Partial liquid ventilation and nitric oxide in experimental acute lung injury

To investigate the effects of inhaled nitric oxide (iNO) and partial liquid ventilation (PLV) on oxygenation and pulmonary haemodynamics in acute lung injury (ALI), and to assess their effects on lung function, systemic haemodynamics and lung injury.

Using saline lung lavage, ALI was induced in 18 piglets. A control group was ventilated with conventional mechanical ventilation (CMV) for 2 h. An iNO-first group received iNO for the first hour and then iNO with PLV. A PLV-first group received PLV for the first hour and then PLV with iNO. Variables were measured at baseline, 5 min postlavage, and at 1 h and 2 h postlavage.

During the first hour, both treatment groups showed improvement in oxygenation index (OI). At 2 h, the dif-ferences in OI were statistically significant (P = 0.037), with a mean +/- SD of 23.8 +/- 20.7 in the control group, 4.4 +/- 0.9 in the PLV-first group and 6.5 +/- 3.1 in the iNO-first group. The OI was similar in both treatment groups (P = 0.178). At 2 h, the pulmonary artery pressure (PAP) was significantly different (P = 0.04) between groups, with a mean +/- SD PAP of 36.3 +/- 7.2 mmHg in the control group, 27.4 +/- 4.0 mmHg in the PLV-first group and 30.0 +/- 4.1 mmHg in the iNO-first group. The PAP was similar in both treatment groups (P = 0.319).

In ALI, oxygenation and pulmonary hypertension are improved with PLV and iNO given together, regardless of the order in which they are commenced.