Respiratory and haemodynamic effects of methoxyflurane anaesthesia
Tóm tắt
Data for this study were obtained from 41 patients during surgery performed under methoxyflurane anaesthesia. In 18 of these, the respiratory effects and acid-base variations were evaluated by spirometry, pH,pO2, andpCO2 determinations. Our results illustrate that light methoxyflurane maintenance neither produces significant respiratory depression nor disturbs the acid-base balance. In 23 patients, cardiovascular reactions were evaluated under methoxyflurane anaesthesia. The blood pressure and pulse rate showed no important alterations. However, in most cases we found a progressive tendency to a decrease in cardiac output and we discovered that each variation in cardiac output was accompanied by an inverse reaction in total peripheral vascular resistance. So every time cardiac output decreases, total peripheral resistance increases in a linear, parallel manner, and vice versa. The discovery of such an interrelationship permitted us to bring logical explanations to many unsolved problems, such as the effects of methoxyflurane on the neurovegetative axis, the pallor and peripheral cyanosis concomitant with prolonged or deep narcosis, and the late emergence of some patients. The meanings of these studies permit us to take a fresh look at methoxyflurane. It certainly is a cardiac depressant but at the same time, it compensates this adverse effect by permitting the normal cardiovascular compensatory mechanisms to work freely towards re-establishing the homeostasis of the cardiovascular system.
Tài liệu tham khảo
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