Functional response to inhaled salbutamol and/or ipratropium bromide in Ascaris suum-sensitised cats with allergen-induced bronchospasms

Abstract

a b s t r a c tKnowledge about the use of inhaled bronchodilators in cats with so-called 'feline asthma' is limited and relies on the experience of clinicians treating these patients. A randomised controlled four-way crossover study was therefore designed to compare the effects of salbutamol (SAL, 100 lg), ipratropium bromide (IB, 20 lg) and a combination of both (SAL/IB, 100 lg/20 lg), delivered through a pressurised metereddose inhaler (pMDI) connected to a spacing chamber, on allergen-induced bronchospasms in five Ascaris suum (AS)-sensitised cats. Four AS bronchial provocation challenges were carried out at 1 week intervals, followed by one of four treatment protocols: SAL, IB, SAL/IB or control (untreated). Enhanced pause (Penh), an estimator of airflow limitation measured by barometric whole-body plethysmography, was repeatedly assessed within 120 min following the administration of each treatment protocol. Responses to inhaled medications were evaluated by calculating the area under the time-response curves (AUC) from 0 to 60 or 120 min after drug administration (AUC 0-60 , AUC 0-120 ), as well as the times required for half-recovery (T 50% ) or for returning to nearly basal conditions (T 20% ).No significant differences were found among the four study groups, with reference to the mean AUC 0-60 , T 20% and T 50% values of Penh (P > 0.05). Mean AUC 0-120 values of Penh were similar between the bronchodilators tested, but were significantly lower than those in the untreated group. It was concluded that inhalation of SAL, IB and SAL/IB via pMDI failed to improve most Penh-derived parameters, which suggested that these bronchodilators were of limited efficacy in reversing allergen-induced bronchospasm in cats. However, further studies using a larger number of animals are warranted to investigate if different drugs or delivery devices or higher dosages may be more effective.

Treatment of the feline atopic syndrome – a systematic review

“…23,25,27,[29][30][31][32][33][34][35] Of the prospective studies, 19 were open and uncontrolled 24,28,[36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52] while 29 were randomised, controlled [53][54][55][56][57][58][59] and often blinded. 26,42,[60][61][62][63][64][65][66][67][68][69][70][71][72][73]…”

“…69 In the cross-over study with five cats sensitised to A. suum, enhanced pause, an estimator of airflow limitation measured by BWBP, was repeatedly assessed within 120 min following the administration of each treatment protocol. 70 Responses to inhaled medications were evaluated by calculating the area under the time-response curves (AUC) from 0 to 60 or 120 min after drug administration (AUC 0-60 , AUC 0-120 ), as well as the times required for half-recovery or for returning to nearly basal conditions. There was no difference in time-related bronchodilating effects between 100 mcg salbutamol, 20 mcg ipratropium bromide, a combination of the two treatments, and the nontreated control.…”

“…69 In another study, the same drugs were used in a doubleblinded, placebo-controlled cross-over design in A. suumsensitised cats. 70 In a clinical study including 19 cats with naturally occuring bronchial disease, therapy with lowdose prednisolone was supplemented with propentofylline in 10 cats. 57 Analysis of efficacy In the first study, cats sensitised to ovalbumin (n = 6), to A. suum (n = 6) and nonsensitised control cats (n = 6) were evaluated.…”

Feline asthma and heartworm disease: Clinical features, diagnostics and therapeutics

“…19 An injectable short-acting beta-2 agonist such as terbutaline is preferred by the authors in cats with status asthmaticus as bronchospasm limits delivery of inhaled bronchodilators to the lower airways. 48 Once the life-threatening crisis has passed, these cats are managed as stable asthmatics. For additional information on feline asthma treatment, including research on novel therapies, the reader is referred to other reviews.…”

Simultaneous visual inspection for barometric whole-body plethysmography waveforms during pulmonary function testing in client-owned cats

“…Simultaneous visual inspection (SVI) of BWBP waveforms, and the recognition and manual elimination of artefactual waveforms that are not automatically detected by the software, have been described in one study with healthy dogs, 18 while many studies in cats have reported that disturbed waveforms were automatically eliminated by the software under similar rejection criteria (when TV <5–10 ml, when Ti <0.15 s or >10 s, or when the difference between inspiratory and expiratory volumes exceeds 20%). 5,6,8,19,20 Although the BWBP system has been applied in clinical studies using client-owned cats, 9–13,21 it is not known whether the commonly used rejection criteria are sufficient for excluding most non-breath artefacts, which may affect the final outcome in these clinical cases. The present study was designed to evaluate the effect of SVI on BWBP waveforms on the results obtained from the examinations.…”