Active transport of sodium across the alveolar epithelium, undertaken in part by the Na,K-adenosine triphosphatase (Na,K-ATPase), is critical for clearance of pulmonary edema fluid and thus the outcome of patients with acute lung injury. Acute lung injury results in disruption of the alveolar epithelial barrier and leads to impaired clearance of edema fluid and altered Na,K-ATPase function. There has been significant progress in the understanding of mechanisms regulating alveolar edema clearance and signaling pathways modulating Na,K-ATPase function during lung injury. The accompanying review by Morty et al. focuses on intact organ and animal models as well as clinical studies assessing alveolar fluid reabsorption in alveolar epithelial injury. Elucidation of the mechanisms underlying regulation of active Na+ transport, as well as the pathways by which the Na,K-ATPase regulates epithelial barrier function and edema clearance, are of significance to identify interventional targets to improve outcomes of patients with acute lung injury.

Patients with chronic obstructive pulmonary disease (COPD) are at increased risk for both the development of primary lung cancer, as well as poor outcome after lung cancer diagnosis and treatment. Because of existing impairments in lung function, patients with COPD often do not meet traditional criteria for tolerance of definitive surgical lung cancer therapy. Emerging information regarding the physiology of lung resection in COPD indicates that postoperative decrements in lung function may be less than anticipated by traditional prediction tools. In patients with COPD, more inclusive consideration for surgical resection with curative intent may be appropriate as limited surgical resections or nonsurgical therapeutic options provide inferior survival. Furthermore, optimizing perioperative COPD medical care according to clinical practice guidelines including smoking cessation can potentially minimize morbidity and improve functional status in this often severely impaired patient population.

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The available literature regarding dietary manipulation as asthma therapy is largely unconvincing. Although mechanistic and epidemiologic studies provide a rationale for diet therapies, there are few interventional studies with positive, clinically relevant endpoints. Future studies must include sufficient numbers of well selected patients and measure effects on exacerbations, symptoms, lung function, and medication use.

Background We recently reported that obese and non-obese patients with asthma have similar airflow limitation and bronchodilator responsiveness, but obese patients have more symptoms overall. There is limited information on the effect of obesity on asthmatics of varying severity measured by objective physiological parameters. Understanding how obesity affects asthmatics of differing severity can provide insights into the pathogenesis of asthma in the obese and a rationale for the therapeutic approach to such patients. Methods Participants with asthma from two American Lung Association-Asthma Clinical Research Center studies were grouped by tertiles of airflow obstruction (FEV1% predicted, FEV1/FVC) and methacholine reactivity (PC20FEV1). Within each tertile we examined the independent effect of body mass index (BMI), divided into normal weight, overweight and obese categories, on lung function, airway reactivity and symptoms. Results Overall, both FEV1 and FVC decreased and symptoms worsened with increasing BMI; airway reactivity was unchanged. When stratified by the degree of airflow obstruction, higher BMI was not associated with greater airway reactivity to methacholine. Higher BMI was associated with more asthma symptoms only in the least obstructed FEV1/FVC tertile. When stratified by degree of airway reactivity, BMI was inversely associated with FVC in all PC20FEV1 tertiles. BMI was directly associated with asthma symptoms only in those with the least airway reactivity. Conclusions Obesity does not influence airway reactivity in patients with asthma and it is associated with more symptoms only in those with less severe disease.