean delivery, moderate spinal hypotension (20% decrease from baseline) primarily reflects decreased systemic vascular resistance. In most cases, venous return is initially maintained and consequently there is a partial compensatory increase in cardiac output, mediated by an increase in stroke volume and heart rate.