You are providing deep sedation with propofol for outpatient colonoscopy procedures. Your next patient is morbidly obese, and a colleague suggests using high-flow nasal cannula (HFNC) oxygen at 60 L/min. According to a recent prospective study, which of the following is most likely if you follow this suggestion instead of using standard low-flow nasal cannula oxygen at 4 L/min?
HFNC oxygen systems deliver humidified oxygen mixtures at a flow rate up to approximately 70 L/min. Because these high flows exceed the inspiratory flow rate, continuous positive pressure is generated in the airways. Although the pressure varies, continuous positive airway pressures as high as 5 to 7 cm H2O may be achieved depending on the degree of mouth opening and amount of leak around the cannula. Reported benefits of HFNC oxygen include reduced likelihood of upper airway collapse, reduced work of breathing, decreased anatomic dead space, improved mucociliary clearance...
