Impact of Pharmacologically Left Shifting the Oxygen-Hemoglobin Dissociation Curve on Arterial Blood Gases and Pulmonary Gas Exchange During Maximal Exercise in Hypoxia.

Stewart, Glenn M., Troy J. Cross, Michael J.

Assessment of Thoracic Blood Volume by Computerized Tomography in Patients With Heart Failure and Periodic Breathing.

Background: Periodic breathing (PB) is often observed in patients with HF at rest, with sleep and during exercise. However, mechanisms underlying abnormal ventilatory control are not entirely established.

Methods: Eleven subjects with HF (10 males, age = 69 ± 12 y) and 12 age-matched control subjects (8 males, age = 65 ± 9 y) participated in the study.

The influence of pulmonary vascular pressures on lung diffusing capacity during incremental exercise in healthy aging.

Alveolar-capillary surface area for pulmonary gas exchange falls with aging, causing a reduction in lung diffusing capacity for carbon monoxide (DLCO). However, during exercise additional factors may influence DLCO, including pulmonary blood flow and pulmonary vascular pressures. First, we sought to determine the age-dependent effect of incremental exercise on pulmonary vascular pressures and DLCO.

The effect of diuresis on extravascular lung water and pulmonary function in acute decompensated heart failure.

Aims: The effect of extravascular lung water (EVLW) and relationship to functional status as a result of acute decompensated heart failure (ADHF) are not well understood. We sought to quantify changes in clinical variables, EVLW, airway anatomy, spirometry, and diffusing capacity for carbon monoxide before and after treatment for ADHF.

Methods And Results: Fifteen patients were recruited within 24 h of hospital admission.

Influence of Inhaled Amiloride on Lung Fluid Clearance in Response to Normobaric Hypoxia in Healthy Individuals.

Unlabelled: Wheatley, Courtney M., Sarah E. Baker, Bryan J.

Influence of Thoracic Fluid Compartments on Pulmonary Congestion in Chronic Heart Failure.

Introduction: Pulmonary congestion is a common finding of heart failure (HF), but it remains unclear how pulmonary and heart blood volumes (V and V, respectively) and extravascular lung water (EVLW) change in stable HF and affect lung function.

Methods: Fourteen patients with HF (age 68 ± 11 y, LVEF 33 ± 8%) and 12 control subjects (age 65 ± 9 y) were recruited. A pulmonary function test, thoracic computerized tomographic (CT) scan, and contrast perfusion scan were performed.

The blood transfer conductance for nitric oxide: Infinite vs. finite θ.

Whether the specific blood transfer conductance for nitric oxide (NO) with hemoglobin (θ) is finite or infinite is controversial but important in the calculation of alveolar capillary membrane conductance (Dm) and pulmonary capillary blood volume (V) from values of lung diffusing capacity for carbon monoxide (DLCO) and nitric oxide (DLNO). In this review, we discuss the background associated with θ, explore the resulting values of Dm and V when applying either assumption, and investigate the mathematical underpinnings of Dm and V calculations. In general, both assumptions yield reasonable rest and exercise Dm and V values.

Effect of β-adrenergic receptor stimulation on lung fluid in stable heart failure patients.

Background: The purpose of this study was to determine: (1) whether stable heart failure patients with reduced ejection fraction (HFrEF) have elevated extravascular lung water (EVLW) when compared with healthy control subjects; and (2) the effect of acute β-adrenergic receptor (βAR) agonist inhalation on lung fluid balance.

Methods: Twenty-two stable HFrEF patients and 18 age- and gender-matched healthy subjects were studied. Lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (Dm), pulmonary capillary blood volume (V) (via re-breathe) and lung tissue volume (V) (via computed tomography) were assessed before and within 30 minutes after administration of nebulized albuterol.

Impact of chronic systolic heart failure on lung structure-function relationships in large airways.

Heart failure (HF) is often associated with pulmonary congestion, reduced lung function, abnormal gas exchange, and dyspnea. We tested whether pulmonary congestion is associated with expanded vascular beds or an actual increase in extravascular lung water (EVLW) and how airway caliber is affected in stable HF Subsequently we assessed the influence of an inhaled short acting beta agonist (SABA). Thirty-one HF (7F; age, 62 ± 11 years; ht.