What Tools Are Used to Measure Blood Pressure
High blood pressure (BP) or hypertension is a key factor in the development of atherosclerosis, the main cause of vascular and cerebrovascular diseases: ischemic heart disease, myocardial infarction, congestive heart failure, and stroke. Elevated blood pressure is also linked causally to kidney failure and dementia. Healthy lifestyle choices coupled with early detection and optimal treatment to control high blood pressure can substantially reduce the risk of developing these problems.
This was first demonstrated by Marey in 1876, and it was subsequently shown that when the oscillations of pressure in a sphygmomanometer cuff are recorded during gradual deflation, the point of maximal oscillation corresponds to the mean intra-arterial pressure. The oscillations begin at approximately systolic pressure and continue below diastolic, so that systolic and diastolic pressure can only be estimated indirectly according to some empirically derived algorithm. This method is advantageous in that no transducer need be placed over the brachial artery, and it is less susceptible to external noise (but not to low frequency mechanical vibration), and that the cuff can be removed and replaced by the patient during ambulatory monitoring, for example, to take a shower. The main disadvantage is that such recorders do not work well during physical activity when there may be considerable movement artifact. The oscillometric technique has been used successfully in ambulatory blood pressure monitors and home monitors. It should be pointed out that different brands of oscillometric recorders use different algorithms, and there is no generic oscillometric technique. Comparisons of several different commercial models with intra-arterial and Korotkoff sound measurements, however, have shown generally good agreement. Devices incorporating this technique use an ultrasound transmitter and receiver placed over the brachial artery under a sphygmomanometer cuff. As the cuff is deflated, the movement of the arterial wall at systolic pressure causes a Doppler phase shift in the reflected ultrasound, and diastolic pressure is recorded as the point at which diminution of arterial motion occurs. Another variation of this method detects the onset of blood flow at systolic pressure, which has been found to be of particular value for measuring pressure in infants and children.
It's important to measure blood pressure more than once because it fluctuates over the course of the day. It can also change due to things like physical exertion, stress, pain, or extreme heat or cold. But this kind of increase in blood pressure is only temporary and it soon returns to normal. So, if blood pressure is measured just once and found to be high, it doesn't necessarily mean that it's always too high (Kasper DL, Fauci AS, 2015). A blood pressure reading taken at the doctor’s office can also be misleading: Going to the doctor makes some people so nervous that their blood pressure goes up. So to get reliable readings, blood pressure is measured on several different days and while you are resting. This means sitting down and relaxing on a chair, and waiting about three minutes before taking a measurement so that your circulatory system comes to rest. The upper arm that is being used for the measurement should rest on a table, at about the same height as the heart, while the reading is being done. You can measure your blood pressure on your own using a digital blood pressure monitor for automated readings or an instrument called a sphygmomanometer for manual readings (Pschyrembel, 2017).
In fact, my essay the skill of recording blood pressure is a vital one for the nurse, as we can not always rely on having electronic equipment to hand. I also gained that if different circumstances can have an effect on the pressure reading. I feel I have gained a learning skill I was quite worried about this skill but practice makes easier. The more blood pressure recordings I took me soon realised that no two patients were the same. I also learned that different factors can affect blood pressure, from the patient rushing in late for his appointment which can lead to elevated blood pressure. It has also given me a lot of confidence in myself and confidence with the patients I care for.
Kasper DL, Fauci AS, Hauser SL, Longo DL, Jameson JL, Loscalzo J. Harrison's Principles of Internal Medicine. New York: McGraw-Hill; 2015.
Pschyrembel. Klinisches Wörterbuch. Berlin: De Gruyter; 2017.