Statistics
Looking to detect a rise of ETCO2 of 1.0 mmHg (Averages for each of the five physiologic variables were calculated over four time periods: 5-min mask free average, first 5-min masked average, second 5-min masked average, and last 5-min masked average. ΔICO2 values were calculated as the rise in mean ICO2 for each 5-min masked period compared to the mask free mean ICO2 level. One-Way Repeated Measures ANOVA was performed to examine differences in the four time periods’ mean ETCO2, ICO2, ΔICO2, RR, SPO2, and HR values. Statistical analyses were first performed on the pediatric and adult groups’ data, with ETCO2 levels remaining in the normal range as described in the Results section. Because changes in mechanical deadspace are expected to have a larger effect on the youngest subjects, In preliminary analyses, the resulting data for the five physiologic variables were screened to assess accuracy, missing data, outliers, and the violation of the normality assumption and homogeneity assumption. Out of 11,900 data points, spurious data entries were identified in one subject’s heart rate and one subject’s ICO2, and the data from these two participants were removed from the respective analyses. The visual inspection of standardized histograms revealed the assumption for normality was met, with slight skewing for some of the physiological markers. Lastly, the homogeneity assumption was met for all the parametric analyses except for the SPO2 and RR physiological markers for the adult participants and ETCO2 and ICO2 for the pediatric participants. Therefore, a Huynh-Feldt or Greenhouse-Geisser correction was used when appropriate.