Comparison of intravenous ketorolac with or without paracetamol in postoperative pain control following ambulatory surgery

Objective: The aim of this randomized, patient-blinded study was to compare efficacy and safety of oral paracetamol plus intra-venous (i.v.) ketorolac with i.v. ketorolac alone after ambulatory uterine evacuation. Research design and methods: Women were randomly assigned to receive either oral paracetamol (1 g), in a melt-in-the mouth, without-water formulation plus ketorolac (30 mg i.v. once daily (o.d.)) or ketorolac (30 mg i.v. o.d.) as monotherapy. The mean duration of uterine evacuation was 11 minutes in the paracetamol+ketorolac group and 13 minutes in the ketorolac-only group. Paracetamol was administered 15 minutes before surgery, on discharge from hospital (mean 6 hours after surgery) and in the morning the day after surgery, while ketorolac was administered at the end of the surgical intervention. Main outcome measures: The numeric rating scale (NRS) was used by patients to rate their pain on an 11 point scale. Results: Overall, 60 women received paracetamol plus ketorolac (group 1) and 60 ketorolac alone (group 2). There were significant differences in pain levels (NRS 0.92 and 2.08; p < 0.01) at T0 (when patients left the operating room 30 minutes after the end of surgery). At T1 (before discharge from hospital but before the next administration of paracetamol) there were no significant differences between NRS scores in the two groups (3.7 vs. 3.5, respectively, p = 0.3453). At T2 (in the morning after surgery; data collected by phone interview), following administration of the next dose of paracetamol, significant differences in pain scores were recorded (1.58 vs. 1.98; p = 0.01). Only a case of dizziness was reported in the paracetamol+ketorolac group, and no other unexpected adverse events were recorded. Conclusion: Despite the small sample size and the monocentric nature of the study being taken into account, this study suggests, for the first time to our knowledge, that oral paracetamol t.i.d. in combination with i.v. ketorolac o.d. is effective and well tolerated in the control of postoperative pain after ambulatory uterine evacuation.