Table 1.
Preoperative demographics and intraoperative data of patients 2 months before and after ventilator exchange
| Preoperative variable | Before vent exchange (n = 1414) | After vent exchange (n = 1635) | p |
|---|---|---|---|
|
Age (mean ± SD, yr) |
51 ± 16 |
51 ± 16 |
0.713 |
|
Male (n,%) |
628 (44%) |
731 (44%) |
0.898 |
|
Patient ASA 3,4 or 5 (n,%) |
443 (31%) |
536 (32%) |
0.413 |
|
Emergent Case (n,%) |
46 (3%) |
54 (3%) |
0.980 |
|
Predicted Body Weight (mean ± SD, kg) |
64 ± 11 |
63 ± 10 |
0.316 |
|
Weight (mean ± SD, kg) |
85 ± 24 |
85 ± 24 |
1 |
|
BMI (mean ± SD, kg/m
2
) |
29 ± 7 |
29 ± 8 |
0.517 |
|
Smoker |
|
|
|
|
Former (n,%) |
247 (18%) |
304 (19%) |
0.448 |
|
Current (n,%) |
228 (16%) |
267 (16%) |
0.917 |
|
Lung Disease (n,%) |
10 (0.7%) |
8 (0.5%) |
0.585 |
|
Asthma (n,%) |
114 (8%) |
134 (8%) |
0.946 |
|
COPD (n,%) |
73 (5%) |
100 (6%) |
0.291 |
|
Diabetes (n,%) |
178 (13%) |
218 (13%) |
0.578 |
|
Hypertension (n,%) |
506 (36%) |
616 (38%) |
0.297 |
|
Coronary Artery Disease (n,%) |
93 (7%) |
126 (8%) |
0.257 |
|
Congestive Heart Failure (n,%) |
40 (3%) |
53 (3%) |
0.579 |
|
Chronic Kidney Disease (n,%) |
76 (5%) |
110 (7%) |
0.139 |
|
Hepatic Disease (n,%) |
19 (1%) |
33 (2%) |
0.195 |
|
Alcohol Abuse (n,%) |
45 (3%) |
47 (3%) |
0.697 |
|
Current Steroid Therapy (n,%) |
46 (3%) |
61 (4%) |
0.538 |
|
Intraoperative variable |
Before vent exchange (n = 15,481) |
After vent exchange (n = 18,945) |
p |
|
Ventilatory Parameters (case medians) |
|
|
|
|
PIP (mean ± SD, cmH
2
O) |
26 ± 6 |
21 ± 6 |
< 0.001 |
|
PEEP (mean ± SD, cmH
2
O) |
2 ± 1.4 |
1.6 ± 2.6 |
< 0.001 |
| ΔP (mean ± SD, cmH
2
O) |
24 ± 6 |
19 ± 6 |
< 0.001 |
|
RR (mean ± SD, breath per minute) |
11 ± 2.5 |
11 ± 3 |
< 0.001 |
|
Vt (mean ± SD, ml) |
588 ± 139 |
562 ± 121 |
< 0.001 |
|
Vt cc/kg PBW (mean ± SD, ml) |
9.3 ± 2.19 |
9.0 ± 1.88 |
< 0.001 |
|
FiO
2
(mean ± SD,%) |
57.2 ± 0.17 |
51.8 ± 18 |
< 0.001 |
|
cc/kg PBW ≤ 6 (n,%) |
90 (6%) |
104 (6%) |
1 |
|
cc/kg PBW ≤ 8 (n,%) |
316 (22%) |
433 (27%) |
0.009 |
|
Epochs of 10 minutes: |
|
|
|
|
PIP > 30 cmH2O |
3.5 ± 7.5 |
1.5 ± 5 |
< 0.001 |
|
Vt > 12 cc/kg PBW |
1.8 ± 5 |
0.9 ± 4 |
< 0.001 |
|
Colloid use (n,%) |
198 (14%) |
184 (11%) |
0.026 |
|
Crystalloid volume (median, 25
th
,75
th
, ml) |
2000 (1200,3000) |
1900 (1000,2700) |
< 0.001 |
|
Case Length (mean ± SD, minutes) |
220 ± 124 |
208 ± 124 |
0.005 |
|
Transfusion (n,%) |
79 (6%) |
76 (5%) |
0.248 |
|
PRBC (n,%) |
77 (5%) |
73 (5%) |
0.244 |
|
FFP (n,%) |
14 (1%) |
17 (1%) |
1 |
| Platelets (n,%) | 7(0.5%) | 8 (0.5%) | 0.813 |
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.