READING YOUR BP
And? Taking an accurate blood pressure requires understanding the three ways to obtain a reading, and making sure the equipment is accurate.
Listening with the old-fashioned Mercury Sphygmomanometer still gives the gold standard BP reading. Unfortunately, they are being phased out because of environmental hazards, and are only used now to check the accuracy of other devices. The mercury BP meters have been replaced with aneroid andoaxilometric devices.
The aneroid device detects blood pressure flow through an artery. Excess room noise, hearing ability, education, terminal digit preference, and the device factors all lead to measurement errors. They require frequent recalibration every six months and errors can occur from 1 to 44%.
To overcome these errors, an osciiillometric method can be used. This detects the vibration in the artery wall and transforms them into electrical signals displayed on a digital readout. Vibrations however often underestimate the true BP when there is stiff test of the arteries or dysrhythmias. This method is used on the wrist, fingers, upper arm, and ambulatory devices.
The upper arm devices measure the blood pressure at the brachial artery and are recommended over the wrist or finger devices. Finger devices are often inaccurate because of vasoconstriction, alteration in blood pressure at distal sites, and error of arm or leg position in relationship to the heart. Wrist devices often are used in very obese people because the risks are often not enlarged; the same errors occur as I’m thinking devices and altered readings occur when the wrist is flexed or extended. Since there are two arteries at the wrist, blood pressure readings are undependable.
A third method uses hybrid sphygmomanometers, similar to the Mercury meters, except a column of mercury it is replaced with an electronic pressure detection system. This is relatively new, and very few of these are certified to meet standards.
All the devices usually result in lower BP readings compared to the listening method. If your home device shows a blood pressure reading of 135/85, this should be considered abnormal.
When your blood pressure is being recorded, you should sit with a supported back, uncrossed lights, feet on the floor, and your arm supported at heart level. This setting should be quiet and private as possible. Some people have elevated blood pressures when visiting a doctor’s office, and have normal blood pressures at home. The medical profession labels this “white colt hypertension”.
If you are buying a home BP unit, purchase an accurate upper arm machine. Good monitors are available on the Dabi educational trust website. Dabi is a leading provider of management and research tools to prevent cardiovascular conditions including high BP. When you are older you need your systolic blood pressure elevated. Since your vessels stiffen with age, you need a higher systolic pressure to keep these vessels filled. In the past the formula was : “100+ your age”. Not so today.
If you have stiffening of your blood vessels, a rapid drop in your blood pressure can cause ischemia to your heart and other organs. The goal is to gradually lower your blood pressure over several months. How on earth does a doctor kmow I have stiff arteries? A crude indicator is your advancing age.
Once you turn 65, your systolic blood pressure, (top number), rises and the diastolic BP, (lower number, keeps falling. The wider the systolic pressure, ithe stiffer your blood vessels.
Answer is, as you age, the goal is to drop your blood pressure very slowly prevent problems. Takes three blood pressure readings at different times in the day, to find out if you have HTN. 11.06.11
