Re-breathing vs single-breath TlCO in patients with unequal ventilation and diffusion

Jansons, H.; Fokkens, J. G.; Tweel, Ingeborg van der; Kreukniet, J

doi:10.1016/s0954-6111(98)90026-9

Cited by 10 publications

(6 citation statements)

References 23 publications

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“…Estimates of DL CO by these two techniques agree well in conscious healthy human subjects at rest and during exercise (22,54). On the other hand, the SB technique is known to underestimate true DL CO in disease states in the presence of ventilatory inhomogeneity (28). In our animals, lung volumes measured by the two techniques were not different, but DL CO measured by RB was systematically higher.…”

Section: Rb Technique In Rodentssupporting

confidence: 54%

Fatty diabetic lung: functional impairment in a model of metabolic syndrome

Yilmaz

Ravikumar²,

Bellotto

et al. 2010

Journal of Applied Physiology

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The Zucker diabetic fatty (ZDF fa/fa) rat with genetic leptin insensitivity develops obesity and Type 2 diabetes mellitus (T2DM) with age accompanied by hyperplastic changes in the distal lung (Am J Physiol Lung Cell Mol Physiol 298: L392-L403, 2010). To determine the functional consequences of structural changes, we developed a rebreathing (RB) technique to simultaneously measure lung volume, pulmonary blood flow, lung diffusing capacity (Dl(CO)), membrane diffusing capacity (Dm(CO)), pulmonary capillary blood volume (Vc), and septal tissue volume in anesthetized tracheostomized male ZDF fa/fa and matched lean (+/+) control animals at 4, 8, and 12 mo of age. Results obtained by RB technique were compared with that measured by a single-breath (SB) technique and to that expected in a wide range of species. In fa/fa animals compared with +/+, lung volumes and compliance were 13-35% lower at different ages, and the normal age-related increase in lung compliance was no longer evident. Mean pulmonary blood flow declined with age in fa/fa but not in +/+ animals. Dl(CO) measured at a given pulmonary blood flow was 20-43% lower at different ages due to reductions in both Dm(CO) and Vc. Septal tissue volume was also reduced in older fa/fa rats. We conclude that obese rats with T2DM develop significant restrictive pulmonary defects with diffusion impairment in a pattern similar to that previously reported in obese human subjects with T2DM. Functional impairment became exaggerated with age and duration of T2DM. In both fa/fa and +/+ animals, Dl(CO) measured by RB was systematically higher than by SB technique whereas lung volume was similar, a finding consistent with heterogeneous distribution of ventilation in the rat lung.

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Section: Rb Technique In Rodentssupporting

confidence: 54%

Fatty diabetic lung: functional impairment in a model of metabolic syndrome

Yilmaz

Ravikumar²,

Bellotto

et al. 2010

Journal of Applied Physiology

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“…This makes sense physiologically. Unequal ventilation increases with lung volume (14) and this is associated with regional perfusion defects (15). This is expected to increase alveolar NO concentration due to a reduced binding of NO by hemoglobin and consequently to increase in eNO diffusion (16).…”

Section: Discussionmentioning

confidence: 99%

Exaled nitric oxide and air trapping correlation in asthmatic children

Mappa

Cardinale

Camodeca

et al. 2005

Allergy

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Exhaled nitric oxide (eNO) levels have been shown to correlate with atopy and with airway hyperresponsiveness but not with standard spirometry. The aim of our study was to evaluate the correlation between eNo levels and functional residual capacity (FRC), residual volume (RV), RV to total lung capacity (TLC) ratio, and pulmonary resistances in asthmatic children ages 6-13 years. Forty-nine patients (35 males) were enrolled in the study. Nineteen of them were not receiving inhaled corticosteroids. The eNO levels were measured by chemiluminescence's analyzer and lung function study were performed by body box plethysmography. As expected, there was no correlation between eNO levels and forced vital capacity (FVC); forced expiratory volume in the first second (FEV1); mid respiratory flow between 25 and 75% of the vital capacity (MEF(25 -75)), FEV1/FVC, and pulmonary resistances. Instead a correlation was found between eNO level and RV both considering all the study population together (r = 0.51, P = 0.001) and separately the asthmatic children not receiving ICS (r = 0.6, P = 0.003). In the patients receiving ICS the correlation was still present (r = 0.43, P = 0.01). The correlation between eNo levels and RV may reflect the effect of airway inflammation on NO production and diffusion as well as peripheral airway trapping and consequent RV.

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“…This method for DL CO is less commonly used, as it requires more expensive equipment, such as a respiratory mass spectrometer, and more complex calculations. However, because with rebreathing the CO gas is distributed in the lung more evenly, an advantage of this method, as opposed to the single-breath, is its relative insensitivity to unequal distribution of ventilation (Jansons et al, 1998; Roberts et al, 1990) and diffusion (Jansons et al, 1998; Kreukniet, 1970). Furthermore, rebreathing is preferred when subjects cannot hold their breath for long periods or, if for some reason, vital capacity is too small.…”

Section: Carbon Monoxidementioning

confidence: 99%

CO and NO pulmonary diffusing capacity during pregnancy: Safety and diagnostic potential

Zavorsky

Blood

Power

et al. 2010

Respiratory Physiology & Neurobiology

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This paper reviews the scientific evidence for the safety of carbon monoxide (CO) and nitric oxide (NO) inhalation to measure pulmonary diffusing capacity (DLCO and DLNO) in pregnant women and their fetuses. In eight earlier studies, 650 pregnant women had DLCO measurements performed at various times during pregnancy, with a minimum of two to four tests per session. Both pregnant subjects that were healthy and those with medical complications were tested. No study reported adverse maternal, fetal, or neonatal outcomes from the CO inhalation in association with measuring DLCO. Eleven pregnant women, chiefly with pulmonary hypertension, and 1105 pre-term neonates, mostly with respiratory failure, were administered various dosages of NO (5–80 ppm for 4 weeks continuously in pregnant women, and 1–20 ppm for 15 min to 3 weeks for the neonates). NO treatment was found to be an effective therapy for pregnant women with pulmonary hypertension. In neonates with respiratory failure and pulmonary hypertension, NO therapy improved oxygenation and survival and has been associated with only minor, transient adverse effects. In conclusion, maternal carboxyhemoglobin ([HbCO]) levels can safely increase to 5% per testing session when the dose-exposure limit is 0.3% CO inhalation for ≤3 min, and for NO, 80 ppm for ≤ 3 min. The risk of late fetal or neonatal death from increased HbCO from diffusion testing is considerably less than the risk of death from all causes reported by the Centers for Disease Control, and is therefore considered “minimal risk”.

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Re-breathing vs single-breath TlCO in patients with unequal ventilation and diffusion

Cited by 10 publications

References 23 publications

Fatty diabetic lung: functional impairment in a model of metabolic syndrome

Fatty diabetic lung: functional impairment in a model of metabolic syndrome

Exaled nitric oxide and air trapping correlation in asthmatic children

CO and NO pulmonary diffusing capacity during pregnancy: Safety and diagnostic potential

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