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Madias N.E.,Caritas St Elizabeths Medical Center | Madias N.E.,Tufts University
Journal of Nephrology | Year: 2010

Respiratory acid-base disorders are those abnormalities in acid-base equilibrium that are expressed as primary changes in the arterial carbon dioxide tension (PaCO2). An increase in PaCO2 (hypercapnia) acidifies body fluids and initiates the acid-base disturbance known as respiratory acidosis. By contrast, a decrease in PaCO2 (hypocapnia) alkalinizes body fluids and initiates the acid-base disturbance known as respiratory alkalosis. The impact on systemic acidity of these primary changes in PaCO2 is ameliorated by secondary, directional changes in plasma [HCO3 -] that occur in 2 stages. Acutely, hypercapnia or hypocapnia yields relatively small changes in plasma [HCO3 -] that originate virtually exclusively from titration of the body's nonbicarbonate buffers. During sustained hypercapnia or hypocapnia, much larger changes in plasma [HCO3 -] occur that reflect adjustments in renal acidification mechanisms. Consequently, the deviation of systemic acidity from normal is smaller in the chronic forms of these disorders. Here we provide an overview of the renal acidification responses to respiratory acid-base disorders. We also identify gaps in knowledge that require further research. © 2010 Società Italiana di Nefrologia - ISSN 1121-8428. Source

Tashkin D.P.,University of California at Los Angeles | Celli B.,Caritas St Elizabeths Medical Center | Kesten S.,Boehringer Ingelheim Pharmaceuticals | Lystig T.,Boehringer Ingelheim Pharmaceuticals | And 2 more authors.
European Respiratory Journal | Year: 2010

UPLIFT (Understanding Potential Long-Term Improvements in Function with Tiotropium), a 4-yr trial of tiotropium in chronic obstructive pulmonary disease, allowed for assessment of smoking status on long-term responses to maintenance bronchodilator therapy. 5,993 patients were randomised (tiotropium/placebo). Lung function, St George's Respiratory Questionnaire, exacerbations and adverse events were followed. Patients were characterised as continuing smokers (CS), continuing ex-smokers (CE), or intermittent smokers (IS) based on self-reporting smoking behaviour. 60%, 14% and 26% of patients were CE, CS and IS, respectively. The rate of forced expiratory volume in 1 s (FEV1) decline for placebo patients was most rapid in CS (-51±4, -36±2 and -23±2 mL•yr-1 in CS, IS, and CE, respectively). Tiotropium did not alter FEV1 decline, but was associated with significant improvements in pre- and post-bronchodilator FEV1 over placebo that persisted throughout the 4-yr trial for each smoking status (pre-bronchodilator: 125, 55 and 97 mL at 48 months in CS, IS and CE, respectively; p≤0.0003). Tiotropium reduced exacerbation risk in CS (HR (95%CI) 0.81 (0.68-0.97)), in CE (0.86 (0.79-0.93)) and trended towards significance in IS (0.89 (0.80-1.01)). At 4 yrs, St George's Respiratory Questionnaire for tiotropium patients improved the most in CS (-4.62 units, p=0.0006) and the least in IS (-0.54 units, p=0.55), compared with control. Tiotropium provided long-term benefits irrespective of smoking status, although differences among categories were observed. Copyright ©ERS Journals Ltd 2010. Source

Snell G.,Allergy Immunology and Respiratory Medicine | Herth F.J.F.,Pneumology and Critical Care Medicine | Hopkins P.,Lung Transplant Unit | Baker K.M.,University of Iowa | And 8 more authors.
European Respiratory Journal | Year: 2012

The need for a less invasive procedure than surgical lung volume reduction that can produce consistent improvements with reduced morbidity remains a medical goal in patients with emphysema. We sought to determine the effect of bronchoscopic thermal vapour ablation (BTVA) on lung volumes and outcomes in patients with emphysema. 44 patients with upper lobe-predominant emphysema were treated unilaterally with BTVA. Entry criteria included: age 40-75 yrs, forced expiratory volume in 1 s (FEV 1) 15-45% predicted, previous pulmonary rehabilitation and a heterogeneity index (tissue/air ratio of lower lobe/upper lobe) from high-resolution computed tomography (HRCT) ≥1.2. Changes in FEV 1, St George's Respiratory Questionnaire (SGRQ), 6-min walk distance (6MWD), modified Medical Research Council (mMRC) dyspnoea score, and hyperinflation were measured at baseline, and 3 and 6 months post-BTVA. At 6 months, mean±SE FEV 1 improved by 141±26 mL (p<0.001) and residual volume was reduced by 406±113 mL (p<0.0001). SGRQ total score improved by 14.0±2.4 points (p<0.001), with 73% improving by ≥4 points. Improvements were observed in 6MWD (46.5±10.6 m) and mMRC dyspnoea score (0.9±0.2) (p<0.001 for both). Lower respiratory events (n=11) were the most common adverse event and occurred most often during the initial 30 days. BTVA therapy results in clinically relevant improvements in lung function, quality of life and exercise tolerance in upper lobe predominant emphysema. Copyright©ERS 2012. Source

Gompelmann D.,University of Heidelberg | Herth F.J.F.,University of Heidelberg | Slebos D.J.,University of Groningen | Valipour A.,Ludwig Boltzmann Research Institute | And 3 more authors.
Respiration | Year: 2014

Background: Patients who achieve significant target lobe volume reduction (TLVR) following endobronchial valve (EBV) treatment may experience substantial improvements in clinical outcome measures. However, in cases of rapid TLVR, the risk of pneumothorax increases due to parenchymal rupture of the adjacent untreated lobe. Target lobe collapse may be more likely in EBV-treated patients who have low collateral ventilation. Objectives: The aim of this study was to evaluate the impact of pneumothorax on outcome following EBV treatment. Methods: Data from three prospective clinical trials (the US and European cohorts of VENT and the Multicenter Chartis study) were retrieved for the analysis. All patients had undergone chest X-ray within 24 h of EBV implantation to explore the presence of pneumothorax. TLVR was assessed at either 30 (Chartis study) or 180 days (VENT), and clinical outcome measures (forced expiratory volume in 1 s (FEV1), St. George's Respiratory Questionnaire (SGRQ) and 6-min-walk distance (6-MWD)) were assessed 180 days after implantation. Results: The overall rate of pneumothorax following valve therapy was 5.9% (25/421). Among these patients, 68% had a prolonged air leak for >7 days. However, patients who experienced a pneumothorax benefitted from EBV therapy, with a mean TLVR of 65% (n = 20). The mean percent change in FEV1 was 15 ± 15%, and the mean change in SGRQ was-7 ± 12 points. Conclusions: Although pneumothorax is a complication of EBV placement, it does not appear to have a negative impact on clinical outcome in terms of FEV1 and health-related quality of life. © 2014 S. Karger AG, Basel. Source

Orlov M.V.,Caritas St Elizabeths Medical Center | Gardin J.M.,St John Medical Center | Slawsky M.,Baystate Medical Center | Bess R.L.,St John Medical Center | And 5 more authors.
American Heart Journal | Year: 2010

Background: Randomized trials have demonstrated benefits of biventricular (BiV) pacing in patients with advanced heart failure, intraventricular conduction delay, and atrial fibrillation (AF) postatrioventricular (AV) node ablation. The AV Node Ablation with CLS and CRT Pacing Therapies for Treatment of AF trial (AVAIL CLS/CRT) was designed to demonstrate superiority of BiV pacing in patients with AF after AV node ablation, to evaluate its effects on cardiac structure and function, and to investigate additional benefits of Closed Loop Stimulation ® (CLS) (BIOTRONIK, Berlin, Germany). Methods: Patients with refractory AF underwent AV node ablation and were randomized (2:2:1) to BiV pacing with CLS, BiV pacing with accelerometer, or right ventricular (RV) pacing. Echocardiography was performed at baseline and 6 months, with paired data available for 108 patients. Results: The RV pacing contributed to significant increase in left atrial volume, left ventricular (LV) end-systolic volume, and LV mass compared to BiV pacing. Ejection fraction decreased insignificantly with RV pacing compared to significant increase with BiV pacing. Interventricular dyssynchrony significantly decreased with BiV compared with RV pacing. Closed Loop Stimulation ® did not result in additional echocardiographic changes; heart rate distribution was significantly wider with CLS. All groups showed significant improvement in 6-minute walk distance, quality-of-life score, and New York Heart Association class. Conclusion: In conclusion, RV pacing results in significant increase in left atrial volume, LV mass, and worsening of LV contractility compared to patients receiving BiV pacing post-AV node ablation for refractory AF. Closed Loop Stimulation ® was not associated with additional structural changes but resulted in significantly wider heart rate distribution. © 2010 Mosby, Inc. All rights reserved. Source

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