Background
Intrathecal (IT) clonidine has been observed to reduce 24-hour opioid requirements and time to first analgesic request after cesarean delivery, but has not been specifically studied in patients with opioid use disorder (OUD).
Methods
Patients with OUD undergoing cesarean delivery under spinal or combined spinal-epidural (CSE) anesthesia at our institution from 2011 to 2020 were identified, and only patients with OUD were included in this study. Subjects that received IT clonidine were compared to a control group that did not receive IT clonidine to observe potential differences in analgesic outcomes (24-hour opioid requirements, pain scores and time to first post-operative pain medication) or side-effects (hypotension, vasopressor dosing and bradycardia).
Results
A total of 160 patients were included (clonidine n = 22, controls n = 138). For the clonidine group, the median IT clonidine dose was 30µg. Clonidine group patients were observed to have greater dose of IT bupivacaine (12 vs 12.75mg; p = 0.01) and IT morphine (100 vs 200µg; p < 0.001). The clonidine group was also observed to have greater incidence of intraoperative hypotension (20% vs 45%; p = 0.01) and maximum phenylephrine dose (50 vs 57.5 µg/min; p < 0.001). The time to first analgesic request (minutes) after surgery was significantly longer for the clonidine group (153.5 vs 207 min; p < 0.001). The average oral oxycodone equivalents taken per 24 hours of hospital admission were significantly less in the clonidine group (82.36 vs 41.67mg; p < 0.001), and the clonidine group also had significantly less oxycodone equivalents taken for each post-operative day.
Conclusion
IT clonidine was observed to result in reduced 24-hour opioid consumption in patients with OUD and may be useful as part of a multimodal analgesic regimen. The incidence of hypotension and vasopressor doses were greater in patients receiving IT clonidine, and this should be anticipated if IT clonidine is being administered.