Intravenous acetaminophen does not reduce inpatient opioid prescription or opioid related adverse events among patients undergoing spine surgery.
Having entered the US market relatively recently, the perioperative role of intravenous acetaminophen (ivAPAP) remains to be established for several surgeries. Using national data, we therefore assessed current utilization and whether it reduces inpatient opioid prescription and opioid related adverse events in spine surgery, a procedure with relatively high opioid utilization.
This study was approved by the Mount Sinai Hospital and Hospital for Special Surgery Institutional Review Boards. 117,269 patients undergoing a lumbar/lumbosacral spinal fusion from 2011-2014 were retrospectively identified in the Premier database, a large nationwide administrative claims database that covers approximately 20% of the nation’s hospitalizations. They were categorized by the amount and timing of ivAPAP administration (1 or >1 dose on postoperative day [POD] 0, 1 or 1+). Multivariable models measured associations between ivAPAP utilization categories and opioid prescription, length of hospital stay, cost of hospitalization and opioid related adverse events; odds ratios (OR; or % change) and 95% confidence intervals (CI) are reported.
Overall, ivAPAP was used in 18.9% (n=22,208) of cases of which 1 dose on POD 0 was the most common (73.6%; n=16,335). After covariate adjustment, use of ivAPAP on POD 0 and 1 was associated with minimal changes in opioid prescription, length and cost of hospitalization particularly favoring >1 ivAPAP dose with a modestly (-5.2% CI -7.2%; -3.1% P<0.0001) decreased length of stay. Use of ivAPAP did not coincide with a consistent pattern of significantly reduced odds for complications. Conversely, use of ivAPAP on POD 1+ was associated with increased resource utilization and complications, likely indicating confounding by indication, i.e. ivAPAP use on POD 1+ may likely happen in those with more pain and higher risk for complications.
Our analysis did not support the assumption that perioperative ivAPAP reduces inpatient opioid prescription or clinically relevant opioid related adverse events. Further, no clinically significant benefit regarding length of stay and cost was found.
While no causal relationships can be established and prescription bias may exist, further studies are warranted to identify if ivAPAP might have the potential to reduce opioid consumption and lower odds for opioid related adverse events under specific conditions and settings.