RS correlated well with findings on physical examination during AHF and closely correlated with LI.

Background: Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA). Methods: Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidencebased review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus. Results: The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated. Conclusion:This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

The instantaneous lung impedance (ILI) is one of the methods to assess pulmonary congestion or edema (PCE) in chronic heart failure (CHF) patients. Due to usually existing PCE in CHF patients when evaluated, baseline lung impedance (BLI) is unknown. Therefore, the relation of ILI to BLI is unknown. Our aim was to evaluate methods to calculate and appraise BLI or its derivative as reflecting the clinical status of CHF patients. ILI and New York Heart Association (NYHA) class were assessed in 222 patients (67 ± 11 years, LVEF <35 %) during 32 months of frequent outpatient clinic visits. ILI, measured in 120 asymptomatic patients at NYHA class I, with no congestion on the chest X-ray and a low-normal 6-min walk, was defined as BLI. Using measured BLI and ILI values in these patients, formulas for BLI calculation were derived based on logistic regression analysis or on the disparity between BLI and ILI values at different NYHA stages. Both models were equally reliable with <3 % difference between measured and calculated BLI (p = NS). ΔLIR = (ILI/BLI - 1) × 100 % reflected the degree of PCE, or deviation from baseline, correlated with NYHA class (r = -0.9, p < 0.001) and could serve for monitoring. Of study patients, 123 were re-hospitalized for PCE during follow up. Their ΔLIR decreased gradually from -21.7 ± 8.2 % 4 weeks pre-admission to -37.8 ± 9.3 % on admission (p < 0.001). Patients improved during hospital stay (NYHA 3.7 ± 0.5 to 2.9 ± 0.8, p < 0.0001) with ΔLIR increasing to -29.1 ± 12.0 % (p < 0.001). ΔLIR based on calculated BLI correlated with the clinical status of CHF patients and allowed the prediction of hospitalizations for PCE.

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