Aspects of the Effects of Enflurane on Cardiovascular Control

In the process of evaluation of new inhalational anesthetics the assessment of cardiovascular effects is important especially in the light of the increasing frequency of operations on patients with serious cardiovascular disorders. Like most other inhalational anesthetics enflurane reduces systemic arterial pressure probably both by causing cardiac depression and decreased peripheral vascular resistance. The mechanisms by which enflurane decreases vascular resistance, however, are not fully understood. The vascular resistance may be diminished by decreased sympathetic vasoconstrictor tone elicited at central and/or peripheral sites of the autonomic nervous system, by interference with local regulatory mechanisms of the peripheral vascular bed or by direct effects on the vascular smooth muscles. For references, see [1, 2]. The lack of detailed knowledge can be explained by the fact that the cardiovascular regulatory system is very complex and composed by a row of interrelated mechanisms with which drugs may interact simultaneously and which therefore are technically very difficult to study.