Background
Methods
Statistical Analysis
Results
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 |
Preoperative variable | Before vent exchange (n = 15,481) | After vent exchange (n = 18,945) | p |
---|---|---|---|
Age (mean ± SD, yr)
| 50 ± 17 | 52 ± 16 | < 0.001 |
Male (n,%)
| 6936 (45%) | 8619 (46%) | 0.776 |
Patient ASA 3,4 or 5 (n,%)
| 4207 (27%) | 6259 (33%) | < 0.001 |
Emergent Case (n,%)
| 697 (4%) | 830 (4%) | 0.605 |
Predicted Body Weight (mean ± SD, kg)
| 64 ± 11 | 64 ± 11 | 0.939 |
Weight (mean ± SD, kg)
| 83 ± 22 | 84 ± 22 | < 0.001 |
BMI (mean ± SD, kg/m
2
)
| 28.6 ± 6.9 | 29.1 ± 7.3 | < 0.001 |
Smoker
| |||
Former (n,%)
| 2717 (18%) | 4009 (21%) | < 0.001 |
Current (n,%)
| 2556 (17%) | 3024 (16%) | 0.174 |
Lung Disease (n,%)
| 45 (0.3%) | 59 (0.3%) | 0.802 |
Asthma (n,%)
| 1153 (7%) | 1633 (9%) | < 0.001 |
COPD (n,%)
| 744 (5%) | 1046 (6%) | 0.003 |
Diabetes (n,%)
| 1758 (11%) | 2658 (14%) | < 0.001 |
Hypertension (n,%)
| 5055 (33%) | 7409 (39%) | < 0.001 |
Coronary Artery Disease (n,%)
| 1143 (7%) | 1633 (9%) | < 0.001 |
Congestive Heart Failure (n,%)
| 378 (2%) | 676 (4%) | 0.545 |
Chronic Kidney Disease (n,%)
| 717 (5%) | 1157 (6%) | < 0.001 |
Hepatic Disease (n,%)
| 235 (2%) | 452 (2%) | < 0.001 |
Alcohol Abuse (n,%)
| 535 (4%) | 582 (3%) | 0.049 |
Current Steroid Therapy (n,%)
| 341 (2%) | 658 (4%) | < 0.001 |
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)
| 25.4 ± 5.9 | 20.2 ± 6.1 | < 0.001 |
PEEP (mean ± SD, cmH
2
O)
| 1.9 ± 1.2 | 2.7 ± 2.8 | < 0.001 |
ΔP (mean ± SD, cmH
2
O)
| 23.4 ± 5.7 | 17.5 ± 5.6 | < 0.001 |
RR (mean ± SD, breath per minute)
| 11.0 ± 2.5 | 10.7 ± 2.5 | < 0.001 |
Vt (mean ± SD, ml)
| 587 ± 146 | 543 ± 118 | < 0.001 |
Vt cc/kg PBW (mean ± SD, ml)
| 9.35 ± 2.29 | 8.67 ± 1.95 | < 0.001 |
FiO
2
(mean ± SD,%)
| 55.3 ± 16 | 54.1 ± 19 | < 0.001 |
cc/kg PBW ≤ 6 (n,%)
| 1221 (8%) | 1643 (9%) | < 0.001 |
cc/kg PBW ≤ 8 (n,%)
| 3534 (23%) | 6465 (34%) | < 0.001 |
Epochs of 10 minutes:
| |||
PIP > 30 cmH2O
| 3.1 ± 7.1 | 1.2 ± 4.2 | < 0.001 |
Vt > 12 cc/kg PBW
| 1.92 ± 4.9 | 0.8 ± 3.4 | < 0.001 |
Colloid use (n,%)
| 1585 (10%) | 1828 (10%) | 0.072 |
Crystalloid volume (median, 25
th
,75
th
, ml)
| 2000 (1200,3000) | 2200 (1600,3100) | < 0.001 |
Case Length (mean ± SD, minutes)
| 214 ± 125 | 206 ± 122 | < 0.001 |
Transfusion (n,%)
| 793 (5%) | 880 (5%) | 0.043 |
PRBC (n,%)
| 727 (5%) | 810 (4%) | 0.064 |
FFP (n,%)
| 175 (1%) | 159 (1%) | 0.007 |
Platelets (n,%)
| 91 (0.6%) | 104 (0.5%) | 0.685 |
Preoperative variable | Before vent exchange (n = 864) | After vent exchange (n = 864) | p |
---|---|---|---|
Age (mean ± SD, yr)
| 49 ± 16 | 48 ± 16 | 0.656 |
Male (n,%)
| 358 (41%) | 362 (42%) | 0.884 |
Patient ASA 3,4 or 5 (n,%)
| 198 (23%) | 188 (22%) | 0.603 |
Emergent Case (n,%)
| 24 (3%) | 16 (2%) | 0.263 |
Predicted Body Weight (mean ± SD, kg)
| 64 ± 10.5 | 63 ± 10.5 | 0.294 |
Weight (mean ± SD, kg)
| 84 ± 23.5 | 84 ± 22.8 | 0.658 |
BMI (mean ± SD, kg/m
2
)
| 28.9 ± 7.4 | 29.0 ± 7.3 | 0.854 |
Smoker
| |||
Former (n,%)
| 141 (16%) | 134 (16%) | 0.693 |
Current (n,%)
| 138 (16%) | 132 (15%) | 0.74 |
Lung Disease (n,%)
| 3 (0.3%) | 5 (0.6%) | 0.726 |
Asthma (n,%)
| 71 (8%) | 72 (8%) | 1 |
COPD (n,%)
| 20 (2%) | 19 (2%) | 1 |
Diabetes (n,%)
| 86 (10%) | 73 (8%) | 0.381 |
Hypertension (n,%)
| 250 (29%) | 230 (27%) | 0.308 |
Coronary Artery Disease (n,%)
| 23 (3%) | 18 (2%) | .527 |
Congestive Heart Failure (n,%)
| 12 (1%) | 12 (1%) | 1 |
Chronic Kidney Disease (n,%)
| 21 (2%) | 20 (2%) | 1 |
Hepatic Disease (n,%)
| 11 (1%) | 11 (1%) | 1 |
Alcohol Abuse (n,%)
| 27 (3%) | 21 (2%) | 0.464 |
Current Steroid Therapy (n,%)
| 24 (3%) | 25 (3%) | 1 |
Intraoperative variable
|
Before vent exchange (n = 864)
|
After vent exchange (n = 864)
|
p
|
Ventilatory Parameters (case medians)
| |||
PIP (mean ± SD, cmH
2
O)
| 25.3 ± 5.7 | 20.3 ± 6.2 | < 0.001 |
PEEP (mean ± SD, cmH
2
O)
| 2.0 ± 1.3 | 1.5 ± 2.5 | < 0.001 |
ΔP (mean ± SD, cmH
2
O)
| 23.3 ± 5.4 | 18.8 ± 5.6 | < 0.001 |
RR (mean ± SD, breath per minute)
| 11.0 ± 2.3 | 10.5 ± 2.2 | < 0.001 |
Vt (mean ± SD, ml)
| 587 ± 146 | 559 ± 125 | < 0.001 |
Vt cc/kg PBW (mean ± SD, ml)
| 9.33 ± 2.22 | 8.98 ± 1.94 | < 0.001 |
FiO
2
(mean ± SD,%)
| 55.5 ± 16 | 51.2 ± 18 | < 0.001 |
cc/kg PBW ≤ 6 (n,%)
| 62 (7%) | 63 (7%) | 1 |
cc/kg PBW ≤ 8 (n,%)
| 188 (22%) | 219 (34%) | 0.089 |
Epochs of 10 minutes:
| |||
PIP > 30 cmH2O
| 2.9 ± 6.4 | 1.4 ± 4.5 | < 0.001 |
Vt > 12 cc/kg PBW
| 1.7 ± 4.3 | 0.9 ± 3.6 | < 0.001 |
Colloid use (n,%)
| 51 (5.9%) | 47 (5.4%) | 0.755 |
Crystalloid volume (median, 25
th
,75
th
, ml)
| 1950 (1100, 2700) | 1900 (1000,2500) | 0.111 |
Case Length (mean ± SD, minutes)
| 198 ± 103 | 195 ± 104 | 0.531 |
Transfusion (n,%)
| 17 (2%) | 15 (2%) | 0.858 |
PRBC (n,%)
| 16 (2%) | 15 (5%) | 1 |
FFP (n,%)
| 2 (0.2%) | 4 (0.5%) | 0.683 |
Platelets (n,%)
| 2 (0.2%) | 1 (0.1%) | 1 |
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 |
Variable | Before vent exchange (n = 864) | After vent exchange (n = 864) | p |
---|---|---|---|
28 day Mortality
| 2 (0.2%) | 3 (0.3%) | 1 |
90 day Mortality
| 8 (0.9%) | 6 (0.7%) | 0.79 |
Acute Lung Injury within 7 days
| 3 (0.3%) | 0 (0.0%) | 0.25 |
Variable | Before vent exchange (n = 13,250) | After vent exchange (n = 13,250) | p |
---|---|---|---|
28 day Mortality
| 83 (0.6%) | 74 (0.6%) | 0.522 |
90 day Mortality
| 190 (1.4%) | 188 (1.4%) | 0.959 |
Acute Lung Injury within 7 days
| 20 (0.2%) | 12 (0.1%) | 0.216 |