Exchange versus simple transfusion for acute chest syndrome in sickle cell anemia adults

Background: There are scant data regarding the relative efficacy of exchange transfusion (XC) versus simple transfusion (ST) for treatment of sickle cell anemia acute chest syndrome (ACS). Study Design and Methods: Twenty patients who received XC for ACS were compared with 20 ST patients. Hemoglobin (Hb) levels, platelet and white blood cell counts, lactate dehydrogenase (LDH), indirect bilirubin, and temperature were used to assess disease severity. Primary outcome was postprocedure length of hospital stay; secondary outcome was total length of stay. Results: Cohorts were similar with regard to age; sex; prior ACS episodes; echocardiogram results; and antibiotic, bronchodilator, and hydroxyurea use. Maximum temperature recorded was higher in the XC group (39.1°C vs. 38.4°C, p = 0.02), but LDH, WBCs, and indirect bilirubin were comparable. Admission Hb levels were higher for XC (XC 8.6 g/dL vs. ST 7.4 g/dL, p = 0.02) and XC had higher peak Hb levels during hospitalization (10.4 ± 1.4 g/dL vs. 9.3 ± 1.0 g/dL, p ≤ 0.01). No differences were demonstrable in postprocedure length of stay (XC 5.6 days vs. ST 5.9 days, p = 0.82) or total length of stay (XC 8.4 days vs. ST 8.0 days, p = 0.76). A total of 10.3 ± 3.0 units were transfused for XC compared to 2.4 ± 1.2 units for ST (p < 0.001). CONCLUSIONS: Based on postprocedure length of stay or total length of stay, we could not detect a difference in the efficacy of XC compared to ST in populations despite red blood cell product usage fourfold higher in the XC group. We suggest that it is time for an adequately powered, randomized trial to examine the true risk:benefit ratio of XC in ACS.