Spinal Nerve Block and Recovery after Spinal Anesthesia in Frail Patients - a Prospective Cohort Study

Background: Frailty in surgical patients is associated with significantly higher incidences of perioperative mortality and complications. Although neuraxial anesthesia is preferable alternative to general anesthesia in frail patients, it remains undetermined whether the pharmacodynamic profiles of local anesthetics used in intrathecal spinal nerve blocks are altered in this population. Methods: This prospective observational cohort study recruited 62 patients scheduled for operations that were able to be performed under spinal anesthesia between April 22 to June 30, 2020 in our hospitals. Levels of dermatome blockage after spinal anesthesia and the recovery of spinal nerve sensory and motor function were recorded. Results: The prevalence of frailty in patients receiving spinal anesthesia in this study was 25.8%. Compared with non-frail patients, frail patients were significantly older, had a higher proportion of females, and tolerated less intense metabolic equivalent activities. The pre-surgical incision sensory blockage levels were not different between frail and non-frail patients following intrathecal administration of similar dose of bupivacaine. Time intervals to pain sensation at surgical sites (sensory recovery) and voluntary knee flexion (motor recovery) were also similar between the frail and non-frail groups. But, frail patients were associated with more episodes of hypotension and required more vasopressors during operations. Conclusion: Our study illustrates that bupivacaine sensitivity in spinal nerve blocks is not significantly affected by frailty. However, special attention should be paid to correct intraoperative hypotension after spinal anesthesia in frail patients.