Comparative Evaluation of Renal and Hepatic Function after Long Duration Low Flow Sevoflurane and Isoflurane Anesthesia

Abstract

The low flow anesthesia is a technique in which the fresh gas flow is significantly lower than the minute volume (less than lL/min). This technique has many advantages including: • Better humidification and warming to the breathing gases. • Environmental benefits due to decrease release of the anesthetic gas to the environment. • Cost saving as a result of reducing the consumption of the anesthetic gas.

However, sevoflurane is degraded by C02 absorbents (sodalime and barium hydroxide lime), the degradation products of which are polyfluorinated haloalkenes, chiefly pentafluoro isopropyl fluoromethyl ether (Also known as compound A). Compound A is nephrotoxic in dose dependent manner in rats and there is a contra verse on its effect on humans.

The rate at which C02 absorbents degrade sevoflurane is dependent on the concentration of the anesthetic gas, the fresh gas flow rate, the temperature of C02 absorbent and types of C02 absorbent. The aim of this work is to compare the effect of low flow sevoflurane and isoflurane anesthesia in humans, following long duration surgery, on renal and hepatic functions.