The measurement of blood pressure after Riva-Rocci is a simple, fast and painless method, which you can use to measure how much is the pressure in the blood vessels. The result of the measurement of blood pressure is evidence about the doctor, how work the heart and circulation in the patients.
Blood pressure is the pressure emanating from the heart, produced in the arteries. This pressure is not a constant value, but constantly changed over time – the blood pressure among other things depends of the respective action of the heart.
For the clinical measurement of arterial blood pressure are but only two values of importance, the systolic and the diastolic blood pressure. The systolic blood pressure is the higher of the two values. The blood pressure is specified in millimeters of mercury (mmHg).
Considered elevated blood pressure values in adults
- of a diastolic pressure of 90 mm Hg, as well as
- on a systolic pressure of 140 mmHg
- so a blood pressure of 140 / 90 mmHg.
There is an increased risk of cardiac vascular disease, physician at values over 130 / 85 mmHg however speak of hypertension.
A high blood pressure (hypertension) is on blood pressure values that are higher than the value of 140 / 90 mmHg. A low blood pressure (hypotension) is when the blood pressure mmHg falls below systolic value of 100; the diastolic value is then usually below from 65 to 60 mmHg.
Blood pressure can be determined by individual measurements; for some diseases, but also a long-term blood pressure measurement may be useful (e.g. in night high blood pressure or daily fluctuations). Then is a 24 hour blood pressure measurement, where a day-long wearing the blood pressure monitor to himself.
Until well into the 19th century, one could only directly determine blood pressure, that is, by insertion of probes in great body arteries or veins. This “bloody” method was linked to fears, complaints and certain risks such as infections for those affected. Until the development of the “bloodless” processes allowed to determine blood pressure simply and without risk.
Early blood pressure equipment of this kind were for example the modified pulse monitors of physiologist Karl Vierodt (1818-1884) and pathologist Samuel Siegfried von Basch (1837-1905). The Italian Riva-Rocci (1863-1937) created the prototype of the modern blood pressure measuring device then with his sphygmomanometers (from Greek sphygmos = pulse metron = measure Greek; hand = lat. manus). Therefore it is called nowadays the blood pressure after “RR” (Riva-Rocci), when in medical everyday life of the blood pressure. Today, any measurable blood pressure has become an important measure for diseases.
Riva-Rocci was an Italian physician who at the end of the 19th century has developed a completely new method of blood pressure measurement. As a resident physician at the medical clinic in Turin, he was initially unhappy with the time inadequate methods to determine-cardiovascular diseases. Such methods were bloody and painful for the patient.
Riva-Rocci alternatives out then a new method for blood pressure measurement, which he described in an article in 1896. He also demonstrated his prototype of the modern blood pressure device for the indirect determination of blood pressure. Riva ROCCIS apparatus consisted of a kind of bicycle tube, which he used as sleeve cuff from a rubber balloon to inflate the cuff and a mercury barometer, with which he measured the pressure in the artery of the arm. By palpation of the Pulsader on the wrist (Pulsus snuff) Riva-Rocci tested during the blood pressure measurement, as the pulse – depending on disappeared from the blood pressure – increasing (systolic) pressure. The modern sphygmomanometer finally prevailed after initial protests. The measuring principle is reflected even today in the modern devices for the measurement of blood pressure, but was followed by technical improvements
In 1905, Russian military doctor Sergeyevich Korotkov (1874-1920) improved the method specified by Riva-Rocci, by he used the stethoscope to the blood pressure measurement. The typical Korotkow’schen sounds are heard. These come about as a result that the blood is swirled, and whose motion sounds are therefore audible. From the late of 1920s, blood pressure monitors were after the “system Riva-Rocci” not only in hospitals but also in medical practices to be found. After World War II, the instruments were small and consisted essentially of a sort of bellows with spring pressure gauge and storage sleeve.
1968 a fully automatic blood pressure monitor as a precursor to the modern 24-hour blood pressure equipment was first used. Since 1976 there are handy, easy-to-use electronic auto meters, which you can use to measure his blood pressure without a doctor. Since 1989, devices for blood pressure measurement on the index finger, and since 1992 are electronic blood pressure monitors with wrist cuff for blood pressure measurement on the wrist available.
To itself carry a blood pressure you must make no calculations, but can read the value directly by your blood pressure monitor.
If you want to better understand the principle of blood pressure measurement, a brief look at the physical fundamentals is worth:
The blood flows through the arteries at a medium speed in healthy humans. It is usually so low that blood flows as it were “controlled” (so called laminar flow) – no turbulence occur it doing so. Turbulence produce audible noises – that takes the blood pressure advantage.
Simply put is the blood pressure in the form of identifying the Außendrücke that cause turbulent flow in an artery: the inflatable blood pressure cuff exert this pressure from outside on the artery of upper arm or wrist. A certain external pressure by inflating the cuff is reached, the blood vessel is locked: no blood flows through the artery; no flow, no noise. Now the air from the cuff back slowly escape, leaving the external pressure on the artery decreases. You will open anything. The narrowed vessel diameter ensures but that the blood can now not laminar flow through the blood vessel. It create audible turbulence. As long as the cuff pressure affects the width of the artery, it remains with the audible turbulent flow. Is the external pressure as far as dropped, that the internal pressure in the blood vessel – so the arterial blood pressure – is continuously higher, the vessel is fully open. The blood laminar flows through the blood vessel, the turmoil and the sounds associated then disappeared.
A physical key value for calculation of blood pressure and the emergence of turbulence is the so-called Reynolds number R s. You depends – blood pressure measurement – the flow of blood, the vastness of the blood vessels and properties of blood (density and turbidity). The Reynolds number exceeds a certain value (about 1,200), the flow is turbulent and audible in the measurement. The equation for the Reynolds number is:
- v m = average speed of fluid (blood)
- R = Gefäß-(Rohr-)RADIUS
- p = density of the liquid (blood)
- n = viscosity (“turbidity”) of the liquid (blood)
Pressure is in the unit Pascal (PA) or cash. For the blood pressure the unit has retained in medicine today, however (mmHg) millimeters of mercury.
Properly measure blood pressure
Measure blood pressure on the upper arm
You will make the blood pressure on the upper arm after Riva-Rocci with a blood pressure monitor. You can measure your blood pressure at your doctor’s Office, at the pharmacy or on their own at home measure. Many devices for the measurement of blood pressure at home require little guide – after creating the cuff, the device automatically perform the measurement. With the “classic” blood pressure monitor, blood pressure measurement on the upper arm is carried out. So the measurement on the upper arm work:
The “classic” blood pressure monitor consists of an inflatable cuff that is connected via a hose with a small bellows. It has a pressure gauge on which the investigator can read the air pressure in the cuff or your blood pressure. In addition, a stethoscope belongs to the sphygmomanometer. Thus, the investigator can perceive during the measurement of pulse sound into the spoke artery in the elbow.
The investigator puts a cuff around your upper arm to measure blood pressure. The lower edge of the cuff should end about two inches above the elbow. The “usual” cuff is sufficient for a upper arm circumference of less than 40 cm. It is 12 inches wide and has an inflatable air reservoir of 26 centimeters in length. Your upper arm circumference is larger than 40 centimetres, a blood pressure cuff 18 inches wide is required.
Next, the investigator puts on the stethoscope. He scans the spoke artery (radial artery) in the elbow and the outer end of the stethoscope (acoustic receiver) sets. With the stethoscope, he controls the pulse during the whole measurement. Then he pumps up the cuff rapidly, until he no longer can – hear the pulse and still something beyond increases the pressure in the cuff. The investigator should make sure that the receiver of stethoscope correctly on the spoke artery lies and does not slip.
The vessel, the spoke artery through the cuff pressure is locked, no blood can happen more. The investigator should stop now, no pulse noise. Then the investigator lowers the pressure in the cuff gradually using a drain plug, two to three millimetres per second so far, until he hears first pulse-synchronous sound. The value in which he for the first time has heard the pulse noise, is the systolic blood pressure.
Systolic is the pressure maximum, which is again able to open the blood vessel a little against the cuff pressure, so that blood through streaming for a brief moment. Because the container is only partially opened by the Systole, it has a diminished RADIUS and in addition a profile change compared to the adjacent blood vessels. Thus, turbulent flows in the blood occur in the vessel – this is heard through the stethoscope. Blood pressure can be measured in this way so, because you can hear the currents. The cuff pressure is at this moment approximately equal the systolic pressure in the vessel concerned, the spoke artery.
The investigator can now continue to fall the cuff pressure, he hears noises continue to pulse-synchronous. Although in the short term, the systolic pressure stretches the vessel to its original width. The pressure fades but shortly after the Systole and the vessel is again opposed. It degrades further, the cuff pressure is sometime also the diastolic pressure able to keep the vessel open. Then, usually no noise are more audible. The point at which the sounds disappear, roughly equivalent to the diastolic blood pressure. The investigator now read off the value to the pressure of the blood pressure measuring device and records both readings. Now, he has measured the systolic and diastolic values after Riva-Rocci. If you would like to measure his blood pressure itself, should pay attention to these points.
Experts are still divided whether one should count the total disappearance of the sounds, or but the sound change as a criterion for the diastolic pressure. This discussion should be addressed here, no further.
Two points are important, however:
Each “calcified” a vessel will (sklerotischer) (as for example with age or arteriosclerosis), the cuff pressure must be higher to squeeze the tube together, because in addition to overcome the increased resistance of the arterial wall. The measurement of blood pressure is so inaccurate, i.e. too high.
When is someone extremely physically struggle and his heart minute volume (HMV) on the 6 normal value is increased, the blood 6 x at equal distance of vessel must flow through the vessel; It can occur already at this speed without cuff pressure turbulence.
In such a case, you would measure a diastolic pressure to zero down. This is however very rarely found. Usually the measurement of the diastolic pressure is sufficient to Riva-Rocci for routine.
The systolic pressure is measured typically up to about 5 mmHg exactly, the diastolic approximately to 10 mmHg.
A high blood pressure (hypertension) is blood pressure from 140 / 90 mmHg. Physicians speak over 130 / 85 mmHg however when values of hypertension, if there is an increased risk of cardiac vascular disease. Low blood pressure (hypotension) is when the blood pressure mmHg falls below systolic value of 100; the diastolic value is then usually below from 65 to 60 mmHg.
Bloody blood pressure
In addition to the indirect measurement of blood pressure after Riva-Rocci, there are bloody, invasive blood pressure measurement. The doctor can measure blood pressure at various sections of the vessel, but also in the heart itself. To do this, he introduces a catheter into the artery, which either contains a small pressure gauge at the top or one at its outer end pressure consumers.
This measurement is usually the opening of catheter the bloodstream contrary to. Therefore, this method of measurement obtained slightly higher values than at the measurement of the static pressure. The static pressure is those who presses from inside against the blood-vessel walls and keeps them open. Invasive blood pressure measurement, the catheter measures also the dynamic pressure exerted by the flowing blood.
To avoid confusion and therefore misinterpretations, the abbreviation “RR” should be used only for the blood pressure, if it actually measured at Riva-Rocci. The doctor noted a “bloody” measured blood pressure, however, with “BD” (blood pressure) or “BP” (blood pressure).