Plethysmography

The classic approach to measuring respiratory function in laboratory animals is plethysmography. It has two basic governing principles [18,22,30]  

If volume, flow rate, and pressure changes are detected at the same time, several respiratory variables can be derived simultaneously from the 

TABLE 6.6 Pulmonary Variables from the Maximal Expiratory Flow-Volume Curve 

Volume of gas expired after full inspiration expiration being as rapid and complete as possible (i.e., forced) 

Peak expiratory flow (liter/min or liter/s) measured by various instruments 

---

HAART Highly-active antiretroviral therapy IPG Impedance plethysmography... 

Using animal models, whole body plethysmography has been used to assess both early and late phase airway responses in guinea pigs, rats and mice [2,28-32], However,... 

Most lung volumes can be measured with a spirometer except total lung capacity (TLC), functional residual capacity (FRC) and residual volume (RV). The FRC can be measured by helium dilution or body plethysmography. 

Spirometry, flow-volume loops, plethysmography Bronchodilators... 

Vasodilatation by venous occlusion plethysmography, laser doppler Vasodilators... 

Strachan FE, Newby DE, Sciberras DG, McCrea JB, Goldberg MR, Webb DJ. 2002. Repeatability of local forearm vasoconstriction to endothelin-1 measured by venous occlusion plethysmography. Br J Clin Pharmacol 54 386-394. 

Fig. 4. Individual reactions of the bronchial system measured by body plethysmography in 4 patients given the same amount of allergen extract (0.5 ml Botrytis cinerea) [15]. 

Whole body plethysmography (Buxco , EMKA Technologies, Paris). (Fig. 1). 

Airway responsiveness is measured by recording respiratory pressure curves by whole body plethysmography in response to inhaled methacholine, for 20 s, using the XA 157 program. The data are analyzed using Excel or datanalyst software (see Fig. 1) (12). 

Hamelmann, E., Schwarze, J., Takeda, K., Oshiba, A., Larsen, G. L., Irvin, C. G and Gelfand, E. W. (1997) Noninvasive measurement of airway responsiveness in allergic mice using barometric plethysmography. Am. J. Respir. Crit. Care Med. 156, 766-775. 

Whole body plethysmography apparatus (Buxco, Hartford, CN). 

Schierok H, Markert M, Pairet M, Guth B (2000) Continuous assessment of multiple vital physiological functions in conscious freely moving rats using telemetry and a plethysmography system. Journal of Pharmacological and Toxicological Methods 43 211-217... 

Lundblad LKA, Irvin CG, Adler A, Bates JHT (2002) A reevaluation of the validity of unrestrained plethysmography in mice. Journal of Applied Physiology 93 1198-1207 Mauderly JL (1974) The influence of sex and age on the pulmonary function of the beagle dog. Journal of Gerontology 29 282-289... 

Nyboer, J. (1972) Workable volume and flow concepts of bio-segments by electrical impedance plethysmography T.-T.-T. 

In a study ot the ettects ot aspirin 325 mg/day, both acute (4 hours atter the dose) and chronic (6 weeks), in 62 patients with mild to moderate heart tailure taking enala-pril (more than 10 mg/day tor at least 3 months), there were no significant changes in mean arterial pressure or in forearm blood flow and vascular resistance measured by venous plethysmography (112). In another arm ot the study the same results were observed with itetroban 250 mg/day, a thromboxane A2 receptor antagonist. 

Both allergic and irritant mechanisms have been proposed as explanations for nasal symptoms. Measures that have successfully been used include nasal swabs (eosinophils), nasal lavage or biopsy, acoustic rhinometry (nasal volume), anterior and posterior rhinomanometry (plethysmography), and measures of nasal hyperreactivity (visual, using a dental prosthesis as a head fixative, and using an ear surgery microscope to measure distances and swelling). 

Hodous, T.K. (1989) Workplace measurement of respirator effects using respiratory inductive plethysmography, Am Ind Hyg Assoc J, 50(7) 372-378. 

Increased static lung volumes (FRC and TLC), as assessed by whole-body plethysmography, are also a diagnostic feature of asthma (Fig. 9). This is presumably due to premature closing of the airways during expiration be-... 

Elastic resistance strain gages. Elastic resistance strain gages are extensively used in biomedical plethysmography (volume measuring), especially in cardiovascular and respiratory monitoring. These systems employ a narrow... 

---