Presentation on theme: "Blood Pressure Measurement"— Presentation transcript:
1 Blood Pressure Measurement Mini CourseBased upon the BP measurement course created by the Virginia Department of Health’s Heart Disease and Stroke Prevention Branch“Miniaturized” by by:NC Department of Health’s Heart Disease and Stroke Prevention Branch and multiple partners.
2 Virginia BP Measurement Course (VA BPMC) The “VA Blood Pressure Training Classes for Health Care Professionals” course:An extensive review of Cardiovascular disease plus a clinical skills component.Information on the larger course is available at:Today’s DVD is available for free by calling sentara.CEU’s available by following the instructions provided with the DVD’s you can receive in the mail from Sentara.There is data to suggest that BP’s are routinely take incorrectly, upwards of 60-75% of the time. “60% of 172 hospital workers were judged to be taking BP’s inaccurately (Villegas HTN 1995).
3 NC BP “mini”Developed with feedback from NC’s public health and health care workforce.Need for a mini “lunch time” length course.Best to focus on how to accurately take a BPincorrect technique and inaccurate equipment results in over and under diagnosis of hypertension. How can we really address BP control, if we are not measuring it consistently?Recent study by Burgess et all reveal that we over estimate the systolic on average12.4 mm Hg systolic and 6.0 mm Hg diastolic; P < , respectively). Similar differences existed forthose with a preexisting diagnosis of hypertension, those without a preexisting diagnosis, nonelderly (ie,< 65 years), and elderly( 65 years). In patients with a preexisting diagnosis of hypertension (n. 92/150), patients were twice as likely to be consideredat goal when following recommended technique (26% vs. 54%; P ).(Journal of the American Society of Hypertension 5(6) (2011) 484–488
4 But First……Where do you take BP’s and who is your patient population? Describe your clinical setting.Community Health CenterHealth DepartmentPrivate Ambulatory Care Practice (or hospital or health system)Hospital (Inpatient, out reach , other)Emergency Service Provider (i.e. EMT)WorksiteCommunity based organization (faith based, coalitions, etc)Other _______Who are the patients you serve? (check all that apply)Over 20% minority populationsMainly Privately insured populations (BCBS, Tricare, Aetna, etc)Mainly Medicaid populationMainly Medicare populationMainly rural residentsMainly urban residentsCDC needs information on “Reach and Impact” thus the HDSP Branch needs to report some data on the populations that participants serve and the settings they work in.
5 How many patients or citizen encounters do you have PER MONTH in your setting? Less than 5050- ≤ 100More than 300 per month
6 Today we will…. Review different manometers. Review correct technique and patient positioning.Review Korotkoff sounds (DVD).Learn how to check your aneroid devices for accuracy.
7 Types of BP Measuring Devices Mercury-Gravity ManometerThe Gold standard.Used less frequently due to safety concerns.Must inflate cuff and listen to Korotkoff sounds.Recalibration is unnecessary.Useful for checking accuracy of other BP devices.Mercury-Gravity Manometer: The BP is determined by inflating a BP cuff to a point above where the brachial artery is occluded, and then the BP cuff pressure is slowly reduced and the SBP and DBP measurements are recorded by listing to the Korotkoff sounds which are discussed in this course.Aneroid devices: the technique of measuring BP’s is essentially the same as with the mercury devices (use a cuff to occlude the brachial artery and listen for Korotokoff sounds).
8 Types of BP Measuring Devices Aneroid manometerMust inflate cuff and listen to Korotkoff sounds.Need to be checked for accuracy (every 6 months, can be checked against a mercury device).NOTE: The dial at the zero mark of an aneroid manometer under no pressure does not mean that the instrument is accurate, routine calibration is necessary.
9 Types of BP Measuring Devices Cont. Automated Electronic DevicesDetects “oscillations” (pulsations) in the brachial artery. Proprietary mathematical algorithms are used to calculate the systolic and diastolic BP.Can be accurate and reliable.Need to be checked for accuracy as recommended by manufacturer (send out?).provides a grading scale for how well hundreds of BP devices have been validated.The oscillations begin approximately at the systolic pressure and continue below the diastolic. The maximal oscillation corresponds to the mean arterial pressure and the systolic and diastolic measurements are then estimated indirectly according to derived algorithms. One can not check these against mercury manometers like can be done with y connectors as described for aneroid manometers. Some providers just periodically have the patients blood pressure checked with a mercury device and then quickly check the patients blood pressure with the electronic devices to make sure the electronic devices readings are “close”, but this is not the same as actually having a mercury device connected via a y connector and directly testing as can be done with aneroid devices as outlined in the NC BP mini course curriculum.Some feel that despite concerns regarding accuracy some electronic devices, there are great advantages to the electronic units as they are easy to use, cuff placement is less critical compared to manometers where listening for korotkof sounds are needed, less likely to have biases such as those that rely on humans (observer error, observer biases (digit preference) and others.
10 Why might a BP reading not be reflective of a clients “true” BP? ErrorsWhy might a BP reading not be reflective of a clients “true” BP?Most common cuff error, use cuff that is too small which over estimates the BP
11 Physiological Variations AnxietyStressEatingFull bladderHot or cold environmentsPainNicotineCaffeinated beveragesOver the counter and prescription medicationsMany feel that some have some diurnal variations (with a early AM “surge”) in their BP’s but the literature that I got on this states that it is really just a matter of the sleep vs. non sleep state and that BP and average heart rates are not higher in the early AM. ( see Mancia G, Circulation research, 1983). Others suggest that indeed the AM surge is real. (Pickering Lancet Blood Pressure Management and the detection of HTN)
12 ErrorsEquipment:Wrong cuff size, equipment out of adjustment (especially aneroid gauges), cracks in tubing.Screener:Impaired eyesight and/or hearing, subconscious biases (previous reading bias, cut point bias, terminal digit preference). Poor technique.Client:Impact of positioning and/or conditions under which the BP is being measured.• Subconscious bias such as 1) terminal digit preference -defaulting to certain numbers such as zero’s or fives instead of what the actual number is- 2) cut point bias- unconscious tendency to under read the blood pressure so as not to have to tell the client their BP is elevated- 3) previous reading bias and assumptions that someone if hypertensive or not.
13 Note bladder is smaller than surrounding material! Anatomy of a BP cuffbladder
14 Find the bladder by feeling it or if possible pulling a little bit of the bladder out of the cuff! picture from
15 80-100% of arm circumference For adults: The bladder of the cuff length must encircle at least 80% of the upper arm circumference (100% in children). The width of the bladder must encircle at least 40% of the arm circumference.80-100% of arm circumference• If the bladder inside the cuff is too small for the client’s arm the reading obtained will be falsely high.• If the bladder inside the cuff is too large for the client’s arm the reading will be falsely low.• The center of the bladder should rest just above the brachial artery. If the bladder is not centered over the artery, the BP reading will be erroneously high.40%
16 Additional checksThe lower edge of the cuff should be at least 1” (2-1/2 cm) above the bend in the elbow (antecubital fossa).Palpate brachial artery (you may need to straighten arm to feel the brachial pulse). Place the middle of the bladder over the brachial artery.Wrap the cuff smoothly and snugly around the arm. Test for proper cuff application by placing both thumbs under the applied cuff and tug gently; the cuff should not move.Are the ear pieces of your stethoscope pointed the right way?
18 PositioningSeated with feet on the floor and back well supported (no crossed legs!).An effort should be made to help the client relax.No smoking or caffeine for 30 minutes prior to the procedure.Sleeveless BP cuff applications are preferred.The arm should be slightly flexed, the palm of the hand up, with the entire forearm supported on a smooth, flat surface. The brachial artery must be at heart level.(if the feet do not reach the floor, use a book or similar object on which to rest the feet). If the client is slouched, both the systolic and diastolic pressures will be inaccurately high. (other examples, sitting on an examining table with no support for the back can cause the BP to read as much as mmHg higher, and if taken in the supine position, the diastolic BP can be 10 mm Hg higher than if in the supine position especially in younger adults (30’s) while this is less of an issue in those over 70 yrs of age).Desk-high tables will position the arm at heart level. If an individual is exceptionally tall or short, adjustments should be made to position the arm properly. If the brachial is above the level of the heart, both the systolic and diastolic blood pressure will be inaccurately low. If the brachial pulse is below the level of the heart, the opposite will be true.If one is going to roll up a sleeve to place the BP cuff, if must be rolled up as high as possible and it must be possible to place two fingers under the sleeve with no difficulty
19 What is wrong in these pictures? bedA – cuff upside downB- arm being held and not supported at heart level & PT on clinic bed instead of a chairC- cuff over clothing & arm not supportedD- stethoscope touching/under the cuff – should not touch cuff or tubing unless using an extra large or thigh cuff.E- arm being held, dial where provider cannot see
20 What is wrong in this picture? This one is hard, maybe the legs are crossed ? (doubtful) actually it is jus the fact that his palm is not up and one wonders if the bell of the stethoscope is touching the cuff. Is the cuff up at least 1 inch from the bend in the elbow?
22 What is this person checking for? Here the clinical staff person is checking the “Maximum Inflation Level” or MIL. Many will not have heard of this recommended step. But the clinical person feels for the radial pulse and then inflates the cuff while continuously feeling for the radial pulse. The point at which the pulse disappears approximates the systolic BP. Then allow the cuff to deflate, wait seconds and re-inflated to a point that is mmHg above the estimated systolic blood pressure and take the BP accordingly. This allows the clinician to know “how high to go” which may make the procedure more comfortable for patients.
23 Maximum Inflation Level (MIL) This technique can help you know how high to inflate the BP cuff!Determining the Maximum Inflation Level (MIL)Apply the pressure cuff.Locate the radial pulse.Palpate the radial pulse while steadily inflating cuff & watching the mercury column or aneroid gauge.Note the point on the mercury column or aneroid gauge at which the radial pulse disappears.The point at which the radial pulse disappeared is approximately the same as the client’s systolic BP.Rapidly deflate the cuff.Maximum Inflation Level (MIL) refers to the maximum level to which the pressure in the cuff needs to be elevated before measuringblood pressure using the auscultatory-palpatory (AP) method
24 Taking the blood pressure After determining the MIL, wait 15 to 20 seconds before measuring BP with stethoscope.Before inflating the cuff, squeeze the bladder to release all air and thus ensure that the pressure level is at zero.After the 15 to 30 second wait, palpate the brachial pulse and place the stethoscope head directly over the brachial pulse make sure head of stethoscope is NOT touching the cuff or tubing.This wait will allow time for the blood to return to the forearm. This wait must occur between every consecutive measurement of blood pressure.Do not let the stethoscope touch cuff or tubing unless absolutely necessary (i.e., in using a large adult or thigh size cuff), never place the stethoscopeunder the cuff. The stethoscope should be applied firmly, but with light pressure. Heavy pressure will distort the artery and may cause sounds to be heardbelow the true diastolic pressure. When using the diaphragm side of the stethoscope, there should be no air between the skin and the stethoscope.When using the bell side of the stethoscope, be certain that all edges of the bell are in contact with the skin
25 How to Take an Accurate BP cont. With stethoscope in place, close valve and by rapidly & steadily squeezing the bulb, inflate the cuff mmHg above the point where the pulse disappeared in the MIL steps.Open the valve and begin deflation of the cuff.Maintain a constant deflation rate of 2-3 mmHg per second.Continue to listen to about 10 mm below where the last sound was heard.If the cuff is deflated too quickly, the column of mercury falls too rapidly resulting in inaccurate, usually low, readings. If deflation is too slow, venous congestion can cause the diastolic to be high.Never allow the mercury to stop during deflation and once the mercury begins to fall, never pump the pressure higher without completely deflating the cuff, waiting 15 seconds and starting over. Both of these situations cause venous congestion and result in erroneously high readings.If the sounds reappear and disappear again, this second disappearance of sound should be recorded as the diastolic since auscultatory gaps can be found at the diastolic level of blood pressure also.
26 Record the BPSystolic BP: the point at which the first of two or more continuous sounds are heard.Diastolic BP: recorded at the disappearance of sound (also called the onset of silence), not at the last sound. Subtract 2mmHg from the last sound you hear.(e.g. if the last sound is at 80mmHg, the diastolic BP is 78mmHg!)Read to the nearest even number. If the reading falls between two numbers, read the number above.We will practice this with the DVD!For example, if the last sound is heard at “90”, then the diastolic blood pressure is recorded as "88”.
27 *CLASS EXERCIZE 1*Review as a class how to check for the bladder size within BP cuffs, how to choose the right size cuff for each person and how to determine the MIL.This requires participants to be in groups of at least 2. Participants should practice sizing technique with at least 2 different sized cuffs.Have everyone pull out a bladder a bit if possible to feel it and really understand the width and length measurements and how these relate to the patients arm circumference. You want people to understand that they can use the bladder alone in choosing the right cuff, no need necessarily for separately measuring the arm circumference. You want to encourage them to feel the bladder dimensions of their own equipment if possible. Do they understand that a “thing” cuff is actually used in some cases on large arms? It is also okay for them to use the cuff on the forearm and listen at the radial pulse when a they do not have a correct cuff or the cuff can not be used correctly due to patient factors.
28 Measure a partners arm with 2 different cuffs. *CLASS EXERCIZE 1*Measure a partners arm with 2 different cuffs.Determine your partners MIL.Have everyone pull out a bladder a bit if possible to feel it and really understand the width and length measurements and how these relate to the patients arm circumference. You want people to understand that they can use the bladder alone in choosing the right cuff, no need necessarily for separately measuring the arm circumference. You want to encourage them to feel the bladder dimensions of their own equipment if possible. Do they understand that a “thing” cuff is actually used in some cases on large arms? It is also okay for them to use the cuff on the forearm and listen at the radial pulse when a they do not have a correct cuff or the cuff can not be used correctly due to patient factors. Have them determine an MIL, many many people have never done this but it is something that you can encourage to do for new patients or when it is particularly difficult to determine a systolic BP. Although it is suggested that one determine the MIL every time, likely most will find this to be overly time consuming for established patients.
29 Korotkoff soundsPhase 1: TAPPING, The first appearance of clear, tapping sounds that gradually become louder.Phase 2: SWISHING, The sounds change to a murmur and have a swishing sound.Phase 3: KNOCKING, The sounds have a loud, knocking quality, but are not quite as clear as those in Phase 1.Phase 4: MUFFLING, The sounds suddenly are muffled and again have a faint, swishing quality.Phase 5: NO SOUND, All sounds disappear (often referred to as the onset of silence).Series of sounds heard through a stethoscope placed over an artery that has been closed off by a blood pressure cuffIssues:“Absent” Fifth Phase?: There are times when sounds can be heard all the way to zeroShould we measure BP’s in one or both armsFirst described in 1905 by a Russian physiologist, Dr. Nikolai Korotkoff
30 *CLASS EXERCIZE 2* Korotkoff sounds and DVD. Practice determining the BP with a mercury and aneroid manometer.Also available at Contact Hours on this material available! SENTARAShow DVD presentation and perform skills evaluation at this time.**Specifically look at chapter 2: the Korotkof soundsThen do chapter 3: exercise one (answers are reviewed in chapter 13) 118/72Chapter 5: exercise 3 (answers chapter 15) 132/86Chapter 8 :exercise 6 (ans cpt 18) 212/132Chapter 9: exercise 7 (answers on chapter 19) 146/94
31 A few more itemsChecking your own aneroid manometers for accuracy against a Mercury device.JNC – 7 BP categoriesBP stagesBP Goals
32 Aneroid Check for Accuracy Technique Are your aneroid gauges accurate?VersionBlood Pressure Measurement Mini Course (NCBPmini)(A manual for studentsSee Appendix D:NC BP mini Manual
33 Aneroid Check for Accuracy Technique 120 mmHg✔60✔120✔180✔240Inflate the mercury gauge to four test levels (60, 120, 180, and 240 mmHg)Compare aneroid reading to reading on mercury manometer at each level, compute average deviationIf not accurate within plus or minus 4 mmHg at any one test level or as an average deviation, then discontinue use and replace or repair faulty gauge.Encourage the participants to read the information that is specific to their individual equipment as it may vary. For instance one Welch allyn product states checking against a standard metric (like mercury manometers) but starting at 300mmHG and then going down by 50 until you reach zero and to not go down any faster than 10mmHg per second..
34 JNC 7 Normal blood pressure in adults (age 18 and older) is: less than 120 mmHg (systolic) andless than 80 mmHg (diastolic)Prehypertension is:mmHg (systolic) ormmHg (diastolic)Hypertension (high blood pressure) is:140 or higher mmHg (systolic) or90 or higher mmHg (diastolic)Normal BP and PHTN- continue to encourage lifestyle changes
36 Other terms and issuesIsolated systolic hypertension occurs when the systolic blood pressure is elevated 140 mmHg but the diastolic remains 90 mmHg (more common in the elderly).Importance of diastolic and systolic BP: It was thought that diastolic BP was the most important and many still believe this due to when they were trained. Recent research has determined that systolic BP is actually more important as it is a better predictor of future complications (especially in those aged 65 and over).Ref: Pastor-Barrluso Annals of Internal Medicine 2003.Pastor-Barriuso R, Banegas JR, Damián J, Appel LJ, Guallar E. Systolic blood pressure, diastolic blood pressure, and pulse pressure: an evaluation of their joint effect on mortality. Ann Intern Med Nov 4;139(9):731-9.
37 Goals General Population (keep an eye out for JNC 8 !) less than 140 mmHg (systolic) andless than 90 mmHg diastolicGoal for diabetic adults, people w/ Chronic Kidney Diseaseless than 130 mmHg (systolic) andless than 80 mmHg (diastolic)Goals vary for those diagnosed with hypertension. Goal for patients with HF, according to AHA (2007) is a BP below 120/80 although this should be “accomplished slowly”. As things may be changing a bit for special populations, let the audience know that many are focusing on the 140/90 for population health measures, even for diabetics such is being done by Medicare’s meaningful use of HIT program.
38 The END and The Challenge What changes can you make in your clinics to improve blood pressure measurement? How will you check to see if your efforts are sustained?
39 What items were helpful today? Learning/reviewing how to choose the appropriate cuff size.Learning/reviewing the different types of manometers.Learning/reviewing the MIL technique.Learning/reviewing the BP taking technique.Learning/reviewing Korotkoff sounds.Reviewing JNC – 7 definitionsTry to get a quick count of how many folks raise their hands for each bullet. Try to write down the number that raise their hand for each item over the total number in the room. Again this is a quick attempt to get some “evaluation” data for the CDC.