Partial Liquid Ventilation Compared with Conventional Mechanical Ventilation in an Experimental Model of Acute Lung Injury
ABSTRACT
Objective:
To compare the effects of partial liquid ventilation with conventional mechanical ventilation on oxygenation and pulmonary mechanics in saline lavaged rabbits.
Methods:
Following acute lung injury (saline-lavage), rabbits were assigned to continue conventional mechanical ventilation (n = 6) or commence partial liquid ventilation (n = 6). In both groups the inspired oxygen concentration was 100% throughout the study. The target PaCO2 of 40 - 60 mmHg was accomplished by keeping the tidal volume between 7 and 10 mL/kg. During the study the peak inspiratory pressure was adjusted to maintain the target PaCO2.
Arterial blood gases were taken pre-lavage, immediately post-lavage (time = 0) and then hourly for 5 hours. Pulmonary mechanics were estimated by measuring compliance and resistance. Pulmonary function was measured pre-lavage, immediately post-lavage and at 1 and 5 hours. At 5 hours the rabbits were killed and the lungs were removed for histological examination.
Results:
Baseline PaO2, compliance and resistance were not significantly different between groups. The partial liquid ventilation group had a higher PaO2 and a significantly better oxygenation index one hour after commencing partial liquid ventilation and a significantly higher PaO2 averaged over the three hours post-treatment. There were no significant differences in compliance, resistance or lung damage scores.
Conclusions:
In this experimental model of acute lung injury, partial liquid ventilation resulted in immediate and sustained increase in PaO2 over 3 hours without significant change in lung mechanics or histological lung damage. (Critical Care and Resuscitation 2001; 3: 81-85)
Key words:
Partial liquid ventilation, surfactant deficiency, disease models, animal, fluorocarbons, respiratory distress syndrome
