Nasal Continuous Positive Airway Pressure Versus Standard Care During Procedural Sedation for Gastrointestinal Endoscopy

Nasal Continuous Positive Airway Pressure Versus Standard Care During Procedural Sedation for Gastrointestinal Endoscopy

A Randomized Controlled Trial of an Intervention to Reduce the Incidence of Hypoxia With Nasal Continuous Positive Airway Pressure Versus Standard Care During Procedural Sedation for Gastrointestinal Endoscopy

This study is a randomized controlled trial comparing oxygen delivery by nasal mask with continuous positive airway pressure versus standard care (nasal cannula or standard facemask) during propofol-based sedation for gastrointestinal endoscopy procedures to reduce the incidence of hypoxia. The primary outcome will be the rate of oxygen desaturation below 90% for ≥15 seconds.

This study is a randomized controlled trial comparing oxygen delivery by nasal mask with continuous positive airway pressure versus standard care (nasal cannula or standard facemask) during propofol-based sedation for gastrointestinal endoscopy procedures to reduce the incidence of hypoxia. The primary outcome will be the rate of oxygen desaturation below 90% for ≥15 seconds. In addition, secondary measures will include evaluation of mechanism and degree of respiratory depression associated with hypoxia and hypoventilation by characterizing changes in minute ventilation, tidal volume, and respiratory rate as well as the rate and degree of airway obstruction. The investigators hypothesize that the addition of nasal continuous positive airway pressure in the intervention arm will lead to decreased obstruction as positive pressure will stent open the obstructed airway. Depth of anesthesia will be monitored by Bispectral Index and investigators hypothesize that the degree of hypoventilation, obstruction, and will be significantly lower in the intervention arm compared to the control arm. Further, the depth of anesthesia will be independent of total propofol dose received. While the primary outcome in this study is hypoxia, investigators also seek to marry end tidal carbon dioxide with minute ventilation and transcutaneous carbon dioxide measurement to better understand the total effects of sedation on respiration. Thus the study will also serve to evaluate which mode(s) of respiratory monitoring might be the best possible intervention to enhance safety during procedural sedation in the future. Further, investigators suspect that the amplitude of end tidal carbon dioxide will not predict the degree of respiratory depression seen with other monitors. In addition, investigators will measure serum short chain fatty acid concentrations as a predictor and possible mechanism for differences in individual variability in anesthesia induced respiratory depression.

Nasal anesthesia mask which covers the nose and attaches to the anesthesia circuit, allowing for variable positive pressure by setting the pop-off valve

Number of subjects undergoing procedural sedation for endoscopy with at least one hypoxic event, defined as oxygen saturation less than 90 percent for 15 seconds.

Hypoventilation in Subjects Undergoing Procedural Sedation for Endoscopy as Assessed by Transcutaneous Carbon Dioxide Monitoring

Evaluate hypoventilation in subjects undergoing procedural sedation for endoscopy by transcutaneous carbon dioxide monitoring in millimeters of mercury (mmHg).

Hypoventilation in Subjects Undergoing Procedural Sedation for Endoscopy as Assessed by Respiratory Volume Monitoring

Evaluate hypoventilation by respiratory volume monitoring for minute ventilation. Reported result is the percentage decrease from baseline in minute ventilation.

Mechanism of Hypoventilation in Subjects Undergoing Procedural Sedation for Endoscopy and Hypoventilation

Correlate respiratory volume monitoring transcutaneous carbon dioxide measurement with number of airway maneuvers to identify mechanism of hypoventilation as predominately obstructive or due to respiratory rate or tidal volume.

Depth of anesthesia by processed electroencephalogram (EEG) bispectral analysis, which is a standard monitor of anesthetic depth using a calibrated dimensionless index that ranges from 0 to 100, with lower numbers corresponding to a deeper anesthetic state.

In subjects experiencing hypoxia during sedation, the total number of episodes of hypoxia for all participants will be recorded.

Measure baseline short chain fatty acids in subjects undergoing procedural sedation for endoscopy and correlate the concentration with the degree of respiratory depression by respiratory volume monitoring and transcutaneous carbon dioxide.

Inclusion Criteria: Adult patients (≥ 18 years of age) undergoing colonoscopy, endoscopic gastroduodenoscopy, and endoscopic gastroduodenoscopy with biopsy and/or ultrasound, or combined upper and lower endoscopy procedure anticipated to last longer than 10 minutes in the Endoscopy Suite at the Johns Hopkins Hospital when the anesthetic plan is monitored anesthesia care with propofol-based anesthesia with a natural airway. Exclusion Criteria: Left ventricular Assist Device Severe Pulmonary Hypertension Ejection fraction less than 35 percent Active Congestive Heart Failure Exacerbation Planned procedure is Balloon Enteroscopy or Endoscopic Retrograde Duodenoscopy. Topical lidocaine administration Pregnancy Previous enrollment in this study