COMPARISON OF FACE MASK TO NASAL MASK VENTILATION IN OBESE SUBJECTS UNDERGOING GENERAL ANESTHESIA

Abstract

Background: During the induction of general anesthesia, the use of a face mask is usually

ineffective in providing adequate ventilation in obese subjects. However, ventilation via nasal mask is shown to be effective in providing CPAP (continuous positive airway pressure) in obese subjects having OSA (Obstructive sleep apnea). Existing literature data is scarce concerning this comparison.

Aim: The present study aimed to comparatively assess the efficacy of face mask to nasal mask ventilation in obese subjects undergoing general anesthesia and having BMI (body mass index) >25 kg/m2.

Methods: The study assessed 180 subjects having BMI >25 kg/m2 that were randomly divided into two groups of 90 subjects each where Group I subjects received ventilation via face mask and Group II subjects via nasal mask during general anesthesia induction. In both the groups, EtCO2 (end-tidal carbon dioxide), SpO2 (oxygen saturation), PPLAT (plateau pressure), PIP (peak inspiratory pressure), and VtE (expired tidal volume) were assessed for 10 breaths and the mean values were recorded and compared.

Results: The study results showed that mean values of expired tidal volume were 455.96±55.62 and 436.88±49.48 mL for nasal mask and face mask ventilation groups depicting a non-significant difference with p=0.07. Mean PPLAT, mean PIP, and mean air-leak were significantly lower in the nasal mask ventilation group compared to the face mask ventilation with respective p-values of

• , 0.001, and 0.001. Hemodynamic measurements, SpO2, and EtCO2 levels were comparable between the two

Conclusions: The present study concludes that nasal mask ventilation has higher efficacy compared to face mask ventilation and can be used as an alternative to face mask ventilation in obese subjects with BMI >25 kg/m2 under general anesthesia.