Table 1. Summary of features for patients who underwent apneic technique, N=38.

Feature	Mean (SD; range)
Age in years	63.7 (14.3; 36-89)
Charlson index	2.3 (2.0; 0-6)
Body mass index	27.2 (5.0; 17.6-37.5)
Preoxygenation time using Optiflow	13.7 (5.5; 5-28)
Starting end-tidal CO2 (N=26)	32.1 (4.7; 20-41)
Ending end-tidal CO2	54.4 (11.9; 20-81)
Apneic time	23.9 (6.1; 13-40)
Rate of CO2 increase (N=26)	1.12 (0.46; 0.38-2.56)
Minimum oxygen saturation	93.6 (6.1; 79-100)
Maximum systolic blood pressure	166 (35; 114-237)
Minimum systolic blood pressure	98 (21; 68-166)
Sex	N (%)
Female	24 (63)
Male	14 (37)
Mallampati grade (N=37)
1	13 (35)
2	14 (38)
3	9 (24)
4	1 (3)