Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, Quebec, Canada.
Equine Vet J. 2019 Sep;51(5):641-645. doi: 10.1111/evj.13091. Epub 2019 Mar 28.
Inhaled corticosteroids are effective in the treatment of equine asthma. A recent study reported that nebulisation of injectable dexamethasone had low systemic bioavailability in healthy horses and could represent a cost-effective therapy for equine inflammatory lung diseases.
To determine the effects of dexamethasone nebulisation on lung function in severe asthmatic horses. It was hypothesised that dexamethasone administered by nebulisation would be more effective than the same dose administered orally.
Randomised blinded experimental study in severe asthmatic horses.
Twelve severe asthmatic horses in clinical exacerbation were randomly assigned to treatment with 5 mg of dexamethasone sodium phosphate by nebulisation (n = 6) or by oral administration (n = 6), once daily for 7 days. Lung function was evaluated at baseline, after four treatment days (D4) and 24 h after the last dose (D8). The presence of residual bronchospasm was assessed on D8 with N-butylscopolammonium bromide administration (0.3 mg/kg i.v.). A respiratory clinical score was performed daily. Serum cortisol concentration was measured at baseline, D4 and D8.
The pulmonary elastance was unchanged in both groups while pulmonary resistance was significantly improved in the oral group on D8 (mean reduction in 1 cm H O/L/s [CI: 0.34-1.65, P = 0.003]). All horses had residual bronchospasm at the end of the study. There was a group difference in the respiratory clinical score as it was significantly reduced in the oral group, from D5 to D8. Serum cortisol concentration decreased in all subjects.
Low number of horses and lack of placebo group.
Considering the lack of improvement of lung function and the hypothalamic-pituitary-adrenal axis suppression, the results of this study do not support aerosolisation of an injectable form of dexamethasone for the treatment of severe equine asthma at the dose and with the nebuliser evaluated.
吸入性皮质类固醇在治疗马气喘方面具有疗效。最近的一项研究报告称，在健康马中，注射用地塞米松的雾化吸入具有较低的全身生物利用度，并且可能是一种具有成本效益的治疗马肺部炎症性疾病的方法。
确定雾化地塞米松对严重气喘马肺功能的影响。假设雾化给予地塞米松比口服相同剂量更有效。
严重气喘马的随机、双盲、实验性研究。
12 匹处于临床恶化期的严重气喘马被随机分为两组，分别接受 5mg 地塞米松磷酸钠雾化吸入（n=6）或口服（n=6），每天一次，共 7 天。在基线、第 4 天治疗后（D4）和最后一次给药后 24 小时（D8）评估肺功能。在 D8 时，通过静脉注射丁溴东莨菪碱（0.3mg/kg）评估是否存在残留支气管痉挛。每天进行呼吸临床评分。在基线、D4 和 D8 时测量血清皮质醇浓度。
两组的肺弹性阻力均无变化，而口服组在 D8 时肺阻力显著改善（1cmH2O/L/s 的平均降低值[CI：0.34-1.65，P=0.003]）。所有马匹在研究结束时均存在残留支气管痉挛。口服组的呼吸临床评分有组间差异，从 D5 到 D8 显著降低。所有研究对象的血清皮质醇浓度均下降。
马匹数量少，缺乏安慰剂组。
考虑到肺功能改善不明显以及下丘脑-垂体-肾上腺轴抑制，本研究结果不支持使用评估剂量和雾化器雾化注射用地塞米松治疗严重马气喘。
