This study sought to answer the question of how much oxyen your patients are inspiring with different devices, with and without tachypea. They simulated tachypnea in healthy volunteers (by chest binding) and measured the Fi02 in the hypopharynx before and after tachypnea (RR>25). They found the Fi02 decreased by 12-24% in rebreathing masks after tachypnea, but did not change in non-rebreathing masks after tachypnea. However, they did find the hypopharynx Fi02 was only 68% in non-rebreathing masks (indicating the term “100% non-rebreather” is a misnomer). It is very important to know the amount of Fi02 your patients are actually inspiring, and to note that it significantly decreases with tachypnea in rebreather devices (abstract).
Dr. Scheurer is a clinical hospitalist and the Medical Director of Quality and Safety at the Medical University of South Carolina in Charleston, South Carolina, and is Assistant Professor of Medicine. She is a graduate of the University of Tennessee College of Medicine, completed her residency at Duke University, and completed her Masters in Clinical Research at the Medical University of South Carolina. She also serves as the Web Editor and Physician Advisor for the Society of Hospital Medicine.