Burnheim K, Hughes K J, Evans D L, Raidal S L
School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, 2650, NSW, Australia.
BMC Vet Res. 2016 Nov 28;12(1):268. doi: 10.1186/s12917-016-0893-3.
Respiratory problems are common in horses, and are often diagnosed as a cause of poor athletic performance. Reliable, accurate and sensitive spirometric tests of airway function in resting horses would assist with the diagnosis of limitations to breathing and facilitate investigations of the effects of various treatments on breathing capacity. The evaluation of respiratory function in horses is challenging and suitable procedures are not widely available to equine practitioners. The determination of relative flow or flow-time measures is used in paediatric patients where compliance may limit conventional pulmonary function techniques. The aim of the current study was to characterise absolute and relative indices of respiratory function in healthy horses during eupnoea (tidal breathing) and carbon dioxide (CO)-induced hyperpnoea (rebreathing) using a modified mask pneumotrachographic technique well suited to equine practice, and to evaluate the reliability of this technique over three consecutive days. Coefficients of variation, intra-class correlations, mean differences and 95% confidence intervals across all days of testing were established for each parameter.
The technique provided absolute measures of respiratory function (respiratory rate, tidal volume, peak inspiratory and expiratory flows, time to peak flow) consistent with previous studies and there was no significant effect of day on any measure of respiratory function. Variability of measurements was decreased during hyperpnea caused by rebreathing CO, but a number of relative flow-time variables demonstrated good agreement during eupnoeic respiration.
The technique was well tolerated by horses and study findings suggest the technique is suitable for evaluation of respiratory function in horses. The use of relative flow-time variables provided reproducible (consistent) results, suggesting the technique may be of use for repeated measures studies in horses during tidal breathing or rebreathing.
呼吸问题在马匹中很常见，常被诊断为运动表现不佳的原因。对静息马匹进行可靠、准确且灵敏的气道功能肺量计测试，将有助于诊断呼吸受限情况，并促进对各种治疗对呼吸能力影响的研究。评估马匹的呼吸功能具有挑战性，且适合的检测方法在马医中并不广泛可用。在儿科患者中，由于依从性可能会限制传统肺功能技术的应用，因此会采用相对流量或流量 - 时间测量方法。本研究的目的是使用一种非常适合马医实践的改良面罩气描技术，来描述健康马匹在平静呼吸（潮式呼吸）和二氧化碳（CO）诱发的深呼吸（重复呼吸）过程中呼吸功能的绝对和相对指标，并评估该技术在连续三天内的可靠性。为每个参数确定了所有测试日的变异系数、组内相关性、平均差异和95%置信区间。
该技术提供了与先前研究一致的呼吸功能绝对测量值（呼吸频率、潮气量、吸气和呼气峰值流量、达到峰值流量的时间），且测试日对任何呼吸功能测量指标均无显著影响。在重复呼吸CO引起的深呼吸过程中，测量的变异性降低，但一些相对流量 - 时间变量在平静呼吸时显示出良好的一致性。
马匹对该技术耐受性良好，研究结果表明该技术适用于评估马匹的呼吸功能。相对流量 - 时间变量的使用提供了可重复（一致）的结果，表明该技术可能可用于马匹在潮式呼吸或重复呼吸期间的重复测量研究。
