Intravenous Versus Oral Acetaminophen in Ambulatory Surgical Center Laparoscopic Cholecystectomies: A Retrospective Analysis.

Study objective: The primary aim was to compare postoperative pain scores in patients undergoing laparoscopic cholecystectomy and receiving intravenous (IV) or oral (PO) acetaminophen (APAP) as part of a multimodal analgesic regimen to examine whether PO APAP is non-inferior to IV APAP.

Design: Retrospective analysis.

Setting: Ambulatory surgical center (ASC) in an academic setting.

Patients: 579 patients (18-70 years old), American Society of Anesthesiologists physical status I-III, undergoing laparoscopic cholecystectomy.

Interventions: Patients received 1,000 mg IV APAP intraoperatively (n = 319) or 1,000 mg PO APAP preoperatively (n = 260).

Measurements: The primary outcome was the median difference in post-anesthesia care unit (PACU) end-pain scores between the groups. Median pain scores were also compared on PACU admission, and at 15, 30, 45, and 60 minutes. Additional measures include PACU rescue-analgesia consumption, time to first PACU rescue analgesia, intraoperative use of opioid and nonopioid analgesics, PACU length of stay, and PACU rescue nausea and vomiting therapy.

Main results: In both groups, the PACU median end-pain score was 2. The 90% confidence interval (CI) for difference in median pain scores between groups was [0, 0]; the CI upper limit was below the non-inferior margin of 1 pain-score point, indicating PO APAP's non-inferiority to IV APAP. There were no statistically significant differences in the percentages of patients receiving PACU hydromorphone equivalents between the IV and PO groups (75% vs. 77%, P = 0.72) or in the mean dose received (0.5 mg vs. 0.5 mg, P = 0.66).

Conclusion: Single-dose PO APAP is non-inferior to IV APAP for postoperative analgesia in ASC laparoscopic cholecystectomy patients. The value of single-dose IV APAP in this population should be further explored.