Table 4.
Changes in ventilator setup
| All patients | Optimized ventilation | Standard ventilation | P | |
|---|---|---|---|---|
| At the beginning of NIV | ||||
| PEEP, cmH2O | 5.1 ± 1.4 | 5.5 ± 1.7 | 4.7 ± .9 | .003 |
| PS, cmH2O | 13.6 ± 3.4 | 14.0 ± 3.7 | 13.2 ± 3.1 | .152 |
| Insp trigger*, L/minute | 3.2 ± 2.0 | 2.3 ± 1.8 | 4.0 ± 1.7 | .002 |
| Expiratory trigger, % | 40 ± 9 | 38 ± 9 | 42 ± 8 | .086 |
| Speed of pressurization | 1.8 ± .6 | 1.7 ± .6 | 2.0 ± .4 | .024 |
| After 30 minutes of NIV | ||||
| PEEP, cmH2O | 5.4 ± 1.3 | 5.9 ± 1.4 | 4.9 ± .9 | .011 |
| PS, cmH2O | 14.3 ± 3.5 | 14.7 ± 3.7 | 14.0 ± 3.4 | .604 |
| Insp trigger*, L/minute | 2.9 ± 2.0 | 2.0 ± 1.7 | 3.8 ± 1.8 | .001 |
| Expiratory trigger, % | 40 ± 12 | 40 ± 14 | 40 ± 9 | .600 |
| Speed of pressurization | 1.6 ± .5 | 1.4 ± .5 | 1.7 ± .4 | .011 |
| After 2 hours of NIV | ||||
| PEEP, cmH2O | 5.4 ± 1.2 | 5.9 ± 1.3 | 4.9 ± .9 | .030 |
| PS, cmH2O | 14.8 ± 3.9 | 14.9 ± 4.2 | 14.7 ± 3.7 | .820 |
| Insp trigger*, L/minute | 2.9 ± 2.0 | 1.9 ± 1.7 | 4.1 ± 1.7 | 0.001 |
| Expiratory trigger, % | 37 ± 12 | 36 ± 14 | 38 ± 10 | .337 |
| Speed of pressurization | 1.4 ± .5 | 1.3 ± .5 | 1.6 ± .5 | .064 |
| After 6 hours of NIV | ||||
| PEEP, cmH2O | 5.4 ± 1.4 | 5.8 ± 1.6 | 5.1 ± 1.0 | .015 |
| PS, cmH2O | 15.3 ± 4.0 | 15.5 ± 4.2 | 15.1 ± 4.0 | .925 |
| Insp trigger*, L/minute | 3.0 ± 2.0 | 2.0 ± 1.7 | 3.9 ± 1.8 | .001 |
| Expiratory trigger, % | 37 ± 11 | 36 ± 12 | 39 ± 10 | .143 |
| Speed of pressurization | 1.6 ± .5 | 1.5 ± .6 | 1.7 ± .5 | .134 |
| After 24 hours of NIV | ||||
| PEEP, cmH2O | 5.4 ± 1.5 | 6.0 ± 1.8 | 4.9 ± .9 | .002 |
| PS, cmH2O | 14.8 ± 3.9 | 15.4 ± 4.2 | 14.3 ± 3.6 | .426 |
| Insp trigger*, L/minute | 3.1 ± 1.9 | 2.4 ± 1.8 | 4.0 ± 1.8 | .009 |
| Expiratory trigger, % | 37 ± 11 | 37 ± 12 | 37 ± 10 | .708 |
| Speed of pressurization | 1.7 ± .6 | 1.5 ± .5 | 1.9 ± .6 | .089 |
Data reported as mean ± standard deviation. Insp trigger, inspiratory trigger; PEEP, external positive end expiratory pressure; PS, pressure support (over PEEP). Speed of pressurization: data are reported in a qualitative scale ranging from 0 (faster pressurization) to 5 (slower pressurization). *Data available in 50 patients. Significant differences in bold.