PRAY-MED TELLS YOU WHY BLOOD PRESSURE MEASUREMENTS ARE INACCURATE

PRAY-MED TELLS YOU WHY BLOOD PRESSURE MEASUREMENTS ARE INACCURATE

Many people will prepare a blood pressure monitor at home to be able to measure their blood pressure routinely and understand their blood pressure, but sometimes when we measure, we find that the data we get is not so accurate. What causes the wrong blood pressure readings? Common reasons include the following points. When we measure blood pressure at home or by medical staff in the hospital, we can pay attention to the measurement process to avoid blood pressure measurement errors.

1. Wrong size of blood pressure cuff

When measuring with a sphygmomanometer, we may not take into account the size of the blood pressure cuff. In fact, the size of the blood pressure cuff affects the reading of the blood pressure monitor. Either too large or too small can cause false blood pressure readings. The American Heart Association has published in the blood pressure measurement guidelines the length and width of the inflatable portion of the cuff, which are 80% and 40% of the arm circumference, respectively. If we want to measure the circumference of the arm, it may be a little troublesome. A quick way to size a blood pressure cuff is to choose a cuff that covers two-thirds of the distance between our elbow and shoulder. If there are several people in the family who need to measure blood pressure, it is recommended to configure cuffs of multiple sizes, including adult cuffs and children's cuffs, because blood pressure measurement for children requires corresponding pediatric size cuffs.

2. Improper limb position

The second common mistake made in blood pressure measurement is that the limbs are not positioned neatly. In order to accurately assess the blood flow of the limbs, the influence of gravity must be eliminated. The standard reference level for measuring blood pressure by any technique is at the heart level. When using the cuff, the arm or leg on which the cuff is attached should be at the same level as the heart. When the measurement position is higher than the heart, the blood pressure is too low and lower than the heart, we may get too high blood pressure value. Sitting upright provides the most accurate blood pressure measurement, as you only need to keep your arms at the same level as your heart. Patients in a lying or other position may present problems with accurate pressure measurements.

3. Incorrect cuff placement

When taking blood pressure measurements, the blood pressure cuff must be in direct contact with the skin. In particular, it is impossible to measure blood pressure with the sleeves rolled above the elbow. The measurement is inaccurate because this is the sleeve that presses against the blood vessel. During the measurement, we should sit with the arms supported in the middle of the heart, with the legs not crossed, and without talking. Notably, mean pressures barely changed between the aorta and peripheral arteries, whereas systolic blood pressure increased and diastolic blood pressure decreased in more distal vessels. Additionally, crossing your legs increases systolic blood pressure by 2 to 8 mm Hg. About 20% of the population has a pressure difference of more than 10 mmHg between their left and right hands. If a significant difference is observed, treatment decisions should be based on the higher of the two pressures.

4. Electronic sphygmomanometers are not properly considered

Usually when we measure blood pressure at home, we use electronic blood pressure monitors, but many medical staff will use traditional blood pressure monitors for blood pressure measurement. Electronic blood pressure monitors sense changes in air pressure in the cuff caused by blood flowing past the end of the blood pressure cuff. Sensors estimate mean arterial pressure and the patient's pulse rate. The software in the machine uses these two values to calculate systolic and diastolic blood pressure. To ensure the accuracy of the electronics, it is important to verify the displayed pulse with the actual patient pulse. A difference of more than 10% will seriously alter the device's calculations and produce erroneous systolic and diastolic values on the display.

Given that mean arterial pressure is the only pressure actually measured by the sphygmomanometer, and since mean arterial pressure varies little throughout the body, it makes sense to use this electronic sphygmomanometer for treatment decisions. The increased use of electronic sphygmomanometer devices, coupled with the recognition that the systolic and diastolic blood pressures they display are actually measured while the average is being calculated, has led clinicians to focus more on mean arterial pressure than in the past. Especially in the critical care transport setting, healthcare workers encounter situations where there is a significant difference between a patient's NIBP (indirect) and arterial (direct) blood pressure measurements. Mean arterial pressure is the most accurate value regardless of whether an arterial catheter or non-invasive blood pressure measurement is required.

Blood pressure measurement is very important for cardiovascular disease. We need to pay attention to get the most accurate measurement results when measuring, so that we can get the best treatment plan.