Table 1.
Baseline characteristics of study patients
| Baseline data | All patients, n = 20 | Low-pendelluft group n = 12 | High-pendelluft group n = 8 | p-value |
|---|---|---|---|---|
| Age, years | 65 ± 9 | 63 ± 9 | 68 ± 7 | .187 |
| Female sex, n (%) | 9 (45) | 5 (42) | 4 (50) | .535 |
| Body mass index, kg/m2 | 25.5 [22.2–27.4] | 25.7 [22–27.7] | 25.2 [22.3–27.3] | .791 |
| SAPS2 (ICU admission) | 55 ± 19 | 56 ± 19 | 52 ± 19 | .661 |
| Reason for admission, n (%) | .109 | |||
| Medical | 15 (75) | 11 (92) | 4 (50) | |
| Emergency surgery | 5 (25) | 1 (8) | 4 (50) | |
| ARDS, n. (%) | 12 (60) | 9 (75) | 3 (37) | .167 |
| Days on CMV | 3 [2:7] | 3 [1:7] | 3 [2:5] | 1 |
| ICU days | 13 [6:19] | 13 [4:27] | 13 [12:16] | .970 |
| AMV days | 10 [3:14] | 12 [2:16] | 9 [5:11] | .343 |
| PaO2/FiO2, torr | 253 ± 62 | 233 ± 60 | 282 ± 54 | .078 |
| PEEP, cmH2O | 8 [7:8] | 8 [7:8] | 8 [7:8] | .970 |
| NIF, cmH2O | 22 ± 11 | 22 ± 11 | 21 ± 11 | .816 |
| Clinical PSV, cmH2O | 10 [8:10] | 10 [8:10] | 9 [8:11] | .624 |
| CPLrs, ml/cmH2O | 48 ± 14 | 46 ± 12 | 51 ± 16 | .413 |
| Tidal volume, mL | 462 [393:541] | 487 [335:541] | 445 [412:562] | .734 |
| Respiratory rate, bpm | 20 ± 7 | 20 ± 7 | 20 ± 7 | .959 |
| Minute ventilation, L/min | 9.5 [6.5:11.5] | 8.7 [6.1:10.6] | 10.3 [6.5:12.7] | .571 |
| End-tidal CO2, mmHg | 38 [31:42] | 38 [30:54] | 38 [31:42] | .762 |
| p0.1, cmH2O | 1.4 [0.8:2.2] | 1.4 [0.9:2.3] | 1.2 [0.5:2.1] | .473 |
| RSBi, bpm/L | 42 [28:64] | 47 [28:65] | 38 [27:63] | .537 |
| Tv DEP, % | 40 ± 12 | 37 ± 12 | 44 ± 12 | .188 |
| Pendelluft, mL | 3.3 [2.1:8.8] | 2.3 [1:3.3] | 8.4 [3.7:22.2] | .003 |
| To ventral ROIs, mL | 0 [0:0.3] | 0 [0:1.3] | 0 [0:0.7] | .415 |
| To dorsal ROIs, mL | 2.6 [1.4:12.9] | 1.6 [0.3:2.8] | 7.9 [3.7:22.2] | .002 |
SAPS2, Simplified Acute Physiology Score II; ICU, intensive care unit; CMV, controlled mechanical ventilation; AMV, assisted mechanical ventilation; PEEP, positive end-expiratory pressure; NIF, negative inspiratory force; PSV, pressure support ventilation; CPLrs, compliance of the respiratory system; bpm, breaths per minute; p0.1, occlusion pressure at 100 ms; RSBi, Rapid Shallow Breathing index; Tv DEP, distribution of tidal volume to dependent lung regions. Data are expressed as mean ± SD or median [25th:75th percentile]