To understand the complete picture of the cardiovascular system, you need to learn how to determine the value of your average blood pressure.
Under the arterial pressure should be understood the force with which blood pushes against the vascular walls.
To assess the functioning of the heart and blood vessels, the main criterion was the concept of blood pressure, which is of two types:
- systolic (upper);
- diastolic (lower).
Systolic blood pressure shows how much blood presses against the walls of blood vessels as the heart throws out a new batch of blood. Diastolic characterizes the moment of a pause, that is, the time for the heart to rest.
Normally, the pressure of an adult person ranges from 110/65 to 130/85 mm. Hg Art. There are limits of the norm – the upper (140/90), lower (100/60). They mean that the patient’s condition is not critical, does not require urgent medical intervention.
By measuring blood pressure on different hands, slightly different data can be obtained. It’s okay if the difference is about 10 mm. Hg Art. Sometimes there is a need to measure the pressure on the legs of the patient.
120/80 is considered to be the ideal pressure, but it has long been a secret that many people can feel great even at lower or higher pressure.
To clarify the pressure of a person, it is necessary to monitor it twice a day:
- in the morning after waking up (without getting out of bed);
- before bedtime (after a short rest).
It is possible that blood pressure changes due to fluctuations in ambient temperature, disruption of water-salt balance, sudden movements, physical exertion.
When systolic pressure does not become lower than 140 for a long time, it is worth talking about the onset of hypertension. If it does not rise above 90, the doctor will diagnose hypotension.
In the absence of adequate and most importantly timely treatment, the patient may receive complications of the disease, stroke and heart attack are especially dangerous.
Mean arterial pressure in humans
In medicine, in addition to the concept of systolic and diastolic blood pressure, there is the term pulse and mean blood pressure.
The average is the pressure of the entire cardiac cycle, which is calculated using a special formula. Normally, its value should range from 80 to 95.
It is very simple to calculate the pulse pressure – it is necessary to subtract diastolic from systolic. Its indicator should not be higher than 45 points.
You need to know that the function of the heart according to mean arterial pressure is not customary to describe. For complete information the doctor needs additional data:
- cardiac output;
- stroke volume;
- cardiac index.
By cardiac output, it is necessary to understand the volume of blood ejected by the heart in 1 minute. Thanks to the stroke volume, you can see the amount of blood emitted for 1 heartbeat.
To calculate the cardiac output, the stroke volume is multiplied by the heart rate. The heart index helps to describe the heart function most accurately.
Mean blood pressure is not the arithmetic mean value between the lower and upper pressure. This is because the time of the cardiac cycle is not equal to the systolic level, but to the diastolic one. The mean arterial pressure of approximately 40% is determined by the systolic level, and by 60% by the diastolic level.
Mean blood pressure means the pressure of the complete heart cycle. On the rubber cuff of the tonometer, such a blood pressure will determine the level that equals the diastole pressure when the lumen is closed.
In medical institutions, the method of arterial oscillography is used. With its help it is possible to register the oscillatory processes occurring in the arterial vessels. Due to oscillography, it is possible to obtain information about the functionality of the cardiovascular system.
There are five ways to calculate the average pressure for men and women on their own without using expensive equipment:
- standard formula;
- Hicam’s formula;
- Wetzler and Boger formula;
- Stavitsky formula.
The standard formula provides for the following calculation: the figure of the lower one is taken away from the value of the upper arterial pressure, and the difference is divided by the number 3 and added to the lower pressure indicator. Norm, if the result is from 80 to 95.
A little differently calculated by the formula of Hicam. In this case, the pulse pressure is divided by the number 3, add the lower pressure or minimum.
According to the formula of Wetzler and Boger, the average pressure should be calculated as follows:
- the number 0.42 is multiplied by the upper pressure or maximum;
- add to the result 0.58 multiplied by the lower pressure.
Stavitsky’s formula: lateral systolic blood pressure is multiplied by the systole time (in seconds), and then the minimum diastole pressure is added (in seconds). The result is divided by the time of the cardiac cycle.
The mean pressure can be easily determined with the help of special equipment, based on other data. Even when the upper and lower pressure values vary with age, the average value should always remain at the same level.
What can affect the result?
You should know that when taking certain medications and some diseases, the perception that there is a normal average pressure may change.
In this situation, the physician should ensure that this indicator does not go far beyond the normal, not provoking any health-threatening complications.
When a patient does not know how the drugs that he takes, or the diseases he suffers from, affect the permissible value of mean blood pressure, it is necessary to immediately consult with his physician or cardiologist.
Problems may occur if:
- head injury;
- some types of aneurysm;
- septic shock;
- treatment with vasoconstrictor drugs;
- infusion of vasodilators.
When the value of the average pressure at rest goes far beyond the limits of the norm, it is necessary to be examined in the clinic. This rule applies to situations where the value of upper and lower blood pressure is also far from the usual.
It should be understood that mean arterial pressure of less than 60 points is often deadly. There is a high risk that the organs do not receive the required amount of blood.
How to measure blood pressure?
In order for the result of measuring blood pressure to be true, certain rules should be followed. 1 hour before the manipulation, the patient should refrain from drinking alcohol, smoking, coffee and products containing caffeine.
It is not necessary to measure the pressure if the bladder is full, as this will cause an increase of about 10 mm. Hg Art.
Each measurement must be carried out in an absolutely calm environment at a comfortable room temperature. The patient should sit in a relaxed state for at least 5 minutes. The hand on which the cuff is put on must be at such a level that the ulnar fold is in line with the heart; the hand must also be relaxed. During the procedure is prohibited:
Between the two measurements should take 5 minutes to normalize the pressure in the hand after squeezing the vessels.
How to measure blood pressure with a mechanical tonometer?
After preliminary preparation, the cuff is put on the arm in such a way that it is 5 centimeters higher than the elbow. If the tonometer is designed to relieve pressure on the wrist, its cuff should still be at the same level as the heart.
The stethoscope is applied to the middle of the inner fold, and then put it on. In this place, when the air is released from the cuff, a distinct pulsation will be heard. The cuff is pumped up to 200-220, but if you suspect that the pressure is even higher, the cuff can be pumped even more.
After, being guided by the dial of the tonometer, slowly let the air down, listening to the pulse beats. As soon as the first strike is heard, it is necessary to memorize the parting evidence:
- this figure will correspond to the upper pressure (systolic);
- when the blows stop, this indicator is responsible for the lower pressure (diastolic).
Such measurements are carried out 2-3 times in a row. The mean value should be taken as true blood pressure values.
How to measure blood pressure with an electronic device, and most importantly, how to measure pressure correctly?
A cuff is put on the arm, the limb is also located in line with the heart. Then everything is extremely simple – they click on the button to start measuring pressure and wait until the device shows the result. The device will independently pump up the cuff with the required amount of air, and then let it go at the right moment. All that remains for the patient is to memorize or record the readings. Some models of automatic tonometers can remember the data and the date of the manipulation.
Each tonometer has its pros and cons. For example, mechanical and semi-automatic models are affordable, but require certain skills or the help of others. But automatic devices are convenient, do not provide for application skills, but they are quite expensive and can often show incorrect data. How to measure pressure will tell the video in this article.