Methods
This is a prospective interventional study with each subject serving as their own mask-free control. Subjects were sequentially assigned to the experimental arm of the study after donning a disposable surgical mask. The protocol was approved by the Missouri State University Institutional Review Board (approval number FY2022-36) and was listed on the The study took place at the Missouri State University School of Anesthesia Simulation Operating Room. Three separate anesthesia machine monitors allowed for evaluation of up to three subjects simultaneously, allowing children and parents to participate seated in the same room. An anesthesia machine D-fend module measured end tidal carbon dioxide (ETCO2), inspired carbon dioxide (ICO2), and respiratory rate (RR) by way of nasal canulae. Oxygen saturation (SpO2) and heart rate (HR) were followed by pulse oximetry. These five physiologic variables were recorded each minute over a 5-min control period while subjects were unmasked. The subjects were then assisted in donning a DemeTECH ASTM Level 3 Surgical Disposable Mask. Appropriate fit was confirmed, using masks of either regular or small size. These three-layer masks provide >98% filtration efficiency and >98% sub-micron particulate filtration efficiency at 0.1 micron. The masks fully covered the mouth and nose, with the nose wire formed around the nose and cheek to close any gap. Each subject used a new nasal canula and a new surgical mask for the study. The five physiologic variables (ETCO2, ICO2, RR, SpO2, HR) were then measured on masked participants each minute for 15 min. This duration was chosen based on a pilot study which showed stability of ETCO2 and ICO2 levels over a 15-min masked period.