The effect of intravenous preemptive paracetamol on postoperative fentanyl consumption in patients undergoing open nephrectomy: A prospective randomized study

Abstract

Aim: We investigated the efficacy of intravenous (IV) preemptive paracetamol on postoperative total fentanyl consumption and fentanyl.related side effects in patients undergoing open nephrectomy.
Materials and Methods: A total of 60 patients scheduled for elective open nephrectomy under general anesthesia were included. All patients received Patient.controlled IV analgesia with fentanyl postoperatively. Patients were randomly allocated into three equal groups: The fentanyl group received 100 mL of IV normal saline as a placebo, with the first dose ending 30 min before intubation. In paracetamol group, IV 1 g paracetamol was given to the patients 30 min after extubation with repeated doses every 6 h totally 4 times a day. In preemptive paracetamol group, patients received IV 1 g paracetamol every 6 h, with the first dose ending 30 min before intubation.
Results: Postoperative cumulative fentanyl consumption for 24 h was significantly higher in the fentanyl group (1009 ± 139.361 µg) than those of paracetamol (752.25 ± 112.665 µg) and preemptive paracetamol  groups (761.10 ± 226.625 µg) (P = 0.001 for both). In early postoperative period (0-4 h); whereas total fentanyl consumption showed no statistically significant difference among groups (P = 0.186), the nausea-vomiting scores were significantly higher in the fentanyl group compared with other groups (P = 0.012).
Conclusion: In patients undergoing open nephrectomy, use of preemptive or postoperative paracetamol reduces fentanyl related nausea.vomiting without a decrease in total fentanyl consumption in the early postoperative period. Furthermore, use of preemptive or postoperative paracetamol  reduces total fentanyl requirements in the first 24 h postoperatively  providing a safe and effective postoperative analgesia.

Key words: Fentanyl, intravenous paracetamol, open nephrectomy, preemptive analgesia