Characteristic | All Parturients n = 584 | Category 2 Parturients n = 193 | Category 3 Parturients n = 391 | Effect measure (95% CI) | P - value |
---|---|---|---|---|---|
Airway insertion attempt, n(%)c | −0.01 (0.08, −0.09) | 0.7367 | |||
1st attempt insertion success | 574 (98.3) | 189 (97.9) | 385 (98.5) | ||
2nd attempt insertion success | 10 (1.7) | 4 (2.1) | 6 (1.5) | ||
Time to effective ventilation (second), mean (SD)a | 15.6 (4.4) | 15.3 (4.5) | 15.7 (4.4) | 0.48 (−0.29, 1.25) | 0.2230 |
Peak airway pressure (cm H2O), median [IQR, min - max]b | 18 [15–21, 11–32] | 17 [14–19, 11–27] | 18 [16–22, 11–32] | 1.00 (0.26, 1.74) | <0.0001 |
Seal pressure (cm H2O), median [IQR, min - max]b | 27 [25–30, 17–39] | 27 [24–29, 18–36] | 28 [25–30, 17–39] | 1.00 (0.36, 1.64) | 0.0003 |
Seal – Peak airway pressure (cm H2O), median [IQR, min - max]b | 9 [5–13, −8 - 24] | 9 [6–13, −8 - 13] | 9 [5–13, −3 - 24] | 0.00 (−1.11, 1.11) | 0.3594 |
Cuff volume (mL), mean (SD)a | 25.0 (2.9) | 25.0 (2.6) | 25.0 (3.0) | 0.03 (−0.44, 0.5) | 0.9073 |
Number of attempts at orogastric tube insertion, median [IQR, min - max]b | 1 [1–1, 1–1] | 1 [1–1, 1–1] | 1 [1–1, 1–1] | – | 1.0000 |
Volume of gastric aspirate (mL), mean (SD)a | 14.2 (14.3) | 12.1 (7.4) | 15.2 (16.6) | 3.16 (1.21, 5.11) | 0.0016 |
pH of gastric aspirate, mean (SD)a | 2.3 (0.8) | 2.4 (0.9) | 2.3 (0.8) | −0.08 (−0.24, 0.07) | 0.2845 |
Respiratory rate (breaths /minute), median [IQR, min - max]b | 12 [12–12, 10–17] | 12 [12–12, 10–15] | 12 [12–12, 10–17] | – | 0.5250 |
Tidal volume (mL), median [IQR, min - max]b | 480 [450–500, 360–650] | 470 [450–500, 360–600] | 480 [450–500, 380–650] | 10.00 (−2.48, 22.48) | 0.0002 |
pH on laryngeal surface, mean (SD)a | 7.0 (0.5) | 7.0 (0.6) | 7.1 (0.4) | 0.04 (−0.05, 0.13) | 0.3985 |