The indirect measurement of arterial blood pressure in the horse

Indirect Blood Pressure Measurement in Horses: Is There an Influence of Age, Sex, Breed, Bodyweight, and Cardiac Diseases on Pressure Values?

Only few data regarding normal resting blood pressure in horses and the influence of cardiac diseases on arterial blood pressure are available in literature. The purpose of the present study was to investigate the possible influence of age, sex, breed, bodyweight, and cardiac diseases and their severity on blood pressure values measured in horses with cardiac disease and in a control group. For this case-control study, indirect blood pressure measurement was performed in 60 horses with different types of cardiac disease and in 23 healthy horses (control group), by means of an ultrasonic blood-flow technique. According to the echocardiographic findings, horses with cardiac abnormalities have been divided into two groups (with and without cardiac dimensional modifications). Multivariable linear regression analysis evaluated the influence of age, breed, sex, and cardiac diseases and their severity (regressors) on blood pressure. The results showed a significant influence of age on diastolic pressure in healthy horses. Furthermore, a significant influence of the presence of cardiac dilation in horses with cardiac disease on systolic and diastolic pressures was found. Single-regressor linear analysis showed that horses with cardiac dilation are significantly older than both horses without cardiac dimensional changes and those of control group. Further studies are necessary to better investigate the possible influence of the type of cardiac disease on blood pressure.

Inotropes and vasopressors in adults and foals

Successful treatment with inotropes and vasopressors depends on an understanding of the interplay of flow, pressure, and resistance in the cardiovascular system and an appreciation of the pathophysiologic mechanisms leading to inadequate tissue perfusion. Any treatment strategy is necessarily a compromise between the requirements of different vascular beds.Furthermore. the underlying hemodynamic derangements can change rapidly. Therefore. inotropes and vasopressors should be titrated to measures of improved hemodynamic status, and the treatments should be frequently reviewed.

Study of arterial blood pressure in newborn foals using an electronic sphygmomanometer

An electronic sphygmomanometer which functions on oscillometric principles, was used to measure arterial blood pressure in foals. Its accuracy was assessed by comparison with results obtained by direct measurement in anaesthetised pony foals, aged 34 to 64 days. Correlations between data obtained by the two methods were highly significant but the sphygmomanometric readings were consistently lower than those obtained by direct measurement. An equation was derived from the pooled values for mean, systolic and diastolic pressure measurements. This was used as a correction factor when the oscillometric method was employed in the field on Thoroughbred foals, during the first three days post partum, and on pony foals during the first day only. There were no significant differences between systolic, diastolic and mean values in Thoroughbreds on Days 1, 2 or 3 after birth. Measurements recorded on the first day after foaling were significantly lower (P less than 0.025) in ponies than in Thoroughbreds. Blood pressure measurements in Thoroughbreds and ponies were substantially higher than those reported previously using the ultrasonic Doppler technique.

Monitoring the anesthetized horse

The objectives of monitoring are to gain much information as possible about the anesthetized horse and to follow changes in that information, with the ultimate aim of making anesthesia and surgery as safe as possible for the horse. Information necessary to achieve that aim will vary depending on patient category. For example, a young, healthy horse undergoing a short elective procedure can be clinically well monitored by patient signs, electrocardiogram, and indirect blood pressure response. More invasive monitoring is justified and warranted if the health status of the horse is in question. The degree of invasion will be determined by the information needed to provide optimal support. The constantly changing picture should be recorded. The anesthetist who defines anesthesia as long stretches of boredom interspersed with moments of sheer panic is surely guilty of failure to heed warning signs that were present, had he looked for them.

A method for indirect measurement of arterial blood pressure in the horse

A method using the Doppler ultrasound principle for indirect determination of arterial blood pressure in the horse is described. The method is simple and suitable for field situations. Validation studies show that systolic and diastolic blood pressure measurements bear a close relationship to true values obtained by direct measurement.

Ultrasonic measurement of arterial blood pressure in conditioned thoroughbreds

Indirect systolic and diastolic arterial pressure measurements of 456 Thoroughbred horses of various ages and sex stabled at 9 different race tracks were measured with an ultrasonic-Doppler device interfaced with a sphygmomanometer cuff. The mean systolic pressure was 111.8 +/- 13.3 mmHg and the mean diastolic pressure was 69.6 +/- 13.8 mmHg in this population.