Effect of Intravenous Acetaminophen on Post-Anesthesia Care Unit Length of Stay, Opioid Consumption, Pain, and Analgesic Drug Costs After Ambulatory Surgery

Objectives: The primary objective was to assess whether the use of intravenous acetaminophen (APAP) in the ambulatory surgery setting is associated with a decreased length of stay in the post-anesthesia care unit (PACU). The secondary outcomes evaluated were pain scores, opioid consumption, and total cost of analgesics used in the PACU.

Methods: This was a retrospective cohort study conducted in adult patients (18 years of age or older) who received an eye, ear, nose, or throat (EENT) procedure at an outpatient surgery center between January 2014 and January 2015. Patients were consecutively included until the desired sample was reached during two six-month time periods: 1) intravenous APAP available on the formulary (APAP group) and 2) intravenous APAP not available on the formulary (non-APAP group).

Results: The cohort included 174 patients who received an EENT procedure (87 patients in the APAP group and 87 patients in the non-APAP group). The median PACU length of stay was 66 minutes (interquartile range [IQR], 48-92) in the APAP group and 71 minutes (IQR, 52-89) in the non-APAP group ( = 0.269). Mean pain score categories in the APAP versus non-APAP group were mild (85% versus 53%, respectively; < 0.001), moderate (13% versus 33%, respectively; = 0.002), and severe (2% versus 14%, respectively; = 0.005). The median opioid consumption in morphine equivalents was 9 mg (IQR, 5-13) in the APAP group and 8 mg (IQR, 5-12) in the non-APAP group ( = 0.081). The total cost of analgesics used in the PACU was significantly greater in the APAP group ($15 versus $1; < 0.001).

Conclusions: Intravenous APAP use in EENT ambulatory surgery is not associated with decreased PACU length of stay. However, it may decrease postoperative pain following EENT procedures.