PLASMA-LEVELS OF ATRIAL-NATRIURETIC-PEPTIDE AND ENDOTHELIN-1 IN EXPERIMENTAL FAT-EMBOLISM

In order to understand the role of vasoactive peptides in fat embolism , arterial plasma atrial natriuretic peptide (ANP) and endothelin-1 co ncentrations were investigated in an experimental study. Nine anesthet ized and mechanically ventilated pigs received an intracaval infusion of allogeneic bone marrow suspension at a dose of 100 mg/kg (fat embol ism group); 9 control pigs received saline. The observation period was 5 h. Ln the Fat embolism group, cardiac index and heart rate decrease d within 30 min, whereas mean arterial pressure remained stationary. P ulmonary capillary wedge pressure rose transiently and central venous pressure rose slightly in time, while mean pulmonary arterial pressure , pulmonary vascular resistance and pulmonary shunt increased immediat ely and persistently after the bone marrow suspension infusion. Simult aneously, arterial oxygen tension and arterial hemoglobin oxygen satur ation decreased markedly. Arterial plasma ANP and endothelin-1 concent rations remained stable in the fat embolism animals, whereas in the co ntrols ANP and endothelin-1 levels decreased at 3 and 5 h. Arterial ep inephrine concentrations were stable in animals receiving bone marrow suspension, while in the controls arterial epinephrine concentrations decreased towards the end of the experiment. Arterial norepinephrine c oncentrations remained unchanged in both groups. To conclude, impaired pulmonary function and consequent systemic hypoxemia distinguish the present fat embolism model. Unchanged arterial ANP and endothelin-l co ncentrations in the fat embolism group suggest that these circulating vasoactive hormones have a minor impact on the pathogenesis of the cur rent experimental fat embolism.