ISSN:
1365-2044
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Observations of heart rate, rhythm and arterial pressure during induction of anaesthesia, intubation of the trachea, and commencement of surgery were made in 42 patients divided into three comparable groups. Group 1, the control group of 15 patients, received an intravenous placebo injection prior to induction of anaesthesia; group 2, 14 patients, was given an intravenous injection of 2 mg of metoprolol, a beta-adrenoreceptor blocking agent; group 3, 13 patients, received 4 mg metoprolol intravenously. In the placebo group, significant mean increases in heart rate of 27 and 38 beats/minute were noted at induction of anaesthesia and at intubation of the trachea respectively (p〈 0·001). Heart rate was significantly reduced after metoprolol in groups 2 and 3 before anaesthesia (7·6 beats/minute, p 〈 0·05; and 12·9 beats/minute, p 〈 0·001). The increases which occurred after induction of anaesthesia (13·7 beats/minute, p 〈 0·01; and 15 beats/minute, p 〈 0·001), were significantly less than those in the control group (p 〈 0·05). Further increases in heart rate of 10 and 11 beats/minute were noted at intubation in groups 2 and 3 respectively (significantly less than placebo, p〈 0·05).Although no change in systolic arterial pressure was noted in the control group following induction of anaesthesia and the mean increase after intubation was modest (9·8 mmHg), increases in three patients exceeded 50 mmHg. Arterial pressure was reduced by metoprolol in the period before anaesthesia in groups 2 and 3 by 7·1 mmHg (p〈 0·05) and 8·1 mmHg (p 〈 0·01). Again no changes were noted at induction. Mean increases in blood pressure after intubation did not exceed control levels, and increases of 20–30 mmHg were noted in six patients.Cardiac rhythm disturbances, of short duration and of no apparent clinical consequence, were noted in association with induction of anaesthesia and intubation. ST segment changes were commonest and occurred in eight patients; five of these were in the placebo group. Six patients had short-lived ventricular and supraventricular ectopics at induction or intubation of the trachea.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2044.1980.tb04995.x
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