scholarly journals Exploring the 175-year history of spirometry and the vital lessons it can teach us today

2021 ◽  
Vol 30 (162) ◽  
pp. 210081
Author(s):  
Andrew Kouri ◽  
Ronald J. Dandurand ◽  
Omar S. Usmani ◽  
Chung-Wai Chow
Keyword(s):  
Lung Function ◽  
Vital Capacity ◽  
Disease Diagnosis ◽  
Flow Volume ◽  
Volume Curve ◽  
The World ◽  
Flow Volume Curve ◽  
History Of ◽  
The Impact ◽  
Over Time

175 years have elapsed since John Hutchinson introduced the world to his version of an apparatus that had been in development for nearly two centuries, the spirometer. Though he was not the first to build a device that sought to measure breathing and quantify the impact of disease and occupation on lung function, Hutchison coined the terms spirometer and vital capacity that are still in use today, securing his place in medical history. As Hutchinson envisioned, spirometry would become crucial to our growing knowledge of respiratory pathophysiology, from Tiffeneau and Pinelli's work on forced expiratory volumes, to Fry and Hyatt's description of the flow–volume curve. In the 20th century, standardization of spirometry further broadened its reach and prognostic potential. Today, spirometry is recognized as essential to respiratory disease diagnosis, management and research. However, controversy exists in some of its applications, uptake in primary care remains sub-optimal and there are concerns related to the way in which race is factored into interpretation. Moving forward, these failings must be addressed, and innovations like Internet-enabled portable spirometers may present novel opportunities. We must also consider the physiologic and practical limitations inherent to spirometry and further investigate complementary technologies such as respiratory oscillometry and other emerging technologies that assess lung function. Through an exploration of the storied history of spirometry, we can better contextualize its current landscape and appreciate the trends that have repeatedly arisen over time. This may help to improve our current use of spirometry and may allow us to anticipate the obstacles confronting emerging pulmonary function technologies.

The University of Groningen in the World

2021 ◽  
Author(s):  
Klaas Berkel ◽  
Guus Termeer
Keyword(s):  
The Netherlands ◽  
Academic Staff ◽  
The World ◽  
History Of ◽  
History Of The University ◽  
International University ◽  
Religious Reasons ◽  
The University ◽  
The Impact ◽  
Over Time

The University of Groningen has been an international university since its foundation in 1614. The first professors formed a rich international community, and many students came from outside the Netherlands, especially from areas now belonging to Germany. Internationalization, a popular slogan nowadays, is therefore nothing new, but its meaning has changed over time. How did the University of Groningen grow from a provincial institution established for religious reasons into a top-100 university with 36,000 students, of whom 25% come from abroad and almost half of the academic staff is of foreign descent? What is the identity of this four-century-old university that is still strongly anchored in the northern part of the Netherlands but that also has a mind that is open to the world? The history of the university, as told by Klaas van Berkel and Guus Termeer, ends with a short paragraph on the impact of the corona crisis.

Density dependence of maximal flow in dogs with central and peripheral obstruction

1983 ◽  
Vol 55 (3) ◽  
pp. 717-725 ◽  
Author(s):  
R. G. Castile ◽  
O. F. Pedersen ◽  
J. M. Drazen ◽  
R. H. Ingram
Keyword(s):  
Density Dependence ◽  
Vital Capacity ◽  
Forced Expiration ◽  
Flow Volume ◽  
Partial Obstruction ◽  
Volume Curve ◽  
Before And After ◽  
Lower Lung ◽  
Maximum Expiratory Flow ◽  
Flow Volume Curve

In 12 anesthetized, tracheotomized, vagotomized, open-chested, mongrel dogs we measured end and side hole airway pressures during forced expiration using a Pitot static probe. Volume was obtained as the integral of flow from a dog plethysmograph with frequency response adequate to 20 Hz. Equal pressure points (EPPs) and choke points (CPs) were located with dogs breathing air or a mixture of 80% helium-20% oxygen (HeO2) before and after partial obstruction of the trachea and intravenous histamine and propranolol. At 50% of vital capacity (VC) the CP was in the trachea in 11 of 12 dogs. Partial obstruction of the trachea decreased flow during the plateau of the maximum expiratory flow-volume curve (MEFVC) with the CP remaining in the trachea. The MEFVC plateau was extended to a lower lung volume. At 50% of VC the EPP moved downstream and density dependence remained high. Histamine and propranolol caused EPPs and CPs to move towards the periphery and density dependence to decrease. The shape of the MEFVC changed as the plateau was shortened and, in some instances, abolished. A plateau on the MEFVC could be regenerated by partial obstruction of the trachea. This was accompanied by return of the CP to the trachea and an increase in density dependence. Changes in density dependence were found to be a result of both the relocation of sites of flow limitation and differences in local CP areas with HeO2 and air.

Changes in flow-volume curve configuration with bronchoconstriction and bronchodilation

1986 ◽  
Vol 61 (6) ◽  
pp. 2243-2251 ◽  
Author(s):  
C. R. O'Donnell ◽  
R. G. Castile ◽  
J. Mead
Keyword(s):  
Vital Capacity ◽  
Normal Subjects ◽  
Flow Volume ◽  
Slope Ratio ◽  
Lung Volumes ◽  
Volume Curve ◽  
Before And After ◽  
Lower Lung ◽  
Maximum Expiratory Flow ◽  
Flow Volume Curve

Changes in the configuration of maximum expiratory flow-volume (MEFV) curves following mild degrees of bronchodilation or bronchoconstriction were studied in five normal and five asthmatic subjects. In a volume-displacement plethysmograph, MEFV curves were performed before and after inhalation of aerosolized isoproterenol (I) or histamine (H). Five filtered MEFV curves were averaged, and slope ratio vs. volume (SR-V) plots were obtained from averaged curves. Following I, maximal flows at 75% of the vital capacity (VC) were decreased in asthmatics but not in normal subjects. Flows at 50 and 25% of the VC increased in normal subjects and asthmatics, whereas VC′s were unchanged. In asthmatics, sudden large decreases in flow (bumps) occurred at lower lung volumes following I. H reduced flows over the entire VC, with greater reductions occurring in asthmatics than in normals, particularly at low lung volumes. In asthmatics, VC was slightly reduced, and bumps in MEFV curve configuration occurred at higher lung volumes or were abolished entirely following H. A reduction in the amount of configurational detail appreciable in MEFV curves following histamine in asthmatics was best seen in SR-V plots. Following H, SR′s decreased regularly with decreasing lung volume in all the asthmatics but in none of the normals. This was the single most striking finding of this study. Mild I- and H-induced perturbations of airway bronchomotor tone produced small but consistent changes in MEFV curve configuration.(ABSTRACT TRUNCATED AT 250 WORDS)

The Impact of Communications in Global History

2020 ◽  
pp. 195-210
Author(s):  
Heidi Tworek
Keyword(s):  
Conspiracy Theory ◽  
Global History ◽  
Cultural Economic ◽  
Media Companies ◽  
Communications Systems ◽  
The World ◽  
History Of ◽  
The Arab Spring ◽  
The Impact ◽  
Over Time

This chapter emphasizes how understanding the impact of communications can help the interdisciplinary thrust to integrate sociology with history and international relations (IR). It discusses a global history of how communications affected populations around the world, which demonstrates why they played a key role in differentiation. It also talks about how colonialism helped to entrench imperial rule for decades before anticolonial activists used some Western communications systems in their favour. The chapter assesses the contemporary situation, where American-owned social media companies appeared to be the drivers of democratic social change during the Arab Spring of 2011, but now seem to foster conspiracy-theory-driven violence. It presents nine different forms of impact, subdivided into cultural, economic, political, and environmental clusters that illustrate the myriad uneven global effects of communications over time and space.

AREA UNDER THE MAXIMUM EXPIRATORY FLOW-VOLUME CURVE: A MEASURE OF LUNG FUNCTION IN PRESCHOOL CHILDREN

CHEST Journal ◽  
2005 ◽  
Vol 128 (4) ◽  
pp. 187S
Author(s):  
Caroline Pesant ◽  
Miriam Santachi ◽  
Mario Geoffroy ◽  
Theophile Niyonsega ◽  
Mario E. Dumas ◽  
...  
Keyword(s):  
Preschool Children ◽  
Lung Function ◽  
Flow Volume ◽  
Volume Curve ◽  
Maximum Expiratory Flow ◽  
Flow Volume Curve ◽  
Expiratory Flow

Smooth Reference Equations for Slow Vital Capacity and Flow–Volume Curve Indexes

2000 ◽  
Vol 161 (3) ◽  
pp. 899-905 ◽  
Author(s):  
FRANCESCO PISTELLI ◽  
MATTEO BOTTAI ◽  
GIOVANNI VIEGI ◽  
FRANCESCO DI PEDE ◽  
LAURA CARROZZI ◽  
...  
Keyword(s):  
Vital Capacity ◽  
Flow Volume ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Reference Equations

Area under the expiratory flow–volume curve (AEX): actual versus approximated values

2019 ◽  
Vol 68 (2) ◽  
pp. 403-411 ◽  
Author(s):  
Octavian C Ioachimescu ◽  
James K Stoller
Keyword(s):  
Diagnostic Performance ◽  
Vital Capacity ◽  
Flow Volume ◽  
Prior Work ◽  
Strong Correlations ◽  
Functional Impairments ◽  
Lung Volumes ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Expiratory Flow

Previous work has shown that area under the expiratory flow–volume curve (AEX) performs well in diagnosing and stratifying respiratory physiologic impairment, thereby lessening the need to measure lung volumes. Extending this prior work, the current study assesses the accuracy and utility of several geometric approximations of AEX based on standard instantaneous flows. These approximations can be used in spirometry interpretation when actual AEX measurements are not available. We analysed 15 308 spirometry tests performed on subjects who underwent same-day lung volume assessments in the Pulmonary Function Laboratory. Diagnostic performance of four AEX approximations (AEX1–4) was compared with that of actual AEX. All four computations included forced vital capacity (FVC) and various instantaneous flows: AEX1 was derived from peak expiratoryflow (PEF); AEX2 from PEF and forced expiratoryflow at 50% FVC (FEF50); AEX3 from FVC, PEF, FEF at 25% FVC (FEF25) and at 75% FVC (FEF75), while AEX4 was computed from all four flows, PEF, FEF25, FEF50 and FEF75. Mean AEX, AEX1, AEX2, AEX3 and AEX4 were 6.6, 8.3, 6.7, 6.3 and 6.1 L2/s, respectively. All four approximations had strong correlations with AEX, that is, 0.95–0.99. Differences were the smallest for AEX–AEX4, with a mean of 0.52 (95% CI 0.51 to 0.54) and a SD of 0.75 (95% CI 0.74 to 0.76) L2/s. In the absence of AEX and in addition to the usual spirometric variables used for assessing functional impairments, parameters such as AEX4 can provide reasonable approximations of AEX and become useful new tools in future interpretative strategies.

scholarly journals The Concavity of the Maximal Expiratory Flow–Volume Curve Reflects the Extent of Emphysema in Obstructive Lung Diseases

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fumi Mochizuki ◽  
Hiroaki Iijima ◽  
Azusa Watanabe ◽  
Naoya Tanabe ◽  
Susumu Sato ◽  
...  
Keyword(s):  
Vital Capacity ◽  
Chronic Obstructive ◽  
Flow Volume ◽  
Obstructive Pulmonary Disease ◽  
Wall Area ◽  
Maximal Expiratory Flow ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Expiratory Flow ◽  
Volume Difference

Abstract A concave-shaped maximal expiratory flow-volume (MEFV) curve is a spirometric feature in chronic obstructive pulmonary disease (COPD). The MEFV curve is characterized by an increase in the Obstructive Index, which is defined as a ratio of forced vital capacity to the volume-difference between two points of half of the peak expiratory flow on the MEFV curve. We hypothesized that the Obstructive Index would reflect the severity of emphysema in patients with COPD and asthma-COPD overlap (ACO). Thus, the aim of this retrospective study was to evaluate whether the Obstructive Index on spirometry is associated with the extent of emphysema on computed tomography (CT) in patients with COPD, ACO, and asthma (N = 65, 15, and 53, respectively). The percentage of low-attenuation volume (LAV%) and wall area (WA%) were measured on CT. The Obstructive Index was higher in patients with COPD and ACO than in those with asthma. Spearman correlation showed that a greater Obstructive Index was associated with a higher LAV%, but not WA%. Multivariate analysis showed that Obstructive Index was associated with LAV% (standardized β = 0.43, P < 0.0001) independent of other spirometric indices. The Obstructive Index is a useful spirometric index that reflects the extent of emphysema.

Heterogeneous regional behavior during forced expiration before and after histamine inhalation in dogs

1994 ◽  
Vol 76 (1) ◽  
pp. 356-360 ◽  
Author(s):  
J. J. McNamara ◽  
R. G. Castile ◽  
M. S. Ludwig ◽  
G. M. Glass ◽  
R. H. Ingram ◽  
...  
Keyword(s):  
Vital Capacity ◽  
Airway Disease ◽  
Forced Expiration ◽  
Flow Volume ◽  
Lung Capacity ◽  
Open Chest ◽  
Volume Curve ◽  
Before And After ◽  
Flow Volume Curve

We studied the evolution of alveolar pressure (PA) heterogeneity during the course of forced expiration in the lungs of six anesthetized open-chest dogs. Using an alveolar capsule technique, we measured PA simultaneously in six lung regions during full maximal forced deflations before and after administering aerosolized histamine. Flow was measured plethysmographically with volume obtained by flow integration. Heterogeneity was expressed as the coefficient of variation (CV) of regional PA after 25% of the vital capacity had been expired from total lung capacity. The CV in in vivo open-chest canine lungs (21.3%) was significantly greater than that we measured previously in excised lungs (8.7%) (P < 0.02). Inhalation of aerosolized solutions of histamine produced significant increases in interregional heterogeneity (CV = 35.5 and 38.8% after 3 and 10 mg/ml of histamine, respectively; P < 0.025). After histamine, the vital capacity was reduced and the configuration of the flow-volume curve demonstrated some shortening of the flow plateau commonly observed in dogs. Changes in the flow-volume relationship failed, however, to reflect well the marked degree of heterogeneity of PA after histamine administration. These findings may be reconciled on the basis of interdependence of regional expiratory flows. Reductions in flow from obstructed regions appear to be compensated by increases in flow from unobstructed regions and thus mask upstream nonuniformities. These mechanisms may explain in part why the maximal expiratory flow-volume curve has been a relatively insensitive tool for the detection of early nonuniform airway disease.

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