Acute Chest SyndromeAnemia, Sickle CellChest PainEmbolism, FatHemoglobin SC DiseaseAntisickling AgentsSyndromeLung DiseasesSickle Cell TraitAcute DiseaseHydroxyureaHemoglobin, SicklePainBlood TransfusionFetal HemoglobinLungRespiratory InsufficiencyPulmonary EmbolismHemolysisFeverLeukocytosisRetrospective StudiesTriageCohort StudiesAcute Coronary SyndromeEmergency Service, HospitalLung NeoplasmsTomography, X-Ray ComputedThorax