Anzeige
Erschienen in:
01.02.2007 | Experimental
Hemodynamics in experimental gastric juice induced aspiration pneumonitis
Erschienen in: Intensive Care Medicine | Ausgabe 2/2007
Einloggen, um Zugang zu erhaltenAbstract
Objective
To characterize hemodynamic changes during experimental aspiration pneumonitis, paying special attention to echocardiographic assessment.
Design and setting
Animal study in a university-based research laboratory.
Subjects
Fourteen mechanically ventilated New Zealand white rabbits
Interventions
We instilled 1 ml/kg human gastric juice (mean pH: 4.1 + 0.2) intratracheally. Hemodynamic and respiratory parameters were measured every hour for 4 h, associated with a transthoracic echocardiography.
Measurements and results
Lung injury occurred within 1 hour with a marked decrease in PaO2/FIO2 and an increase in plateau pressure; after this initial drop the ratio remained stable throughout the experiment. Seven rabbits experienced only a mild to moderate alteration in lung oxygenation function as defined by a PaO2/FIO2 ratio above 200 (group A), while the other seven developed a severe alteration with a ratio below 200 (group B). At the end of the experiment pH and cardiac output were lower in group B than in group A. Using a PaO2/FIO2 threshold value of 150, pH, mean arterial pressure, and cardiac output were lower in the animals with the more severe hypoxemia. Neither left nor right ventricular dysfunction occurred during the experiment, and no animal experienced circulatory failure
Conclusion
Experimental aspiration pneumonitis after intratracheal infusion of human gastric juice is characterized by a stable fall in PaO2/FIO2. Animals with the most severe lung injury experienced a lower systemic arterial pressure, cardiac output, and metabolic acidosis without circulatory failure or cardiac dysfunction.