- Comparison of in-group and between-group fraction of expired oxygen values.
| Time | Group 1 n (33) | Group 2 n (33) | P-value* | ||
|---|---|---|---|---|---|
| Mean±SD | Median (min–max) | Mean±SD | Median (min–max) | ||
| T1 | 91.97±3.5 | 92 (81–97)c | 93.85±4.67 | 95 (82–99)b | 0.012 |
| T2 | 90.33±5.42 | 92 (74–97)c | 90.24±5.41 | 91 (78–98)b | 0.908 |
| T3 | 58.94±5.52 | 60 (49–69)b | 57.15±4.36 | 58 (49–64)a | 0.081 |
| T4 | 55.39±4.77 | 58 (46–60)a | 55.18±4.18 | 57 (46–60)a | 0.287 |
| P-value† | <0.001 | <0.001 | |||
Group 1: 3 min at normal tidal volume, Group 2: 30 s with the 4 deep vital capacity technique. SD: standard deviation, Min: minimum, Max: maximum, T1: after preoxygenation, T2: immediately after intubation, T3: at the 3rd min after intubation, T4: at the 7th min after intubation, *P-value: Comparison between groups. †P-value: Compared within the group, a-c: There is no difference between times with the same letter in a group.