Guidelines for monitoring arterial blood pressure

The article was professionally consulted with Specialist Doctor I Le Thanh An - Interventional Cardiologist - Department of Medical Examination & Internal Medicine - Vinmec Nha Trang International General Hospital.

Monitoring arterial blood pressure is essential in nursing and patient care. Based on the arterial blood pressure measurement results to judge the health situation before and after treatment.

1.1 Definition of arterial blood pressure Arterial blood pressure is the force exerted by the blood on the artery walls, made up of the following factors:
Blood flow in the arteries Contraction strength of the heart Peripheral resistance . Systolic blood pressure: The pressure of blood in the arteries is at its highest when the heart contracts, so it is also called the maximum blood pressure. Systolic blood pressure is recorded in the numerator position.
Diastolic blood pressure: The pressure of the blood at the lowest position when the heart is in diastole, also known as the minimum blood pressure, the diastolic blood pressure value recorded in the denominator.
1.2 Factors affecting blood pressure Age : People's blood pressure tends to increase as they get older, children will have low blood pressure readings, gradually increasing in adults and highest in the elderly . Gender: At the same age, men will have higher blood pressure values ​​than women. Exercise: Movement and exercise can temporarily raise blood pressure Psychological: When people are in a state of anxiety, fear or excitement, blood pressure can increase. Use of drugs: Use of vasopressors increases blood pressure; taking vasodilators that lower blood pressure; Sleeping pills also lower blood pressure.

1.3 Some diseases of blood pressure 1.3.1 Low blood pressure Arterial blood pressure is lower than normal, systolic blood pressure value < 90 mmHg, diastolic blood pressure < 60 mmHg. Some people have frequent low blood pressure values ​​but no signs of disease. Low blood pressure accompanied by manifestations of shock such as sweating, cold hands and feet, fast heart rate, ... need prompt treatment so as not to affect life. Low blood pressure may occur in some patients: acute infection, bleeding, dehydration. 1.3.2 Trapped blood pressure Trapped blood pressure occurs when the difference between systolic and diastolic blood pressure is less than 20 mmHg. When experiencing this condition, it is necessary to notify the doctor immediately for timely treatment.

2.1 Some types of blood pressure monitors: Mercury sphygmomanometers: High accuracy, cumbersome. Watch sphygmomanometer: Convenient to use, but need to periodically calibrate accuracy with mercury sphygmomanometer, the measurer needs to be trained how to use. Electronic blood pressure monitor: Convenient to use, no need to use a stethoscope, the measurement results will be displayed on the screen, simple operation. 2.2. Components of a sphygmomanometer 2.2.1 Bandage: A cloth roll band with a rubber air bag inside, connected to two rubber hoses, one is connected to a rubber ball to pump air into the bag. steam, a tube connected to the gauge manometer. The top of the rubber ball will have a valve for air release and air injection.
2.3.2 Cardiopulmonary stethoscope Placed in the brachial artery position on the same side of the cuff, the gauge will listen during deflation to record the arterial blood pressure.
How to choose the size of the cuff
This is a very important issue, if choosing the wrong cuff size can make measurement errors up to 10 - 50 mmHg in obese patients. The size of the cuff depends on the circumference of the limb used to measure blood pressure (arm circumference). The cuff length should be 80% and the cuff width should be at least 40% of the arm circumference.
The size of the cuff corresponds to the arm circumference as follows:
Arm circumference 22 - 26 cm, "small adult" cuff, 12 x 22 cm Arm circumference 27 to 34 cm, cuff "adult", 16 x 30 cm Arm circumference 35 to 44 cm, "large adult" cuff, 16 x 36 cm Arm circumference 45 to 52 cm, "adult thigh", 16 x 42 cm

3.1 Principle of arterial blood pressure measurement The principle of arterial blood pressure measurement is that the arm area is wrapped with a rubber band, the compression pressure of this cuff will press on the brachial artery and cause a temporary loss of pulse. , then the cuff is deflated to slowly relieve pressure, the circuit will return. During this procedure, the sphygmomanometer records changes in the arteries.
The systolic blood pressure point is (the point where you can hear/or feel the murmur/pulse return) while the pressure of the rubber band gradually decreases. The diastolic blood pressure score is (the point at which a murmur is heard/or felt and/or pulse is lost) when the pressure of the rubber band is removed. 3.2 What to pay attention to when measuring arterial blood pressure Patients need to rest for 15 minutes before taking arterial blood pressure measurement. Check arterial sphygmomanometer, details such as valve, rubber pump, manometer, cuff. During the measurement it is necessary to use a single meter. The location of arterial blood pressure measurement is usually in the arm, in some other cases it will be measured as prescribed by the doctor. If you want to measure blood pressure at any location, you need to find the artery there first. During the pumping process, do not stop in the middle of the process, causing erroneous results. The steam release process must be continuously discharged until the mercury column or needle drops to zero. During the measurement, if you detect any abnormal signs of blood pressure, you should immediately notify a specialist. For patients who need to monitor their blood pressure at home, we recommend using an electronic blood pressure monitor, because it is easy to use, has many parameters, and can monitor values ​​over time. However, in the process of use, the party needs to adhere to some basic measurement principles, and pay attention to bring the device to calibrate at medical equipment centers every 6 months to 1 year to ensure the best results. precise measurement.

3.3 Recording results after measuring blood pressure Two ways of measuring arterial blood pressure:
Recording as fractions (systolic/diastolic blood pressure) Charting, this method is used with patients who need care Routine care such as anesthesia, shock, bleeding, after surgery,... It is not recommended to measure arterial blood pressure more than once in the same position because it will give inaccurate results. In some cases it is necessary to measure in both arms to compare the results, or compare the results in the thigh with the arm.