Effect of Preoperative Cannabis Use on Postoperative Pain and Outcomes Following Cardiothoracic Surgery

Cannabis use has grown both recreationally and medicinally in the United States over the past decades, alongside increased legalization and social acceptance. However, there remains little research investigating the effects of preoperative cannabis use on postoperative pain in patients undergoing surgery. We conducted a single-center prospective study in adults undergoing cardiac surgery via sternotomy. Patients seen for preoperative consultation in clinic were asked a standardized survey about cannabis use. Clinical data was collected via chart review. Primary outcomes were morphine equivalents in the first 48 hours postoperatively and Visual Analog Scale (VAS) scores. Secondary outcomes were time to extubation, postoperative nausea/vomiting, ICU length of stay (LOS), reoperation, and in-hospital mortality. The non-cannabis user group had 50 patients, and the cannabis user group had 23 patients. Average morphine equivalents in the first 48 hours were similar between cannabis users and non-users (60.98 vs 59.90; <i>P</i> = 0.93), as were VAS scores at 24 hours (5.52 vs 4.84; <i>P</i> = 0.414) and 48 hours (4.74 vs 3.90; <i>P</i> = 0.23). Average time to extubation (minutes) was nearly identical between cannabis users and non-users (718.41 vs 718.67; <i>P</i> = 0.99). There was also no significant difference in average LOS (days) between cannabis users and non-users (2.91 vs 3.48; <i>P</i> = 0.26). There were no differences in postoperative nausea/vomiting, reoperation, or in-hospital mortality. In patients undergoing cardiac surgery via sternotomy, there was no effect of cannabis use on any outcomes, including morphine equivalents, Visual Analog Scale scores, time to extubation, ICU length of stay, postoperative nausea or vomiting, reoperation, or in-hospital mortality.