Alterations in bronchoalveolar lavage fluid after experimental fulminant hepatic failure

The fulminant hepatic failure (FHF) could be a risk factor for acute lung injury (ALI). However, there is little information on the pathophysiology of pulmonary involvement during the early course of acute liver failure. Alterations in lung permeability, surfactant metabolism and local inflammation are significant markers of acute lung injury. The objective of this study was to evaluate alterations of protein as a marker of permeability, phospholipid as a marker of surfactant alterations and PAF-acetylhydrolase (PAF-AcH) as inflammatory marker in bronchoalveolar lavage (BAL) fluid from pigs in an experimental surgical model of FHF.

Methods

Twelve anesthetized, intubated and mechanically ventilated pigs weighting 20–25 kg, with a pulmonary artery in place were studied. In seven pigs FHF was induced by surgical devascularization of the liver and the other five animals were sham-operated. BAL was performed by fiberoptic bronchoscopy before, 4 hours and 7 hours after the surgical procedure respectively using 4 × 20 aliquots of normal saline after the first aspirated fluid. BAL fluids were collected in ice-cold tubes (4°C). Total protein concentration, phospholipids and PAF-AcH were subsequently measured.

Results

Total protein was found significantly higher in animals with FHF, while the protein concentration of the BAL fluid in sham-operated animals was not changed. Reduction of total BAL phospholipids was observed in animals with FHF. In contrast, pospholipids increased in sham animals during mechanical ventilation. PAF-AcH was also reduced in FHF (Table 1). Pulmonary wedge pressure remained low in both groups during the study.

Table 1 Biochemical characteristics of BAL fluid from animals with FHF and those sham-operated

Conclusion

Experimental FHF is associated with an increase of pulmonary permeability as indicated by increased proteins in BAL fluid, and surfactant alteration as indicated by the change in total BAL phospholipids. The decreased PAF-AcH, an anti-inflammatory factor, implies an inflammatory process. These findings suggest that lung injury occurs early in the course of FHF.