Previous studies on animals suggest that inhalational anesthetics can reduce vascular tension
in vitro resulting in vasodilation and decrease in blood pressure. This role for inhalational
anesthetics has essential clinical implications such as the condition of sepsis or septic
shock or other shock-associated states during which the blood vessel constricts strongly and
leads to circulation dysfunction. The vasodilation property of these anesthetics including
halothane, isoflurane, sevoflurane, desflurane and enflurane enables them to be better
options than other general anesthetics in many clinical conditions needing the vasculature to
be dilated. The investigators hypothesized that these inhalational anesthetics can evoke
vasodilation measured with ultrasonography during general anesthesia in vivo as the in vitro
studies displayed.