A Rapid Plethysmographic Method for Measuring Thoracic Gas Volume: A Comparison With a Nitrogen Washout Method for Measuring Functional Residual Capacity in Normal Subjects 1

DuBois, Arthur B.; Botelho, Stella Y.; Bedell, George N.; Marshall, Robert; Comroe, Julius H.

doi:10.1172/jci103281

Cited by 1,140 publications

(331 citation statements)

References 10 publications

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“…Interestingly, Vb determined by Boyle's law is underestimated by 40% of the thoracic gas volume (V TG ) partly because the air in the lungs is isothermic and 40% more compressible than adiabatic air. Thus, failure to correct for this phenomenon will result in an overestimation of total body density (Db) and, consequently, an underestimation of percent fat mass (%FM); therefore, measurement of V TG by the BOD POD is incorporated into the testing procedure (Dubois et al, 1956). Alternatively, the BOD POD provides the use of a predicted V TG (V TGPredicted ) (Crapo et al, 1982).…”

Section: Introductionmentioning

confidence: 99%

Changes in thoracic gas volume with air-displacement plethysmography after a weight loss program in overweight and obese women

et al. 2007

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Objective: This study was designed to compare measured and predicted thoracic gas volume (V TG ) after weight loss and to analyze the effect of body composition confounders such as waist circumference (WC) on measured V TG changes. Design: Prospective intervention study. Setting: Outpatient University Laboratory, Lisbon, Portugal. Subjects: Eighty-five overweight and obese women (body mass index ¼ 30.073.5 kg/m 2 ; age ¼ 39.075.7 years) participating in a 16-month university-based weight control program designed to increase physical activity and improve diet. Methods: Body weight (Wb), body volume (Vb), body density (Db), fat mass (FM), percent fat mass (%FM) and fat-free mass (FFM) were assessed by air-displacement plethysmography (ADP) at baseline and at post-intervention (16 months). The ADP assessment included a protocol to measure V TG and a software-based predicted V TG . Dual-energy X-ray absorptiometry (DXA) (Hologic QDR 1500) was also used to estimate FM, %FM and FFM. Maximal oxygen uptake (VO 2 max) was assessed with a modified Balke cardiopulmonary exercise testing protocol with a breath-by-breath gas analysis. Results: Significant differences between the baseline and post-weight loss intervention were observed for body weight and composition (Vb, Db, %FM, FM and FFM), and measures of V TG (measured: D ¼ 0.2 l, Po0.001; predicted: D ¼ 0.01 l, Po0.010) variables. Measured V TG change was negatively associated with the change in the WC (P ¼ 0.008), controlling for VO 2 max and age (P ¼ 0.007, P ¼ 0.511 and P ¼ 0.331). Linear regression analysis results indicated that %FM and FM using the measured and predicted V TG explained 72 and 76%, and 86 and 90% respectively, of the variance in %FM and FM changes using dual-energy x-ray absorptiometry. Conclusions: After weight loss, measured V TG increased significantly, which was partially attributed to changes is an indicator of body fat distribution such as WC. Consequently, measured and predicted V TG should not be used interchangeably when tracking changes in body composition. The mechanisms relating the reduction of an upper body fat distribution with an increase measured V TG are worthy of future investigation.

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Section: Introductionmentioning

confidence: 99%

Changes in thoracic gas volume with air-displacement plethysmography after a weight loss program in overweight and obese women

et al. 2007

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“…Specific airway resistance (sRaw) and thoracic gas volume (TGV) were measured in a constant-volume body plethysmograph (Model 2000 TB; Cardio-Pulmonary Instruments, Houston, TX, USA), according to DUBOIS and colleagues [17,18]. The gas flow/box pressure slopes were measured at a gas flow of 0.5± -0.5 L .…”

Section: Whole Body Plethysmographymentioning

confidence: 99%

Short-term exposure to air pollution in a road tunnel enhances the asthmatic response to allergen

Svartengren¹,

Strand²,

Bylin³

et al. 2000

Eur Respir J

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The aim of this study was to assess whether air pollution in road tunnels would promote asthmatic reactions in persons with mild allergic asthma.Twenty volunteers with mild allergic asthma were exposed, inside a car, for 30 min in a Stockholm city road tunnel. As a control, the subjects were exposed to much lower pollution levels in a suburban area. Four hours after the exposure, the subjects inhaled a low dose of allergen. Asthmatic reaction during the early phase was measured as the increase in specific airway resistance 15 min after allergen inhalation and during the late phase as the decrease in lung function forced expiratory volume in one second 3±10 h after allergen inhalation. Asthma symptoms and drug use were monitored up to 18 h after allergen inhalation.The median nitrogen dioxide level during exposure was 313 mg . m -3 (range 203± 462). The median levels of particles with 50% cut-off aerodynamic diameters of 10 (PM10) and 2.5 mm (PM2.5) were 170 (range 103±613) and 95 (range 61±218) mg . m -3 , respectively. Subjective symptoms during tunnel exposure were not pronounced. However, subjects exposed to tunnel NO 2 levels of $300 mg . m -3 had a significantly greater early reaction, following allergen exposure, as well as lower lung function and more asthma symptoms during the late phase, compared to control. Also, subjects with PM2.5 exposure $100 mg . m -3 had a slightly increased early reaction compared to control.In conclusion, exposure to air pollution in road tunnels may significantly enhance asthmatic reactions to subsequently inhaled allergens. Eur Respir J 2000; 15: 716±724.

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“…Routine pulmonary function studies were performed on all. The displaceable lung volumes were measured with a spirometer and functional residual capacity and airway resistance (panting at 1-2 cycles/s up to 0.5 liter/s inspiratory flow rate) with a body plethysmographic technic (11,12). Single breath diffusing capacity (13), single breath nitrogen test (14), closing volume, and flow volume curves (15) were also obtained.…”

Section: Vt1 Vt2mentioning

confidence: 99%

Relationship between Frequency Dependence of Lung Compliance and Distribution of Ventilation

Wanner¹,

Zarzecki²,

Atkins³

et al. 1974

J. Clin. Invest.

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A Rapid Plethysmographic Method for Measuring Thoracic Gas Volume: A Comparison With a Nitrogen Washout Method for Measuring Functional Residual Capacity in Normal Subjects 1

Cited by 1,140 publications

References 10 publications

Changes in thoracic gas volume with air-displacement plethysmography after a weight loss program in overweight and obese women

Changes in thoracic gas volume with air-displacement plethysmography after a weight loss program in overweight and obese women

Short-term exposure to air pollution in a road tunnel enhances the asthmatic response to allergen

Relationship between Frequency Dependence of Lung Compliance and Distribution of Ventilation

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