Upper airway obstruction (UAO) is an unpredictable and frequently occurring complication during induction of general anesthesia. Since obese patients are more vulnerable to develop airway obstruction either during sleep1 or under anesthesia, and the segment of obese individuals in the entire population keep growing, difficult airway management under anesthesia becomes even more challenging than ever. The most serious event related to difficult airway management under anesthesia is cannot intubate, cannot ventilate.~The mechanism of UAO during anesthesia has not been well understood. Obese patients are a high-risk group for perioperative airway catastrophe and prone to develop progressively narrower pharyngeal airways due to an increase of soft tissue volume surrounding the pharyngeal airway. The mechanism of UAO during anesthesia shares many similarities with the upper airway obstruction observed during obstructive sleep apnea (OSA). Nasal continuous positive airway pressure (nCPAP) via nasal mask (NM) can maintain the airway patent with near 100% success in patients with OSA. Obesity is a major risk factors for obstructive sleep apnea and obese patients have a higher prevalence of UAO during anesthesia. Therefore, the investigators hypotheses that nCPAP should eliminate airway obstruction in obese patients under anesthesia. The investigators propose to test this hypothesis and determine the efficacy of nCPAP on maintaining airway patency in obese patients who require general anesthesia.
The mechanism of Upper airway obstruction (UAO) during anesthesia shares many similarities with the upper airway obstruction observed during obstructive sleep apnea (OSA). Nasal continuous positive airway pressure (nCPAP) via nasal mask (NM) can maintain the airway patent with near 100% success in patients with OSA. Obesity is a major risk factors for obstructive sleep apnea and obese patients have a higher prevalence of UAO during anesthesia. The investigators hypotheses that nCPAP should eliminate airway obstruction in obese patients under anesthesia. The investigators propose to test this hypothesis and determine the efficacy of nCPAP on maintaining airway patency in obese patients who require general anesthesia compared with CPAP administering face mask.