Background
Methods
Study design
Patients and data collection
Statistical analysis
Results
Prevalence of ARDS with no risk factor identified
Clinical presentation of ARDS patients with and without risk factor
Parameters | ARDS patients with ≥1 risk factor identified (n = 2579) | ARDS patients with no risk factor identified (n = 234) |
p valuea
|
---|---|---|---|
Age (years) | 61 ± 17 | 65 ± 15 | <0.01 |
Chronic disease | |||
COPD | 527 (20.4) | 80 (34.2) | <0.01 |
Diabetes | 548 (21.2) | 65 (27.8) | 0.025 |
Immunoincompetence | 544 (21.9) | 40 (17.9) | 0.17 |
Chronic cardiac failure | 252 (9.8) | 38 (16.2) | <0.01 |
Chronic renal failure | 248 (9.6) | 38 (16.2) | <0.01 |
Active neoplasm | 210 (8.1) | 22 (9.4) | 0.58 |
Hematological malignancy | 134 (5.2) | 4 (1.7) | 0.03 |
Chronic liver failure | 106 (4.1) | 6 (2.6) | 0.33 |
Type of admission | <0.001 | ||
Medical | 1979 (76.7) | 179 (76.5) | |
Postoperative | 127 (4.9) | 26 (11.1) | |
Surgical | 365 (14.1) | 28 (12.0) | |
Trauma | 108 (4.2) | 1 (0.4) | |
ARDS severity | <0.001 | ||
Mild | 651 (25.2) | 63 (26.9) | |
Moderate | 1026 (39.8) | 80 (34.2) | |
Severe | 524 (20.3) | 33 (14.1) | |
ARDS receiving only NIV | 378 (14.7) | 58 (24.8) | |
Day 1 SOFA scoreb
| 9.5 ± 4.1 | 8.5 ± 3.7 | <0.01 |
Day 1 non-pulmonary SOFA scorec
| 6.3 ± 4.1 | 5.3 ± 3.7 | <0.01 |
Worst SOFA score | 11.2 ± 4.4 | 9.8 ± 4.1 | <0.01 |
Worst non-pulmonary SOFA score | 8.1 ± 4.2 | 6.8 ± 4.1 | <0.01 |
FiO2
| 0.60 [0.45–0.80] | 0.50 [0.40–0.80] | 0.03 |
Total respiratory rate (1/min) | 21.8 ± 8.9 | 21.3 ± 6.5 | 0.42 |
Tidal volume (mL/kg PBW) | 7.7 ± 2.0 | 7.9 ± 2.3 | 0.20 |
In intubated patients | 7.6 ± 1.9 | 7.7 ± 1.9 | 0.59 |
In NIV patients | 8.3 ± 2.7 | 8.7 ± 3.2 | 0.52 |
Set PEEP (cmH2O) | 8.2 ± 3.2 | 7.5 ± 2.4 | <0.01 |
Peak pressure (cmH2O) | 25.6 ± 8.8 | 23.5 ± 8.0 | <0.01 |
Plateau pressure (cmH2O)d
| 23.2 ± 6.1 | 22.8 ± 5.4 | 0.65 |
Respiratory system compliance (mL/cmH2O)d
| 36.8 ± 22.1 | 33.5 ± 15.2 | 0.16 |
Driving pressure (cmH2O)d
| 14.7 ± 5.4 | 11.8 ± 6.0 | 0.67 |
Standardized minute ventilation (L/min)e
| 11.3 ± 5.4 | 11.9 ± 6.0 | 0.42 |
PaO2/FiO2 ratio (mmHg) | 159 ± 67 | 169 ± 68 | 0.03 |
SpO2 (%) | 96 [93−98] | 96 [94–98] | 0.18 |
PaCO2 (mmHg) | 45.6 ± 15.3 | 48.8 ± 18.0 | 0.01 |
pH | 7.33 ± 0.12 | 7.33 ± 0.12 | 0.90 |
Diagnostic investigations and management of ARDS patients with and without risk factor
Parameters | ARDS patients with ≥1 risk factor identified (n = 2579) | ARDS patients with no risk factor identified (n = 234) |
p valuea
|
---|---|---|---|
Diagnostic procedures
| |||
Assessment of LHFP | 1780 (68.4) | 160 (69.4) | >0.99 |
Echocardiography | 1636 (63.4) | 151 (64.5) | 0.79 |
Pulmonary artery catheter | 103 (4.0) | 14 (6.0) | 0.20 |
TTP | 166 (6.4) | 10 (4.3) | 0.24 |
Other methods | 155 (6.0) | 12 (5.1) | 0.69 |
Chest CT scan | 617 (23.9) | 75 (32.1) | <0.01 |
Number of chest CT scan | 0 [0–0] | 0 [0–1] | <0.01 |
Open lung biopsy | 5 (0.2) | 6 (2.6) | <0.01 |
Treatment of ARDS
| |||
Neuromuscular blocking agents | |||
In the 1st 72 h of ARDS | 440 (17.1) | 26 (11.1) | 0.02 |
At any time during ICU stay | 517 (20.0) | 33 (14.1) | 0.04 |
Recruitment maneuvers | |||
In the 1st 72 h of ARDS | 446 (17.3) | 30 (12.8) | 0.10 |
At any time during ICU stay | 506 (19.6) | 33 (14.1) | 0.05 |
Prone positioning | |||
In the 1st 72 h of ARDS | 134 (5.2) | 8 (3.4) | 0.30 |
At any time during ICU stay | 190 (7.4) | 11 (4.7) | 0.17 |
ECMO | |||
In the 1st 72 h of ARDS | 60 (2.3) | 6 (2.6) | >0.99 |
At any time during ICU stay | 70 (2.7) | 8 (3.4) | 0.67 |
Inhaled vasodilators | |||
In the 1st 72 h of ARDS | 156 (6.0) | 7 (3.0) | 0.08 |
At any time during ICU stay | 200 (7.9) | 10 (3.8) | 0.02 |
Corticosteroids | |||
In the 1st 72 h of ARDS | 367 (14.2) | 39 (16.7) | 0.36 |
At any time during ICU stay | 467 (18.1) | 41 (17.5) | 0.89 |
Common risk factors
a
identified in 2579 ARDS patients
b
| |
Pneumonia | 1683 (65.2) |
Non-pulmonary sepsis | 455 (17.6) |
Aspiration of gastric contents | 402 (15.6) |
Non-cardiogenic shock | 214 (8.3) |
Major trauma | 112 (4.3) |
Blood transfusion | 111 (4.3) |
Pulmonary contusion | 87 (3.4) |
Inhalational injury | 70 (2.7) |
Pancreatitis | 59 (2.3) |
Drug overdose | 51 (2.0) |
Pulmonary vasculitisc
| 38 (1.5) |
Burn | 8 (0.3) |
Drowning | 2 (0.1) |
Othersd
| 74 (2.9) |
Etiologies for ARDS in 234 patients having no common risk factor identified
| |
Interstitial lung disease | 9 (3.8)e
|
Drug-induced ARDS | 8 (3.4)f
|
Massive hemoptysis | 8 (3.4) |
Pulmonary embolism | 3 (3.4) |
Diffuse alveolar hemorrhage | 3 (3.4) |
Alveolar proteinosis | 3 (3.4) |
Miscellaneous | 11 (4.7)g
|
No etiology identified | 189 (80.8) |
Parameters | ARDS patients with ≥1 risk factor identified upon ARDS diagnosis (n = 2579) | ARDS patients with no risk factor identified upon ARDS diagnosis (n = 234) |
p value |
---|---|---|---|
Open lung biopsy
| 5a (0.2) | 6 (2.6) | <0.001 |
DAD | 0 | 2b
| |
Pulmonary fibrosis | 0 | 2 | |
Normal lung histology | 2 | 2 | |
Autopsy
c
| 50 (5.5) | 6 (9.4) | 0.26 |
Pulmonary edema | 11 | 3 | |
Pneumonia | 12 | 1 | |
DAD | 10 | 2 | |
Pulmonary fibrosis | 7 | 2 | |
Atelectasis | 4 | 1 | |
Normal lung histology | 2 | 3 | |
Intra-alveolar hemorrhage | 1 | 1d
|
Patients with and without ARDS risk factor identified: prognostic comparison
Parameters | Before propensity score matching | After propensity score matching | ||||
---|---|---|---|---|---|---|
ARDS patients with ≥1 risk factor identified (n = 2579) | ARDS patients with no risk factor identified (n = 234) |
p valuea
| ARDS patients with ≥1 risk factor identified (n = 214) | ARDS patients with no risk factor identified (n = 214) |
p valuea
| |
Matched variables
| ||||||
Age (years) | 61 ± 17 | 65 ± 15 | <0.01 | 68 ± 14 | 66 ± 15 | 0.08 |
Immunoincompetence | 544 (21.9) | 40 (17.9) | 0.17 | 34 (15.9) | 38 (17.8) | 0.67 |
Diabetes | 548 (21.2) | 65 (27.8) | 0.025 | 62 (29.0) | 61 (28.5) | 0.99 |
COPD | 527 (20.4) | 80 (34.2) | <0.01 | 73 (34.1) | 72 (33.6) | 0.99 |
Chronic renal failure | 248 (9.6) | 38 (16.2) | <0.01 | 30 (14.0) | 33 (15.4) | 0.75 |
Chronic cardiac failure | 252 (9.8) | 38 (16.2) | <0.01 | 38 (17.8) | 34 (15.9) | 0.66 |
Chronic liver failure | 106 (4.1) | 6 (2.6) | 0.33 | 5 (2.3) | 6 (2.8) | 0.99 |
pH | 7.33 ± 0.12 | 7.33 ± 0.12 | 0.90 | 7.33 ± 0.12 | 7.33 ± 0.12 | 0.99 |
PaO2/FiO2 ratio (mmHg) | 159 ± 67 | 169 ± 68 | 0.03 | 169 ± 65 | 168 ± 68 | 0.86 |
Set PEEP (cmH2O) | 8.2 ± 3.2 | 7.5 ± 2.4 | <0.01 | 7.7 ± 2.8 | 7.5 ± 2.4 | 0.43 |
Day 1 non-pulmonary SOFA scorec
| 6.3 ± 4.1 | 5.3 ± 3.7 | <0.01 | 5.6 ± 3.9 | 5.5 ± 3.7 | 0.70 |
NIV | 378 (14.7) | 58 (24.8) | <0.01 | 46 (21.5) | 47 (22.0) | 0.91 |
Outcome variables
| ||||||
Invasive ventilation free days to day 28 (days) | 9 [0–21] | 14 [0–24] | <0.01 | 10 [0–21] | 14 [0–24] | 0.16 |
Duration of invasive ventilation (days) | ||||||
All patients | 8 [4–15] | 6 [3–14] | <0.01 | 8 [4–16] | 6 [3–14] | <0.01 |
Surviving patients | 9 [4–15] | 5 [3–12] | <0.01 | 8 [4–16] | 8 [4–14] | <0.01 |
ICU length of stay (days) | ||||||
All patients | 10 [5–18] | 8 [4–16] | <0.01 | 11 [5–20] | 8 [4–16] | 0.02 |
Surviving patients | 11 [6–20] | 8 [4–15] | <0.01 | 11 [5–22] | 8 [4–16] | 0.02 |
Decision of withholding or withdrawing treatments | 639 (24.8) | 63 (26.9) | 0.52 | 53 (24.8) | 59 (27.6) | 0.56 |
ICU Mortality | 902 (35.0) | 64 (27.3) | 0.02 | 67 (31.3) | 59 (27.6) | 0.44 |
Hospital length of stay (days) | ||||||
All patients | 17 [8–32] | 14 [8–26] | 0.03 | 18 [10–32] | 14 [8–26] | <0.01 |
Surviving patients | 23 [13–40] | 16 [11–31] | <0.01 | 25 [14–44] | 16 [10–32] | <0.01 |
Hospital mortality | 1029 (40.0) | 81 (34.6) | 0.12 | 81 (37.9) | 75 (35.1) | 0.60 |
OR | 95% IC |
p value | |
---|---|---|---|
ICU mortality before matching | 0.70 | 0.52–0.94 | 0.02 |
ICU mortality after matching | 0.84 | 0.55–1.27 | 0.40 |
Hospital mortality before matching | 0.79 | 0.60–1.05 | 0.11 |
Hospital mortality after matching | 0.89 | 0.60–1.31 | 0.55 |