Table 1.

Average tidal volume by mask type and order of use, and differences by mask type or order. All values are estimated from a linear mixed model

Mask Type or Comparison	Mean (95% CI)	p
Standard (Used 1st)	137.4 (126.8, 148.0)
Standard (Used 2nd)	190.7 (180.1, 201.3)
Tao (Used 1st)	167.9 (157.3, 178.5)
Tao (Used 2nd)	192.0 (181.4, 202.6)
Tao 1st vs. Standard 1st	30.5 (15.4, 45.6)	0.002
Tao 2nd vs. Standard 2nd	1.28 (−13.8, 16.3)	1.000
Standard 2nd vs. Standard 1st	53.3 (38.2, 68.4)	< 0.001
Tao 2nd vs. Tao 1st	24.1 (9.05, 39.2)	0.020