Objective
To test the hypothesis that PLV combined with a high PEEP and a moderate Vt results in improved gas exchange and lung mechanics compared to CMV in acute lung injury in piglets. ALI was induced in 12 piglets weighing 9.0 ± 2.4 kg by repeated intravenous injections of oleic acid and repeated lung lavages. Thereafter the animals were randomly assigned either for PLV (n = 6) or CMV (n = 6) at a FiO2 of 1.0, a PEEP of 1.2 kPa, a tidal volume < 10 ml/kg, a respiratory rate of 24 breaths/min, and an I:E ratio of 1:2. Perfluorocarbon liquid (30 ml/kg b.w.) was instilled into the endotracheal tube over 10 min followed by 5 ml/kg b.w./h. Cardiorespiratory monitoring was done at baseline, after induction of ALI, and every 30 min up to 120 min. When compared with control animals, PLV resulted in significant better oxygenation, significant lower dead space ventilation, and significant better CO and DO2.
Conclusions
PLV combined with high PEEP and moderate tidal volume significantly improves oxygenation, dead space ventilation, cardiac output, and oxygen delivery in piglets with ALI, but has no significant influence on lung mechanics.
Table 1.
PA-aO2 and DO2 in 12 piglets with ALI during PLV or CMV
| Parameters | Group | Baseline | ALI | t-60 | t-120 |
|---|---|---|---|---|---|
| PA-aO2 (kPa) | Control | 5.8 ± 2.3† | 80.2 ± 2.9 | 72.7 ± 6.3* | 71.9 ± 7.2* |
| PLV | 7.5 ± 4.1† | 80.5 ± 2.3 | 47.9 ± 20.0†§ | 45.6 ± 21.3†§ | |
| DO2 (ml/min) | Control | 18.7 ± 3.5† | 11.3 ± 2 | 11.7 ± 4.0 | 10.5 ± 2.6 |
| PLV | 22.5 ± 4.1† | 15.3 ± 4.5 | 18.9 ± 6.9‡ | 18.7 ± 7.2‡ |
*P < 0.05, †P < 0.01 vs ALI levels within the groups, ‡P < 0.05, §P < 0.01 between groups.