RESUMO
Background: The difficult airway (DA) assessment and management of pregnant woman has always brought specific challenges. The aim of this study was to investigate the effect of labor on the airway by assessing changes in the upper lip bite test (ULBT) classes and to explore its correlation with the first trimester's body mass index (BMI). Methods: According to the BMI of the first trimester, 354 full-term women were divided into low BMI group, normal BMI group and high BMI group. The ULBT class and pregnancy outcome were recorded and compared at early labor, after delivery, and 48 h after delivery. Results: The ULBT class was increased in 75(21.1%) patients after delivery. Compared to the normal BMI group, the high BMI group had a higher probability of increasing (34.8 vs. 17.5%; P = 0.002). The number of women with ULBT class 2-3 increased to 157, which was 1.48 times that of early labor. The number of women with ULBT class 3 increased from 4 to 16, of which 7 (53.8%) were from the high BMI group. Binary logistic regression analysis showed that first trimester's BMI was associated with a significant increase in ULBT class after delivery (adjusted odds ratio [aOR] = 2.13 [0.91-4.98], P = 0.02). The ULBT classes of the three groups tended to return to their initial level 48 h after delivery (P > 0.05). Conclusion: Labor results in an approximately one-fifth increase in ULBT class. Being overweight or obese in the first trimester is associated with an increased risk of DA during labor. Trial registration: This study was registered in the Chinese Clinical Trial Registry (http://www.chictr.org.cn) on September 26, 2020. Registration number ChiCTR2000038643.
RESUMO
BACKGROUND: THE AIM OF THE PRESENT STUDY WAS TO COMPARE THE ABILITY TO PREDICT DIFFICULT VISUALIZATION OF THE LARYNX FROM THE FOLLOWING PREOPERATIVE AIRWAY PREDICTIVE INDICES, IN ISOLATION AND COMBINATION: modified Mallampati test (MMT), the ratio of height to thyromental distance (RHTMD) and the Upper-Lip-Bite test (ULBT). METHODS: We collected data on 603 consecutive patients scheduled for elective surgery under general anesthesia requiring endotracheal intubation and then evaluated all three factors before surgery. An experienced anesthesiologist, not informed of the recorded preoperative airway evaluation, performed the laryngoscopy and grading (as per Cormack and Lehane's classification). Sensitivity, specificity, and positive and negative predictive value, Receiver operating characteristic (ROC) Curve and the area under ROC curve (AUC) for each airway predictor in isolation and in combination were determined. RESULTS: Difficult laryngoscopy (Grade 3 or 4) occurred in 41 (6.8%) patients. The main endpoint of the present study, the AUC of the ROC, was significantly lower for the MMT (AUC, 0.511; 95% CI, 0.470-0.552) than the ULBT (AUC, 0.709; 95% CI, 0.671-0.745, P=0.002) and the RHTMD score (AUC, 0.711; 95% CI, 0.673-0.747, P=0.001). There was no significant difference between the AUC of the ROC for the ULBT and the RHTMD score. By using discrimination analysis, the optimal cutoff point for the RHTMD for predicting difficult laryngoscopy was 21.06 (sensitivity, 75.6%; specificity, 58.5%). CONCLUSION: The RHTMD is comparable with ULBT for prediction of difficult laryngoscopy in general population.