Holcombe S J, Beard W L, Hinchcliff K W
Exercise Physiology Laboratory, College of Veterinary Medicine, Ohio State University, Columbus 43210-1089, USA.
Am J Vet Res. 1996 Mar;57(3):250-3.
To investigate the effect of a mask and pneumotachograph on ventilation, respiratory frequency, and tracheal and nasopharyngeal pressures in horses running on a treadmill.
Six horses ran at 50, 75, and 100% of the speed that resulted in maximum oxygen consumption, with and without a mask and pneumotachograph. Tracheal and pharyngeal inspiratory and expiratory pressures, respiratory frequency, and arterial blood gases were measured.
Six Standardbred horses.
Oxygen consumption was measured during an incremental exercise test to determine the speed that resulted in maximal oxygen consumption for each horse. Tracheal and pharyngeal pressures were measured, using transnasal tracheal and pharyngeal side-hole catheters connected to differential pressure transducers. Carotid arterial blood samples were collected and PAO2, PaCO2, and pH were measured with a blood gas analyzer.
Peak tracheal and pharyngeal inspiratory pressures were significantly more negative, peak tracheal and pharyngeal expiratory pressures were significantly more positive, and respiratory frequency was significantly lower (all P < 0.05) at all speeds when horses wore a mask. The PaCO2 was higher and arterial pH and PaO2 were lower (P < 0.05) when horses wore a mask.
The mask and pneumotachograph altered upper airway pressures, respiratory frequency, and ventilation in horses running on a treadmill.
研究面罩和呼吸流速仪对在跑步机上奔跑的马匹的通气、呼吸频率以及气管和鼻咽部压力的影响。
六匹马在导致最大耗氧量的速度的50%、75%和100%下奔跑，分别在佩戴和不佩戴面罩及呼吸流速仪的情况下进行。测量气管和咽部的吸气及呼气压力、呼吸频率和动脉血气。
六匹标准赛马。
在递增运动试验期间测量耗氧量，以确定每匹马达到最大耗氧量时的速度。使用连接到压差传感器的经鼻气管和咽部侧孔导管测量气管和咽部压力。采集颈总动脉血样，并用血气分析仪测量动脉血氧分压（PAO2）、动脉血二氧化碳分压（PaCO2）和pH值。
当马匹佩戴面罩时，在所有速度下，气管和咽部的吸气峰值压力显著更负，气管和咽部的呼气峰值压力显著更正，呼吸频率显著更低（所有P < 0.05）。当马匹佩戴面罩时，动脉血二氧化碳分压更高，动脉pH值和动脉血氧分压更低（P < 0.05）。
面罩和呼吸流速仪改变了在跑步机上奔跑的马匹的上呼吸道压力、呼吸频率和通气。
