Bedside ultrasound as a predictive tool for acute chest syndrome in sickle cell patients.

ABSTRACT

BACKGROUND: Acute chest syndrome (ACS) is the leading cause of death for patients with sickle cell disease (SCD). Early recognition of ACS improves prognosis. OBJECTIVE: Investigate the use of bedside lung ultrasound (BLU) in identification of early pulmonary findings associated with ACS in SCD patients. METHODS: Prospective, observational study of a convenience sample of SCD patients presenting to the Emergency Department (ED) for a pain crisis. BLU interpretations were made by an emergency physician blinded to the diagnosis of ACS, and were validated by a second reviewer. The electronic medical record was reviewed at discharge and at 30 days. RESULTS: Twenty SCD patients were enrolled. Median age was 31 years, median hemoglobin was 7.7 g/dL. Six patients developed ACS. Five patients in the ACS group had lung consolidations on BLU (83%) compared to 3 patients in the non-ACS group (21%), p = 0.0181, (OR = 12.05, 95% CI 1.24 to 116.73). The ACS group was also more likely to have a pleural effusion and B-lines on BLU than the non-ACS group, p = 0.0175; 0.1657, respectively. In the ACS group, peripheral and frank consolidations on BLU was 83% and 50% sensitive, 79% and 100% specific for ACS, respectively; whereas an infiltrate on initial chest X-ray (CXR) was only 17% sensitive. BLU identified lung abnormalities sooner than CXR (median 3.6 vs. 31.8 h). CONCLUSIONS: Pulmonary abnormalities on BLU of an adult SCD patient presenting to the ED for a painful crisis appear before CXR, and highly suggest ACS. BLU is a promising predictive tool for ACS.