Postoperative Intravenous Patient-Controlled Analgesia in Thyroid Surgery: Comparison of Fentanyl and Ondansetron Regimens With and Without the Nonsteriodal Anti-Inflammatory Drug Ketorolac

Abstract

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs), through synergistic action with opioids, can reduce postoperative nausea and vomiting via intravenous patient-controlled analgesia (PCA). We compared the efficacy of three PCA regimens. METHODS: Patients (n = 135) undergoing thyroidectomy were randomly allocated to three PCA regimens. All groups received 12 mg ondansetron (a serotonin 5-HT(3) receptor antagonist). In addition, Group I received the opioid fentanyl, 15 microg/kg. Group II received fentanyl 12.5 microg/kg and the NSAID ketorolac, 1.5 mg/kg, and Group III received fentanyl 10 microg/kg and ketorolac 3 mg/kg. Pain scores, nausea and vomiting, and dizziness were assessed 1, 6, 12, and 24 hours postoperatively. RESULTS: Pain scores were similar among the three groups. However, postoperative nausea and vomiting was significantly lower in groups II and III (p < 0.05) than group I. Postoperative dizziness was significantly lower in group III than groups I and II (p < 0.05). CONCLUSIONS: The NSAID ketorolac when combined with lower doses of the opioid fentanyl and the same dose of ondansetron is associated with the same analgesic efficacy but less nausea and vomiting after thyroid surgery. A higher ratio of NSAID to opioid, when used as reported here, is associated with less postoperative dizziness.