The most common identifiable cause of ACS in this study was pulmonary fat embolism (PFE). 4 Originally described in trauma victims, PFE is a frequent complication of bone fracture and may progress to involve the lungs and CNS with multiorgan failure and death. 10,11 The NACSS made the diagnosis by using BAL to identify fat-laden macrophages; less-invasive means of making the diagnosis are not well established, and even the specificity of fat-laden macrophages in BAL specimens has been questioned. 12 Vichinsky et al, 13 in the first systematic, prospective search for PFE in sickle cell disease, found that 44% of patients with moderate-to- severe ACS had PFE as a probable etiology. These patients had longer,.
