Table 2. Summary of associations with apneic time, N=38.

Feature	Correlation		P-value
Age in years	0.14		0.14
Charlson index	0.11		0.51
Body mass index	-0.24		0.15
Preoxygenation time using Optiflow	-0.03		0.86
Starting end-tidal CO2 (N=26)	0.43		0.029
Ending end-tidal CO2	0.18		0.28
Minimum oxygen saturation	0.39		0.018
Maximum systolic blood pressure	0.20		0.23
Minimum systolic blood pressure	0.09		0.58
Sex	Mean (SD, range)
Female	24.1 (6.3; 13-40)
Male	23.5 (6.0; 16-35)
Mallampati grade (N=37)
1	22.7 (5.6; 14-33)
2	23.1 (5.4; 13-33)
3 or 4	26.3 (7.8; 16-40)