Are we missing the mark? Fever, respiratory symptoms, chest radiographs, and acute chest syndrome in sickle cell disease

Abstract

Acute chest syndrome (ACS) is defined as a new pulmonary infiltrate detected by chest radiography (CXR) associated with fever, respiratory symptoms, or chest pain [1,2]. It is the second most common cause of hospital admissions in SCD, and can lead to significant morbidity and mortality [2]. Evidence in the literature has established that clinical assessment alone is not a sensitive predictor of ACS [1,2]. Although these studies were performed nearly 20 years ago, they advocate for empiric CXR utilization all febrile children with SCD [1,2]. Since then, the incidence of ACS in febrile children has decreased from 27 to 17.4% (P < 0.001) [3], likely due in part to routine penicillin prophylaxis, expanded pneumococcal immunization coverage, and hydroxyurea use. National Institutes of Health (NIH) guidelines for febrile SCD patients were updated in 2014 recommending that patients with fever associated with shortness of breath, tachypnea, cough, and/or rales should undergo CXR to evaluate for ACS [4]. No systemic review of the literature was done regarding these SCD/fever guidelines, which utilized panel consensus expert opinion. Since there are discrepancies between the current NIH guidelines, many institutional clinical pathway recommendations and evidence from the literature, this study was undertaken to help identify febrile children with SCD requiring a CXR as part of their assessment.2013 emergency department (ED) data were obtained by electronic medical record using ICD-9 codes linked to fever and SCD in children 2 months-18 years through a retrospective chart review at two urban tertiary-care campuses of Children's Healthcare of Atlanta (CHOA). Demographics, past medical history, vital signs, review of systems (ROS), physical exam (PE) findings, CXR radiology interpretation, and ACS diagnosis were obtained by chart review; see "Supporting Information Methods" for details. Children with Negative Vs. Positive CXR (ACS). Supporting Information Table II summarizes demographics, clinical characteristics and risk factors for patients with ACS (n 5 66) compared to those with negative CXRs. Of encounters evaluated by CXR, the prevalence of ACS was 17.2% in our cohort. Risk factors for ACS as determined by univariate analysis include the presence of tachypnea, history of ACS, and abnormal ROS (presence of cough, wheeze, or chest pain). An abnormal lung exam was also more frequently found in children diagnosed with ACS. However, 62% of patients with ACS had a normal lung exam. Patients with ACS were also more frequently admitted to the hospital. Of all admitted patients, those with ACS more frequently utilized oxygen and BiPAP. However, there was no difference in age, gender, height of fever, asthma diagnosis, presence of rhinorrhea, congestion, grunting, or shortness of breath in children diagnosed with ACS compared to those with a negative CXR. Clinical characteristics involving patients discharged from the ED and <72-h ED returns are summarized in Supporting Information Methods/Results. One patient who was discharge...

Predictors of impending acute chest syndrome in patients with sickle cell anaemia

“…As reported previously 20,21 , a higher WBC count at baseline predicted a higher risk of ACS and was also seen in our study. Furthermore, these patients demonstrated a further rise in WBC count associated with a considerable drop in haemoglobin from baseline and with significantly higher platelet counts, as these patients more frequently progressed to ACS when compared to VOC patients in the control group.…”

“…Nevertheless, fever, hypoxia, and abnormal lung findings on clinical examination at admission are significant predictors for evolving to full blown ACS 9 . These findings also reemphasize the observations made in other studies, including the corporative study on SCA and others 20,21 . Table 2.…”

“…Although only 4% of the ACS group showed culture-proven bacterial infection, all of our patients received empiric broad-spectrum antibiotics. Infection is a major cause of morbidity and mortality in patients with SCA 9,19,21 . Our data are also consistent with a previous prospective study suggesting that bacterial pneumonia is not frequent in adult episodes of ACS 22 .…”

Predicting risk factors for thromboembolic complications in patients with sickle cell anaemia – lessons learned for prophylaxis

“… 19 This current study found that a high percentage of the VTE patients had a history of ACS (82.4%), implying that it did predispose to the occurrence of VTE, and such patients suffered from ACS as a complication of PE. Furthermore, previous research has demonstrated that PE is considered to significantly predispose for ACS, with PE episodes developing during ACS, 25 which is again similar to these current observations. However, it is difficult to conclude (from the current data), whether PE is a cause or a consequence of ACS.…”

“… 18 It has been suggested that thrombosis-in-situ could be responsible for this striking difference and that PE may be an aetiological factor in SCA patients that develop respiratory symptom. 25 Pulmonary hypertension with tricuspid regurgitation jet velocity ≥2.5 m/s is linked to VTE. 26 Although, SCD is a hypercoagulable state, the contribution of VTE to an elevated tricuspid regurgitation velocity is unknown.…”