Comparison of Hemodynamic Status with Three Different Doses of Lidocaine as an Adjunct to Propofol-Remifentanil During Endotracheal Intubation in Elderly Female Patients: A Prospective Randomized Study

Lidocaine was reported to stabilize the hemodynamic status and reduce the incidence of postinduction hypotension in elderly patients. However, the optimal dose of lidocaine as an adjuvant to propofol-remifentanil during endotracheal intubation in elderly female patients remains uncertain. In this study, we aimed to determine the optimal dose of lidocaine as an adjuvant for propofol-remifentanil in elderly female patients. Two hundred and forty patients were randomly assigned to one of three groups in a ratio of 1:1:1, each receiving a different dosage of lidocaine: 0.5 mg/kg, 1.0 mg/kg, or 1.5 mg/kg, with propofol-remifentanil for endotracheal intubation. Patients' hemodynamic parameters were continuously monitored 10 minutes after the induction of anesthesia. Hypotension, defined as a mean arterial pressure <70% of the baseline value and/or <65 mm Hg, and treated with norepinephrine 4 μg, repeated as necessary. Norepinephrine consumption (primary outcome), mean arterial pressure, heart rate, and propofol consumption were recorded. The incidence of hypotension was 51.4% (37/72), 13.0% (9/69), and 13.8% (9/65) in Groups 0.5, 1.0, and 1.5, respectively. The median (25th and 75th quartiles) consumption of norepinephrine was 4 (0-4) μg, 0 (0-0) μg, and 0 (0-0) μg across the groups, respectively; there was a significant difference among the groups (p = 0.0006). The incidence of hypertension was 15.7% (11/72), 5.8% (4/69), and 6.2% (4/65) across the groups, respectively. In summary, under the conditions of this study, we propose that 1.0 mg/kg lidocaine may be considered as an optimal dose when used as an adjuvant to propofol-remifentanil for endotracheal intubation. Chinese Clinical Trial Registry number: ChiCTR2400092990 https://www.chictr.org.cn/bin/project/edit?pid=231367.