Hospitalization costs and resource allocation in cholecystectomy with use of intravenous versus oral acetaminophen

Objective: To evaluate intravenous (IV) acetaminophen (APAP) vs oral APAP use as adjunctive analgesics in cholecystectomy patients by comparing associated hospital length of stay (LOS), hospital costs, opioid use, and rates of nausea/vomiting, respiratory depression, and bowel obstruction. Methods: We conducted a retrospective analysis of the Premier Database (January 2012 to September 2015) including cholecystectomy patients who received either IV APAP or oral APAP. Differences in LOS, hospitalization costs, mean daily morphine equivalent dose (MED), and potential opioid-related adverse events were estimated. Multivariable logistic regression was performed for the binary outcomes and instrumental variable regressions, using the quarterly rate of IV APAP use for all hospitalizations by hospital as the instrument in two-stage least squares regressions for continuous outcomes. Models were adjusted for patient demographics, clinical risk factors, and hospital characteristics. Results: Among 61,017 cholecystectomy patients, 31,133 (51%) received IV APAP. Subjects averaged 51 and 57 years of age, respectively, in the IV and oral APAP cohorts. In the adjusted models, IV APAP was associated with 0.42 days shorter LOS (95% CI=-0.58 to -0.27; p < .0001), $1,045 lower hospitalization costs (95% CI =-$1,521 to -$569; p < .0001), 2 mg lower average daily MED (95% CI = -3 mg to -0.9 mg; p=.0005), and lower rates of respiratory depression (odds ratio [OR]= 0.89, 95% CI = 0.82-0.97; p= .006), and nausea and vomiting (OR= 0.86, 95% CI = 0.86-0.86; p < .0001). Conclusions: In patients having cholecystectomy, the addition of IV APAP to perioperative pain management is associated with shorter LOS, lower costs, reduced opioid use, and less frequent nausea/vomiting and respiratory depression compared to oral APAP. These findings should be confirmed in a prospective study comparing IV and oral APAP.