If body pletiysmography shows a marked hyperinsuflation associated to a low DLCO the presence of emphysema associated to asthma should be suspected. Emphysema may explain a poor response of bronchial obstruction to antiasthma therapy in a patient with the diagnosis of severe asthma. Presence of emphysema in an asthma patient supports the add tiotropium or other anticolinergic drug in the regular treatment of the patient.

I suspect that there is no more sensitive method to detect even very small bronchoconstriction in potentially asthmatic subjects. The possibility to obtain specific airway resistance and possibility to use it in children are important advantages. Therefore it could offer valuable clinical information. You may want to see this article, it is free: http://onlinelibrary.wiley.com/doi/10.1111/j.1440-1843.2012.02206.x/abstract;jsessionid=93FA7462D70446DD663BB8AA5BC56D54.f01t01.

Lung volums measured by pletiysmography provide information about hyperinsuflation and gas trapping, help to fix lung restriction pattern when forced spirometry its non obstructive, with unclear FEV1/FVC ratio.

To dateplethysmography has been used to augment the information given by simple spirometry because of the dependence of the latter on operator bias both the patient and technician. however the plethysmography technique does not reflect what happens in real life and newer techniques are being suggested and evaluated to be able to have tests which reflect better what happens in real life and can help more in the patient management.

In human medicine, pulmonary function tests (PFT) are widely used to objectively characterize lung function as well as response to therapy. In veterinary medicine the utility of PFT has been described in dogs and cats, including evaluation of respiratory patterns, bronchial reactivity, as well as the response to bronchoconstrictive and bronchodilatory agents. However, PFT in dogs and cats can be challenging, as most PFT for people require voluntary maximal effort, which is not possible in animals.

Barometric whole-body plethysmography (BWBP) is a non-invasive PFT that allows a dynamic study of breathing patterns by placing the patient within an unrestrained Plexiglas chamber. Using specialized software, a unitless variable called enhanced Pause, or Penh, may be calculated as an index of bronchoconstriction. Penh has been shown to correlate with airway resistance, bronchoconstriction and bronchodilation, age-related changes in bronchial reactivity, and airway inflammation. So BWBP is a promising noninvasive method that can be used for diagnosis and monitoring lung function.

Here you are an attachment about the use of BWBP in small animal practice (maybe you could think about its use in newborn infants or children).

Here is one interesting article that should give you an answer...

http://www.thelancet.com/journals/lanres/article/PIIS2213-2600%2813%2970184-X/fulltext#article_upsell

Yes, it may not help you choose change in therapy but may help you rule in or rule out Air Trapping and Dynamic Hyperinflation and effect of therapy on reducing it in Asthma (esp Severe Persistent with AW remodelling) ILD whether associated with OB (obliterative Bronnchiolitis) or not; choosing severe COPDs for Volume Reduction (Surgical or Non Surgical) and conditions such as ARDS sequelae with residual fibrosis whether Bronchodilators need to be given or not.So not much added to diagnosis or prognosis but finetuning for decision making, certainly.And research of course.

In conjunction with bronchoprovocation testing with methacholine, whole body plethysmography is the gold standard for diagnosing human asthma in the United States.

I thank all of you for your thoughtful opinion. From the answers it appears hardly any clinical decisions can be taken based on body plethysmography in current scenario. However, plethysmo does add clinically meaningful information which may influence decision making. Any thoughts on using body plethysmography for identifying cases with mixed obstructive and restrictive abnormalities. What could be the prevalence of such patients? How does treatment get affected after making a diagnosis of mixed pattern?

Plethysmography is necessary to find out whether one has a restrictive deffect or no, the same will be for a mixed deffect.

Mixed deffects seem to be rather infrequent.... This is a situation when at the same time TLC is below LLN and FEV1/(F)VC is also below LLN.

In a study of my colleagues, among the patients who had FEV1/FVC

I guess that the major validity of body plethysmography to estimate lung volumes is when the lung pathology includes airspaces (cysts, bullae, blebs etc.) that are not measured by gas techniques (He, N2). Conditions with that pathology include emphysema (especially bullous), advanced fibrosis, extensive bronchiectasis, fibrobullous sarcoidosis, ankylosing spondylitis, Langerhans histiocytosis etc. In all other cases of either obstructive or restrictive pattern diseases, body plethysmography equals the other techniques.

Hello, bodyplethysmography gives you the best informations about airway resistance at rest and the degree of hyperinflation. We always perform bodyplethysmographie in our patients. Especially in emphysema, where FEV1 is always low you have informations about the variability of airway obstruction and hyperinflation in order to control the effect of your therapy. Best regards. Kurt Rasche

Much has been said. Restrictive and mixte ventilatory defects must be diagnosed by a plethysmography, as already shown. But whole body plethysmography also has a role in obstructive defects. It's very important to look at airway resistances and specific airway conductance (sGaw). There are cases where tiffeneau index is normal, but sGaw is reduced, and you can diagnose an obstructive ventilatory defect.

Regarding the question whether bodyplethysmography is helpful in clinical decision making I would point out to the aspect of lung volume reduction therapy that was mentioned by Dr. Bohme earlier in this discussion.

As hyperinflation is the crucial point that is addressed by endoscopic (or surgical) lung volume reduction, this parameter has to be measured properly. In our institution a residual volume of >200% predicted represents the lower limit of eligibility for ELVR. Hence, bodyplethysmography is indispensable in ELVR evaluation process.

In addition, a lot of other reasons to use this technique have been mentioned before.

Many aspects are already mentioned above. For me, the most important value of the "body" is to measure hyperinflation in terms of lung emphysema. Another aspect is that even severe ill patients are able to do the maneuver.

Whole-body plethysmography is a technique allowing the recording of breathing parameters (frequency and tidal volume) on awake and nonrestricted animals. The major advantage of this technique is the very limited stress resulting from animal manipulation