Methods of measuring blood pressure in animals


The blood pressure measurement of experimental animals can be divided into direct method and indirect method. This article mainly deals with blood pressure measurement methods in animals such as rats, mice and dogs commonly used in hypertension research. In most cases, the choice of measurement method is determined by the observer. It is important to emphasize that regardless of the method of blood pressure measurement, we must avoid general anesthesia. It has been recognized for a long time that anesthesia affects the cardiovascular system in many ways, and that the response of the cardiovascular system in anesthetized and awake animals is very different.

Indirect blood pressure measurement method.
The most commonly used method of indirect blood pressure measurement in animals is the cuff method, which measures blood pressure in the tail or limbs. The blood flow is altered by blocking or loosening the collar, and the pressure within the collar is determined by the blood flow. There are many ways to sense changes in blood flow when cuff blood flow is blocked, including photoelectric sensors, oscillometric sensors, Doppler sensors, chamber volume sensors, and auditory sensors. Although these sensors have some improvements, each has its advantages and disadvantages, which should be taken into account regardless of the method used in the research.
 1. Advantages Indirect blood pressure measurement has played a large role in experimental hypertension research for many years and will continue to be used in some kind of research. Indirect blood pressure measurement has the following four main advantages:
(1) It is non-invasive and does not require surgery;
(2) systolic blood pressure in awake animals can be measured repeatedly in short-term and long-term studies;
(3) It is more direct and economical;
(4) It is used to screen systolic periods Differences in hypertension and systolic blood pressure in a large sample of animals. This approach should be considered if the observer intends to detect or determine a pure systolic elevation, compare significant differences in systolic BP between groups or change over time, especially if the sample size is large (see Table 25-2). 

Table 25-2 Recommendations for the use of indirect methods to measure blood pressure in animals

Non-invasive assays are recommended for detection and screening:
Quantitative study of the relationship between blood pressure and other variables (eg, target organ damage)
isolated systolic blood pressure
Non-blood pressure reliability effects of research interventions or variables
Significant differences in systolic blood pressure between groups
Except for intermittent hypertension or mild hypertension or changes in blood pressure
Significant changes in blood pressure over time
Variability in measuring blood pressure
Changes in systolic blood pressure in large samples (eg, extensive genetic screening)
Measuring diastolic or pulse pressure in awake rodents
Inferring blood pressure in animals without striated muscles or in freely moving animals