A comparative study on the effects of intrathecal morphine added to levobupivacaine for spinal anesthesia

In this prospective, randomized, double-blind, controlled study, we investigated the sensory, motor, and analgesic block characteristics oftwo diferent doses of morphine compared with saline when added to 0.5 percent levobupivacaine.

Prospective, randomized, double-blinded, controlled study.

University hospital. PATIENTS, PARTICIPANTS, INTERVENTIONS: One hundred and twelve ASA I or II adult patients undergoing cesarean section with combined-spinal epidural anesthesia (CSEA) were randomly allocated to receive 0.5 mL of0.9 percent sodium chloride in group S, 0.1 mg of morphine in group M1, or 0.2 mg of morphine in group M2 following 15 mg of isobaric spinal levobupivacaine 0.5 percent (3 mi).

We recorded the following: onset and duration of sensory and motor block, duration of spinal anesthesia, time to first request for analgesia, and side effects.

The onset time ofsensory block was significantly less in group M2 (3.5 + 3 minutes) than S (4 +/- 3 minutes; p < 0.003). Parturientsgiven morphine had a significantly greater duration of analgesia (554 +/- 350 minutes in group M1 and 879 -725 minutes in group M2) than the saline group (80 +/- 70 minutes; p < 0.001). Similarly, the time to first request for analgesia was longer in groups M1 (582 +/- 470 minutes) and M2 (917+/- 709 minutes) than in group S (92 +/- 77 minutes; p < 0.001).

In patients undergoing cesarean delivery with CSEA, adding intrathecal morphine (0.1 and 0.2 mg) to 15 mg of spinal levobupivacaine prolonged the duration of spinal analgesia and provided rapid onset of action and longer time to first analgesic request without causing any significant side effect compared to saline.