Table 2.
Emergency department ventilator variables
| Variable | Pre-intervention Group (n= 186) | Intervention Group (n= 43) | P value |
|---|---|---|---|
|
| |||
| Tidal volume, mL | 500 (500 – 550) | 434 (385 – 450) | <0.01 |
|
| |||
| Tidal volume, mL/kg PBW | 8.1 (7.0 – 9.1) | 6.4 (6.1 – 6.7) | <0.01 |
|
| |||
| PEEP | 5 (5 – 7) | 8 (5 – 10) | <0.01 |
|
| |||
| Respiratory rate | 16.5 (4.4) | 20.7 (3.8) | <0.01 |
|
| |||
| FiO2 | 100 (70 – 100) | 70 (40 – 100) | <0.01 |
|
| |||
| Head-of-bed elevation, n (%) | 151 (37.1) | 67 (91.8) | <0.01 |
|
| |||
| Lung protective ventilation, n (%)* | 12 (11.1) | 24 (61.5) | <0.01 |
|
| |||
| Ventilator Mode, n (%) | |||
| VC-AC | 347 (85.3) | 68 (93.2) | 0.07 |
| PC-AC | 39 (9.6) | 2 (2.7) | 0.05 |
| PRVC-AC | 10 (2.5) | 2 (2.7) | 0.89 |
| Other | 11 (2.7) | 1 (1.4) | 0.50 |
|
| |||
| Peak pressure, cm H2O | 33.9 (8.8) | 28.9 (7.6) | <0.01 |
|
| |||
| Plateau pressure, cmH2O | 22.3 (7.3) | 22.4 (6.4) | 0.98 |
|
| |||
| Mean airway pressure, cmH2O | 11.0 (9.0 – 14.0) | 12.0 (9.9 – 17.0) | 0.47 |
|
| |||
| Compliance respiratory system (mL/cm H2O) | 32.9 (25.0 – 42.4) | 34.5 (23.7 – 45.0) | 0.93 |
|
| |||
| Driving Pressure (cm H2O) | 14.0 (12.0 – 19.3) | 13.0 (9.0 – 17.0) | 0.04 |
|
| |||
| Oxygenation index | 7.3 (4.2 – 11.9) | 9.7 (4.8 – 16.9) | 0.04 |
|
| |||
| pH | 7.24 (0.16) | 7.21 (0.18) | 0.31 |
|
| |||
| PaO2 | 113 (78 – 198) | 85 (67 – 124) | <0.01 |
|
| |||
| PaCO2 | 46 (37 – 61) | 43 (34 – 58) | 0.64 |
|
| |||
| PaO2:FiO2 | 133 (85 – 244) | 114 (88 – 207) | 0.94 |
A total of 480 ventilator settings were analyzed (407 pre-intervention group; 73 intervention group). In the pre-intervention group, peak pressure was monitored for 322 settings (79.1%), plateau pressure for 70 settings (17.2%), and mean airway pressure for 306 settings (75.2%). In the intervention group, all pressures were monitored for each recorded ventilator setting (100%).
Sixty-five patients had ARDS while in the ED (44 pre-intervention group, 108 ventilator settings; 21 intervention group, 39 ventilator settings). Lung protective ventilation was defined as a tidal volume of ≤ 6.5mL/kg PBW.
PBW: predicted body weight; PEEP: positive end-expiratory pressure; FiO2: fraction of inspired oxygen; VC: volume control; AC: assist control; PC: pressure control; PRVC: pressure regulated volume control; PaO2: partial pressure of arterial oxygen; PaCO2: partial pressure of arterial carbon dioxide
Continuous variables are reported as mean (standard deviation) and median (interquartile range).