Measurement of respiratory impedance in healthy calves using the impulse oscillation technique—Physiological and methodological aspects

Reinhold, Petra; Smith, H. J.; Langenberg, A; Lekeux, Pierre

doi:10.1016/s1090-0233(98)80032-4

Cited by 18 publications

(12 citation statements)

References 21 publications

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“…The R rs (f) curve in healthy mature horses showed a positive frequency dependence up to 20 Hz then decreased from 20 to 35 Hz. The shape of resistance-frequency curves from 5 to 20 Hz obtained in our horses were similar to those determined with other FOT in healthy ponies (Young and Hall 1989), calves (Gustin et al 1988;Reinhold et al 1998a) and dogs (Clercx et al 1993). Similar cases of positive frequency-dependent behaviour of R rs up to 20 Hz were reviewed by Cutillo and Renzetti (1993), who concluded that an increase of resistance and a concurrent decrease of compliance with frequency reflected the combined influence of factors such as inhomogeneous distribution of time units, inertial distortion of velocity profile, interference of spontaneous breathing and shunt characteristics of the mouth.…”

Section: Interpretation Of Normal Ios Values In Horsessupporting

confidence: 88%

Measurement of respiratory function by impulse oscillometry in horses

Erck

Votion

Art

et al. 2004

Equine Veterinary Journal

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Reasons for performing study: Due to technical implementations and lack of sensitivity, pulmonary function tests are seldom used in clinical practice. Impulse oscillometry (IOS) could represent an alternative method. Objectives: To define feasibility, methodology and repeatability of IOS, a forced oscillation technique that measures respiratory resistance (Rrs) and reactance (Xrs) from 5 to 35 Hz during spontaneous breathing, in horses. Methods: Using 38 healthy horses, Rrs and Xrs reference values were defined and influence of individual biometrical parameters was investigated. In addition, IOS measurements of 6 horses showing clinical signs of heaves were compared to those of 6 healthy horses. Results: Airtightness and minimal dead space in the facemask were prerequisites to IOS testing and standardisation of head position was necessary to avoid variations in Rrs due to modified upper airway geometry. In both healthy and diseased animals, measurements were repeatable. In standard‐type breeds, the influence of the horse's size on IOS parameters was negligible. An increase in R5Hz greater than 0.10 kPa/l/sec and R5Hz>R10Hz, combined with negative values of Xrs between 5 and 20 Hz, was indicative of heaves crisis. Conclusions: IOS is a quick, minimally invasive and informative method for pulmonary function testing in healthy and diseased horses. Potential relevance: IOS is a promising method for routine and/or field respiratory clinical testing in the equine species.

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Section: Interpretation Of Normal Ios Values In Horsessupporting

confidence: 88%

Measurement of respiratory function by impulse oscillometry in horses

Erck

Votion

Art

et al. 2004

Equine Veterinary Journal

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“…After an adaptation period of approximately 5 min, three non-invasive lung function techniques (all JAEGER, CareFusion) were applied consecutively to each animal per time point: (1) impulse oscillometry system to assess respiratory mechanics, (2) volumetric capnography to measure the concentration of exhaled CO 2 against exhaled volume, and (3) re-breathing system to assess FRC (functional residual capacity). All systems were originally produced for human medicine and have been successfully applied to calves previously [19-22]. In each system, a Lilly-type pneumotachograph (mesh resistance: 36 Pa/(L/s)) was used for continuous measurement of airflow (V’).…”

Section: Methodsmentioning

confidence: 99%

“…Complex respiratory impedance, consisting of both respiratory resistance (Rrs) and respiratory reactance (Xrs), was analysed in the frequency range 3 Hz - 15 Hz as described elsewhere [15,22,23]. In addition, proximal airway resistance (Rprox) and distal airway resistance (Rdist) were calculated [15,21].…”

Section: Methodsmentioning

confidence: 99%

Evaluation of pulmonary dysfunctions and acid–base imbalances induced by Chlamydia psittaci in a bovine model of respiratory infection

Ostermann

Linde

Siegling-Vlitakis

et al. 2014

Multidisciplinary Respiratory Medicine

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BackgroundChlamydia psittaci (Cp) is a respiratory pathogen capable of inducing acute pulmonary zoonotic disease (psittacosis) or persistent infection. To elucidate the pathogenesis of this infection, a translational large animal model was recently introduced by our group. This study aims at quantifying and differentiating pulmonary dysfunction and acid–base imbalances induced by Cp.MethodsForty-two calves were grouped in (i) animals inoculated with Cp (n = 21) and (ii) controls sham-inoculated with uninfected cell culture (n = 21). For pulmonary function testing, impulse oscillometry, capnography, and FRC (functional residual capacity) measurement were applied to spontaneously breathing animals. Variables of acid–base status were assessed in venous blood using both (i) traditional Henderson-Hasselbalch and (ii) strong ion approach.ResultsBoth obstructive and restrictive pulmonary disorders were induced in calves experimentally inoculated with Cp. Although disorders in respiratory mechanics lasted for 8–11 days, the pattern of spontaneous breathing was mainly altered in the period of acute illness (until 4 days post inoculation, dpi). Expiration was more impaired than inspiration, resulting in elevated FRC. Ventilation was characterised by a reduction in tidal volume (−25%) combined with an increased percentage of dead space volume and a significant reduction of alveolar volume by 10%. Minute ventilation increased significantly (+50%) due to a compensatory doubling of respiratory rate. Hyperventilatory hypocapnia at 2–3 dpi resulted in slightly increased blood pH at 2 dpi. However, the acid–base equilibrium was additionally influenced by metabolic components, i.e. the systemic inflammatory response, all of which were detected with help of the strong ion theory. Decreased concentrations of albumin (2–10 dpi), a negative acute-phase marker, resulted in a decrease in the sum of non-volatile weak acids (Atot), revealing an alkalotic effect. This was counterbalanced by acidic effects of decreased strong ion difference (SID), mediated by the interplay between hypochloraemia (alkalotic effect) and hyponatraemia (acidic effect).ConclusionsThis bovine model was found to be suitable for studying pathophysiology of respiratory Cp infection and may help elucidating functional host-pathogen interactions in the mammalian lung.

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“…Impulse rate and sampling interval. Impulse rate and selected sampling interval effects on calculated impedance have been evaluated in vitro as well as in calves of comparable size to adult humans [20,21]. No significant effect of impulse rate was observed between 1 and 5 impulses per second.…”

Section: Multifrequency Input Impedancementioning

confidence: 99%