CHANGES IN VENTILATORY PATTERNS DURING HALOTHANE ANAESTHESIA IN CHILDREN

Abstract
Changes in ventialtory variables (VE, VE, f, T1/Ttot. VT/T1. PE′co2) were studied in 12 unpremeicated children, weighing between 10 and 20 kg, during halothane anaesthesia. at an inspired concentration of 0.5% halothane, respiratory rate increased, VT decreased, and VE did not change markedly. When the inspired.; halothane concentration increased further, there was a significant decrease in VE, mainly as a result of a marked decrease inVT. PE′CO2 increased significantly and inspiratory duty cycle decreased at high inspired halothane concentrations. On return to baseline (0.5% halothane), there was a significant decrease in inspiratory timing and a significant increase in PE′CO2- The relations between these changes and the effect of halothane on inspiratory muscles are discussed.