Fei Xiao,1,2 Lu-Qi Xu,2 Hai-Ya Yan,1 Si Zhou,2 Jia-Ming Fan,2 Lin Liu2 

1Department of Anesthesiology, The Affiliated Women and Children’s Hospital of Ningbo University, Ningbo, People’s Republic of China; 2Department of Anesthesiology, Jiaxing Women and Children’s Hospital, Wenzhou Medical University, Jiaxing, People’s Republic of China

Correspondence: Lin Liu, Department of Anesthesiology, Jiaxing Women and Children’s Hospital, Wenzhou Medical University, 2468#, East Zhonghuang Road, Jiaxing, People’s Republic of China, Tel +86 573 83963131, Email 13967358623@163.com Jia-Ming Fan, Department of Anesthesiology, Jiaxing University Affiliated Women and Children Hospital, 2468#, East Zhonghuang Road, Jiaxing, People’s Republic of China, Tel +86 573 83963131, Email 254602480@qq.com

Background: 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.
Methods: 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.
Results: 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.
Conclusion: 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.
Clinical Trial Registration: Chinese Clinical Trial Registry number: ChiCTR2400092990 https://www.chictr.org.cn/bin/project/edit?pid=231367.

Keywords: lidocaine, propofol, hypotension, elderly, anesthesia