A haemodynamic comparison of intrathecal morphine and sufentanil supplemented with general anaesthesia for abdominal aortic surgery.

Abstract

The haemodynamic changes associated with intrathecal morphine (IM) compared to intrathecal sufentanil (IS) as a supplement to general anaesthesia for elective bypass grafting in patients with aortoiliac occlusive disease were studied. Thirty-six, ASA Grade 2, patients randomly received morphine hydrochloride (0.1%) 50 micrograms kg-1 (n = 18) or undiluted sufentanil, 150 micrograms (n = 18) intrathecally at T12-L1, combined with light general anaesthesia. Haemodynamics were measured before and after endotracheal intubation, abdominal incision, aortic cross-clamping and the first revascularisation. The major differences were recorded after abdominal incision. Heart rate, systemic blood pressure and coronary perfusion pressure were significantly lower in the IS group. The probable cause was greater systemic absorption of sufentanil and its faster binding to the specific opiate receptors, resulting in a more efficacious supraspinal and spinal blockade during the first surgical period. However, both opioids provided adequate analgesia during the whole surgical procedure.