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Breath-hold technique

Breath holding. For compounds fliat achieve equilibrium slowly, some researchers have used the breath holding technique, which involves holding die breath for 5-30 seconds prior to exhaling into the collection device. This results in a more constant concentration in the exhaled breath. The extent to which the lungs are filled with air (as with a deep inhalation) will affeet the results. Kelman showed, however, that breadi holding is not necessary for solvents with blood/gas partition coefficients greater than 10. [Pg.1084]

Ogilvie, C. M., R. E. Forster, W. S. Blakemore, and J. W. Morton, 1957, A Standardized Breath Holding Technique for the Clinical Measurement of the Diffusing Capacity of the Lung for Carbon Monoxide, J. Clin, Invest., 36 1-17. [Pg.566]

Kalender W, Seissler W, Klotz E, Vock P (1990) Spiral volumetric CT with single-breath-hold technique, continuous transport and continuous scanner rotation. Radiology 176 181-183... [Pg.23]

Rominger MB et al. (2000) Left ventricular heart volume determination with fast MRI in breath holding technique how different are quantitative heart catheter, quantitative MRI and visual echocardiography Fortschr Roentgenstr... [Pg.283]

Sergiacomi G, Sodani G, Fabiano S et al. MRI lung perfusion 2D dynamic breath-hold technique in patients with severe emphysema. In Vivo 2003 17 319 324. Haraldseth O, Amundsen T, Rinck PA. Contrast-enhanced pulmonary MR imaging. Magma 1999 8 146 153. [Pg.133]

SAACh/SAACh combined followed by 10 s breath holding. Open mouth technique holding MDI 2 inches away from open mouth, is comparable to closed-mouth technique (closing Ups around MDI mouthpiece) requires lower doses per actuation... [Pg.642]

Clark et al. (40) developed what is a mathematically similar approach to Theil s, which was applied to both DPIs and pMDIs plus spacer and chambers. (Clark et al. deliberately avoided using data from pMDIs alone because of the difficulties associated with the ballistic nature of the plume.) The basis of the technique is the assumption that lung deposition is simply the inhaled dose minus that deposited in mouth and oropharynx. This approach does not require the application of a lung deposition model and is justified for most DPIs and pMDI since the fractions exhaled after a typical 5- to 10-s breath-hold are always close to zero. As an oral deposition function, Clark et al. chose to use the function proposed by Stahlhofen et al. and Rudolf et al., which is then numerically integrated with the size distribution derived from cascade impactor data to calculate oral deposition. Subtracting oral deposition from the inhaled dose allows calculation of the lung dose. Clark used gamma camera data from seven clinical studies, four DPI and three pMDI, to evaluate the approach. On analysis, it was seen that... [Pg.134]

The most common errors are the inability to coordinate inhalation with MDI actuation, to inhale too quickly, and to exhale without a breath-hold (12,49,50). Crompton (49) identified 215 patients with inadequate inhaler technique. Of these, 50% failed to synchronize aerosol release with inhalation and 36% stopped inhaling when the propellant spray hit the back of the throat. Patients may stop breathing in when propellants impact on the back of the throat and rapidly evaporate, causing almost instantaneous cooling in that area. This is known as the cold freon effect (51). It is difficult to argue with the advice that old patients, young patients, and anyone else should be assumed to be unable to use pMDIs properly unless proved otherwise (49). Nasal inhalation is also a common error among children (51). [Pg.349]

Lawford P, MacKenzie F. Pressurised bronchodilator aerosol technique influence of breath holding, time and relationship of inhaler to the mouth. Br J Dis Chest 1982 76 229-233. [Pg.365]

Pedersen S, Stefensen G. Fenoterol powder inhaler technique in children Influence of inspiratory flow rate and breath-holding. Eur Respir Dis 1986 68 207-214. Nielsen K, Skov M, King B, Ifversen M, Bisgaard H. Flow-dependent effect of formoterol dry-powder inhaled from the Aerolizer. Eur Respir J 1997 10 2105-2109. [Pg.445]

McKenzie CA, Lim D, Ransil BJ et al (2004) Shortening MR image acquisition time for volumetric interpolated breath-hold examination with a recently developed parallel imaging reconstruction technique clinical feasibility. Radiology 230 589-594... [Pg.27]

Two less frequently used techniques include breath holding or rebreathing to homogenize the breath sample ... [Pg.1084]


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