Acute chest syndrome (ACS) is a leading cause of morbidity and mortality in patients with Sickle Cell Disease (SCD). Although the NIH recommends transfusion as standard of care therapy for this diagnosis, practice patterns vary. In 2000, the National Acute Chest Study group found that 72% of patients with ACS were transfused. This study, which was perfomed at academic medical centers with sickle cell treatment programs, used specific diagnostic inclusion criteria. As ACS may be difficult to distinguish from pneumonia, recognition and treatment of the diagnosis may vary by hospital and by presence or absence of a sickle cell specialist. With access to hospital discharge data from all California hospitals seeing SCD patients, we aimed to describe transfusion practices in ACS.
This retrospective cohort study uses 2005–2008 public data from the California Office of Statewide Health Planning and Development (OSHPD). Data included all inpatient and emergency department (ED) discharges from all non-federal California hospitals. Cases were selected based on discharge from or admission via an ED and the presence of a sickle cell disease ICD-9 code in the primary or a secondary diagnosis (282.60-282.69, 282.41–282.42). Further inclusion criteria included presence of ACS (517.3) or respiratory diagnoses including pneumonia, pulmonary edema, acute respiratory distress syndrome, hypoxia and respiratory failure in any primary or secondary diagnosis. Frequency of transfusion, intubation and mortality were described and chi-square tests were performed to determine the statistical significance of differences between groups of patients treated with or without transfusion as well as between groups of adults and children.
Between 2005–2008, 4306 ED visits by Californians with SCD were associated with either ACS or a related respiratory diagnosis and only 42.5% of these cases were associated with transfusion. Limiting the diagnosis to ACS only, 1399 cases were identified, and still only 50.4% of these cases were associated with transfusion. Among patients with ACS or a related diagnosis, the majority were admitted to the hospital (90.9%); only 59.2% of intubated cases (n=238) were transfused; and of the 92 deaths during this period, only 46.7% were associated with transfusion. Patients who were 18 and over were transfused more often than young children (43.2% vs. 35.7%; 2(1)=12.37, p<0.001).
Despite transfusion being the standard of care for treatment of ACS as well as other sickle–related complications, many ACS cases in California are not being treated in this manner. Surprisingly, the most severely ill patients, those who were either intubated or died during the study period, had a lower transfusion frequency than the cohort as a whole. Although some mild pediatric cases may not be transfused, a minority of the total cohort was under 18 years old. Recent studies imply that patients transitioning out of pediatric SCD programs have an increased risk of dying due to ACS and other serious SCD complications. Our study suggests that underutilization of transfusion may play a role in these poor adult outcomes in SCD. These findings prompt further investigation into the role of transition to adult care and appropriate medical homes in access to quality SCD care.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.