Table 3.
Ventilator parameters and respiratory mechanics variables in patients with and without a high prevalence of asynchronies
| Variable | IE >10% | AI >10% | ||||
|---|---|---|---|---|---|---|
|
Absent (n = 55) |
Present (n = 14) |
P |
Absent (n = 48) |
Present (n = 21) |
P | |
| PS (cmH2O) |
15 (3) |
18 (4.3) |
0.03 | 16 (3) |
16 (4.4) |
0.51 |
| PEEPe (cmH2O) |
4 (2 to 4) |
4 (2 to 5) |
0.99 | 4 (2 to 4) |
4 (2 to 5) |
0.72 |
| Respiratory rate | 21(8) | 26 (9) | 0.08 | 21 (7) | 24(9) | 0.26 |
| VT (ml) |
480 (395 to 633) |
500 (321 to 620) |
0.69 | 497 (405 to 638) |
435 (321 to 610) |
0.15 |
| CLdyn (l/cmH2O) |
0.061 (0.04 to 0.10) |
0.035 (0.03 to 0.07) |
0.06 | 0.06 (0.04 to 0.1) |
0.05 (0.03 to 0.11) |
0.39 |
| RL (cmH2O/l/s) |
10 (5.6 to 16.4) |
8.3 (5.15 to 16.2) |
0.84 | 10.1 (5.6 to 15.6) |
8.6 (5.6 to 19.7) |
0.83 |
| PEEPdyn (cmH2O) |
1.15 (0.6 to 2) |
1 (0.8 to 2.9) |
0.55 | 1.2 (0.6 to 2.2) |
1.05 (0.6 to 2.8) |
0.81 |
| PTPdi (cmH2Oxs) |
12 (7 to 18) |
11.8 (6 to 15) |
0.46 | 12 (7.1 to 18.5) |
12 (6 to 17) |
0.78 |
| PTPdi/min (cmH2Oxs/min) |
257 (152 to 318) |
247 (167 to 334) |
0.91 | 258 (150 to 326) |
249 (180 to 307) |
1 |
| Tolerance | 2 (1 to 2) | 3 (2 to 3) | 0.006 | 2 (1 to 2) | 2 (2 to 3) | 0.007 |
AI, asynchrony index; CLdyn, dynamic lung compliance; IE, ineffective effort; PEEPdyn, dynamic positive end-expiratory pressure; PEEPe, external end-expiratory positive pressure; PS, pressure support; PTPdi, pressure-time product of diaphragmatic pressure per breath; PTPdi/min, pressure-time product of diaphragmatic pressure per minute; RL, pulmonary resistance at mid-inspiratory volume; VT, tidal volume measured during spontaneous breathing. The median and interquartile ranges (IQRs) are reported for each variable except PS and respiratory rate which did not deviate from the normal distribution, and for which the mean and standard deviation (SD) are reported. The P-values were computed by Wilcoxon's test, except for PS and respiratory rate for which the t-test was applied.