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Table 4 Preoperative demographics and intraoperative data of patients 2 years before and after ventilator exchange after risk matching

From: Replacement of anesthesia machines improves intraoperative ventilation parameters associated with the development of acute respiratory distress syndrome

Preoperative variable

Before vent exchange (n = 13,250)

After vent exchange (n = 13,250)

p

Age (mean ± SD, yr)

51 ± 16

50 ± 16

< 0.001

Male (n,%)

5932 (45%)

5956 (45%)

0.776

Patient ASA 3,4 or 5 (n,%)

3788 (28.6%)

3604 (27.2%)

0.012

Emergent Case (n,%)

591 (4.5%)

588 (4.4%)

0.952

Predicted Body Weight (mean ± SD, kg)

63 ± 10.6

64 ± 10.6

0.247

Weight (mean ± SD, kg)

83 ± 22

83 ± 22

0.568

BMI (mean ± SD, kg/m 2 )

29 ± 7

29 ± 7

0.906

Smoker

   

 Former (n,%)

2410 (18.2%)

2637 (19.9%)

< 0.001

 Current (n,%)

2182 (16.5%)

2195 (16.6%)

0.843

Lung Disease (n,%)

37 (0.3%)

33 (0.2%)

0.72

Asthma (n,%)

1054 (8%)

998 (7.5%)

0.206

COPD (n,%)

664 (5%)

643 (4.9%)

0.57

Diabetes (n,%)

1531 (12%)

1477 (11%)

0.305

Hypertension (n,%)

4670 (35%)

4366 (33%)

< 0.001

Coronary Artery Disease (n,%)

1028 (8%)

989 (7%)

0.379

Congestive Heart Failure (n,%)

307 (2%)

323 (2%)

0.545

Chronic Kidney Disease (n,%)

616 (5%)

605 (5%)

0.77

Hepatic Disease (n,%)

212 (2%)

277 (2%)

0.003

Alcohol Abuse (n,%)

467 (4%)

396 (3%)

0.015

Current Steroid Therapy (n,%)

304 (2%)

415 (3%)

< 0.001

Intraoperative Variable

Before vent exchange (n = 13,250)

After vent exchange (n = 13,250)

p

Ventilatory Parameters (case medians)

   

 PIP (mean ± SD, cmH 2 O)

25.5 ± 6

20 ± 6

< 0.001

 PEEP (mean ± SD, cmH 2 O)

1.9 ± 1.2

2.7 ± 2.8

0.257

 ΔP (mean ± SD, cmH 2 O)

23.6 ± 6

17.3 ± 6

< 0.001

 RR (mean ± SD, breath per minute)

11 ± 2.5

11 ± 2.5

< 0.001

 Vt (mean ± SD, ml)

590 ± 144

541 ± 120

< 0.001

 Vt cc/kg PBW (mean ± SD, ml)

9.41 ± 2.26

8.62 ± 1.96

< 0.001

 FiO 2 (mean ± SD)

55 ± 16

54 ± 19

< 0.001

 cc/kg PBW ≤ 6 (n,%)

953 (7%)

1223 (9%)

< 0.001

 cc/kg PBW ≤ 8 (n,%)

2915 (22%)

4584 (35%)

< 0.001

Epochs of 10 minutes:

   

 PIP > 30 cmH2O

3.2 ± 7.1

1.1 ± 4

< 0.001

 Vt > 12 cc/kg PBW

2 ± 4.8

0.7 ± 3.1

< 0.001

Colloid use (n,%)

1202 (9%)

1157 (9%)

0.343

Crystalloid volume (median, 25 th ,75 th , ml)

2000 (1300,3000)

2000 (1500,3000)

< 0.001

Case Length (mean ± SD, minutes)

215 ± 122

197 ± 116

< 0.001

Transfusion (n,%)

560 (4%)

554 (4%)

0.878

PRBC (n,%)

509 (4%)

513 (4%)

0.924

FFP (n,%)

103 (0.8%)

91 (0.7%)

0.428

Platelets (n,%)

64 (<0.5%)

60 (<0.5%)

0.787

  1. ASA = American Society of Anesthesiology Classification, BMI = body mass index, COPD = chronic obstructive pulmonary disease, PIP = peak inspiratory pressure, PEEP = positive end expiratory pressure, RR = respiratory rate, Vt = tidal volume, PBW = predicted body weight, FiO2 = fraction inspired oxygen, PBW = predicted body weight, PRBC = packed red blood cells, FFP = fresh frozen plasma.