Modified Mallampati Class Rating Before and After Cesarean Delivery: A Prospective Observational Study

Abstract

Background: The modified Mallampati classification (MMC) provides an estimate of the tongue size relative to the oral cavity size, and is a usual screening tool for predicting difficult laryngoscopy. Previous studies have indicated an increase of MMC during the progression of pregnancy, but there is no comprehensive study in pregnant women undergoing cesarean delivery. The primary aim of this study was to evaluate the MMC before and after cesarean delivery.

Methods: This is a prospective observational study of 104 women who underwent cesarean section. MMC, thyromental distance, neck circumference, and upper lip bite test were evaluated at 4 different time points: during the pre-anesthetic visit (T0) and at 1 (T1), 6 (T2), and 24 (T3) hours after delivery. Factors evaluated for their predictive validity included gestational weight gain, operation time, amount of intravascular fluids, oxytocin dosage, and blood loss. The correlation between each factor and the MMC classification was tested by logistic regression.

Results: From 104 participants, 59.6% experienced Mallampati class changes. The proportions of patients classified as Mallampati III and IV at different time points were: T0 = 48.1% (MMC III only), T1 = 75.0%, T2 = 80.8%, and T3 = 84.6%, respectively. Gestational weight gain, duration of surgery, anesthetic method, blood loss, oxytocin dosage, or amount of intravenous fl uid were not correlated with the MMC change.

Conclusion: The number of patients with initial Mallampati III was high. In addition, a significant increase in MMC occurred after cesarean delivery. The data confirm the particular risk status of women undergoing cesarean delivery particularly regarding airway anatomy.