• P J Cole, D A Craske, and R G Wheatley.
• Acute Pain Management Unit, York District Hospital, UK.
• Br J Anaesth. 2000 Aug 1;85(2):233-7.

AbstractA randomized, double-blind study of 38 patients undergoing total knee replacement was undertaken to compare the efficacy and respiratory effects of low-dose spinal morphine and patient-controlled i.v. morphine against patient-controlled i.v. morphine alone. Patients received either morphine 0.3 mg or saline 0.3 ml with 0.5% heavy spinal bupivacaine 2-2.5 ml. Respiratory effects were measured continuously for 14 h postoperatively with an Edentec 3711 respiratory monitor. There was an improvement in pain relief in the intrathecal morphine group, with significantly lower median VAS pain scores on movement at 4 h (0 (median 0-1.5) vs 5 (1.25-7.75) P < 0.01), 12 h (2 (1-5) vs 6 (3-8) P < 0.01) and 24 h (3 (1-5) vs 5 (3-7) P < 0.05) postoperatively, despite using significantly less patient-controlled morphine (20 mg (10.25-26.25) vs 38.5 mg (27-51) P < 0.01) in the first 24 h. There was a small but statistically significant reduction in the median oxygen saturation (SpO2) in the intrathecal morphine group 97 (95-99)% compared with the placebo group 99 (97-99)% (P < 0.05). Although marked disturbances in respiratory pattern were observed in both groups, none of the patients in the study had severe hypoxaemia (SpO2 < 85% > 6 min h-1) and there was no significant difference in the incidence of mild (SpO2 < 94% > 12 min h-1) or moderate (SpO2 < 90% > 12 min h-1) hypoxaemia or in the incidence of episodes of apnoea or hypopnoea in the two groups.

28 keywords...

hide…