Design of the Reducing Diagnostic Error to Improve Patient Safety (REDEfINE) in COPD and asthma study: A cluster randomized comparative effectiveness trial.

Although spirometry is a simple, portable test and recommended for the diagnosis of asthma and chronic obstructive pulmonary disease (COPD), it is not routinely used in the primary care setting. Minorities and underserved populations are less likely to have spirometry assessment, leading to both over and misdiagnosis of asthma and COPD. Because dyspnea is a common symptom across multiple diseases, use of spirometry as a diagnostic tool is important. Missed, delayed, or misdiagnosis of asthma and COPD, which are considered diagnostic errors (DE), can lead to poor quality of care, increased morbidity and mortality, and increased costs to patients and health systems. Barriers to the use of spirometry have been identified at clinician/clinic and health systems levels. The REDEFINE program is designed to overcome identified barriers to spirometry use in primary care by utilizing health promoters (HPs) who perform spirometry within primary care clinics and work collaboratively with clinicians to incorporate the results at the point of care without interrupting clinic workflow. The REDEFINE trial is a comparative effectiveness study comparing outcomes of the REDEFINE program with usual care (UC) in primary care patients determined to be at increased risk of DE for asthma and COPD. The primary outcome will be all-cause hospitalizations. The secondary outcomes will be the proportion of accurate diagnosis of COPD, asthma, or asthma-COPD overlap based on initial diagnosis and spirometry and all cause and respiratory-related acute outpatient care and emergency department visits. In this report, we describe the design and methods for the REDEFINE trial. Trial registration: NCT03137303https://clinicaltrials.gov/ct2/show/NCT03137303?term=REDEFINE&draw=2&rank=1.

The clinical implications of tests confirming COPD in subjects hospitalized with exacerbations.

BACKGROUND: The diagnosis of COPD in patients hospitalized for AECOPD can be confirmed by spirometry showing obstruction or radiographs showing emphysema. The evidence for COPD is sometimes absent or contradicts this diagnosis. The inaccurate attribution of the exacerbation to COPD can lead to suboptimal care and worse outcome. OBJECTIVES: We determined if the presence of tests that confirm the diagnosis of COPD has any implications on the course of the hospitalization and readmission rate. METHODS: We selected subjects hospitalized between 2012 and 2014 for AECOPD. We divided them into four hierarchical, mutually exclusive groups based on the presence of tests that confirm the diagnosis of COPD: spirometry (COPDSPIRO), radiology (COPDRAD), clinical diagnosis (COPDCLIN), and no COPD by spirometry (NotCOPD). We compared the presentation, hospital course, outcome, and readmission rate between the four groups. RESULTS: We identified 974 subjects: COPDSPIRO 22%, COPDRAD 24%, COPDCLIN 46% and 7% NotCOPD. The vital signs, use of respiratory support, admission to the MICU, and length of stay were similar between the groups. The age, gender, BMI, presence of comorbidities, and readmission rate were different between the groups. The NotCOPD group had the highest BMI (38 kg/m2), comorbidities, and 30-day all-cause readmission (17%). Logistic regression showed that serum creatinine and presence of any comorbidity were the independent predictors of 30-day all-cause readmission. CONCLUSION: COPD was confirmed by spirometry or radiographs in half of the subjects hospitalized for AECOPD. The presence of confirmation did not influence the hospital course. The presence of confirmation was associated with different readmission rate, but was accounted for by the presence of comorbidities.

Hypoxia-mediated degradation of Na,K-ATPase via mitochondrial reactive oxygen species and the ubiquitin-conjugating system.

We set out to determine whether cellular hypoxia, via mitochondrial reactive oxygen species, promotes Na,K-ATPase degradation via the ubiquitin-conjugating system. Cells exposed to 1.5% O2 had a decrease in Na,K-ATPase activity and oxygen consumption. The total cell pool of alpha1 Na,K-ATPase protein decreased on exposure to 1.5% O2 for 30 hours, whereas the plasma membrane Na,K-ATPase was 50% degraded after 2 hours of hypoxia, which was prevented by lysosome and proteasome inhibitors. When Chinese hamster ovary cells that exhibit a temperature-sensitive defect in E1 ubiquitin conjugation enzyme were incubated at 40 degrees C and 1.5% O2, the degradation of the alpha1 Na,K-ATPase was prevented. Exogenous reactive oxygen species increased the plasma membrane Na,K-ATPase degradation, whereas, in mitochondrial DNA deficient rho(0) cells and in cells transfected with small interfering RNA against Rieske iron sulfur protein, the hypoxia-mediated Na,K-ATPase degradation was prevented. The catalase/superoxide dismutase (SOD) mimetic (EUK-134) and glutathione peroxidase overexpression prevented the hypoxia-mediated Na,K-ATPase degradation and overexpression of SOD1, but not SOD2, partially inhibited the Na+ pump degradation. Accordingly, we provide evidence that during hypoxia, mitochondrial reactive oxygen species are necessary to degrade the plasma membrane Na,K-ATPase via the ubiquitin-conjugating system.

Oxygen sensing requires mitochondrial ROS but not oxidative phosphorylation.

Mammalian cells detect decreases in oxygen concentrations to activate a variety of responses that help cells adapt to low oxygen levels (hypoxia). One such response is stabilization of the protein HIF-1 alpha, a component of the transcription factor HIF-1. Here we show that a small interfering RNA (siRNA) against the Rieske iron-sulfur protein of mitochondrial complex III prevents the hypoxic stabilization of HIF-1 alpha protein. Fibroblasts from a patient with Leigh's syndrome, which display residual levels of electron transport activity and are incompetent in oxidative phosphorylation, stabilize HIF-1 alpha during hypoxia. The expression of glutathione peroxidase or catalase, but not superoxide dismutase 1 or 2, prevents the hypoxic stabilization of HIF-1 alpha. These findings provide genetic evidence that oxygen sensing is dependent on mitochondrial-generated reactive oxygen species (ROS) but independent of oxidative phosphorylation.