title: Randomized trial of a novel double lumen nasopharyngeal catheter versus traditional nasal cannula during total intravenous anesthesia for gastrointestinal procedures.
abstract: OBJECTIVE
  Patients undergoing general anesthesia routinely experience episodes of hypoxemia. There are multiple causes of procedural oxygen desaturation including upper airway obstruction and central hypoventilation. We hypothesize that oxygen supplementation via nasopharyngeal catheter (NPC) will decrease the number of episodes of hypoxemia as compared to traditional NC oxygen supplementation in patients undergoing general anesthesia provided by an anesthesia provider for gastrointestinal endoscopy procedures.
  
  
  METHODS
  Randomized control trial.
  
  
  METHODS
  Endoscopy suite.
  
  
  METHODS
  Sixty patients undergoing intravenous general anesthesia for endoscopic gastrointestinal procedures that did not require endotracheal intubation were enrolled.
  
  
  METHODS
  Patients were randomized to receive supplemental oxygen by either a standard nasal cannula or a nasopharyngeal catheter. Initial oxygen flow rate was 4l/min and titrated at the anesthesia provider's discretion. Intravenous anesthetic consisted of a propofol infusion.
  
  
  METHODS
  Hypoxemia was defined as a pulse oximetry reading of <92%. Secondary outcomes included number of airway assist maneuvers such as jaw lift or other airway interventions.
  
  
  RESULTS
  Of the 60 enrolled patients; three subjects in the NPC group were excluded from further analysis. There was no difference between group in age, ASA classification, Body Mass Index, oropharyngeal classification or total propofol dose. Patients who received nasopharyngeal oxygen supplementation were less likely to experience a clinically significant oxygen desaturation event 3 of 27 (11.0%) versus 12 of 30 subjects (40.0%), p=0.013. Interventions to assists with airway management were required for fewer patients in the NPC group 4 (14.8%) versus the NC group, 17 (56.7%), p=0.001.
  
  
  CONCLUSIONS
  Oxygen supplementation via a nasopharyngeal catheter during intravenous general anesthesia resulted in significantly fewer episodes of hypoxemia and number of airway assist maneuvers. Future studies are needed to assess the utility of NPC in other clinical environments where supplemental oxygen is required in the setting of potential airway obstruction.
authors.affiliation: Department of Anesthesiology and Critical Care, Vanderbilt University Medical Center, 1211 21st Ave South, Suite 526 MAB, Nashville, TN 37232, USA. Electronic address: adam.b.king@vanderbilt.edu.
authors.forename: Adam B
authors.initials: AB
authors.lastname: King
authors.affiliation: Department of Anesthesiology and Critical Care, Vanderbilt University Medical Center, 1211 21st Ave South, Suite 526 MAB, Nashville, TN 37232, USA. Electronic address: bret.d.alvis@vanderbilt.edu.
authors.forename: Bret D
authors.initials: BD
authors.lastname: Alvis
authors.affiliation: Department of Anesthesiology, Division of Multi-Specialty, Vanderbilt University Medical Center, 1301 Medical Center Drive, 4648 TVC, Nashville, TN 37232-5614, USA. Electronic address: douglas.hester@vanderbilt.edu.
authors.forename: Douglas
authors.initials: D
authors.lastname: Hester
authors.affiliation: Department of Anesthesiology, Perioperative Clinical Research Institute, Vanderbilt University Medical Center, 1211 Medical Center Drive, MAB 504, Nashville, TN 37232; USA. Electronic address: susan.taylor@vanderbilt.edu.
authors.forename: Susan
authors.initials: S
authors.lastname: Taylor
authors.affiliation: Department of Anesthesiology, Division of Multi-Specialty, Vanderbilt University Medical Center, 1301 Medical Center Drive, 4648 TVC, Nashville, TN 37232-5614, USA. Electronic address: mike.higgins@vanderbilt.edu.
authors.forename: Michael
authors.initials: M
authors.lastname: Higgins
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General / Q000009:adverse effects*; D000771:Anesthesia, Intravenous / Q000009:adverse effects*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D000072601:Cannula; D057785:Catheters; D016099:Endoscopy, Gastrointestinal / Q000009:adverse effects; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx; D010092:Oximetry; D010100:Oxygen / Q000008:administration & dosage*; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation*; D015742:Propofol / Q000008:administration & dosage; D012131:Respiratory Insufficiency / Q000150:complications* / Q000628:therapy
chemical_list: D018686:Anesthetics, Intravenous; D010100:Oxygen; D015742:Propofol
keywords: Ambulatory anesthesia; Endoscopy; Nasal cannula; Nasopharyngeal catheter