Randomized trial of a novel double lumen nasopharyngeal catheter versus traditional nasal cannula during total intravenous anesthesia for gastrointestinal procedures.

Study 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.

Design: Randomized control trial.

Setting: Endoscopy suite.

Patients: Sixty patients undergoing intravenous general anesthesia for endoscopic gastrointestinal procedures that did not require endotracheal intubation were enrolled.

Interventions: 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.

Measurements: 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.

Main 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.

Conclusion: 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.