S-ketamine used during anesthesia induction increases the perfusion index and mean arterial pressure after induction: A randomized, double-blind, placebo-controlled trial

BACKGROUND: Abnormal peripheral perfusion and postinduction hypotension are associated with postoperative adverse outcomes. S-ketamine may stimulate blood circulation by activating the sympathetic nervous system. This study aimed to identify whether S-ketamine may improve the hemodynamic profile, relative to saline. METHODS: 115 patients were assessed for eligibility for participation in this study. A total of 100 patients were included. The patients (n = 50 for each group) were randomly allocated to the Test group, treated with S-ketamine plus propofol, cisatracurium and sufentanil, and to the Control group, treated with saline plus propofol, cisatracurium, and sufentanil. Maintenance of anesthesia in both groups was accomplished with sevoflurane. The perfusion index (PI) was recorded at intervals of 1 min, and mean arterial pressure (MAP) and heart rate (HR) were collected continuously at intervals of 3 min. The number of patients with MAP < 60 mmHg was also analyzed. RESULTS: The PI remained higher in the Test group than in the Control group at the following time points: initial induction (mean difference: 1.01 [95% CI: 0.27-1.74]; P = 0.007), preintubation (mean difference: 1.46 [95% CI: 0.57-2.34]; P = 0.001) and postintubation (mean difference: 1.28 [95% CI: 0.26-2.30]; P = 0.014), before (mean difference: 2.66 [95% CI: 1.22-4.1]; P < 0.001) and after making the skin incision (mean difference: 1.03 [95% CI: 0.28-1.78]; P = 0.007). Compared with Control group, a higher MAP trend from preintubation to postincision appeared in patients assigned to S-ketamine (P = 0.003). The number of patients with MAP < 60 mmHg in the Test group was lower than Control group (10.0% vs. 34.0%, P < 0.003) in the preincision. The HR was similar throughout the test, with no statistical difference. CONCLUSIONS: During anesthesia induction and maintenance, the use of S-ketamine may improve the peripheral perfusion and blood pressure as compared to the Control group. CLINICAL TRIAL NUMBER: ChiCTR2100051167.