Hemodynamics in experimental gastric juice induced aspiration pneumonitis.
OBJECTIVE
To characterize hemodynamic changes during experimental aspiration pneumonitis, paying special attention to echocardiographic assessment.


METHODS
Animal study in a university-based research laboratory.


METHODS
Fourteen mechanically ventilated New Zealand white rabbits


METHODS
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.


RESULTS
Lung injury occurred within 1 hour with a marked decrease in PaO(2)/FIO(2) 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 PaO(2)/FIO(2) 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 PaO(2)/FIO(2) 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


CONCLUSIONS
Experimental aspiration pneumonitis after intratracheal infusion of human gastric juice is characterized by a stable fall in PaO(2)/FIO(2). Animals with the most severe lung injury experienced a lower systemic arterial pressure, cardiac output, and metabolic acidosis without circulatory failure or cardiac dysfunction.
Fraisse
Alain
A
Cardiologie Pédiatrique, Département de Cardiologie, Hôpital de la Timone, 264 rue St. Pierre, 13385, Marseille Cedex 5, France.
Bregeon
Fabienne
F
Delpierre
Stéphane
S
Gaudart
Jean
J
Payan
Marie José
MJ
Pugin
Jérome
J
Papazian
Laurent
L
D000818:Animals; D001794:Blood Pressure; D002302:Cardiac Output; D004452:Echocardiography; D005750:Gastric Juice; D006339:Heart Rate; D006863:Hydrogen-Ion Concentration; D011015:Pneumonia, Aspiration / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D011817:Rabbits