Circulatory Effects of Atropine During Halothane Anaesthesia

Abstract

The circulatory response to the injection of 0.6 mg atropine during nitrous oxide, oxygen and halothane anaesthesia was studied in fifteen patients. Cardiac output was measured by the dye-dilution method and blood pressure and heart rate by manual methods. There was an immediate mean increase in heart rate from 61 to 110 beats/ min, accompanied by a 48 per cent increase in cardiac output and a 24 per cent increase in mean arterial pressure. Stroke volume fell by 17 per cent and peripheral resistance by 17 per cent. These changes were of shorter duration than the change in heart rate. No change was observed in left ventricular stroke work or "central" blood volume. Three patients developed transient arrhythmias after the injection of atropine.

Role of Muscarinic Cholinergic Transmission in Edinger-Westphal Nucleus-induced Choroidal Vasodilation in Pigeon

“…Based on the overall similarity in the cardiovascular responses to muscarinic antagonists in birds and mammals, we assume that the pressor effect of atropine in pigeons is unlikely to be due to an increase in peripheral resistance. In general, the pressor effect of atropine in humans and dogs (when it is present) is associated with an increased cardiac output and a decreased peripheral resistance (Farman, 1967 ;Eger, 1962 ;Page and Olmsted, 1963 ;Liard, 1984). It may be that increased cardiac output also accounts for the pressor effect of atropine in pigeons.…”

Halothane Anaesthesia and Suxamethonium III. Atropine 30 s Before a Second Dose of Suxamethonium During Inhalation Anaesthesia: Effects and Side‐Effects

“…It has been shown, that the maximum increase in heart rate after intravenous injection of atropine in normal patients is reached after 30-60 s (KEMP & MORTON 1962, FARMAN 1967, VIBY-MOGENSEN et al 1976, and that the mean time from the injection of the second dose of suxamethonium to maximal bradycardia is 26 s (VIBY-MOGENSEN et al 1976). In a clinical situation it may be necessary to repeat an injection of suxamethonium, for instance because of difficult intubation.…”

Halothane Anaesthesia and Suxamethonium III. Atropine 30 s Before a Second Dose of Suxamethonium During Inhalation Anaesthesia: Effects and Side‐Effects

“…In a clinical situation it may be necessary to repeat an injection of suxamethonium, for instance because of difficult intubation. It has been shown, that the maximum increase in heart rate after intravenous injection of atropine in normal patients is reached after 30-60 s (KEMP & MORTON 1962, FARMAN 1967, VIBY-MOGENSEN et al 1976, and that the mean time from the injection of the second dose of suxamethonium to maximal bradycardia is 26 s (VIBY-MOGENSEN et al 1976). Thus, when giving atropine 30 s before suxamethonium, the maximal bradycardia1 effect of suxamethonium occurs at the same time as the peak effect of atropine.…”