Etomidate versus Propofol as Induction Agents in Patients Undergoing Decompressive Procedures for Cervical Compressive Myelopathy with and without Impaired Heart Rate Variability

Background Patients with cervical compressive myelopathy (CCM) are known to have autonomic dysfunction, which can impact surgical outcomes. In such patients, screening patients for heart rate variability (HRV) may enable the anesthesiologist to predict hypotension, thereby attempting to modify the anesthetic technique. This study aimed to compare the hemodynamic changes in CCM patients between propofol and etomidate induction. Methods Sixty CCM patients aged 18 to 70 years underwent an autonomic function test using HRV before decompressive surgery. The selected patients were randomized into two groups of 30 patients each to receive either etomidate or propofol for induction of anesthesia. The groups were compared for hemodynamic changes, the incidence of pain on injection, and the occurrence of myoclonus. While analyzing the hemodynamic changes, the two groups were subdivided into four groups, namely, propofol group with or without autonomic dysfunction (AD) and etomidate group with or without AD. Results In the abnormal HRV group, patients induced with propofol showed a significantly higher incidence of hypotension at 3-minute ( p = 0.02) and 5-minute ( p = 0.04) time points. On the other hand, in HRV normal patients, induction with propofol showed a significantly higher ( p = 0.03) incidence of hypotension at 5 minutes. During induction, higher grades of pain ( p = 0.01) were observed in the propofol group, whereas the occurrence of myoclonus was more in the etomidate group ( p = 0.07). Conclusion As compared with propofol, the use of etomidate in patients with CCM undergoing decompressive procedures reduces hypotensive episodes, more so in patients with impaired HRV. Thus, HRV-based AD categorization may assist in optimal management of postinduction hypotension in patients with CCM.