Maternal hypotension and efficacy of intrathecal clonidine for cesarean delivery: a retrospective cohort study (2011-2022)

BACKGROUND: Off-label intrathecal adjuvants such as α 2-agonists and lipophilic opioids are often used to intensify and prolong neuraxial anesthesia during cesarean delivery. We aimed to assess its side effects, efficacy, and safety in cesarean delivery.

METHODS: This single-center retrospective cohort study was conducted at a university hospital in the Netherlands. Data from cesarean deliveries with spinal anesthesia, performed between July 1, 2011, and January 1, 2023, were extracted from electronic records. Cases were categorized according to spinal solution: hyperbaric bupivacaine without adjuvants, hyperbaric bupivacaine with lipophilic opioids, and hyperbaric bupivacaine with clonidine. The two primary outcomes were intraoperative and postoperative hypotension. Logistic regression and sensitivity analyses were performed to assess robustness. Secondary outcomes included conversion to general anesthesia, intravenous supplementation, neonatal Apgar scores, and maternal neurology consultation.

RESULTS: There were 6,103 cesarean deliveries included in the analysis: 57.3% with bupivacaine only, 11.2% with bupivacaine and opioids, and 31.4% with bupivacaine with clonidine. Intraoperative hypotension was significantly more frequent with bupivacaine and clonidine compared with bupivacaine only (aOR 1.34 95% CI 1.15-1.57) and bupivacaine with opioids (aOR 0.93, 95% CI 0.74-1.18). Hypotension in the recovery room was most frequent with bupivacaine with clonidine (aOR 3.44 95% CI 2.89-4.10). Intravenous supplementation and conversion to general anesthesia were less frequent with addition of opioids or clonidine. There were no relevant differences in other secondary outcomes.

CONCLUSION: Intrathecal clonidine increases the risk of intraoperative and postoperative hypotension despite the use of prophylactic vasopressors. It improves neuraxial block efficacy when added to hyperbaric bupivacaine alone, as reflected by lower rates of intravenous supplementation and conversion to general anesthesia, similar to lipophilic opioids. Its use should be limited to selected cases at risk of severe pain and where postoperative hypotension can be monitored and treated appropriately.