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