To investigate the acute effects of experimental fat embolism on splanchnic and peripheral perfusion and oxygenation in pigs.
Randomized, controlled trial.
Eighteen domestic pigs, weighing 25 to 31 kg.
The 18 pigs were randomized to either the fat embolism or control groups. Nine anesthetized and mechanically ventilated pigs were intracavally infused with a 10% allogeneic bone marrow suspension at a dose of 100 mg/kg over 5 mins (the fat embolism group); nine control pigs received normal saline in the same volume and speed (control group).
Measurements and Main Results
Mean pulmonary arterial pressure, pulmonary vascular resistance, and pulmonary shunt increased, and PaO2 decreased immediately after the bone marrow suspension infusion. In the fat embolism animals, oxygen delivery decreased, oxygen content difference widened, and total oxygen consumption remained high, indicating enhanced oxygen extraction. Further, superior mesenteric artery blood flow and mesenteric oxygen delivery decreased, while intramucosal pH in the small bowel was stable. Subcutaneous PO2 decreased in both groups, whereas transcutaneous PO2 decreased only in the animals receiving bone marrow suspension. Skin red cell flux showed no significant changes.
The present model of fat embolism results in significant impairment in systemic oxygenation. Despite this fact, the intestinal oxygenation remains unaffected probably due to sufficient compensatory mechanisms. Transcutaneous PO2 measurements may provide a useful index for early detection of fat embolism.
(Crit Care Med 1996; 24:1018-1024)