Effect of Halothane on Cardiovascular and Plasma Catecholamine Responses to Tracheal Intubation

Abstract

The catecholamine and cardiovascular responses to intubation were investigated during halothane anaesthesia. Thirty patients were allocated randomly to two groups. Following induction of anaesthesia and muscle relaxation, group 1 was ventilated with 70% nitrous oxide in oxygen before intubation; group 2 received 1% halothane in addition. After intubation, both groups received 0.5% halothane. Arterial pressure and heart rate, and plasma noradrenaline and adrenaline concentrations were measured throughout the induction sequence. In group 1 intubation was associated with increases (from pre-induction values) in systolic arterial pressure of 13% and diastolic arterial pressure of 35%, although the plasma concentrations of noradrenaline did not alter significantly. In group 2, although there was a pressor response to intubation, no overall change in systolic arterial pressure and only a 13% increase in diastolic arterial pressure occurred when compared with pre-induction values. This response was associated with a 78% increase in the noradrenaline concentration; the adrenaline concentration did not alter significantly.

Anaesthesia and the QT interval in humans

“…Halothane, when given alone in the absence of laryngoscopy or surgical stimulation. does not itself produce any changes in plasma noradrenaline concentrations [24]. Laryngoscopy and tracheal intubation are.…”

Reflex circulatory responses after three stages of nasotracheal intubation and two stages of orotracheal intubation: A comparative study

“…20 It has been shown that there are significant differences in circulatory responses to airway stimulation at different sites. 9 The circulatory responses during tracheal intubation also varies with depth of anaesthesia 21 , duration of the procedure 22 and the difficulties encountered during laryngoscopy and intubation 23 as well as patient dependent variables including age 24 and co-existing medical illness 24,25 .…”

Possible indications of beta-blockers in the perioperative period other than prevention of cardiac ischemia

“…The degree of response to laryngeal stimulation appears to vary with the depth of anesthesia [104], the duration [105] and difficulties encountered during tracheal intubation [106,107], as well as on patient-dependent variables, including age and history of diabetes or cardiovascular disease [108,109]. Although the hemodynamic changes are transient, drastic hemodynamic changes in patients with pre-existing ischemic coronary disease, hypertension or cerebrovascular disease may increase the risk of myocardial ischemia, arrhythmia, and even infarction and cerebral hemorrhage [110,111].…”