ALFENTANIL CONTROLS THE HEMODYNAMIC-RESPONSE DURING RAPID-SEQUENCE INDUCTION OF ANESTHESIA

Laryngoscopy and tracheal intubation often cause hypertension and tachycardia, which may be exaggerated during rapid-sequence induction of anaesthesia. A placebo-controlled,doubleblind study was conducted in 60 patients to determine doseresponse and effects on myocardial performance of alfentanil when used to attenuate this cardiovascular response. Patients were divided into four groups to receive a pre-induction bolus from a coded syringe, which contained either normal saline (PLAC), alfentanil 30 μg · kg-1 (ALF 30), alfentanil 45 μg · kg-1 (ALF 45) or alfentanil 60 μg · kg-1 (ALF 60). Anaesthesia was induced in rapid sequence with thiopentone 4.0 mg · kg-1 and succinylcholine 1.5 mg · kg-1, and the trachea was intubated 60 sec later. Increases in heart rate (21 ±10 bpm), mean arterial pressure (28 ±13 mmHg), and systemic vascular resistance index (1420 ±780 dynes · sec-1 · cm-5) were observed in response to intubation with PLAC but in none of the 3 ALF groups (P < 0.05). However, heart rate and mean arterial pressure decreased significantly in both the ALF 45 and ALF 60 groups (P < 0.05), whereas ALF 30 resulted in no change in these variables over time. Cardiac index, stroke volume index, and ejection fraction tended to decrease in all four groups, but none of these variables was different at corresponding time when comparing the ALF groups with PLAC. We conclude that ALF 30 μg · kg-1 administered prior to rapid-sequence induction of anaesthesia, effectively attenuates the hypertensive, tachycardic response to intubation, without altering global indices of cardiac function. Alfentanil in doses of 45 and 60 μg · kg-1 result in transient but significant decreases in HR and MAP with this anaesthetic technique. © 1990 Canadian Anesthesiologists.