The median effective dose (ED50) of cis-Atracurium for laryngeal mask airway insertion during general Anaesthesia for patients undergoing urinary surgery

The effects of laryngeal mask airway versus endotracheal tube on atelectasis in patients undergoing general anesthesia assessed by lung ultrasound: A protocol for a prospective, randomized controlled trial

Background

The incidence of atelectasis is high in patients undergoing general anesthesia. This may cause oxygenation impairment and further contribute to postoperative pulmonary complications (PPCs). As important airway management devices for general anesthesia, few studies have compared the effects of laryngeal mask airway (LMA) and endotracheal tube (ETT) on atelectasis. Additionally, lung ultrasound has been increasingly used for bedside atelectasis diagnosis. For the above considerations, this trial is designed to compare the effects of LMA and ETT on atelectasis assessed by lung ultrasound scores, further providing more powerful clinical evidence for perioperative respiratory management of non-laparoscopic elective lower abdominal surgery under general anesthesia.

Methods

This is a prospective, single-center, single-blind, randomized controlled trial. From July 2021 to July 2022, 180 patients undergoing elective non-laparoscopic lower abdominal surgery under general anesthesia will be recruited and randomly divided into the ETT and LMA groups at a ratio of 1:1. The primary outcome is the total atelectasis LUS of 12 lung regions 15 min after the establishment of the artificial airway. The total atelectasis LUS at the end of surgery and 30 min after extubation, oxygenation index, postoperative airway complications, PPCs, and length of stay will be analyzed as secondary indicators.

Trial registration

ClinicalTrials.gov identifier: ChiCTR1900020818. Registered on January 20, 2019. Registered with the name of “Laryngeal mask airway versus endotracheal tube for atelectasis.” URL: https://www.chictr.org.cn/showproj.aspx?proj=35143.

Determination of the median effective dose of sufentanil for inhibiting the laryngeal mask insertion response in geriatric patients: a prospective, double-blinded, dose-response trial

Background

Laryngeal mask airway(LMA) have been widely used in clinical practice. Irritation to the patient during the insertion of a laryngeal mask can cause hemodynamic fluctuations, which is particularly unsafe for geriatric patients. We used probit regression analysis to determine the median effective dose of sufentanil to inhibit the response to LMA insertion in geriatric patients.

Methods

A total of 90 patients were selected for the study using the following inclusion criteria: age ≥ 65 years old, ASA grade I–III, and scheduled to undergo intravenous general anesthesia with LMA insertion. Each patient received a dose of sufentanil for anesthesia induction in one of six levels: 0.05, 0.1, 0.15, 0.2, 0.25, or 0.3 μg kg⁻¹. LMA insertion was scored with a 3-point, 6-category scale, with scores ≥ 16 indicating effective LMA insertion, and < 16 indicating ineffective LMA insertion. Mean arterial blood pressure (MAP), heart rate (HR), and bispectral index (BIS) were recorded 1 min before induction (T1), 1 min after induction (T2), 1 min after LMA insertion (T3), and 5 min after LMA insertion (T4) in each group. In addition, the plasma norepinephrine (NE) levels and adverse reactions were measured at T2 and T3 in each dosage group.

Results

Probit regression analysis showed that the ED50 of sufentanil inhibiting the response to LMA insertion in geriatric patients was 0.18 μg kg⁻¹ (95% CI: 0.16–0.21 μg kg⁻¹), and the ED95 was 0.31 μg kg⁻¹ (95% CI: 0.27–0.38 μg kg⁻¹), and the probit(p) = -2.34 + 12.90 × ln(Dose)(\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\chi^{2}$$\end{document}χ2 = 0.725, p = 0.948). Among all the patients, the number of effective LMA insertions was 57 (group A), and the number of ineffective LMA insertions was 33 (group B). The MAP, HR, and NE in group B were significantly higher than in group A at T3.

Conclusions

Sufentanil can effectively inhibit the patient’s response to LMA insertion, with stable hemodynamics and small stress response. The ED50 and ED95 were 0.18 μg kg⁻¹ (95% CI: 0.16–0.21 μg kg⁻¹) and 0.31 μg kg⁻¹(95% CI: 0.27–0.38 μg kg⁻¹), respectively.

Trial registration

This study was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2100051827) on October 6, 2021.