Optimization of Endotracheal Tube Cuff Filling by Continuous Upper Airway Carbon Dioxide Monitoring

Inappropriate cuff filling is responsible for various complications related to the use of an endotracheal tube (ETT). In this study, we evaluated an objective, nonin-vasive method for continuous assessment of leak around the ETT cuff by monitoring carbon dioxide pressure (Pco2) in the upper airway. Pco2 levels were measured by capnography simultaneously between theETT cuff and the vocal cords, at the oropharynx, and in the nares of the nose. Cuff fillingwas regulated by an electronic controller to achieve the minimal pressure needed to prevent CO2 leak. Feasibility of the method was assessed in a human simulator and in a porcine model. Clinical function was evaluated in 60 patients undergoing surgery, comparing themethod to the stan-dard anesthesiologist evaluation. Linear correlation