Clinical Trial: Safety Study of Positive Airway Pressure Via a Nasal Mask in Obese Patients

Study Status: Withdrawn
Recruit Status: Withdrawn
Study Type: Interventional

Official Title: Safety Study of Positive Airway Pressure Via a Nasal Mask on Upper Airway Patency During Induction of Anesthesia in Obese Patients

Brief Summary:

Upper airway obstruction (UAO) is a frequently occurring complication during induction of general anesthesia. The American Society of Anesthesiologist (ASA) closed claim analysis of anesthesia complications indicate that a difficult airway is one of the most challenging scenarios continuously facing anesthesia providers.

The mechanism of UAO during anesthesia has not been well understood. Posterior displacement of soft palate, tongue and epiglottis are believed to be the primary contributing factors. Obesity is well known to be an essential characteristic which reflects propensity to UAO. 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.


Detailed Summary:

Upper airway obstruction (UAO) is an unpredictable and frequently occurring complication during induction of general anesthesia. Since obese patients ( BMI>30 km/ m2) are more vulnerable to develop airway obstruction either during sleep 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". Unfortunately, even with modern technologic advances, 16% of death and permanent brain damage related to anesthesia have been attributed to failure of difficult airway management 3. The American Society of Anesthesiologist (ASA) closed claim analysis of anesthesia complications indicate that a difficult airway is one of the most challenging scenarios continuously facing anesthesia providers. Indeed, it can be a fatal complication of general anesthesia. Therefore, measures used to reduce the incidence of difficult airways during anesthesia remain to be improved.

The mechanism of UAO during anesthesia has not been well understood. Posterior displacement of soft palate, tongue and epiglottis are believed to be the primary contributing factors. Obesity is well known to be an essential characteristic which reflects propensity to UAO. Accordingly, 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. More and more evidence indicates that 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 w
Sponsor: Massachusetts General Hospital

Current Primary Outcome: Expired tidal volume [ Time Frame: About two minute during induction of general anesthesia ]

Original Primary Outcome: Same as current

Current Secondary Outcome: Volume of CO2 [ Time Frame: About two minute during induction of general anesthesia ]

Original Secondary Outcome: Same as current

Information By: Massachusetts General Hospital

Dates:
Date Received: June 22, 2012
Date Started: June 2012
Date Completion: June 2013
Last Updated: January 15, 2017
Last Verified: January 2017