McKane S A, Slocombe R F
Cotts Farm Equine Hospital, Narberth, Pembrokeshire, UK.
Equine Vet J Suppl. 2010 Nov(38):235-9. doi: 10.1111/j.2042-3306.2010.00295.x.
Histological studies of exercise-induced pulmonary haemorrhage (EIPH) reveals inflammatory infiltrates within areas of lung that contain haemorrhage. This has resulted in the hypothesis that pulmonary inflammation could cause EIPH or contribute to an increased risk or severity of EIPH.
To determine whether experimentally-induced pulmonary inflammation predisposes the lung to haemorrhage during exercise, by evaluating the bronchoalveolar lavage (BAL) cytology of normal and inflamed regions of lung following high speed treadmill exercise.
Transendoscopic airway inoculations of 0.01% acetic acid were used to induce mild localised inflammation within bronchopulmonary segments. Horses underwent high speed exercise 24 h after inoculation. Following exercise, inoculated sites and corresponding segments in the opposite lung underwent BAL. The cytology results from inflamed and control bronchopulmonary segments were compared, using paired t tests.
Erythrocytes were present in BAL samples from 12.5% (1/8) control segments compared with 75% (6/8) inoculated segments following exercise, indicating a significant increase (P = 0.04) in the relative risk of EIPH following the development of pulmonary inflammation. Samples from inoculated segments had significantly higher percentages and numbers of neutrophils (12.1 ± 1.0% and 601 ± 98 cells/μl) than control samples (4.3 ± 0.3% and 214 ± 52 cells/μl). Significantly higher erythrocyte numbers were observed in samples from inoculated segments (14,304 ± 6862 cells/μl) compared with control samples (3.5 ± 3.5 cells/μl).
The results showed inflammation increased the risk of developing pulmonary haemorrhage during exercise. These findings do not conflict with current theories on the common causes of EIPH, but suggest that care should be taken when recommending exercise in horses suspected to be suffering from pulmonary inflammatory disease. In addition, specific therapy to reduce pulmonary inflammation may benefit horses prone to the development of EIPH.
运动性肺出血（EIPH）的组织学研究显示，在肺内有出血的区域存在炎性浸润。由此产生了一种假说，即肺部炎症可能导致EIPH，或增加EIPH的风险或严重程度。
通过评估高速跑步机运动后正常和发炎肺区域的支气管肺泡灌洗（BAL）细胞学，确定实验性诱导的肺部炎症是否会使肺部在运动时更容易出血。
经内镜气道接种0.01%醋酸以诱导支气管肺段内轻度局部炎症。马匹在接种后24小时进行高速运动。运动后，对接种部位和对侧肺的相应节段进行BAL。使用配对t检验比较发炎和对照支气管肺段的细胞学结果。
运动后，12.5%（1/8）对照节段的BAL样本中存在红细胞，而接种节段为75%（6/8），表明肺部炎症发生后EIPH的相对风险显著增加（P = 0.04）。接种节段的样本中中性粒细胞的百分比和数量（分别为12.1±1.0%和601±98个细胞/μl）显著高于对照样本（分别为4.3±0.3%和214±52个细胞/μl）。与对照样本（3.5±3.5个细胞/μl）相比，接种节段的样本中红细胞数量显著更高（14,304±6862个细胞/μl）。
结果表明炎症增加了运动时发生肺出血的风险。这些发现与目前关于EIPH常见病因的理论并不冲突，但建议在怀疑患有肺部炎症疾病的马匹中推荐运动时应谨慎。此外，减少肺部炎症的特异性治疗可能对易发生EIPH的马匹有益。
