PREMEDICATION WITH PROMETHAZINE AND TRANSDERMAL SCOPOLAMINE REDUCES THE INCIDENCE OF NAUSEA AND VOMITING AFTER INTRATHECAL MORPHINE

Intrathecal morphine provides effective postoperative pain relief in m ajor orthopaedic surgery. Its use, however, is associated with unpleas ant side effects like nausea and vomiting. The effect of different pre medications on postoperative emetic sequelae induced by intrathecal mo rphine was studied in a prospective, double blind study. Sixty patient s scheduled for arthroplasty surgery of the lower extremity were anaes thetized with spinal anaesthesia with a combination of isobaric bupiva caine 20 mg and morphine 0.3 mg. For premedication the patients were r andomised to three groups of equal size. They received either oral dia zepam (5-15 mg), oral promethazine (10 mg) or a combination of prometh azine and transdermal scopolamine (1.5 mg). Sixty percent of the patie nts with both promethazine and transdermal scopolamine were totally fr ee from postoperative nausea and vomiting (PONV) symptoms compared to those premedicated with diazepam (40%) or promethazine alone (30%). Pr omethazine together with transdermal scopolamine reduced significantly the number of patients with vomiting (to 25%) and also vomiting episo des. This combination was also more efficient in reducing the incidenc e of nausea (to 25%) and nausea episodes than promethazine alone (P<0. 05). Combination also reduced the requests for additional pain relief (P<0.05). PONV occurred in a majority of patients during the first 12 hours of the 24 hour study period and the need for additional analgesi cs thereafter. The incidence of itching (50-65%) and urinary catheteri sation (55-70%) was similar in all groups. In conclusion, the combinat ion of oral promethazine and transdermal scopolamine was most effectiv e in reducing PONV symptoms and also reduced the need For postoperativ e pain treatment.