Langsetmo I, Meyer M R, Erickson H H
Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan 66506-5602, USA.
Equine Vet J. 2000 Sep;32(5):379-84. doi: 10.2746/042516400777591066.
Exercise-induced pulmonary haemorrhage (EIPH) is characterised by blood in the airways after strenuous exercise and results from stress failure of the pulmonary capillaries. The purpose of this experiment was to establish a threshold value of transmural pulmonary arterial pressure at which haemorrhage occurs in the exercising horse. Five geldings, age 4-14 years, were run in random order once every 2 weeks at 1 of 4 speeds (9, 11, 13, 15 m/s); one day with no run was used as a control. Heart rate, pulmonary arterial pressure and oesophageal pressure were recorded for the duration of the run. Transmural pulmonary arterial pressure was estimated by electronic subtraction of the oesophageal pressure from the intravascular pulmonary arterial pressure. Within 1 h of the run, bronchoalveolar lavage was performed and the red and white blood cells in the fluid were quantified. Red cell counts in the lavage fluid from horses running at 9, 11 and 13 m/s were not significantly different from the control value, but after runs at 15 m/s, red cell counts were significantly (P<0.05) higher. White cell counts were not different from control values at any speed. Analysis of red cell count vs. transmural pulmonary arterial pressure indicated that haemorrhage occurs at approximately 95 mmHg. Red cell lysis in the lavage fluid was also apparent at transmural pulmonary arterial pressures above 90 mmHg. We conclude that, in the exercising horse, a pulmonary arterial pressure threshold exists above which haemorrhage occurs, and that pressure is often exceeded during high speed sprint exercise.
运动性肺出血（EIPH）的特征是剧烈运动后气道内出现血液，是由肺毛细血管应激性衰竭所致。本实验的目的是确定运动中的马匹发生出血时的跨壁肺动脉压阈值。选用5匹4至14岁的去势公马，以4种速度（9、11、13、15米/秒）之一，每2周随机顺序奔跑一次；以一天不奔跑作为对照。在奔跑过程中记录心率、肺动脉压和食管压。通过从血管内肺动脉压中电子减去食管压来估算跨壁肺动脉压。在奔跑后1小时内，进行支气管肺泡灌洗，并对灌洗液中的红细胞和白细胞进行定量。以9、11和13米/秒速度奔跑的马匹灌洗液中的红细胞计数与对照值无显著差异，但在以15米/秒速度奔跑后，红细胞计数显著（P<0.05）升高。在任何速度下，白细胞计数与对照值均无差异。红细胞计数与跨壁肺动脉压的分析表明，出血发生在约95毫米汞柱时。在跨壁肺动脉压高于90毫米汞柱时，灌洗液中的红细胞溶解也很明显。我们得出结论，在运动中的马匹中，存在一个肺动脉压阈值，高于该阈值会发生出血，并且在高速冲刺运动期间该压力经常被超过。
