Physiologic contributors to reduced exercise capacity in individuals with sickle cell anemia (SCA) are not well understood. The objective of this study was to characterize the cardiopulmonary response to maximal cardiopulmonary exercise testing (CPET) and determine factors associated with reduced exercise capacity among children and young adults with SCA. A cross-sectional cohort of 60 children and young adults (mean 15.1 ± 3.4 years) with hemoglobin SS or S/β0 thalassemia and 30 matched controls (mean 14.6 ± 3.5 years) without SCA or sickle cell trait underwent maximal CPET by a graded, symptom-limited cycle ergometry protocol with breath-by-breath, gas exchange analysis. Compared to controls without SCA, subjects with SCA demonstrated significantly lower peak VO2 (26.9 ± 6.9 vs. 37.0 ± 9.2 mL/kg/min, P < 0.001). Subjects demonstrated slower oxygen uptake (ΔVO2/ΔWR, 9 ± 2 vs. 12 ± 2 mL/min/watt, P < 0.001) and lower oxygen pulse (ΔVO2/ΔHR, 12 ± 4 vs. 20 ± 7 mL/beat, P < 0.001) as well as reduced oxygen uptake efficiency (ΔVE/ΔVO2, 42 ± 8 vs. 32 ± 5, P < 0.001) and ventilation efficiency (ΔVE/ΔVCO2, 30.3 ± 3.7 vs. 27.3 ± 2.5, P < 0.001) during CPET. Peak VO2 remained significantly lower in subjects with SCA after adjusting for age, sex, body mass index (BMI), and hemoglobin, which were independent predictors of peak VO2 for subjects with SCA. In the largest study to date using maximal CPET in SCA, we demonstrate that children and young adults with SCA have reduced exercise capacity attributable to factors independent of anemia. Complex derangements in gas exchange and oxygen uptake during maximal exercise are common in this population.

Cystic fibrosis transmembrane conductance regulator (CFTR) modulators are small molecules that directly impact the CFTR protein, improving the function of the CFTR chloride and bicarbonate channel. Beginning in 2012 with the Food and Drug Administration approval of the first CFTR modulator, ivacaftor, this class of medications has had largely positive effects on many outcomes in people with cystic fibrosis (PwCF), including lung function, growth, and other clinical parameters. There have been continued exciting developments in the current research on CFTR modulators, expanding beyond original studies. This first part of a three-part cystic fibrosis (CF) year in review 2020 will focus on research on CFTR modulators. In addition to reviewing new clinical insights, we describe work done on novel outcomes, adverse effects, issues related to cost, and next steps for clinical trials. The review focuses on articles from Pediatric Pulmonology published in 2020, but it includes articles from other journals that are of particular interest to clinicians. New developments in CF research continue to be brought forth to the CF community, deepening the understanding of this disease and improving clinical care.

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ObjectiveTo reduce the risk of pathogen transmission between patients with cystic fibrosis (CF) and decrease the rate of acquisition of new CF pathogens in our patients.DesignUsing the Model for Improvement, we developed a new process for infection prevention and control in our outpatient CF clinics.SettingPaediatric CF programme at Ann & Robert H. Lurie Children's Hospital of Chicago; approximately 180 paediatric patients aged birth to 21 years.ParticipantsAll paediatric patients enrolled in the Cystic Fibrosis Foundation Patient Data Registry at this institution.InterventionsImplemented contact precautions withallpatients, regardless of respiratory tract culture results.MeasurementRespiratory tract culture rates of specific pathogens by quarter were compared prior to and after implementation.ResultsOur percentage of patients with a positive respiratory tract culture forPseudomonas aeruginosadropped from 30% to 21% (p<0.0001) and for methicillin-resistantStaphylococcus aureus(MRSA) dropped from 10.8% to 8.7% (p=0.008).ConclusionsUse of contact precautions by all care providers, for all patients, regardless of respiratory tract culture results resulted in decreasedP aeruginosaand MRSA infection rates.