Robinson N Edward, Berney Cathy, Eberhart Sue, deFeijter-Rupp Heather L, Jefcoat Andrew M, Cornelisse Cornelis J, Gerber Vincent M, Derksen Frederik J
Pulmonary Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA.
Am J Vet Res. 2003 May;64(5):550-7. doi: 10.2460/ajvr.2003.64.550.
To investigate relationships between cough frequency and mucus accumulation, airway obstruction, and airway inflammation and to determine effects of dexamethasone on coughing and mucus score.
13 horses with recurrent airway obstruction (RAO) and 6 control horses.
6 RAO-affected and 6 control horses were stabled for 3 days. Coughing was counted for 4 hours before and on each day horses were stabled. Before and on day 3 of stabling, tracheal mucus accumulation was scored, airway obstruction was assessed via maximal change in pleural pressure (deltaPpl(max)), and airway inflammation was evaluated by use of cytologic examination of bronchoalveolar lavage fluid (BALF). Effects of dexamethasone (0.1 mg/kg, IV, q 24 h for 7 days) were determined in 12 RAO-affected horses.
To assess frequency, coughing had to be counted for 1 hour. In RAO-affected horses, stabling was associated with increases in cough frequency, mucus score, and deltaPpl(max). Control horses coughed transiently when first stabled. In RAO-affected horses, coughing was correlated with deltaPpl(max), mucus score, and airway inflammation and was a sensitive and specific indicator of deltaPpl(max) > 6 cm H2O, mucus score > 1.0, and > 100 neutrophils/microL and > 20% neutrophils in BALF Dexamethasone reduced cough frequency, mucus score, and deltaPpl(max), but BALF neutrophil count remained increased.
Because of its sporadic nature, coughing cannot be assessed accurately by counting during brief periods. In RAO-affected horses, coughing is an indicator of airway inflammation and obstruction. Corticosteroid treatment reduces cough frequency concurrently with reductions in deltaPpl(max) and mucus accumulation in RAO-affected horses.
研究咳嗽频率与黏液积聚、气道阻塞及气道炎症之间的关系，并确定地塞米松对咳嗽和黏液评分的影响。
13匹复发性气道阻塞（RAO）马和6匹对照马。
6匹患RAO的马和6匹对照马被关厩3天。在马被关厩前及关厩的每一天，记录4小时的咳嗽次数。在关厩前及关厩第3天，对气管黏液积聚进行评分，通过胸膜压力最大变化值（deltaPpl(max)）评估气道阻塞情况，并通过支气管肺泡灌洗液（BALF）的细胞学检查评估气道炎症。在12匹患RAO的马中确定地塞米松（0.1mg/kg，静脉注射，每24小时1次，共7天）的效果。
为评估频率，咳嗽次数需记录1小时。在患RAO的马中，关厩与咳嗽频率、黏液评分及deltaPpl(max)增加有关。对照马在首次关厩时短暂咳嗽。在患RAO的马中，咳嗽与deltaPpl(max)、黏液评分及气道炎症相关，并且是deltaPpl(max)>6cm H2O、黏液评分>1.0以及BALF中中性粒细胞>100个/微升且中性粒细胞>20%的敏感且特异指标。地塞米松降低了咳嗽频率、黏液评分及deltaPpl(max)，但BALF中性粒细胞计数仍升高。
由于咳嗽具有间歇性，在短时间内计数无法准确评估咳嗽情况。在患RAO的马中，咳嗽是气道炎症和阻塞的指标。皮质类固醇治疗在降低患RAO马的deltaPpl(max)和黏液积聚的同时，降低了咳嗽频率。
