One hundred seven patients with extremity fractures and no preexisting respiratory or coagulation disorders were studied. Respiratory alkalosis was found in 83 patients. Although an arterial oxygen pressure less than 70 mm Hg was found in 34 patients and an alveolar-arterial oxygen difference (A-a DO2) greater than 40 mm Hg was found in 46, clinical or x-ray evidence of respiratory problems was rare. Incidence of moderate respiratory abnormalities (A-a DO2 >40 mm Hg) in patients with thrombocytopenia was almost double that found in patients with normal platelet counts, suggesting presence of fat embolism. Average fibrinogen levels rose from 320 to 540 mg/100 ml by the fifth to sixth days.
Serial blood gas determinations, platelet counts, and fibrinogen levels should be obtained on all patients with trauma at time of admission and every 24 to 48 hours thereafter if significant abnormalities are noted.