Prostaglandin E1, lidocaine, and prostaglandin E1-lidocaine combination for attenuating cardiovascular responses to extubation

Abstract

Purpose: Tracheal extubation produces haemodynamic changes that may cause myocardial ischaemia in patients with coronary arterial disease. Intravenous infusion of prostaglandin E1 (PGE1) attenuated the hypertensive response to tracheal extubation but failed to blunt the tachycardia, which was attenuated by intravenous lidocaine. Thus, we investigated whether a combination of PGE1 and lidocaine can overcome the drawbacks of treatment with PGE1 alone. Methods: One hundred adult. patients (ASA 1) undergoing elective minor surgery were randomly assigned to receive one of four treatments: saline (as a control), 1 mg·kg-1 lidocaine, infusion of 0.1 μg-1·kg-1·min-1 PGE1, or infusion of 0.1 μg-1·kh-1·min-1 PGE1 plus injection of 1 mg-1·kg-1 lidocaine. Lidocaine was injected two minutes before tracheal extubation. The PGE1 was infused from completion of surgery until five minutes after-tracheal extubation. Anaesthesia was maintained with sevoflurane 1.0%-2.5% and nitrous oxide 60%. Heart rate (HR) and blood pressure (BP) were measured before and after tracheal extubation. Results: Lidocaine alone and PGE1-lidocaine combination attenuated the increases in BP and HR observed in the control group: PGE1 alone was effective in attenuating hypertensive response but ineffective for tachycardia. The suppressive effect of the PGE1-lidocaine combination on BP increase was superior to that of each drug alone, and the combined effect on HR increase was similar to that of lidocaine alone. Conclusion: The combination of PGE1 infusion and lidocaine is a more effective method of attenuating hypertension and tachycardia associated with tracheal extubation than either drug alone.