Pulmonary Physiologists Research Articles

André Cournand, Bellevue's Cardiopulmonary Laboratory, and Research on Heart Failure.

In 1954-1955, the author served as a research fellow in the cardiopulmonary laboratory led by André Cournand at Bellevue Hospital in New York. Cournand was a pulmonary physiologist and a professor of medicine at Columbia University. In his quest to obtain mixed venous blood to calculate pulmonary blood flow, he catheterized the right atrium, right ventricle, and pulmonary artery in patients and also measured the pressures in these chambers. Cournand and his collaborators soon appreciated the enormous potential of cardiac catheterization in deepening the understanding of cardiovascular pathophysiology. After a series of groundbreaking studies, Cournand and his coworker Dickinson Richards, as well as German physician Werner Forssmann, were awarded a Nobel Prize in 1956. Cournand's laboratory, his work habits, and his rigorous approach to science are described, as well as the stimulation the author received during the author's fellowship. As a result, the author went on to extend to the left side of the heart the observations that the Cournand group had conducted in the right heart. Also, the author continued Cournand's work on heart failure by developing techniques to measure ventricular function in patients and to describe the neurohumoral changes that occur in human heart failure.

P239 Junior Doctors Performance and Interpretation of Spirometry

BackgroundSpirometry is a fundamental respiratory function assessment tool. A significant proportion of junior doctors have great apprehension in performing and interpreting spirometry. The NICE (CG12) COPD guidelines state that all...

Lung perfusion measured using magnetic resonance imaging: New tools for physiological insights into the pulmonary circulation

Since the lung receives the entire cardiac output, sophisticated imaging techniques are not required in order to measure total organ perfusion. However, for many years studying lung function has required physiologists to consider the lung as a single entity: in imaging terms as a single voxel. Since imaging, and in particular functional imaging, allows the acquisition of spatial information important for studying lung function, these techniques provide considerable promise and are of great interest for pulmonary physiologists. In particular, despite the challenges of low proton density and short T2* in the lung, noncontrast MRI techniques to measure pulmonary perfusion have several advantages including high reliability and the ability to make repeated measurements under a number of physiologic conditions. This brief review focuses on the application of a particular arterial spin labeling (ASL) technique, ASL-FAIRER (flow sensitive inversion recovery with an extra radiofrequency pulse), to answer physiologic questions related to pulmonary function in health and disease. The associated measurement of regional proton density to correct for gravitational-based lung deformation (the "Slinky" effect (Slinky is a registered trademark of Pauf-Slinky incorporated)) and issues related to absolute quantification are also discussed.

Last Word on Point:Counterpoint: Lung impedance measurements are/are not more useful than simpler measurements of lung function in animal models of pulmonary disease

LETTERS TO THE EDITORLast Word on Point:Counterpoint: Lung impedance measurements are/are not more useful than simpler measurements of lung function in animal models of pulmonary diseaseWayne MitznerWayne MitznerPublished Online:01 Nov 2007https://doi.org/10.1152/japplphysiol.00748.2007MoreSectionsPDF (27 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat THE ABILITY TO MAKE A MEASUREMENT IS NOT A SUFFICIENT CONDITIONto the editor: After reading all the comments (2) on our debate (1, 3), it may seem that Jason has won this round, with five letters clearly in support of his position, one relatively neutral, one with lukewarm support of both of us (thank you, Ken), and one that dumped on both of us. However, of these writers, since five have had part of their careers invested in such impedance modeling, perhaps this first round vote tally is not entirely unbiased. Nevertheless, despite these otherwise thoughtful comments, still no one has told me what any measurement of G has done to improve our understanding of lung structure or pathology. This is after 15 years of making such measurements. And although Dr. Hantos tried to link G to older measures of tissue resistance, no one can even explain what the structural origins of “tissue” resistance are. Furthermore, despite Fredberg's mathematical rearrangement to focus on eta, reports of eta with experimental manipulations, mice are often as variable as they are constant. So perhaps the constant phase model as applied to the intact lung is not so constant after all.The critically important issue is that the great majority of researchers using animal models of lung disease are now making measurements of impedance for no other reason than it is now very easy (and acceptable) to do. Dr. Zeldin and colleagues suggest that we measure and report both impedance variables along with traditional R and E, but then why not also include the slope of phase III or N2 washout, or closing volume, or frequency dependence of compliance, or DLCO, or etc., etc., etc.? All of these many pulmonary function indexes might also provide improved ability to separate pathology from normal, but they are not included because they are just not so easy to measure in mice. In the recent past, many investigators with little knowledge of pulmonary function, but with a critical need to measure it, were unfortunately hoodwinked into buying snake oil (i.e., Penh). When that elusive and mysterious variable was unmasked, another system took its place that can provide indexes more acceptable to pulmonary physiologists and bioengineers. So now we have mouse asthma models reporting G and eta, without any discussion of what they mean. The primary goal of an animal model of any disease is to help learn something relevant about the disease. As I emphasized previously (1), experimental data without some meaningful link to structure and function provide little insight into what we really want to know. If investigators can't intelligently discuss what each of their measured variables means, it still seems entirely inappropriate to include them in publications or grant applications.REFERENCES1 Bates JH. Point: Lung impedance measurements are more useful than simpler measurements of lung function in animal models of pulmonary disease. J Appl Physiol; doi:10.1152/japplphysiol.00369.2007.Google Scholar2 Cohen JC, Hudak J, Fredberg JJ, Hantos Z, Zeldin DC, Card JW, Carey MA, Voltz JW, Suki B, Lutchen KR, Kaczka DW, Simon BA, Lundblad LKA. Comments on Point:Counterpoint “Lung impedance measurements are/are not more useful than simpler measurements of lung function in animal models of pulmonary disease.” J Appl Physiol; doi:10.1152/japplphysiol.00759.2007.Google Scholar3 Mitzner W. Counterpoint: Lung impedance measurements are not more useful than simpler measurements of lung function in animal models of pulmonary disease. J Appl Physiol; doi:10.1152/japplphysiol.00369.2007a.Google ScholarAUTHOR NOTESAddress for reprint requests and other correspondence: W. Mitzner, 615 N. Wolfe St, Baltimore, MD 21205 (e-mail: [email protected]) Download PDF Previous Back to Top Next FiguresReferencesRelatedInformation More from this issue > Volume 103Issue 5November 2007Pages 1910-1910 Copyright & PermissionsCopyright © 2007 the American Physiological Societyhttps://doi.org/10.1152/japplphysiol.00748.2007History Published online 1 November 2007 Published in print 1 November 2007 Metrics

Pulmonary Oedema following Exercise in Humans

Pulmonary physiologists have documented many transient changes in the lung and the respiratory system during and following exercise, including the incomplete oxygen saturation of arterial blood in some subjects, possibly due to transient pulmonary oedema. The large increase in pulmonary arterial pressure during exercise, leading to either increased pulmonary capillary leakage and/or pulmonary capillary stress failure, is likely to be responsible for any increase in extravascular lung water during exercise. The purpose of this article is to summarise the studies to date that have specifically examined lung water following exercise. A limited number of studies have been completed with the specific purpose of identifying pulmonary oedema following exercise or a similar intervention. Of these, approximately 50% have observed a positive change and the remaining have provided results that are either inconclusive or show no change in extravascular lung water. While it is difficult to draw a firm conclusion from these studies, we believe that pulmonary oedema does occur in some humans following exercise. As such, this is a phenomenon of significance to pulmonary and exercise physiologists. This possibility warrants further study in the area with more precise measurement tools than has previously been undertaken.

Heart rate variability in athletes.

This review examines the influence on heart rate variability (HRV) indices in athletes from training status, different types of exercise training, sex and ageing, presented from both cross-sectional and longitudinal studies. The predictability of HRV in over-training, athletic condition and athletic performance is also included. Finally, some recommendations concerning the application of HRV methods in athletes are made.The cardiovascular system is mostly controlled by autonomic regulation through the activity of sympathetic and parasympathetic pathways of the autonomic nervous system. Analysis of HRV permits insight in this control mechanism. It can easily be determined from ECG recordings, resulting in time series (RR-intervals) that are usually analysed in time and frequency domains. As a first approach, it can be assumed that power in different frequency bands corresponds to activity of sympathetic (0.04-0.15 Hz) and parasympathetic (0.15-0.4 Hz) nerves. However, other mechanisms (and feedback loops) are also at work, especially in the low frequency band. During dynamic exercise, it is generally assumed that heart rate increases due to both a parasympathetic withdrawal and an augmented sympathetic activity. However, because some authors disagree with the former statement and the fact that during exercise there is also a technical problem related to the non-stationary signals, a critical look at interpretation of results is needed. It is strongly suggested that, when presenting reports on HRV studies related to exercise physiology in general or concerned with athletes, a detailed description should be provided on analysis methods, as well as concerning population, and training schedule, intensity and duration. Most studies concern relatively small numbers of study participants, diminishing the power of statistics. Therefore, multicentre studies would be preferable. In order to further develop this fascinating research field, we advocate prospective, randomised, controlled, long-term studies using validated measurement methods. Finally, there is a strong need for basic research on the nature of the control and regulating mechanism exerted by the autonomic nervous system on cardiovascular function in athletes, preferably with a multidisciplinary approach between cardiologists, exercise physiologists, pulmonary physiologists, coaches and biomedical engineers.

J'accuse!-M. LeComte de LaPlace a Prohibé le Recrutement des Alvéoles du Poumon

A recurrent concept throughout all the natural sciences is that of capacitance—"the extension or displacement of a loaded structure per unit load." The electrical engineer knows capacitance as the ratio of charge/voltage. Physicists (since Hooke, who first enunciated the concept) recognize strain/stress as compressibility (the inverse of the modulus). Pulmonary physiologists look at volume/pressure and call it compliance, while biochemists view the volume of molecules that can be liganded to a carrier and call it a binding curve. Clinicians recognize this form as the oxygen-dissociation curve, instantly identified by its sigmoid shape. This shape also describes the inflation curve of the gasless lung—in the following sequence of increasing transpulmonary pressure: (1) a flat portion with only a small increase in volume—this segment describes the discontinuous openings of the smaller airways and alveoli, once their interfacial tensions have been overcome;

Clinical Tests of Respiratory Function.

Edited by G.J. Gibson Published by Hodder Arnold, UK Pages: 432. Price: £85.00. ISBN: 978-0340925614 Knowledge of clinical physiology is unquestionably a major step in the understanding of most respiratory disorders. Despite the abundance of knowledge gained in this field over the past 60 years, the value of pulmonary function testing in clinical practice has not been fully appreciated. This is possibly due to the complexity of respiratory function and a lack of clear communication between pulmonary physiologists and clinicians. After an outburst of enthusiasm for …

Operant Conditioning and the Modulation of Cardiovascular Function

Operant learning appears to be one of the primary mechanisms underlying what cardiovascular and pulmonary physiologists have called adaptation, habituation, and central command. In general, studies that have attempted to use operant conditioning alone to create experimental models of behaviorally induced disease have been unsuccessful because the cardiovascular responses adapted or habituated over time. Thus, these studies have provided implicit demonstrations of the roles played by CNS and conditioning processes in achieving and preserving homeostasis. During the past few years those interested in behavioral contributions to cardiovascular pathology have therefore begun to look at interactions between behavior and other variables that might predispose organisms towards pathology (e.g. genetic background; excessive sodium intake). Perhaps even more promising has been the growth in the number of technically competent, well-controlled studies designed to investigate: (a) broad scientific questions of how behaviorally important processes such as learning and reinforcement interact with physiologically important variables such as blood flow redistribution and cardio-pulmonary integration; and (b) the role of behavioral variables in CNS control of the circulation. Based upon our survey of the recent literature, we believe that the time is ripe for those interested in cardiovascular neurobiology increasingly to include behavioral variables in their studies, because the raison d'etre of the CNS is to optimize the organism's ability to interact with its environment. Only when these organismic-environmental interactions are studied both behaviorally and physiologically, in a broad biological context, will it be possible to develop rational models of neuro-circulatory regulation.

Pulmonary function testing in small laboratory mammals.

The lung is the primary organ likely to be exposed by inhalation studies and, therefore, measurement of changes in lung function are of particular interest to the pulmonary physiologist and toxicologist. Tests of pulmonary function have been developed which can be used with small animals to measure spirometry (lung volumes), mechanics, distribution of ventilation, gas exchange or control of ventilation. These tests were designed on the basis of similar tests which are used in humans to diagnose and manage patients with lung disease. A major difference is that many of the measurements are performed in anesthetized animals, while human pulmonary function is usually measured in awake cooperating individuals. In addition, the measurement of respiratory events in small animals requires sensitive and rapidly responding equipment, because signals may be small and events can occur quickly. In general, the measurements described provide information on the change in normal lung function which results primarily from structural changes. These tests of pulmonary function can be repetitively and routinely accomplished and the results appear to be highly reproducible. Although some are quite sophisticated, many can be undertaken with relatively inexpensive equipment and provide useful information for toxicological testing.

Pulmonary Function Testing in Small Laboratory Mammals

The lung is the primary organ likely to be exposed by inhalation studies and, therefore, measurement of changes in lung function are of particular interest to the pulmonary physiologist and toxicologist. Tests of pulmonary function have been developed which can be used with small animals to measure spirometry (lung volumes), mechanics, distribution of ventilation, gas exchange or control of ventilation. These tests were designed on the basis of similar tests which are used in humans to diagnose and manage patients with lung disease. A major difference is that many of the measurements are performed in anesthetized animals, while human pulmonary function is usually measured in awake cooperating individuals. In addition, the measurement of respiratory events in small animals requires sensitive and rapidly responding equipment, because signals may be small and events can occur quickly. In general, the measurements described provide information on the change in normal lung function which results primarily from structural changes. These tests of pulmonary function can be repetitively and routinely accomplished and the results appear to be highly reproducible. Although some are quite sophisticated, many can be undertaken with relatively inexpensive equipment and provide useful information for toxicological testing.

The role of the pulmonary physiologist in managing intractable asthma and respiratory failure.

The role of the pulmonary physiologist in managing intractable asthma and respiratory failure.

Diagnosis of Diseases of the Chest: An Integrated Study Based on the Abnormal Roentgenogram.

This is a truly remarkable work, comprising 1,269 pages of text, 4,330 references, 58 pages of index, and 1,268 remarkably clear illustrations. The vast radiologic experience of Fraser has been expertly illustrated by J. Gebhardt Smith, medical artist of the Royal Victoria Hospital, and superbly depicted in this masterpiece of printing by Saunders. The experience and acumen of Paré, the clinician of the pair, is evident throughout the entire work and has been supplemented by the help of the eminent pulmonary pathologist, William Thurlbeck and pulmonary physiologists, Peter Maklen, John Henderson, and Margot Becklake. The authors have addressed themselves principally to the diagnosis of diseases of the lungs, but they have covered the necessary physiology, pathology, microbiology, and embryology most admirably in the process. The roentgenographic aspects are, of course, the highlight. No area of pulmonary disease has been overlooked, however, even where physiologic measurements overshadow the roentgenogram among diagnostic

Airway Dynamics: Physiology and Pharmacology.

Immediately following the 24th International Congress of Physiological Sciences in Washington DC in 1968 several satellite were held at various locations in this country. Although not apparent from its title, this book consists of the papers presented at one of these symposia held at Haverford College. In the preface to the text it states that the scope of the conference was ... limited, deliberately, the physical and physiological properties of the airways and how they can be altered by drugs, dust or disease. The highly laudible intent of this conference was to provide for communication between pulmonary physiologists and pulmonary pharmacologists because some felt there had not been adequate exchange of information concerning mechanisms of drug actions and methods for detecting the same. An outstanding group of contributors from both Europe and the United States were recruited by the editor and his program committee to participate in the conference. It

Inhalation and perfusion radionuclide studies of pediatric chest disease.

DELINEATION of the physiological changes in chronic pediatric pulmonary diseases continues to evade pediatricians and pulmonary physiologists, largely because present study methods are inadequate for the task. The obstacles to accurate clinical evaluation of children with pulmonary pathology are great. Personnel must be specially trained to perform the studies. Equipment must have low resistance and minimal dead space because of the smaller bronchial diameters and lung volumes involved. The child must be able to cooperate, a factor which depends upon his age, learning ability, fears, and physical strength. Finally, the results cannot be assessed on a single standard, but must be interpreted according to each child's age and size. Even when all contributing factors combine to create ideal conditions, areas of uneven ventilation are difficult to assess (10). Recent advances in nuclear medicine have yielded new and possibly better approaches to this problem. We have used a technic of inhalation lung-scanning...

Pulmonary-Function Tests

All physicians, regardless of their types of practice, are seeing more patients with various forms of chronic lung disease. Pulmonary symptoms may be the primary complaint, or they may become apparent during another illness or after an operation. Pulmonary-function tests offer the means of elucidating the type of physiological impairment present, quantitating the degree of malfunction, and allowing for objective follow-up studies in the natural history of the disease and the efficacy of therapeutic measures. Tests of lung function vary from simple measurements of vital capacity to the use of gaseous radioactive isotopes for measurements of regional blood flow, ventilation, and gas exchange. The physician in practice should be able to interpret the results of ventilatory tests and arterial-blood gas analyses, and rely on the pulmonary physiologist and the chest physician for interpretation of the more refined tests of lung function. In this communication, lung-function tests will be reviewed briefly

Nasal surgery. Physiological considerations of nasal obstruction.

CONTINUED medical contributions have been made in the field of pulmonary physiology, especially in the last decade, with the development of medical electronics. However, little attention has been paid to nasal breathing by most pulmonary physiologists. By applying the methods which are widely employed for pulmonary function tests, to nasal as well as mouth respiration, we have shown that nasal obstruction has a definite influence on pulmonary functions.1-4 This paper deals with changes in pulmonary mechanics in patients with nasal obstruction, through the separation of pulmonary resistance into its components, airway and pulmonary tissue resistance. Preoperative and postoperative data is presented showing the return of various abnormalities in function to normal following successful nasal surgery upon the obstructed nose. Review of Literature A few pulmonary physiologists such as Speizer et al5and Ferris et al,6using their own techniques, measured the resistance of various parts of the

Bronchodilators, pulmonary function, and asthma.

Editorial Notes1 April 1968Bronchodilators, Pulmonary Function, and AsthmaMAURICIO J. DULFANO, M.D.MAURICIO J. DULFANO, M.D.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-68-4-955 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptThe previously undisputed benefits of isoproterenol, epinephrine, and aminophylline in treatment of bronchial asthma have recently come under critical review. For decades pulmonary physiologists characterized the asthmatic disturbance primarily in terms of increased work of breathing resulting from augmented airway resistance and uneven distribution of ventilation throughout the lung, while little attention was directed to the characteristics of pulmonary blood flow (Q) distribution, and the resultant effects on alveolar ventilation-perfusion ratios (VA/QT), "physiological" shunt (QS/QT), and the alveolar-arterial oxygen tension gradient (A-ao2D). The concept that hypoxemia and hypercapnia are infrequent in asthma (1) went unchallenged for years until convincing evidence...

The Regulation of Human Respiration: The Proceedings of the J. S. Haldane Centenary Symposium Held in the University Laboratory of Physiology, Oxford.

The centenary (1960) of the birth of J. S. Haldane was the occasion for a symposium, held in 1961, in which most of the world's important pulmonary physiologists participated. Although Haldane contributed basic knowledge to many branches of respiratory physiology, this symposium primarily discusses respiratory control. The proceedings are divided into five principal sections, each comprising four to six papers. Individual sections are devoted to specific features of respiratory control such as: peripheral receptors and effectors, central receptors, response to CO 2 , altitude adaptation, and hyperpnea of exercise. Ten to twenty pages of excellent discussion conclude each division. An additional section presents tributes to Haldane, not the usual eulogy often found in medical publications but serious scientific reviews in which the role of Haldane's contributions to the development of present knowledge is traced by an accomplished investigator with an intimate knowledge of the field. A final portion contains brief reports

Physiological Research in Chronic Pulmonary Disease: An Evaluation of Alveolar Aeration, Oxygen and Carbon Dioxide Transfer and the Pulmonary Circulation

An adequate clinical evaluation of pulmonary function requires measurements on the ventilatory status, on the transfer of oxygen and carbon dioxide in the lungs and on the pulmonary blood flow. Single tests of lung function on only one aspect are unsatisfactory. There is need for more extensive application of accurate pulmonary function testing, for better diagnosis of the individual case for medical treatment, for better surgical evaluation in the problem case and more accurate disability appraisal in compensation cases. The pulmonary function evaluation should be used along with the history, the physical and the roentgenological examination. Spirograms are satisfactory screening tests, but lung volume measurements are required for accurate evaluation of emphysema and fibrosis. Measurements on arterial blood and the expired air complete the pulmonary function evaluation. The clinician, chest surgeon, consultant or others, when provided with an accurate pulmonary function evaluation of their problem cases, will come to use and rely on this new field of medicine more and more. On the other hand, inadequate pulmonary function testing will have the reverse effect engendering suspicion and distrust. The pulmonary physiologist must employ an adequate battery of tests well standardized and suitable for routine use on the individual case regardless of the problem, and the information obtained must be interpreted correctly and be dependable for use in arriving at a decision for the best method for handling or managing the individual problem case.