Blood pressure and heart rate during orthostatic stress and walking with continuous postoperative thoracic epidural bupivacaine/morphine

Abstract
Thirty-one patients scheduled for elective cholecystectomy performed through a mini-laparotomy, were randomized to received either combined thoracic epidural anaesthesia/light general anaesthesia and postoperative balanced analgesia with continuous epidural bupivacaine 10 mg.h-1 and morphine 0.2 mg.h-1 for 38 h after surgery plus systemic ibuprofen 600 mg x 8 h-1 (N = 15) or general anaesthesia and postoperative analgesia with systemic morphine and ibuprofen 600 mg x 8 h-1 (N = 16). During postoperative epidural infusion sensory blockade to pinprick was Th4 to L1, and analgesia at rest and during mobilisation was superior compared to systemic morphine and NSAID. There were no significant differences between groups in haemodynamic responses (BP and heart rate) during rest, orthostatic stress and after walking assessed before, 24 and 48 h after operation except for a clinically unimportant lower heart rate (approximately 10 bpm) 48 h after surgery at rest and during orthostatic stress in the epidural group. There was no significant difference between groups in number of patients with a reduction > 20 mmHg (2.7 kPa) in systolic blood pressure during orthostatic stress (two in each group at 24 h) or in number of episodes of dizziness, nausea or vomiting during rest or mobilisation. These results do not support the common belief that low-dose thoracic epidural bupivacaine/morphine may prevent ambulation due to sympathetic blockade or to impaired cardiovascular adaptation to the upright position.