Comparison of the use of different doses of intrathecal morphine added to levobupivacaine for spinal anesthesia during unilateral inguinal herniorraphy

Our study was performed with a total of 60 ASA group I or II patients. The patients were randomly distributed into 3 groups, including 20 patients in each group, of which were levobupivacaine (Grup L), levobupivacaine-morphine 50 ?g (Group LM50) and levobupivacaine-morphine100 ?g (Grup LM100).The patients were not premedicated before the operation. After proper iv fluid replacement, all patients were placed in sitting position and a local anesthetic solution of 2.5 ml was applied intrathecally thorough a dural puncture performed at the L3-4 interspace with a midline approach. Hemodynamic parameters of blood pressures, pulse rates, SpO2 values, characteristics of sensory and motor blocks, analgesia free intervals, times to first micturition and mobilization, the scores of patients? and surgeons? satisfactions, as well as adverse effects were recorded for each case during and after the operation.The maximal level of sensory block and the intra-operative distribution of the levels of the sensory block (between 20 to 60th minutes) of the group LM100 were significantly higher compared to other groups. The post-operative distribution of the levels of the sensory block (between 20 to 30th minutes) of the morphine groups was significantly higher as compared to levobupivacaine only group. The two segment sensory block regression time of the levobupivacaine only group was significantly shorter as compared to two morphine groups. The total sensory block regression time was not different between the groups.The degree of the motor blocks was not different between the groups. Time to maximum motor block of the morphine groups was shorter as compared to levobupivacaine only group. Motor block regression times were also longer in the morphine groups. Although, time to first demand for analgesia of the levobupivacaine group was shorter as compared to morphine groups; this was not different between morphine groups. The scores of patients? and surgeons? satisfactions were higher in morphine groups.Post-operative first time to micturition and gas relief of the patients were longer in morphine groups. Urinary retention was detected in 3 patients in group LM50 and in 5 patients in group LM100, where as it was not detected in any patients in group L.In conclusion; a synergistic effect to local anesthetic was found for morphine when added to intrathecal levobupivacaine for unilateral inguinal hernia herniorraphy. Intrathecal adjuvant morphine was also found to improve the quality of analgesia peri- and post-operatively. Apart from few cases of urinary retention seen in morphine groups, the degree of patients? and surgeons? satisfactions was superior in adjuvant morphine groups as compared to levobupivacaine only group. Intrathecal doses of 50-100 µg of adjuvant morphine was found to improve the quality of the anesthesia and analgesia in the intra- and post-operative periods without causing adverse effects.