Efficacy of Intravenous Acetaminophen as Adjunct Post-Operative Analgesic in Cardiac Surgery: A Retrospective Study

INTRODUCTION: The dose-dependent adverse events associated with post-operative opioid use may be reduced when opioids are used in conjunction with intravenous acetaminophen. The purpose of this study was to compare outcomes in median sternotomy patients receiving intravenous acetaminophen in addition to intravenous opioids versus intravenous opioids only. METHODS: A retrospective study was conducted on 122 adult patients undergoing median sternotomy at a regional tertiary-referral center. Data collected included patient demographics, length of stay, opioid and intravenous acetaminophen use, adverse effects, and transition time to oral pain medication. RESULTS: There was no difference between groups in demographics, preoperative risk scores, operative procedures, intravenous opioid consumption, transition time to oral pain medications, or length of stay. Acetaminophen use was associated with lower rates of atrial fibrillation (7.0% vs. 24.6%, p = 0.009) and nausea/vomiting (8.9% vs. 32.3%, p = 0.002), but higher rates of urinary retention (15.8% vs. 3.1%, p = 0.014), constipation (50.0% vs. 20.0%, p = 0.001) and respiratory depression (7.1% vs. 0.0%, p = 0.043). CONCLUSION: Intravenous acetaminophen was not associated with a reduction in length of stay or opioid consumption, but was associated with lower rates of atrial fibrillation, nausea, and vomiting. Additional studies are needed to determine if intravenous acetaminophen administration reduces atrial fibrillation in this population.