Evaluation of the reliability of the upper lip bite test and the modified mallampati test in predicting difficult intubation under direct laryngoscopy in apparently normal patients: a prospective observational clinical study

Observation of the validity of the upper lip bite test in predicting difficult intubation

The upper lip bite test (ULBT) is considered an effective method for predicting difficult airways, but data on the ULBT for predicting difficult tracheal intubation are lacking. This study aimed to examine the clinical utility of the ULBT in predicting difficult endotracheal intubation. We conducted an observational case-cohort study of adult patients undergoing elective surgery and requiring endotracheal intubation for general anesthesia. Difficult airway assessment was performed on the recruited patients before the operation, including the ULBT, mouth opening, thyromental distance, modified Mallampati test, and body mass index. The primary outcome was the incidence of difficult tracheal intubation. The receiver operating characteristic curve analysis was used to compare the performance of variables in predicting difficult tracheal intubation. We successfully recruited 2522 patients for analysis and observed 64 patients with difficult tracheal intubation. When predicting difficult tracheal intubation, grade 2 ULBT had a sensitivity of 0.75 and a specificity of 0.54, and grade 3 had a sensitivity of 0.28 and a specificity of 0.75. Compared with mouth opening, the area under the receiver operating characteristic curve of the ULBT was lower in predicting difficult tracheal intubation (0.69 [95% confidence interval: 0.67-0.71] vs. 0.84 [95% confidence interval: 0.82-0.87], P < 0.05).Clinical Trials Registry: ChiCTR-ROC-16009050, principal investigator: Weidong Yao.

Safety and effectiveness of endotracheal intubation in critically ill emergency patients with videolaryngoscopy

To investigate the safety and efficacy of video laryngoscopy for endotracheal intubation in critically ill patients. A total of 106 critically ill emergency patients treated at our hospital between January 2021 and June 2022 were randomly divided into 2 groups, the visual and direct groups, with 53 patients in each group. Both groups were treated with endotracheal intubation; the visual group was treated with video laryngoscopy, and the direct group was treated with conventional direct laryngoscopy. The Cormack-Lehane grade, percentage of glottic opening score, success rate of one intubation, intubation time, number of intubation attempts, hemodynamic values, and complications were compared between the 2 groups. The success rates of glottis exposure and one-time intubation were significantly higher while the intubation time and number of intubation attempts significantly lower in the visual group than in the direct group. The heart rate, mean arterial pressure (MAP), or blood oxygen saturation did not differ significantly between the 2 groups 10 minutes after entering the room (T0) or after anesthesia induction (T1). MAP was significantly lower in the visual group than in the direct group during immediate intubation (T2). The heart rate and MAP were significantly lower in the visual group than in the direct group 1 minute (T3) and 5 minutes (T4) after intubation. The incidences of intubation-related complications in the visual and direct groups were 7.55% and 22.60%, showing a significant difference. Endotracheal intubation under videolaryngoscopy is safer and more effective for critically ill emergency patients than conventional direct laryngoscopy. This can improve the success rate of intubation, reduce the intubation time, and reduce its effect on hemodynamics. Therefore, it is worthy of further clinical application.

Preoperative lignocaine nebulisation for attenuation of the pressor response of laryngoscopy and tracheal intubation in patients with severe preeclampsia undergoing caesarean section delivery: A randomised double-blind controlled trial

Background and Aims

Following induction of general anaesthesia, direct laryngoscopy and endotracheal intubation usually cause tachycardia and hypertension due to increased sympathetic activity. This response is generally exaggerated in hypertensive patients. This study aimed to evaluate the effectiveness of preoperative lignocaine nebulisation in attenuating the pressor response to laryngoscopy and endotracheal intubation in patients with severe preeclampsia undergoing caesarean delivery.

Methods

After ethical approval, we conducted this randomised, double-blind study, which included 110 patients with severe preeclampsia who underwent caesarean delivery under general anaesthesia. These patients were randomly allocated into two groups to receive either preoperative nebulisation of lignocaine 2% in a dose of 4.5 mg/kg (not exceeding 400 mg) in the lignocaine group or nebulisation of an equivalent volume of 0.9% NaCl in the saline group. The primary objective was the systolic blood pressure after tracheal intubation. The secondary objectives included heart rate, maternal serum cortisol and blood glucose levels, grade of cough during emergence, postoperative sore throat and hoarseness of voice, neonatal Apgar score and umbilical blood gas.

Results

The systolic blood pressure was significantly lower in the lignocaine group compared to the saline group at 1, 3 and 5 min after endotracheal intubation and after delivery of the foetus (P = 0.001, 0.003, 0.002 and 0.019, respectively). Similarly, the heart rate was significantly lower in the lignocaine group versus saline group at 1 and 3 min after endotracheal intubation (P = 0.041 and 0.042, respectively).

Conclusion

Preoperative lignocaine nebulisation in a dose of 4.5 mg/kg effectively attenuated the pressor response to laryngoscopy and endotracheal intubation in patients with severe preeclampsia undergoing caesarean delivery.