Abstract

As with many other forms of induced hypotension, the main cardiovascular effect of spinal or epidural block is one of vasodilation leading to a reduced peripheral resistance. Cardiac output is not generally much affected even at low pressures if there is no impediment to venous return or vagal overactivity.

Arterial pressure will not fall markedly in the absence of cardiac output decreases, unless a general anesthetic is added.

The hypotension can be used during surgery with benefit, or it may be reversed or prevented by appropriate therapy.

It is axiomatic that a proper understanding of the cardiovascular changes are necessary for proper patient care during spinal or epidural anesthesia.