HYPOTENSIVE anesthesia to reduce bleeding during surgery has recently evoked a great interest among surgeons and anesthesiologists. For the past two years we have been using hypotensive anesthesia in selected cases of radical pelvic and abdominal surgery at the Memorial Cancer Center in New York City. The physiological basis for this type of anesthesia will be discussed very briefly.
It is known that the blood pressure varies mainly as the product of cardiac output and peripheral resistance; blood pressure equals cardiac output times peripheral resistance.
In case of hemorrhage the blood volume is reduced, leading to decrease in venous return to the heart, with subsequent fall in cardiac output. The compensatory mechanism of the body acting via the sympathoadrenal system tries to maintain normal blood pressure levels by increasing the peripheral resistance. The produced vasoconstriction achieves temporarily this goal, but with further blood loss the blood pressure falls and reaches low