Methods for studying blood pressure

Methods for measuring pressure depend on the age of the patient, the characteristics of the blood flow, the availability of the necessary instruments and experience. Most often, at home, this indicator is measured using a manual tonometer.

Fluctuations in blood pressure contribute to the deterioration of the general condition of a person. These changes occur as a result of pathologies in the functioning of the cardiovascular system, under the influence of atmospheric, psychological or emotional factors.

To be able to determine this indicator at any time, you need to know all the methods for studying blood pressure.

Methods for determining pressure

There are the following ways to determine the presence of arterial hypertension:

• Direct - is used mainly in surgical practice, as it requires arterial catheterization and the use of specialized solutions.
• Indirect - subdivided into auscultatory, palpatory and oscillometric. These methods of measuring blood pressure involve the use of special devices - tonometers.

The patient must be relaxed and at rest in order for the device to give the correct readings.

Pulsation in the phonendoscope is heard as a result of fluctuations in the elastic wall of the artery, which is manifested by a certain sound phenomenon - a blow. It is advisable to carry out the procedure several times with breaks of 2 or 3 minutes and on different hands.

If the patient is diagnosed with vascular pathologies, then it is necessary to measure the pressure on the femoral artery (in particular, with obliterating atherosclerosis of the arteries of the lower extremities).

In this case, the patient is placed on the stomach, and the phonendoscope is placed in the popliteal fossa.

Invasive measurement method

The direct method of measurement, which consists in the introduction of a catheter or cannula into the lumen of the artery, is used when it is necessary to constantly monitor the hemodynamic parameters of the blood in a particular patient.

The choice of vessel for catheterization depends on the following factors:

• the place for the introduction of the cannula should be protected from getting body secrets on it, and also be as accessible as possible;
• the diameter of the cannula and the vessel must match;
• the blood flow in the vessel must be sufficient to prevent occlusion of the artery.

Most often, the radial artery is used for catheterization. It is easily palpable, slightly reduces the patient's motor activity and has a superficial location.

To determine the state of the vessel and the characteristics of the blood flow, an Allen test is preliminarily performed.

The patient is clamped the arteries located in the region of the cubital fossa (ulnar and radial), asked to work with his fist until the brush begins to turn pale.

Then the arteries are released and set for what period of time the color of the brush will be restored:

• 5/7 sec. - indicator with adequate blood flow in the artery;
• 7/15 sec. - indicates a violation of the process of blood flow in the artery;
• over 15 sec. - with such an indicator, catheterization of the radial artery must be abandoned.

It is necessary to carry out catheterization under sterile conditions, having previously processed the system for measuring blood pressure with saline solution with the addition of 5 thousand units of heparin.

auscultatory method

Indirect methods for studying blood pressure do not require special skills. The auscultatory method for determining hypertension is the most common in home practice.

In this case, a manual tonometer is used, which includes a cuff worn on the forearm and a phonendoscope. The cuff should freely wrap around the arm, so that you can easily insert your finger. The forearm must first be bared or a change in blood pressure should be carried out through thin matter.

The phonendoscope is placed in the cubital fossa, it is in this place that the artery is localized, which provides maximum pulsation. This pulsation will be heard with a phonendoscope.

After preparation, you can start measuring:

1. The phonendoscope is inserted into the ears, the valve on the pear is closed and it is squeezed vigorously to pump air into the cuff. It is necessary to pump air until the pulse ceases to be heard, and then make an additional 4/7 squeezes of the pear so that the arrow rises another 20 mm Hg. Art.
2. The cuff must be deflated very slowly. To do this, the valve on the pear is slightly unscrewed. At the moment of lowering the cuff, you should listen carefully to hear the first and last beat. Systolic pressure (upper) is determined by the indicator when the first knock was noted, and diastolic (lower) - by the last beat heard in the phonendoscope.

In the event that the beats in the phonendoscope are not audible or there is uncertainty about the accuracy of the measurement, you need to repeat the procedure. The patient needs to work with his hand, bending and unbending it in the elbow joint, and then do all the actions from the very beginning.

Normally, in an adult, blood pressure should be equal to 120/80 mm Hg. Art. Allow fluctuations in systolic pressure from 110 to 139 mm Hg. Art., and the change in diastolic pressure should not go beyond 60-89 mm Hg. Art.

Palpation method

With this method, a pneumatic cuff is also involved, only the study of hypertension occurs not by listening to the pulse beats in the phonendoscope, but by probing it.

The procedure is as follows:

• The cuff is put on the forearm, a few centimeters above the elbow, inflated with air.
• After that, the doctor presses the radial artery with his fingers.
• When you feel the first pulsating contraction of the artery, you need to remember the number: it shows the systolic pressure. The last pulse will show the diastolic pressure.

This method is used mainly for young children, whose pressure cannot be determined using the auscultatory method. It is also possible to examine the pressure in the child and on the femoral artery, in this case the cuff is put on the thigh so that a finger can freely pass between it and the surface of the child's leg, is inflated with air, and then slowly descends.

The pulse must be felt on the popliteal artery, to determine in this way only the upper pressure will be obtained (at the moment the pulsation appears). It is important to note that the systolic pressure indicator with the palpation method of measurement will be 5-10 units lower than when using the auscultatory method.

To conduct a study of arterial hypertension in this way at home, you must have some experience and know how, why and when an artery begins to pulsate in the cubital fossa.

Oscillometric method

This method is very convenient to use at home. All you need to know is how the device used to study hypertension works. You can find out this information from the instructions.

The oscillometric method requires a semi-automatic or automatic blood pressure monitor, which will independently determine the correct blood pressure reading and display it on the screen.

Tonometers, depending on the method of injecting air into the cuff, are divided into:

• for automatic;
• to mechanical.

In mechanical devices, the patient will need to independently inflate the cuff with air using a pear, while in automatic blood pressure monitors, air fills the cuff without assistance.

The oscillometric method for determining hypertension has a significant difference from all other methods. In this case, the blood pressure in the cuff will not decrease smoothly, but in steps. In imperceptible stops, the device will record the pressure, amplitude and pulse rate.

At the moment of the largest amplitude, systolic pressure is determined, at an average amplitude, the average indication of hypertension is measured, and when the amplitude of the pulse decreases, the lower (diastolic) pressure is measured.

How to measure pressure correctly

To get the correct readings, you must follow certain rules for measuring pressure:

• carry out the procedure regularly and at the same time;
• between measurements take breaks of no more than 5 minutes;
• avoid smoking and drinking coffee 1 hour before measuring pressure;
• the cuff should be at the level of the heart;
• the patient should be relaxed and in a sitting or lying position;
• Do not move or talk during the measurement.

In addition, an hour before measuring pressure, you need to stop using medicines (even nasal drops, for example, Naphthyzinum, as it contributes to the production of adrenaline). Physical activity must also be stopped in a timely manner so that by the time the procedure is carried out, the pulse and pressure are restored.

The manifestation of hypertension is also observed with an overflowing bladder. In this case, the error is 10 mm Hg. Art. That is why it is important to visit the toilet in a timely manner in order to get the correct pressure readings.

Another interesting point is that it is necessary to take pressure measurements on both hands, and write down in the diary the indicator that turned out to be higher. And in the future, take measurements on the arm, the blood pressure on which is higher. The excess of indicators in a healthy person can differ on different hands up to 15 mm Hg. Art. This is considered normal and does not indicate the development of any pathological processes.

A careful and regular study of arterial hypertension will allow you to monitor your health and promptly seek medical help with strong fluctuations in systolic and diastolic pressure.