Multimodal Analgesia and Enhanced Recovery Outcomes in Cardiac Surgical Patients: An Observational Cohort Study.

BACKGROUND Multimodal analgesia, the use of more than 1 pharmacologic agent targeting different receptors, is a cornerstone of enhanced recovery after cardiac surgery (ERACS), but there are limited studies to support its efficacy. We aimed to explore associations between multimodal analgesia and enhanced recovery outcomes after cardiac surgery. METHODS We performed a retrospective cohort study using data from the Society of Thoracic Surgeons database from 2020 to 2023. Adults undergoing elective coronary artery bypass grafting (CABG), valve, or combined CABG-valve surgery were included. Our primary hypothesis was that multimodal analgesia would be associated with a lower maximum postoperative pain score on postoperative day 3 (POD3). Secondarily, we hypothesized that multimodal analgesia would be associated with reduced mechanical ventilation hours, intensive care unit stay, delirium, pneumonia, and reintubation. Linear mixed-effects regression models and generalized linear mixed-effects regression models were used to examine the extent the use of multimodal analgesia was associated with study outcomes after controlling for confounders. RESULTS Over the 4-year study period, there were 17,371 eligible cardiac surgical cases and 15,515 patients (89.3%) received multimodal analgesia. There was no association between multimodal analgesia use and maximum postoperative pain score on POD3 (b = -0.07, 95% confidence interval [CI], -0.32 to 0.18, P = .57), after adjusting for confounders. There was an association between multimodal analgesia use and initial mechanical ventilation hours (b = 0.45 hours, 95% CI, 0.04-0.86, P = .03). Compared to patients who received multimodal analgesia, those who did not receive multimodal analgesia had approximately 30 minutes longer of initial mechanical ventilation time on average. Initial mechanical ventilation time decreased as the number of multimodal analgesic increased (b= -0.33 hours, 95% CI, -76 to -0.10, P = .14) for 1 multimodal analgesic; Est = -1.98 hours, 95% CI, -3.79 to -0.18, P = .03 for 5 multimodal analgesics). Acetaminophen use was associated with a reduced likelihood of delirium (odds ratio [OR] = 0.75, 95% CI, 0.57-0.94, P = .02), while use of a regional nerve block was associated with increased likelihood of unplanned reintubation (OR = 1.59, 95% CI, 1.12-2.27, P = .01). CONCLUSIONS In this retrospective study, multimodal analgesia was not associated with the primary outcome of reduction in maximum pain score but was associated with more rapid extubation. Larger prospective observational and randomized controlled trials of individual analgesic drugs are needed to optimize ERACS protocols.