The effects of different doses of caudal morphine with levobupivacaine on postoperative vomiting and quality of analgesia after circumcision

Abstract

The study aim was to investigate the effect of three different morphine doses added to levobupivacaine 0.125% for caudal analgesia after circumcision surgery in children, particularly in relation to the frequency of postoperative vomiting within the first 24 hours following surgery. Two hundred and forty patients aged 5 to 12 years undergoing circumcision were included in the study. Following induction, caudal 0.125% levobupivacaine 0.5 ml/kg was given after adding 7.5, 10 or 15 µg/kg morphine. The postoperative incidence of vomiting was 5%, 12.5% and 17.5% in the groups 7.5, 10 and 15 µg/kg morphine, respectively (P=0.012, 7.5 versus 15 µg/kg groups). Five percent of the 7.5 µg/kg group and none of the patients in the other groups required paracetamol within the first 12 hours, and there was a significantly greater need for rescue paracetamol over the 24 hours in the 7.5 group versus the 15 µg/kg group (P=0.013). Postoperative analgesic durations were long and did not differ between groups (1273±338, 1361±192 and 1426±48 minutes, respectively, P=0.08). In conclusion, because the incidence of vomiting is very low, the duration of postoperative analgesia is long and a dose of 7.5 µg/kg caudal morphine is much lower than doses previously reported to be associated with respiratory depression, this study supports the use of 7.5 µg/kg caudal morphine added to 0.125% levobupivacaine for circumcision surgery.

Keywords: caudal analgesia; circumcision; morphine.