Background and Aims Patients who sustain hip fractures are at high risk for opioid related adverse events. Acetaminophen (APAP) and specifically intravenous acetaminophen (IVAPAP) have been proposed as part of many opioid-sparing multimodal analgesic pathways. The aims of this study are to describe the current use of IVAPAP and APAP in hip fracture patients and elucidate the effectiveness of IVAPAP and APAP on opioid utilization and opioid-related adverse effects.

Methods This retrospective cohort study used the Premier Healthcare database and included patients undergoing hip fracture repair surgery from 2011 to 2019. Primary exposure was use of APAP or IVAPAP. The primary outcome was opioid utilization over the hospital stay; secondary outcomes included opioid-related adverse effects, length and costs of hospital stay. Mixed-effects models measured the association of IVAPAP/APAP and outcomes. We report effect estimates and 95% confidence intervals (CI).

Results Among 649,960 hip fracture repair surgeries 16.4% (106,315) received 1 dose of IVAPAP. Upon adjusting for all relevant covariates, the use of >1 dose of IVAPAP on the first postoperative day (POD1) was associated with a 6% reduction in opioid use (95% CI -8%, -4%) compared to patients who did not receive IVAPAP. Patients who received > 1 dose oral APAP on POD1 one had a 14% reduction in total opioid use (95%CI -15%, -13%). (Table 1).

Conclusions Both IV and oral APAP show modest reductions in opioid use; these results do not support the use of IV over oral APAP as oral APAP showed more of an opioid sparing effect.