Auscultatory Measurement Of Systolic And Diastolic Pressure
Digit preference, whereby observers choose to record a favourite number, most commonly 0 or 5 mm Hg, is a serious source of bias. It is important to realise that such digit preference may introduce substantial errors that could lead to incorrect decisions being made, especially in patients with borderline blood pressures. Such bias is best avoided by recording systolic and diastolic pressures to the nearest 2 mm Hg.
The silent or auscultatory gap occurs when the sounds disappear between the systolic and diastolic pressures. The importance of the gap is that unless the systolic pressure is palpated first it may be underestimated. The presence of a silent gap should be recorded on the case sheet or blood pressure chart.
Second Step: Measure Blood Pressure
Now, you can start to measure blood pressure. Place the bell of the cleansed stethoscope over the brachial artery using a light touch and complete seal. Inflate the cuff to the maximum pressure inflation number . Open the valve slightly. Deflate the cuff slowly and evenly at about 2 mm Hg per second. See Film Clip 5.3 which focuses on the speed of the needle when deflating the blood pressure cuff.
Note the points at which you hear the first appearance of Korotkoff sounds and the point at which the Korotkoff sounds go silent . These sounds are called Korotkoff sounds and vary in quality from tapping, swooshing, muffled sounds, and silence. The pressure at which the first Korotkoff sound is noted signifies the systolic pressure, while the pressure at which the Korotkoff sounds are no longer heard marks the diastolic pressure. See Audio Clip 5.1 to listen to Korotkoff sounds and noting systolic and diastolic blood pressure. Alternatively, if viewing textbook as a pdf, use this link: https://www.youtube.com/embed/lPlYNt8cVnI?rel=0
Film clip 5.3: Deflation rate of sphygmomanometer
Alternatively, if viewing textbook as a pdf, use this link: https://www.youtube.com/embed/QbGPzUluT5c?rel=0
Your Blood Pressure Numbers And What They Mean
Your blood pressure is recorded as two numbers:
- Systolic blood pressure indicates how much pressure your blood is exerting against your artery walls when the heart beats.
- Diastolic blood pressure indicates how much pressure your blood is exerting against your artery walls while the heart is resting between beats.
Read Also: What Animal Has The Highest Blood Pressure
Auscultatory Measurement Of Systolic And Diastolic Pressures
The stethoscope is placed gently over the artery at the point of maximal pulsation. It must not be pressed too firmly or touch the cuff, or the diastolic pressure may be underestimated. The pressure is then raised by inflating the bladder to 30 mm Hg above the systolic blood pressure as estimated by palpation. Next the pressure is reduced at 2-3 mm Hg per second. The point at which repetitive, clear tapping sounds first appear for at least two consecutive beats gives the systolic blood pressure. The point where the repetitive sounds finally disappear gives the diastolic blood pressure . Both measurements should be taken to the nearest 2 mm Hg to avoid .
Automated Blood Pressure Machines
The easiest and most accurate way to measure the blood pressure at home is to buy an automated blood pressure monitor with an upper arm cuff.
The instructions for use may vary with each machine, and a person should follow them carefully to ensure proper operation. If the instructions are difficult to understand, a local pharmacy or doctors office will be able to show a person how to operate the machine correctly.
Doctors may ask a person to bring their at-home machine to the office during their next visit to test the accuracy compared to the doctors reading.
Using a high-quality machine is important, as inaccurate readings may cause unnecessary or harmful changes in medications or treatments.
A variety of blood pressure monitors are available for purchase online and in most drug stores. A person may wish to speak to a doctor about which brand they recommend.
There are apps and wrist devices that claim to measure the blood pressure, but these results are frequently inaccurate and are not a reliable way to monitor a persons health.
Apps that log blood pressure results may be helpful for people who need to take regular blood pressure tests, however.
Recording a set of readings into these apps may help doctors identify trends in blood pressure and recommend treatments.
Recommended Reading: Barton Publishing High Blood Pressure Solution Kit Reviews
Taking Your Blood Pressure
If you have a manual or digital blood pressure monitor, follow the instruction booklet carefully. The following steps provide an overview of how to take your blood pressure using either a manual or digital blood pressure monitor.
1. Locate your pulse
Locate your pulse by lightly pressing your index and middle fingers slightly to the inside center of the bend of the elbow. Here you can feel the pulse of the brachial artery. If you cannot locate a pulse, place the head of the stethoscope or the arm cuff in the same general area.
2. Secure the cuff
A. Thread the cuff end through the metal loop and slide the cuff onto your arm, making sure that the stethoscope head is over the artery. The lower edge of the cuff should be about 1 inch above the bend of your elbow. Use the Velcro wrap to make the cuff snug, but not too tight.
B. Place the stethoscope in your ears. Tilt the earpiece slightly forward to get the best sound.
3. Inflate and deflate the cuff
If you are using a manual monitor:
A. Hold the pressure gauge in your left hand and the bulb in your right.
B. Close the airflow valve on the bulb by turning the screw clockwise.
C. Inflate the cuff by squeezing the bulb with your right hand. You may hear your pulse in the stethoscope.
D. Watch the gauge. Keep inflating the cuff until the gauge reads about 30 points above your expected systolic pressure. At this point, you should not hear your pulse in the stethoscope.
G. Continue to slowly deflate the cuff.
Palpate The Brachial Artery
Seat the patient comfortably with legs uncrossed and palms facing up, the arm resting at the level of the fourth inter-costal space and not tensed.
Place the pads of your index and middle fingers halfway between the shoulder and elbow, in the middle of the inner arm, between the bicep and tricep muscles. Start the palpation of the brachial artery just below the bend of the elbow.
Apply slight pressure with your fingers and palpate the brachial artery just below the bend of the elbow. If you place your fingers in the center of the armpit and slide them half the distance to the inner side of the elbow, they should be in the correct position.
Along with the use of a stethoscope and sphygmomanometer, the brachial artery is often used to measure blood pressure.
It can be tricky to find and palpate the brachial artery, especially when the individual has large muscles. Press your index and middle fingers down, maneuvering them around the muscles by pressing the artery against the bone.
Palpation is not the same as palpitation. Palpitation is the awareness of the heartbeat.
Be careful when applying pressure to the brachial artery. If you apply too much pressure, you might stop the flow of blood which may cause an inaccurate pulse reading.
Do not use your thumb to palpate the brachial artery, especially if you are checking for the pulse since the thumb has its own pulse too and might be mistaken for the pulse of the patient. This will lead to inaccuracy.
Read Also: Blood Pressure Mayo Clinic
How To Take Blood Pressure
Carrington College Registered Nursing students demonstrate the proper technique for taking blood pressure.
Ask your patient to hold their arm out so you can begin.
And thats how you take a patients blood pressure!
For comprehensive consumer information, visit carrington.edu/cc/rn
The Apprehensive Patient Or White Coat Hypertension
Ambulatory blood pressure measurement is increasingly being used in clinical practice . ABPMs correlate better than clinical measurements on patients with end-organ injury . Twenty-four-hour ABPM is the most efficient means for assessing white coat hypertension , particularly in the absence of end-organ disease. WCH has been defined as clinical BP greater than 140 mm Hg systolic and 90 mm Hg diastolic . Ambulatory measurements are also valuable in assessing patients with apparent drug resistance, low BP symptoms, and in patients taking antihypertensive medications. There is now wider acceptance of BP readings taken by patients in their homes. Patients should be encouraged to monitor their BP at home with validated devices followed by appropriate recording and reporting to their clinician.
Thomas G. Pickering, in, 2007
Recommended Reading: To Lower Blood Pressure
Stethoscope Usage And Korotkoff Sounds
The stethoscope is used on bare skin so that a clients clothing does not affect the sounds. The stethoscope does not make sounds louder it simply blocks out extraneous noises so you can better hear the Korotkoff sounds. These sounds are heard through a stethoscope applied over the brachial artery when the blood pressure cuff is deflating. You will not hear anything when you first place the stethoscope over the brachial artery, because unobstructed blood flow is silent. The Korotkoff sounds appear after you inflate the cuff and then begin to deflate the cuff. The Korotkoff sounds are the result of the turbulent blood caused by the inflated cuff compressing the artery and oscillations of the arterial wall when the heart beats during cuff deflation.
Here are a few tips:
- Use a high quality stethoscope with durable, thick tubing. Avoid stethoscopes with long tubing because this can distort sounds.
- Ensure quiet surroundings so that you can better hear the Korotkoff sounds.
- Make sure that the slope of the stethoscope earpieces point forward or toward your nose.
- Use a stethoscope that has both bell and diaphragm capacity. See Figure 5.4 for bell and diaphragm.
Figure 5.4: Stethoscope with bell and diaphragm
Film clip 5.2: Opening and closing the bell and diaphragm
Alternatively, if viewing textbook as a pdf, use this link: https://www.youtube.com/embed/rp_4h-tCmvs?rel=0
Casual Blood Pressure Measurement
Blood pressure measurements that are taken intermittently in the clinical setting are usually referred to as casual or clinic measurements. The most established method is the auscultatory measurement, classically performed with the mercury sphygmomanometer, but largely replaced in recent years by aneroid manometry due to safety concerns about the use of mercury. Satisfactory accuracy of aneroid manometry depends heavily on regular servicing of the devices, which is often not achieved in clinical practice.69 For auscultatory measurements the fifth Korotkoff sound has been established as diastolic BP in all children of all ages since the 1980s.10
A problem inherent to auscultatory measurements is significant observer bias. Even experienced, well-trained observers tend to round figures and approximate the measured towards expected and target values. The phenomenon of terminal digit preference is common even in specialized hypertension centers and in clinical trial settings.1113 For the purposes of clinical trials, observer bias can be overcome by use of random zero devices, which blind the examiner with respect to the absolute BP value until the end of the measurement, but are generally too complicated for everyday use.14
Bonita Falkner, in, 2007
You May Like: Prevention Of Low Blood Pressure
S On How To Take A Manual Blood Pressure Using The Two
Looking For A List Of Symptoms
If you are looking for a list of symptoms and signs of high blood pressure , you wont find them here. This is because most of the time, there are none.
Myth: People with high blood pressure will experience symptoms, like nervousness, sweating, difficulty sleeping or facial flushing.
Truth: High blood pressure is a largely symptomless silent killer. If you ignore your blood pressure because you think a certain symptom or sign will alert you to the problem, you are taking a dangerous chance with your life.
Also Check: Does Claritin Lower Blood Pressure
How To Take A Blood Pressure Reading
Your child should be calm and still when you take his or her blood pressure . Try to keep your child from crying crying makes the blood pressure higher.
- An infant can be encouraged to drink a bottle, breast-feed or suck on a pacifier.
- A toddler can hold the blood pressure cuff and pretend to take the BP of someone else, or practice on a teddy bear or doll.
Your child will be less likely to cry if he is distracted this way.
New Aha Recommendations For Blood Pressure Measurement
Am Fam Physician. 2005 Oct 1 72:1391-1398.
Diagnosis and treatment of hypertension depend on accurate measurement of auscultatory blood pressure. The lowering of target blood pressure for patients with diabetes or renal disease has made detection of small differences more important. However, blood pressure reading is one of the most inaccurately performed measurements in clinical medicine.
True blood pressure is defined as the average level over a prolonged duration. Thus, in-clinic blood pressure measurement, which generally makes no allowance for beat-to-beat variability, can be a poor estimation and may fail to catch high blood pressure that occurs only outside the clinic setting. In addition, faulty methods and the white coat effect may lead to misdiagnosis of hypertension in normotensive patients.
To increase accuracy of clinic readings, and in recognition of major changes over the past 10 years , the American Heart Association has published a new set of recommendations for the measurement of blood pressure. The AHA scientific statement, written by Pickering and colleagues, was first published in the January 2005 issue of Hypertension and also appears in the February 8, 2005, issue ofCirculation. It can be accessed online at. A summary of the AHA scientific statement follows.
Also Check: Low Blood Pressure Heart Attack
How Do You Check Your Blood Pressure With Your Fingers
Most doctors recommend the use of a blood pressure machine to check blood pressure. An individual may check heart rate with their fingers, but not blood pressure. Data shows checking blood pressure using fingers may not be accurate though there is an obscure method to correlate the pulse reading with systolic blood pressure. Blood pressure must be always measured using validated equipment.
Place the fingers on the inside of the wrist to locate the pulse. Now, take two fingers and place them just below the wrist creases on the thumb side of the hand. A strong pulse felt at the wrist correlates to the systolic blood pressure of at least 80 mmHg. This method is not always correct and hence not recommended.
It is important to use the correct technique to obtain an accurate measurement. Blood pressure is the force the blood exerts on the sides of the blood vessels as it moves ahead and is an important indicator of health. The pulse will give the basic information required to estimate the systolic blood pressure . Keep in mind this is a very rough estimate and only indicates if the systolic blood pressure is not low. Blood pressure monitoring should be done with a cuff and a stethoscope. However, recent advances in technology have made budget-friendly automatic blood pressure monitors easily available in pharmacies.