Inhalation cough challenge

Tussive Agents used in Inhalation Cough Challenge. 298... 

Published Data on Reproducibility of Inhalation Cough Challenge.303... 

A high degree of reproducibility is essential for the performance of quality research, especially when serial cough challenges are required. Several aspects of inhalation cough challenge methods must be recognized and controlled to yield maximally reproducible results. 

Fig. 5 Citric acid cough challenge in a patient with cough-variant asthma the effect of inhaled corticosteroids...

Once these modifications have been performed, the exact output (milliliters per minute) of the nebulizer is measured (characterized nebulizer nSpire Health). With the exact nebulizer output known, modulation of the duration of aerosol delivery by the dosimeter allows the determination of aerosol output per inhalation. For example, the author currently uses a characterized nebulizer with an output of 1.007ml min with a dosimeter programmed to deliver pressurized air for 1.2 s, thus allowing the nebulizer to deliver exactly 0.02 ml aerosol per inhalation. Since investigators worldwide will likely continue to use different equipment for the performance of cough challenge studies, one way to achieve a measure of standardization would be to control nebulizer output per breath, with the aforementioned... 

The safety of citric acid cough challenge was reported during the initial development of the method over a half century ago (Bickerman et al. 1954, 1957), but more recent data have not been published. Citric acid inhalation can induce a small decrease in the forced expiratory volume in 1 s (less than 5%) that is unlikely to be of clinical significance (Laude et al. 1993). 

Morice AH, Marshall AE, Higgins KS, Grattan TJ (1994) Effect of inhaled menthol on citric acid induced cough in normal subjects. Thorax 49 1024-1026 Morice AH, Kastehk JA, Thompson R (2001) Cough challenge in the assessment of cough reflex. Br J Chn Pharmacol 52 365-375... 

Two of the four patients showed inproved FEV,. Tracheal mucous velocity is decreased in asthmatics challenged with antigen. Inhalation of 0.5-1% FPL-55712 prevents the decrease in mucous velocity but does not inhibit the bronchospasm. Inhalation of LTC. or LTD. by normal subjects induces coughing which is blocked by aerosol FPL-55712. isi in Basenji-Greyhound dogs, the bronchospasm to inhaled citric acid is associated with increased plasma levels of SRS (but not histamine) and is partly blocked by FPL-55712. 1=2... 

Cho YS, Park SY, Lee CK, Lee EY, Shin JH, Yoo B, Moon HB (2003) Enhanced cough response to hyperpnea with cold air challenge in chronic cough patients showing increased cough sensitivity to inhaled capsaicin. Allergy 58 486 91... 

Table 1 Tussive agents used in cough inhalation challenge...

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