Intrathecal morphine in the management of pain following cardiac surgery. A comparison with morphine i.v.

Forty-four patients undergoing coronary revascularization received either intrathecal morphine 1 mg (n = 15), intrathecal morphine 2 mg (n = 15), or i.v. morphine 30 mg (n = 14) after the induction of anaesthesia. Morphine 2.5 mg i.v. was given, as required, in the postoperative period and pain score, respiratory rate and PaCO2 measured every 2 h. FVC, FEV1 and PEFR were measured before, and 24 h after, the induction of anaesthesia. Mean overall pain scores in both intrathecal groups were significantly lower than in the i.v. group (P less than 0.01), but did not differ significantly between the intrathecal groups. Consumption of supplementary morphine was significantly lower in both intrathecal groups (P less than 0.01). Mean PaCO2 was significantly higher in patients given intrathecal morphine 2 mg. This was significant at 12, 14 and 16 h after induction of anaesthesia. Respiratory rate did not differ significantly between the groups. Postoperative PEFR was significantly better in patients given intrathecal morphine (P less than 0.01). These results suggest that intrathecal morphine provided better analgesia after cardiac surgery than did a conventional regimen. The lower dose (1 mg) was associated with less respiratory depression as assessed by PaCO2 measurements.

RCT Entities:   Population Interventions Outcomes