Zayir M Malik’s research while affiliated with University of Chicago and other places

Study objective: Acute chest syndrome is a leading cause of mortality in patients with sickle cell disease (SCD). Because early detection of acute chest syndrome is directly tied to prognosis, young patients with SCD undergo countless chest radiography screenings throughout their lifetime for commonly occurring acute chest syndrome risk factors such as fever, chest pain, or cough. Chest radiography is not an ideal screening method because it is associated with radiation exposure, which accumulates with repeated imaging. Point-of-care lung ultrasonography is a nonradiating imaging modality that has been used to identify other lung pathology and may have a role in SCD. The goal of this study was to determine the accuracy of point-of-care lung ultrasound to identify an infiltrate suggestive of acute chest syndrome in patients with SCD compared to chest radiography as the gold standard. Methods: This was a prospective observational study in 2 urban pediatric emergency departments to evaluate the accuracy of point-of-care lung ultrasonography in identifying patients with SCD who were aged 0 to 21 years and had an infiltrate suggestive of acute chest syndrome compared with chest radiography. Clinicians and trainees with point-of-care lung ultrasonographic training obtained informed consent and performed investigational point-of-care lung ultrasonography to evaluate for lung consolidation. A blinded point-of-care lung ultrasonographic expert reviewed results for quality assurance and agreement. Accuracy, sensitivity, specificity, likelihood ratios, and positive and negative predictive value were calculated for point-of-care lung ultrasonography test performance characteristics, with chest radiography as a reference standard. Results: Point-of-care lung ultrasonography was performed on 191 SCD patients with a mean age of 8 years; 41% were female patients, and there was a 17% prevalence of acute chest syndrome. Accuracy of point-of-care lung ultrasonography to detected acute chest syndrome was 92%, sensitivity was 88%, and specificity was 93% compared with that for chest radiography. Conclusion: Point-of-care lung ultrasonography is a feasible alternative to chest radiography for screening for acute chest syndrome in young patients with SCD. Further studies are needed to determine how this test performs within clinical practice.

Background: Acute chest syndrome (ACS) is a common complication in patients with sickle cell disease (SCD) and is a leading cause of morbidity and mortality.Chest X-ray (CXR) is recommended for evaluating ACS in patients with SCD because clinical findings alone have a low sensitivity. Children with SCD are repeatedly exposed to diagnostic radiation for the evaluation of ACS. Lung ultrasound (LUS) has been compared to CXR as an alternative imaging modality for evaluating ACS, and a lung consolidation > 1 cm is sensitive and specific for diagnosing patients with ACS. Consolidations < 1 cm, or subpleural consolidations, can detect pneumonia earlier than CXR; however, the significance of these findings for evaluating ACS is unknown. We evaluated LUS with consolidations <1 cm to determine if they could identify patients with ACS. Methods: This is a prospective observational study that took place from November 2014-July 2016 in 2 urban pediatric emergency departments (EDs). The study population consisted of a convenience sample of patients with SCD from birth to 18 years of age at risk for ACS and who received a clinically-indicated CXR for suspected ACS. ACS was defined as a new pulmonary infiltrate on CXR together with the presence of fever, cough, chest pain, or respiratory symptoms. LUS were performed to evaluate for lung consolidation and determine the sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-) of LUS to identify ACS. In a subanalysis, the charts of patients who had a negative CXR interpreted by a pediatric radiologist or consolidation < 1 cm on LUS at the time of enrollment were reviewed for development of ACS within 7 days of the visit. The development of ACS in patients with subpleural findings on LUS was compared to patients with negative ultrasound findings. Fischer's-Exact Test was used to determine significance between the 2 groups with α = 0.05. Results: One hundred sixty-eight patients were enrolled. ACS was diagnosed in 14% of patients, while a CXR was negative in 150 cases. The sensitivity of LUS to predict ACS was 91%, specificity was 91%, LR+ 10.5, LR- 0.1. Thirty-six cases had subpleural consolidation on LUS and 3 patients (8%) developed ACS. Of the 114 patients with negative LUS, 7 (6%) developed ACS. There was no statistical difference between these groups with p-value of 0.7. Conclusions: Patients with subpleural consolidations on LUS were no more likely to develop ACS than those patients with a negative LUS. The small number of patients who developed ACS may have failed to show a statistical difference between these groups. Further studies with serial ultrasound examinations are needed to better define the significance of this finding. Disclosures Morris: MAST: Research Funding; Pfizer: Consultancy; Calithera: Consultancy; Nourish Life: Patents & Royalties: I am the inventor of IP owned by UCSF-Benioff Children's Hospital that is licensed to NL; Endeavor: Consultancy; Nestle: Honoraria.

Background: Acute chest syndrome (ACS) is a common complication in patients with sickle cell disease (SCD) and is a leading cause of morbidity and mortality. Physical assessment alone is not sensitive for diagnosing ACS and therefore Chest x-ray (CXR) is recommended because of the difficulty of diagnosing ACS on clinical grounds alone. Children with SCD are repeatedly exposed to diagnostic radiation for the evaluation of ACS. Focused chest ultrasound (US) has been used to evaluate for lung consolidation. If lung US can identify patients with ACS this application could potentially limit radiation exposure in patients with SCD at risk for ACS. We evaluated the utility of physician performed US as compared to CXR to identify patients with SCD who have ACS. Methods: This is a prospective observational study that took place from November 2014-July 2015 in 2 urban pediatric emergency departments (EDs). The study population consisted of a convenience sample of patients with SCD from birth to 18 years of age at risk for ACS and who received a CXR for suspected ACS. Medical students and clinicians with training in lung sonography consented patients and performed a focused study to evaluate for lung consolidation. A blinded expert in point-of-care US reviewed for quality assurance and agreement. Sensitivity, specificity, and likelihood ratios were calculated for test performance characteristics of ultrasound using CXR as a reference standard. Inter-observer agreement (κ) between enrolling sonologists and reviewer was also calculated. Results: 85 patients were enrolled for a total of 98 cases. Median age was 7 years (IQR 2-13 years) and 53% of patients were male. The prevalence of ACS by CXR was 14%. Lung US was able to detect consolidation with a sensitivity of 86% (95% CI, 56-97%), specificity of 95% (95% CI, 87%-98%), positive likelihood ratio (LR) 18 (95% CI, 7-48) and negative LR 0.2 (95% CI, 0.04-0.5). The agreement between enrolling novice sonologists' interpretation and blinded reviewer's interpretation was very good with a Cohen κ of 0.86 (95% CI, 0.7-1). Conclusions: Focused lung US was able to identify ACS with high specificity. There was very good agreement between novice and expert sonologist interpretation. Lung US may decrease the need for CXR in patients at risk for ACS. Further studies are needed to see how this test performs within current clinical practice guidelines. Disclosures No relevant conflicts of interest to declare.