Effects of experimental fat embolism on central hemodynamics and oxygenation in pigs

Nine anesthetized and mechanically ventilated test pigs were intracavally infused with a 10% allogeneic bone marrows suspension at a dose of 100 mg/kg over 5 min; 9 control pigs received saline. The cardiac index decreased slightly in the fat embolism animals. Left ventricular stroke work remained unchanged in both groups, whereas right ventricular stroke work rose in the fat embolism animals. Mean arterial pressure remained stationary in the test group but rose in the controls. Pulmonary capillary wedge pressure and central venous pressure rose slightly in the test group. After infusion of the bone marrow suspension, mean pulmonary arterial pressure, pulmonary vascular resistance, pulmonary shunt and alveoloarterial oxygen tension difference increased immediately and remained elevated throughout the study period. Simultaneously, arterial and mixed venous oxygen tension and hemoglobin oxygen saturation decreased. Arterial carbon dioxide tension and hematocrit remained stationary. The fat embolism animals developed gradual fever. In conclusion, increased mean pulmonary arterial pressure, pulmonary vascular resistance, pulmonary shunt and alveoloarterial oxygen tension difference proved to be useful early indicators of experimental fat embolism.