Aims: To investigate the roles of MDR1 (1236C>T, 2677G>T/A, and 3435C>T) and OPRM1 (118A>G) gene polymorphisms on the anesthetic and adverse effects of propofol-remifentanil total intravenous anesthesia in pediatric surgery. Materials & methods: The genotypes were identified through Sanger sequencing. The clinical data including hemodynamics on anesthesia, postanesthesia pain and sedation score and the occurrence of adverse effects were recorded and compared against the genetic data. Results: A total of 72 pediatric patients undergoing surgery were recruited. A weak to no association was found between the genetic polymorphisms of MDR1 and OPRM1 and the anesthetic and adverse effects of propofol-remifentanil. Conclusion: Genetic polymorphisms in OPRM1, but not in MDR1, gene polymorphism, demonstrated plausible association with the effects of propofol-remifentanil.
We studied the effect of fentanyl pretreatment on alleviating pain during the injection of Propofol-Lipuro. One hundred and seventy patients were randomly allocated to receive either 100 mcg of intravenous fentanyl or normal saline (placebo) followed by intravenous Propofol-Lipuro premixed with 20 mg lignocaine. The incidence of injection pain was 32% and 13% in the placebo and fentanyl groups, respectively. We found a statistically significant reduction in incidence of injection pain in the fentanyl group when compared with the placebo group (p<0.003). The number needed to treat was 6 (3.2< 95% CI <15.1). In conclusion, fentanyl pretreatment is effective in alleviating pain during injection of Propofol-Lipuro.
We conducted a double-blind, randomised, placebo-controlled study evaluating the efficacy of prophylactic metaraminol for preventing propofol-induced hypotension. Thirty patients aged 55-75 years undergoing general anaesthesia were randomly allocated to receive either metaraminol 0.5 mg or saline before administration of fentanyl 1 microg.kg(-1) and propofol 2 mg.kg(-1). Induction of anaesthesia was associated with a decrease in mean and systolic arterial pressure in both groups (p = 0.0001). However, there was no significant difference between the two groups. These results show that prophylactic use of metaraminol 0.5 mg does not prevent the decrease in blood pressure following fentanyl and propofol induction in older patients.