A Clinical Evaluation Of Postoperative Alfentanil Infusion In Cardiac Surgical Patients: Effects On Hemodynamics, Sedation And Shivering

Abstract

We conducted a randomized prospective double-blind pilot study followed by an open main study to assess the effects of alfentanil infusion on postoperative hemodynamics, sedation and shivering following coronary artery bypass graft surgery. Two groups of 10 patients were randomized to receive 15 or 25mcg.kg-1 alfentanil bolus. The 15mcg.kg-1 dose caused less changes in heart rate and systolic arterial pressure (SAP) and was chosen for the main study. After admission to intensive therapy unit (ITU), 30 patients received alfentanil bolus followed by an infusion for 3 hours at a rate of 0.7±0.2mcg.kg-1.min-1. Changes from baseline in mean arterial pressure (MAP), cardiac index and pulmonary capillary wedge pressure were not significant during sedation and the early post-extubation periods, however, 30% of patients required nitroglycerin/nitroprusside infusions to avoid hypertension (SAP<140mmHg and/or MAP<95mmHg). Sedation was assessed on 0-6 grading scale. Sedation scores during alfentanil infusion were 4.9±0.8. Addition of midazolam was required in 16% of patients (4.8±1mg per patient). Shivering occurred in 20% of patients. Mean extubation time was 225±103min from the time of discontinuing alfentanil infusion. None of the patients required re-intubation. The ITU length of stay was confined to 24h period. In conclusion, postoperative administration of alfentanil achieved effective sedation, adequate cardiovascular stability, and provided good patient tolerance to ventilation and minimal shivering.