Table 1 Comparison of baseline characteristics between weaning success and weaning failure.

From: Mechanical power is associated with weaning outcome in critically ill mechanically ventilated patients

Variables

All

Weaning success

Weaning failure

p value

(n = 3695)

(n = 2274)

(n = 1421)

Age (years)

66.8 (55.4–77.5)

67.3 (55.7–77.9)

66.5 (54.6–76.4)

0.052

Gender (male)

2102 (56.9)

1275 (56.1)

827 (58.2)

0.203

BMI (kg/m2)

28.0 (24.2–33.3)

27.6 (24.1–32.5)

28.5 (24.5–34.0)

 < 0.001

Smoking history

315 (8.5)

187 (8.2)

128 (9.0)

0.406

SAPS II

43 (34–53)

42 (33–52)

44 (36–55)

 < 0.001

SOFA

7 (4–10)

6 (4–9)

8 (5–11)

 < 0.001

Sources of admission

MICU

871 (23.6)

546 (24.0)

325 (22.9)

0.427

SICU

609 (16.5)

404 (17.8)

205 (14.4)

0.008

TSICU

620 (16.8)

371 (16.3)

249 (17.5)

0.339

MICU/SICU

547 (14.8)

328 (14.4)

219 (15.4)

0.411

CVICU

465 (12.6)

267 (11.7)

198 (13.9)

0.051

CCU

359 (9.7)

216 (9.5)

143 (10.1)

0.573

NSICU

203 (5.5)

129 (5.7)

74 (5.2)

0.546

Others

21 (0.6)

13 (0.6)

8 (0.6)

0.973

Comorbidities

Hypertension

1479 (40.0)

902 (39.7)

577 (40.6)

0.571

Diabetes mellitus

1138 (30.8)

685 (30.1)

453 (31.9)

0.261

COPD

256 (6.9)

157 (6.9)

99 (7.0)

0.942

Congestive heart failure

1107 (30.0)

675 (30.0)

432 (30.4)

0.643

Coronary artery disease

1015 (27.5)

620 (27.3)

395 (27.8)

0.724

Chronic kidney disease

838 (22.7)

513 (22.6)

325 (22.9)

0.826

Stroke

733 (19.8)

439 (19.3)

294 (20.7)

0.305

Parameters before SBT 4 h

VT (ml)

451 (395–512)

452 (392–519)

451 (398–507)

0.498

PEEP (cmH2O)

5.0 (5.0–8.0)

5.0 (5.0–5.3)

6.0 (5.0–10.0)

 < 0.001

Pplat (cmH2O)

17.5 (15.0–20.5)

17.0 (14.0–20.0)

19.0 (16.0–22.0)

 < 0.001

ΔP (cmH2O)

11.3 (9.0–14.0)

11.5 (9.0–14.0)

11.0 (9.0–14.0)

0.271

Ppeak (cmH2O)

19.0 (15.0–24.0)

17.0 (12.8–21.0)

23.0 (19.0–27.0)

 < 0.001

ΔPaw (cmH2O)

13.0 (9.4–16.5)

11.7 (8.0–15.5)

15.0 (12.0–18.0)

 < 0.001

RR (bpm)

19 (16–22)

18 (16–22)

20 (17–24)

 < 0.001

MV (l/min)

8.2 (6.9–9.9)

7.9 (6.7–9.5)

8.8 (7.3–10.6)

 < 0.001

FiO2 (%)

40 (40–50)

40 (40–50)

40 (40–50)

 < 0.001

MP (J/min)

11.1 (7.4–16.2)

9.2 (6.0–13.2)

14.6 (10.6–20.2)

 < 0.001

Cdyn (ml/cmH2O)

33.9 (26.2–49.2)

39.0 (28.5–62.0)

29.6 (24.2–36.7)

 < 0.001

Cdyn-MP (J/min × cmH2O/ml × 10–3)

331.5 (163.9–563.6)

231.5 (101.7–421.6)

501.3 (323.4–744.8)

 < 0.001

PBW-MP (J/min/kg)

0.1881 (0.1234–0.2696)

0.1520 (0.0995–0.2200)

0.2452 (0.1837–0.3331)

 < 0.001

RSBI (bpm/L)

41.7 (32.6–53.7)

40.2 (31.0–51.7)

44.3 (35.1–56.5)

 < 0.001

Laboratory data at the start of SBT

WBC (k/μl)

11.5 (8.5–15.8)

11.2 (8.3–15.3)

11.9 (8.8–16.9)

 < 0.001

PLT (k/μl)

163 (109–228)

162 (111–224)

164 (108–233)

0.502

Hb (g/dl)

10.0 (8.6–11.5)

9.9 (8.6–11.4)

10.0 (8.6–11.6)

0.282

Albumiun (g/dl)

2.9 (2.5–3.4)

3.0 (2.6–3.4)

2.9 (2.4–3.4)

0.013

SCr (mg/dl)

1.1 (0.7–1.8)

1.0 (0.7–1.7)

1.2 (0.8–2.0)

 < 0.001

Uorate before SBT (ml/kg/h)

0.6 (0.4–1.1)

0.7 (0.4–1.2)

0.6 (0.3–1.1)

 < 0.001

Physiological variables during SBT

HR (bpm)

83 (72–97)

82 (71–95)

86 (73–99)

 < 0.001

BF (bpm)

19 (16–22)

18 (15–21)

20 (17–24)

 < 0.001

MBP (mmHg)

75 (68–84)

76 (68–85)

74 (67–83)

 < 0.001

SPO2 (%)

98 (97–100)

99 (97–100)

98 (96–100)

 < 0.001

Temperature (℃)

37.1 (36.8–37.5)

37.1 (36.8–37.4)

37.1 (36.8–37.6)

0.024

PH (mmHg)

7.39 (7.34–7.44)

7.40 (7.35–7.44)

7.38 (7.33–7.43)

 < 0.001

PaO2 (mmHg)

105 (84–130)

106 (86–132)

105 (83–129)

0.331

PaCO2 (mmHg)

39 (34–45)

39 (34–44)

39 (34–45)

0.926

PF (mmHg)

240 (180–323)

253 (193–333)

226 (163–305)

 < 0.001

  1. Data are median (interquartile range) or no./total (%).
  2. BMI, body mass index; SAPS II, simplified acute physiology score II; SOFA, sequential organ failure assessment; MICU, Medical Intensive Care Unit; SICU, Surgical Intensive Care Unit; TSICU, Trauma SICU; MICU/SICU, Medical/ Surgical Intensive Care Unit; CVICU, Cardiac Vascular Intensive Care Unit; CCU, Coronary Care Unit; NSICU, Neuro Surgical Intensive Care Unit; COPD, chronic obstructive pulmonary disease; SBT, spontaneous breathing trial; VT, tidal volume; PEEP, positive end expiratory pressure; Pplat, plateau pressure; ΔP, driving pressure; Ppeak, peak inspiratory pressure; ΔPaw, dynamic driving pressure (defined as Ppeak – PEEP); RR, respiratory rate; MV, minute ventilation; MP, mechanical power; Cdyn, dynamic lung compliance; Cdyn-MP, MP normalized to dynamic lung compliance; PBW-MP, MP normalized to predicted body weight; RSBI, rapid shallow breathing index; WBC, white blood cell; PLT, platelet count; Hb, hemoglobin; SCr, serum creatinine; Uorate, Urine output rate; HR, heart rate; BF, breathing frequency; MBP, mean blood pressure; SPO2, pulse oximetry; PF, arterial partial pressure of oxygen (PaO2) divided by the inspired oxygen concentration (FiO2).
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