Rationale: Chronic obstructive pulmonary disease (COPD) guidelines make no recommendations for allergy diagnosis or treatment. Objectives: To determine whether an allergic phenotype contributes to respiratory symptoms and exacerbations in patients with COPD. Methods: Two separate cohorts were analyzed: National Health and Nutrition Survey III (NHANES III) and the COPD and domestic endotoxin (CODE) cohort. Subjects from NHANES III with COPD (n ¼ 1,381) defined as age . 40 years, history of smoking, FEV 1 /FVC , 0.70, and no diagnosis of asthma were identified. The presence of an allergic phenotype (n ¼ 296) was defined as self-reported doctor diagnosed hay fever or allergic upper respiratory symptoms. In CODE, former smokers with COPD (n ¼ 77) were evaluated for allergic sensitization defined as a detectable specific IgE to perennial allergens. Bivariate and multivariate models were used to determine whether an allergic phenotype was associated with respiratory symptoms and exacerbations. Measurements and Main Results: In NHANES III, multivariate analysis revealed that individuals with allergic phenotype were more likely to wheeze (odds ratio [OR], 2.1; P , 0.01), to have chronic cough (OR, 1.9; P ¼ 0.01) and chronic phlegm (OR, 1.5; P , 0.05), and to have increased risk of COPD exacerbation requiring an acute doctor visit (OR, 1.7; P ¼ 0.04). In the CODE cohort, multivariate analysis revealed that sensitized subjects reported more wheeze (OR, 5.91; P , 0.01), more nighttime awakening due to cough (OR, 4.20; P ¼ 0.03), increased risk of COPD exacerbations requiring treatment with antibiotics (OR, 3.79; P ¼ 0.02), and acute health visits (OR, 11.05; P , 0.01). An increasing number of sensitizations was associated with a higher risk for adverse health outcomes. Conclusions: Among individuals with COPD, evidence of an allergic phenotype is associated with increased respiratory symptoms and risk of COPD exacerbations.Keywords: atopy; allergic sensitization; allergy; chronic obstructive pulmonary disease Chronic obstructive pulmonary disease (COPD), a chronic disease of the airways, is caused by tobacco smoke and other air pollutant exposures (1). In the United States, COPD affects 14% of the adult population and is the third leading cause of death (2). Annually, COPD is responsible for 726,000 hospitalizations and over $32 billion in estimated cost, reflecting a large public health burden (3). Patients with COPD suffer significant morbidity, including respiratory symptoms that adversely affect quality of life and limit activity (4). Given the significant morbidity, understanding the different factors that contribute to symptom burden in COPD is an important focus of research.Allergic sensitization, assessed by allergen-specific IgE or skin prick testing, is a known risk factor for asthma (5, 6), and exposure to specific allergens in sensitized patients with asthma is known to worsen pulmonary symptoms (7,8). National and international guidelines recommend assessment of allergic sensitization and environmental exposur...

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Background: High Flow Nasal Cannula (HFNC) has gained widespread use for acute hypoxemic respiratory failure on the basis of recent publications demonstrating fewer intubations and perhaps lower mortality in certain situations. However, a subset of patients initiated on HFNC for respiratory failure ultimately do require intubation. Our goal is to identify patient level features predictive of this outcome. Materials and methods: This is a retrospective cohort study of patients with hypoxemic respiratory failure treated with HFNC. Individuals were described as having "succeeded" (if weaned from HFNC) or "failed" (if they required intubation). A variety of easily measurable variables were evaluated for their ability to predict intubation risk, analyzed via a multivariate logistic regression model. Results: Of a total of 74 subjects, 42 "succeeded" and 32 "failed." Net fluid balance in the first 24 hours after HFNC initiation was significantly lower in the success group (-33 ± 80 vs. +72 ± 117 mL / h, p <0.01). An adjusted model finds only fluid balance and the previously described Respiratory Rate-Oxygenation (ROX) index (a ratio of the oxygen saturation (SpO 2) divided by the fraction of inspired oxygen (FiO 2) to the respiratory rate (RR), [SpO 2 /FiO 2 ]/RR) at 12 hours as significant predictors of successful weaning (negative fluid balance adjusted OR 0.77 [0.62-0.96] for-10 mL/Hr increments, p = 0.02; ROX adjusted OR 1.72 p <0.01). Conclusions: Negative fluid balance while on HFNC discriminates well between those who will require intubation versus those who will be successfully weaned.

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