Table 2 Clinical and biological variables, cardiac function, lung aeration, and EIT derived indices before extubation, according to extubation outcome
Characteristics | Overall N = 40 | Extubation failure N = 12 | Extubation success N = 28 | p-value |
|---|---|---|---|---|
Clinical variables | ||||
Systolic arterial blood pressure, mmHg | 130 (125–140) | 130 (126–138) | 128 (121–140) | 0.627 |
Heart rate, min−1 | 95 (80–116) | 99 (83–120) | 94 (79–105) | 0.481 |
Respiratory rate, min−1 | 23 (20–28) | 28 (25–30) | 22 (18–26) | 0.006 |
IC-RDOS | 2.37 (2.22–2.83) | 2.48 (2.27–2.88) | 2.35 (2.20–2.70) | 0.570 |
Laboratory variables | ||||
pH | 7.45 (7.43–7.49) | 7.48 (7.45–7.50) | 7.44 (7.42–7.48) | 0.074 |
PaO2/FiO2 ratio, mmHg | 257 (203–314) | 198 (164–214) | 290 (245–329) | < 0.001 |
PaCO2, mmHg | 41 (38–46) | 39 (36–41) | 42 (39–46) | 0.077 |
Hematocrit, % | 27.8 (24.6–31.0) | 30.5 (24.7–31.2) | 27.6 (24.6–30.2) | 0.570 |
Protein, g.L−1 | 62 (59–68) | 64 (61–68) | 62 (58–68) | 0.665 |
Cardiac function | ||||
Left ventricle ejection fraction, % | 50 (42–51) | 50 (48–58) | 45 (40–50) | 0.106 |
E/A ratio | 1.1 (0.9–1.3) | 1.2 (0.8–1.5) | 1.1 (0.9–1.2) | 0.792 |
E/E’ ratio | 7.5 (6.3–9.9) | 8.6 (5.9–10.9) | 7.5 (6.6–9.9) | 0.973 |
Cardiac output, L.min−1 | 7.2 (5.9–8.5) | 8.2 (6.7–8.9) | 7.1 (5.7–8.4) | 0.182 |
Lung aeration | ||||
Lung ultrasound score | 12 (8–18) | 19 (14–22) | 10 (6–15) | 0.003 |
Posterior lung ultrasound score | 6 (3–8) | 8 (7–10) | 5 (2–7) | < 0.001 |
Electrical impedance tomography | ||||
Surface, nb of pixels | 394 (352–443) | 352 (324–399) | 406 (382–451) | 0.042 |
Global inhomogeneity index | 0.38 (0.36–0.40) | 0.38 (0.37–0.40) | 0.37 (0.36–0.40) | 0.718 |
Center of ventilation (front-back), % | 50 (46–52) | 50 (47–52) | 50 (46–52) | 0.766 |
Regional ventilation delay, % | 8.0 (6.6–10.0) | 9.1 (7.6–9.7) | 7.7 (5.7–10.5) | 0.167 |