Corley Kevin T T, Donaldson Lydia L, Durando Mary M, Birks Eric K
Equine Referral Hospital, Royal Veterinary College, Hertfordshire, UK.
J Vet Intern Med. 2003 May-Jun;17(3):262-72. doi: 10.1111/j.1939-1676.2003.tb02447.x.
Critical illness, anesthesia, primary cardiovascular disease, and exercise may result in marked hemodynamic alterations. Measuring cardiac output (CO) is central to defining these alterations for both clinician and researcher. In the past 10 years, several new methods of measuring CO have been developed for the human medical market. Some of these methods are now validated in the horse and are in clinical use. The Fick method has been used in equine research for more than a century. It depends on simultaneous measurement of mixed venous (pulmonary arterial) and peripheral arterial oxygen content and oxygen uptake by the lungs. The technique is technically demanding, which restricts its clinical use. Indicator dilution techniques, with indocyanine green, cold (thermodilution), or lithium as the marker, have also been widely used in the horse. The indocyanine technique is cumbersome, and thermodilution requires right heart catheterization, which is not a benign procedure, making both of these methods less than ideal for clinical use. Lithium dilution requires catheterization of a peripheral artery and a jugular vein. It has recently been validated in anesthetized adult horses and neonatal foals. Doppler echocardiography is a noninvasive ultrasound-based technique. More accurate measurements are obtained with transesophageal than with transthoracic measurements; however, both methods require considerable technical expertise. Bioimpedance and pulse contour analysis are 2 new methods that have yet to be validated in the horse. With the currently available technology, lithium dilution appears to be the method of measuring CO best suited to the equine clinic.
危重病、麻醉、原发性心血管疾病和运动都可能导致显著的血流动力学改变。对于临床医生和研究人员而言，测量心输出量（CO）是明确这些改变的核心。在过去十年中，已为人类医疗市场开发了几种测量CO的新方法。其中一些方法现已在马匹中得到验证并应用于临床。菲克法在马的研究中已使用了一个多世纪。它依赖于同时测量混合静脉血（肺动脉血）和外周动脉血的氧含量以及肺的氧摄取量。该技术对技术要求较高，限制了其临床应用。指示剂稀释技术，以吲哚菁绿、冷（热稀释）或锂作为标志物，也已在马匹中广泛使用。吲哚菁绿技术操作繁琐，热稀释需要进行右心导管插入术，而这并非无害操作，这使得这两种方法都不太适合临床应用。锂稀释需要对一条外周动脉和一条颈静脉进行插管。它最近已在麻醉的成年马和新生驹中得到验证。多普勒超声心动图是一种基于超声的非侵入性技术。经食管测量比经胸测量获得的结果更准确；然而，这两种方法都需要相当的技术专长。生物电阻抗和脉搏轮廓分析是两种尚未在马匹中得到验证的新方法。就目前可用的技术而言，锂稀释似乎是最适合马临床的心输出量测量方法。
