High blood pressure today is one of the main causes of disability and mortality in the adult population. Every year, the number of cardiovascular disasters resulting from high blood pressure is progressively increasing. In many ways, the cause of this situation is the lack of proper diagnosis and ongoing therapy. And if the rational pharmacotherapy of this disease can be attributed to medical activity, then the measurement and control of blood pressure is entirely the responsibility of the patient himself. Let's look at an algorithm for measuring blood pressure in peripheral arteries.
Physiological basis of blood pressure measurement
For a long time, people could not measure pressure by indirect methods, since it was popular and a direct measurement of blood pressure was carried out . The algorithm of action in this case was as follows: a special cannula was introduced into the vessel, which communicated with the manometer. Blood pulsation and pressure were directly transmitted through the tubes to the device. Of course, this method allows you to accurately and reliably measure blood pressure, but it is associated with a significant drawback - the need to puncture the vessel and introduce a foreign body into it. Therefore, indirect methods have gained great popularity, and technological progress has allowed the creation of tonometers (apparatus for measuring blood pressure), which are not inferior in accuracy to direct methods. With their help, the daily measurement of blood pressure is currently being successfully carried out. The algorithm of action, as well as the necessary equipment will be discussed below.
The theoretical basis of indirect methods for measuring blood pressure is the following principle. When an air tonometer is injected into the cuff (provided that the pressure in the cuff is higher than the systolic blood pressure in the vessel), the latter are compressed. As a result of higher pressure in the cuff, blood does not pass through the vessels. If you gradually begin to bleed air from the cuff, when the pressure in the cuff is completely slightly lower than in the artery, blood will begin to flow into the limb. This principle formed the basis for the blood pressure measurement methods described below.
The main methods of measuring blood pressure
Official science knows two main methods that are used to measure blood pressure: the Korotkov method and the Riva-Rocci method. Another appropriate name for these methods is auscultatory and palpation. Let's look at the features of each of the methods.
Riva-Rocci method (palpation)
How is blood pressure measured using it? The action algorithm is as follows. A cuff for measuring blood pressure is applied to the shoulder, which is connected to the tonometer.
Next, air is pumped into the cuff, and after the pulsation of the radial artery on the wrist stops, they begin to gradually reduce air pressure. In this case, the pulsation of the radial artery is continued to be controlled with one hand, and the rate of pressure decrease in the cuff (which should be about 3-4 mm / s) is controlled with the second. As soon as the pressure in the cuff becomes lower than the systolic pressure in the artery, blood will begin to flow into the limb, which will feel like the passage of a pulse wave. When a tactile sensation of pulse oscillations occurs, the data is compared with the gauge scale and the systolic blood pressure value is obtained. The disadvantages of this method include the absolute impossibility of obtaining the value of diastolic blood pressure without the help of a stethoscope, but among the advantages it should be noted the possibility of application in emergency conditions of catastrophes and emergency situations. In this case, obtaining the diastolic pressure value plays a much smaller diagnostic role than systolic.
Korotkov method (auscultatory)
Using a stethoscope, this method allows you to measure blood pressure. The algorithm for the implementation of actions using this method is as follows. The cuff is superimposed on the middle third of the forearm so that 1-2 fingers can be freely placed under it. After that, air is injected into the cuff until the pulsation of the radial artery on the wrist is stopped.
A feature of the method is the use of a stethoscope or phonendoscope to listen to auscultatory phenomena in the ulnar fossa. For this, the head of the device is placed in the elbow fossa and a gradual decrease in air pressure in the cuff is carried out. If auscultatory phenomena occur in a stethoscope, a value is indicated on the tonometer scale, which corresponds to the value of systolic blood pressure, and when this phenomenon disappears, the value of diastolic pressure is noted.
The method has an indisputable advantage - obtaining information about systolic and diastolic pressure, but among its shortcomings, the need to have a stethoscope and the presence of silence in the room where blood pressure is measured are noted.
The main classes of blood pressure monitors used to measure blood pressure
Today, the market is quite saturated with devices that measure blood pressure. The action algorithm of their electronics and mechanics can be divided into three main types: mechanical, semi-automatic and automatic. Moreover, provided that they are used correctly, the instruments have comparable measurement accuracy. The difference is only in ease of use and, of course, in cost.
Assessment of blood pressure using an automatic blood pressure monitor
The use of an automatic blood pressure monitor is most convenient and limits the interference with the results of the human factor. When using devices of this type, the patient only needs to put the cuff on his shoulder and press the button on the device. The device will perform all other actions on its own: pump air into the cuff to a certain value, conduct a smooth and uniform decrease in pressure and give the final result, i.e., it will automatically measure blood pressure.
The algorithm of actions of the device in this case is registered in its non-volatile memory and has been tested in many international services and associations. Among the advantages of this type of device, it is necessary to note the high information content of the results obtained, since the devices are able not only to measure pressure, but also to calculate the heart rate and evaluate the heart rate. And in case of arrhythmia, they will give a warning signal.
Assessment of blood pressure using a semi-automatic tonometer
Using a tonometer of this type, it is also possible to measure blood pressure with no less accuracy. The algorithm briefly looks as follows. Measuring blood pressure using devices of this type is in many ways similar to automatic, with the only difference being that semi-automatic blood pressure monitors do not have a compressor and are not able to pump and bleed air from the cuff.
The rest of the applied electronic components are not inferior in accuracy to the components of automatic blood pressure monitors. Moreover, it is believed that semi-automatic blood pressure monitors are reliable, since they do not contain rubbing and mechanical parts in their design. In addition, the battery of these devices has a long service life. Next, we will consider measuring blood pressure in children. The algorithm of actions, as will be said, will remain the same, but some nuances will appear. They must be taken into account without fail.
Algorithm for measuring blood pressure in children
In principle, in children the measurement of blood pressure (algorithm) is practically no different from an adult. Children need to use the appropriate cuff size, which depends entirely on the child’s age and shoulder diameter. Compliance with this simple rule (when the applied cuff corresponds to the age of the child) is the key to obtaining the correct results of blood pressure values.
Conclusion
If the algorithm for measuring blood pressure using a mechanical tonometer is difficult to learn, it is safe to dwell on the acquisition of an automatic or semi-automatic tonometer.
They will always act as devices capable of providing a high level measurement of blood pressure. The algorithm of actions in their application is very simple, and the results obtained are highly reliable and informative.