Table 3.

Comparison of Geometric Mean Diameter with Various Breathing Maneuvers

	Geometric Mean Diameter (μm) [Median (IQR)]			Adjusted P Value
Oxygen Delivery	Normal Breathing	Deep Breathing	Cough	Normal Breathing vs. Deep Breathing	Normal Breathing vs. Cough	Deep Breathing vs. Cough
RA	1.48 (1.22–1.54)	1.00 (0.98–1.14)	1.03 (0.94–1.46)	0.11	0.39	0.56
4 L/min NC	1.58 (1.43–1.61)	1.16 (1.02–1.31)	1.01 (0.93–1.20)	0.0060	0.012	0.49
15 L/min FM	1.46 (1.24–1.86)	1.12 (1.00–1.36)	1.35 (0.95–1.45)	0.059	0.13	0.63
10 L/min HFNC	1.42 (1.28–1.51)	1.14 (1.00–1.33)	1.09 (1.01–1.27)	0.029	0.055	0.77
30 L/min HFNC	1.30 (1.12–1.50)	1.19 (0.99–1.33)	1.04 (0.93–1.17)	0.65	0.25	0.77
50 L/min HFNC	1.19 (1.01–1.56)	1.25 (0.92–1.42)	0.93 (0.86–1.09)	0.77	0.11	0.11
NIPPV 12/5	1.45 (1.32–1.83)	1.38 (1.09–1.50)	1.18 (1.02–1.38)	0.55	0.11	0.55
NIPPV 20/10	1.43 (1.21–1.95)	1.53 (1.09–1.70)	1.20 (0.88–1.95)	0.85	0.70	0.70

Definition of abbreviations: FM = face mask; HFNC = heated and humidified high-flow nasal cannula; IQR = interquartile range; NC = nasal cannula; NIPPV = noninvasive positive-pressure ventilation; RA = room air.

Talking was not included in this analysis in order to limit the amount of multiple comparisons. Pairwise group comparisons made with the Wilcoxon matched-pairs signed rank test. P values were adjusted for multiple comparisons with the Holm method.