Sleep related respiratory disorders in end-stage renal disease patients on peritoneal dialysis.

Study Objective: To assess the possible effects of peritoneal dialysis (PD) on sleep-related respiration, which might result from dialysate bulk load in the abdomen and/or alterations in metabolic control of respiration during sleep.

Design: Subjective and objective measures of sleep were prospectively compared on randomly assigned nights with PD fluid (2.0 L) and without PD fluid in the peritoneal cavity in 11 end-stage renal disease (ESRD) patients on PD.

Airway insufflation. Increasing flow rates progressively reduce dead space in respiratory failure.

We have previously shown that airway insufflation (AI) reduces dead space (VD) and minute ventilation (VL) in patients with respiratory failure, and when used chronically leads to lowered and more stable arterial PCO2. The present study was designed to measure the effect of increasing AI flow rate on VD and other aspects of gas exchange in respiratory failure in order to examine the hypothesis that AI exerts its main physiologic effect by progressive reductions of VD. Five patients with varying degrees of respiratory failure caused by either restrictive or obstructive lung disease were studied by means of the specialized techniques we developed to analyze gas exchange during AI.

The lung mucosa: a critical environmental battleground.

The entirety of the lung mucous membrane and epithelial surface are exposed to the environment; react to noxious environmental gases, vapors, and particles; and are under physiologic and humoral mediator control. In recent years much information has been gained regarding the mucous membrane of the tracheobronchial tree, its physiology, and its reaction to environmental hazards. The pharmacologic control of secretion, ciliary beat rate, and net mucus flow governs both the clearance of mucus and the clearance of particles.

Survival in patients with primary pulmonary hypertension. Results from a national prospective registry.

Objective: To characterize mortality in persons diagnosed with primary pulmonary hypertension and to investigate factors associated with survival.

Design: Registry with prospective follow-up.

Setting: Thirty-two clinical centers in the United States participating in the Patient Registry for the Characterization of Primary Pulmonary Hypertension supported by the National Heart, Lung, and Blood Institute.

Supramicron-sized particle clearance from alveoli: route and kinetics.

Particles inhaled and deposited in the alveoli of the lung, i.e., distal to the tracheobronchial mucociliary escalator, may theoretically be cleared by several routes, including solubilization, lymphatic drainage, and the mucociliary pathway.

Clinical role of bronchoalveolar lavage in adults with pulmonary disease.

BAL remains a powerful investigative tool. In a short span of 20 yr, it has helped tremendously in understanding some of the aspects of the pathogenesis of diseases involving the lower respiratory tract. To realize its full potential in the diagnosis and management of diseases involving the lower respiratory tract, there is a great need for standardization of the technical aspects of BAL as well as processing and analysis of the BAL cellular- and fluid-phase components.

Effects of hemodialysis on sleep apnea syndrome in end-stage renal disease.

A high prevalence of sleep apnea syndrome has been reported in previous studies of patients with chronic renal failure. The possible effects of chronic hemodialysis on the magnitude and severity of sleep apnea have not yet been clarified. The present study was undertaken to understand this relationship, by examining subjective and objective measures of sleep on nights following hemodialysis compared to those without hemodialysis.

Determining deposition sites of inhaled lung particles and their effect on clearance.

An essential component of lung defense is clearance of particulates and infectious vectors from the mucus membrane of the tracheobronchial tree and the alveolar regions of the lung. To partition clearance between these areas we determined the bronchial branching pattern, the anatomical sites of particle deposition, and subsequent clearance in the same animal. Using a 2.

Large and small airway responses to bronchoconstrictors in the guinea pig and ferret.

In the isolated, perfused lung lobe of the ferret we evaluated the bronchoconstrictor response of its airways to methacholine and histamine, pharmacologic agents associated with the asthmatic state. The bronchus of excised lobes was cannulated and needle scarifications were made on the pleural surface to allow perfusate to exit. Lung airways were perfused at constant flow with equilibrated 95% O2/5% CO2, warmed Krebs-Ringers solution.

The acute administration of vasodilators in primary pulmonary hypertension. Experience from the National Institutes of Health Registry on Primary Pulmonary Hypertension.

The hemodynamic responses to acute vasodilator administration were evaluated in 163 patients who were entered into the National Institutes of Health Registry on Primary Pulmonary Hypertension (PPH) between 1981 and 1985. Of a total of 491 drug administrations in these patients, 135 administrations in 104 patients were performed in a manner acceptable to the Registry. A single vasodilator was tried in 79 patients and more than one vasodilator in 25 patients.

Histopathology of primary pulmonary hypertension. A qualitative and quantitative study of pulmonary blood vessels from 58 patients in the National Heart, Lung, and Blood Institute, Primary Pulmonary Hypertension Registry.

Qualitative and quantitative studies were performed on pulmonary blood vessels in lung tissue obtained by biopsy, pneumonectomy, or autopsy from 58 patients in the Registry of Primary Pulmonary Hypertension sponsored by the Heart, Lung, and Blood Institute of the National Institutes of Health. In 49 patients (84%), the hypertensive vascular disease involved predominantly or exclusively muscular pulmonary arteries and arterioles. In each of these 49 patients, pulmonary artery medial hypertrophy was observed, and in 48 patients, it was also associated with intimal or luminal lesions.

Airway insufflation: physiologic effects on acute and chronic gas exchange in humans.

Reduction in dead space through conventional tracheostomy has been used to treat patients with chronic CO2 retention. The insufflation of air directly into the trachea by transtracheal catheter (airway insufflation, AI) provides reductions in dead space as great or greater than those of tracheostomy. The physiologic effects of AI on gas exchange have not been adequately studied because instillation of gases into the trachea contaminates minute ventilation (VL), dead space volume (VD), tidal volume (VT), and other indices of gas exchange, as measured by usual technics.

Calculating concentration of inhaled radiolabeled particles from external gamma counting: external counting efficiency and attenuation coefficient of thorax.

We determined the overall external counting efficiency of radiolabeled particles deposited in the sheep lung. This efficiency permits the noninvasive calculation of the number of particles and microcuries (microCi) from gamma-scintillation lung images of the live sheep. Additionally, we have calculated the attenuation of gamma radiation (120 keV) by the posterior chest wall and the gamma-scintillation camera collection efficiency of radiation emitted from the lung.

Primary pulmonary hypertension. A national prospective study.

A national registry was begun in 1981 to collect data from 32 centers on patients diagnosed by uniform criteria as having primary pulmonary hypertension. Entered into the registry were 187 patients with a mean age (+/- SD) of 36 +/- 15 years (range, 1 to 81), and a female-to-male ratio of 1.7:1 overall.

Airway mucus membrane: effects of beta-adrenergic and anticholinergic stimulation.

Mucus hypersecretion and non-continuous clearance of tracheobronchial mucus contribute to airflow obstruction in several pulmonary disease entities. Bronchospasm, which is frequently associated with bronchial asthma, can present simultaneously with mucus transport abnormalities. Therapy designed to dilate airways may produce secondary effects, which are deleterious to effective transport of lung mucus.

Cardiovascular and respiratory consequences of tension pneumothorax.

The physiologic responses to acute pneumothorax were investigated in awake, standing sheep. Pleural pressure (Ppl) was raised in graded increments by injecting air from a 500 ml syringe into the pleural cavity of eight sheep to produce pneumothorax volumes of 0, 17, 35 and 45 ml.kg-1.

The adrenergic innervation of pulmonary vasculature in the normal and pulmonary hypertensive rat.

It would appear that susceptibility to chronic proliferative pulmonary hypertension in response to chronic alveolar hypoxia is most severe in species in which adrenergic innervation of pulmonary arteries is reduced or lacking. Intrapulmonary arteries of the rat have been reported to lack adrenergic innervation by some workers but not others. Since the rat develops severe proliferative pulmonary hypertension in response to prolonged alveolar hypoxia, the different divisions of the lung vasculature of Sprague-Dawley rats were thoroughly examined to determine the presence or absence of an adrenergic innervation.

Disassociation in the mucociliary function of central and peripheral airways of asymptomatic smokers.

Mucociliary function of peripheral airways in asymptomatic smokers may be impaired and contribute to the abnormal airway changes described in these subjects. Techniques using the inhalation and deposition of radioactive particles followed by gamma camera imaging were applied to healthy subjects discordant for smoking habit to determine if mucus transport of peripheral and central airways was altered by smoking. Smokers (n = 8) averaged 26 +/- 2 yr (mean +/- SEM) and less than 7.

How alterations in pleural pressure influence esophageal pressure.

Although esophageal pressures have been substituted for direct pleural pressure measurement in humans, we have investigated the validity of this approach under circumstances when left and right pleural pressures are not equal. Esophageal and bilateral pleural pressures in awake sheep were compared by using matched balloon catheters in close proximity. In standing sheep, both end-expiratory pressures and inspiratory pressure swings were similar in all three catheter systems.