scholarly journals Shrinking Lung Syndrome as a Manifestation of Pleuritis: A New Model Based on Pulmonary Physiological Studies

2013 ◽  
Vol 40 (3) ◽  
pp. 273-281 ◽  
Author(s):  
LAUREN A. HENDERSON ◽  
STEPHEN H. LORING ◽  
RITU R. GILL ◽  
KATHERINE P. LIAO ◽  
RUMEY ISHIZAWAR ◽  
...  

Objective.The pathophysiology of shrinking lung syndrome (SLS) is poorly understood. We sought to define the structural basis for this condition through the study of pulmonary mechanics in affected patients.Methods.Since 2007, most patients evaluated for SLS at our institutions have undergone standardized respiratory testing including esophageal manometry. We analyzed these studies to define the physiological abnormalities driving respiratory restriction. Chest computed tomography data were post-processed to quantify lung volume and parenchymal density.Results.Six cases met criteria for SLS. All presented with dyspnea as well as pleurisy and/or transient pleural effusions. Chest imaging results were free of parenchymal disease and corrected diffusing capacities were normal. Total lung capacities were 39%–50% of predicted. Maximal inspiratory pressures were impaired at high lung volumes, but not low lung volumes, in 5 patients. Lung compliance was strikingly reduced in all patients, accompanied by increased parenchymal density.Conclusion.Patients with SLS exhibited symptomatic and/or radiographic pleuritis associated with 2 characteristic physiological abnormalities: (1) impaired respiratory force at high but not low lung volumes; and (2) markedly decreased pulmonary compliance in the absence of identifiable interstitial lung disease. These findings suggest a model in which pleural inflammation chronically impairs deep inspiration, for example through neural reflexes, leading to parenchymal reorganization that impairs lung compliance, a known complication of persistently low lung volumes. Together these processes could account for the association of SLS with pleuritis as well as the gradual symptomatic and functional progression that is a hallmark of this syndrome.

1975 ◽  
Vol 38 (6) ◽  
pp. 1148-1152 ◽  
Author(s):  
S. Watanabe ◽  
R. Frank

We measured lung weight, lung volumes, pulmonary mechanics, and carbon monoxide transfer (DLCO, single-breath method) in healthy cats (3.3 +/- 0.4 kg) that were anesthetized, paralyzed, and mechanically ventilated through a tracheal cannula. Compared with Stahl's predicted values which were based on regression analyses of data collected from several species, our cats had larger and more compliant lungs in relation to body weight, higher DLCO per unit body weight, and similar DLCO/TLC (size independent constant). Compared with Robinson et al.'s values derived entirely from studies on dogs, our cats had significantly smaller lung volumes and DLCO per unit body weight, DLCO/TLC and similar ratios of CL/FRC. Several factors appear to contribute to the functional variations among mammalian species: differences in the relation of lung to body weight, differences in the relation of chest wall compliance to lung compliance, and differences in the fundamental structure and design of the respiratory systems. Differences in methodology are acknowledged to be an additional factor.


1978 ◽  
Vol 17 (04) ◽  
pp. 261-272 ◽  
Author(s):  
Y. Brault ◽  
G. Atlan ◽  
H. Lorino ◽  
A. Harf ◽  
A.-M. Lorino ◽  
...  

A system was built up around a minicomputer to process in real time pressure and flow signals collected during the course of three ventilatory mechanics tests: the calculation of the lung volume, the evaluation of the static lung compliance, the analysis of the forced expiratory performance. The subject is seated in an open body Plethysmograph, which allows for the instantaneous calculation of changes in the volume of his thorax and abdomen. The system is controlled through a graphics console which displays the sampled curves and the results of data processing. In addition, the signals can be stored on demand onto a magnetic tape so that the method can be tested and improved off line. The results obtained in healthy volunteers are highly reproducible. A close correspondence is found both in patients and volunteers between computer-derived and hand-calculated results. The computerized system has become a standard equipment of our Lung Function Department, where it allows for a rapid quantitative analysis of lung volumes, lung elasticity and bronchial airflow.


PEDIATRICS ◽  
1959 ◽  
Vol 24 (2) ◽  
pp. 181-193
Author(s):  
C. D. Cook ◽  
P. J. Helliesen ◽  
L. Kulczycki ◽  
H. Barrie ◽  
L. Friedlander ◽  
...  

Tidal volume, respiratory rate and lung volumes have been measured in 64 patients with cystic fibrosis of the pancreas while lung compliance and resistance were measured in 42 of these. Serial studies of lung volumes were done in 43. Tidal volume was reduced and the respiratory rate increased only in the most severely ill patients. Excluding the three patients with lobectomies, residual volume and functional residual capacity were found to be significantly increased in 46 and 21%, respectively. These changes correlated well with the roentgenographic evaluation of emphysema. Vital capacity was significantly reduced in 34% while total lung capacity was, on the average, relatively unchanged. Seventy per cent of the 61 patients had a signficantly elevated RV/TLC ratio. Lung compliance was significantly reduced in only the most severely ill patients but resistance was significantly increased in 35% of the patients studied. The serial studies of lung volumes showed no consistent trends among the groups of patients in the period between studies. However, 10% of the surviving patients showed evidence of significant improvement while 15% deteriorated. [See Fig. 8. in Source Pdf.] Although there were individual discrepancies, there was a definite correlation between the clinical evaluation and tests of respiratory function, especially the changes in residual volume, the vital capacity, RV/ TLC ratio and the lung compliance and resistance.


2008 ◽  
pp. 91-97 ◽  
Author(s):  
G. A. Lyubimov ◽  
I. M. Skobeleva ◽  
G. M. Sakharova ◽  
A. V. Suvorov

This report introduces a mathematical model of forced expiration to analyze pulmonary function. Results of 3-year lung function monitoring of an ex-smoker have been shown in the paper. Actual values of lung volumes and airway resistance were used for modeling. The computerized data were compared to the flow-volume curve parameters and lung volumes measured during the forced expiration. Weak correlation between the "flow-volume" curve parameters and the time after quitting smoking together with significant change in the lung volumes and the airway resistance seen in the study could be due to some processes which have not been followed in this study (lung compliance, airway resistance at forced expiration, and elastic properties of airway walls).The results demonstrated that mathematical models could increase informative value of pulmonary functional tests. In addition, the model could emphasize additional functional tests for better diagnostic usefulness of functional investigations.


1959 ◽  
Vol 14 (2) ◽  
pp. 177-186 ◽  
Author(s):  
C. D. Cook ◽  
J. Mead ◽  
G. L. Schreiner ◽  
N. R. Frank ◽  
J. M. Craig

In order to study the mechanisms underlying the changes in the mechanical properties of the lungs during pulmonary edema, pulmonary vascular congestion was produced in spontaneously breathing, anesthetized dogs by partial aortic obstruction and intravenous infusion. Brief periods of congestion were associated with small changes in the lung compliance compared with the progressive and striking compliance reduction (-78%) noted with more prolonged congestion. Lung volume at end-expiration showed little change if edema fluid and trapped gas as well as the ventilated gas volume were taken into account. When edematous lungs were forcibly inflated beyond the tidal range, it was found that the overall compliance at a distending pressure of 30 cm H2O was not much less (-6%) than that of normal lungs. Furthermore, edematous lungs manifested marked ‘static’ hysteresis during such maneuvers. These findings suggested that surface phenomena were responsible for the mechanical behavior of edematous lungs rather than vascular congestion, per se, or intrinsic tissue changes. This was borne out by experiments on excised lungs which showed that the elastic properties of edematous lungs were not significantly different from normal lungs when surface forces were minimized. Submitted on August 25, 1958


1972 ◽  
Vol 33 (6) ◽  
pp. 808-812 ◽  
Author(s):  
N E Robinson ◽  
J R Gillespie ◽  
J D Berry ◽  
A Simpson

CHEST Journal ◽  
2016 ◽  
Vol 150 (3) ◽  
pp. 613-620 ◽  
Author(s):  
Daniel R. Murphy ◽  
Ashley N.D. Meyer ◽  
Viraj Bhise ◽  
Elise Russo ◽  
Dean F. Sittig ◽  
...  

Author(s):  
Mark Harrison

This chapter describes the pathophysiology of the respiratory system as it applies to Emergency Medicine, and in particular the Primary FRCEM examination. The chapter outlines the key details of the control of ventilation, reflexes, pressure, chemical, and irritant receptors, J receptors, pulmonary stretch receptors, Golgi tendon organs, muscle spindles, lung volumes, pulmonary mechanics, oxygen and carbon dioxide transport, DO2/VO2 relationships, carbon monoxide, pulse oximetry, effects of altitude, and dysbarism. This chapter is laid out exactly following the RCEM syllabus, to allow easy reference and consolidation of learning.


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