Project Lead Amy Auerbach, PGY-2 Title Blood Pressure and Therapeutic Inertia Team Tom Keyserling MD, Annie Whitney, Robin Woodford, Stephanie Degraffenreid Change Evaluate blood pressure measurement in clinic setting Date Range October 28- November 26, 2008 Cycle # 1 Key Words Blood pressure, measurement, hypertension, JNC-7 *BACKGROUND: (What led you to start this project? Is this cycle a continuation of another cycle? Why is this topic relevant? Include any baseline data that has already been collections) The role of hypertension and increased risk of cardiovascular disease events is a well established link that has been found to be independent of other risk factors. Hypertension increases the risk of heart attack, heart failure, strokes, and kidney disease and the risk beginning at a BP of 115/75 doubles with each increment of 20/10mm Hg. According to the JNC 7 s evaluation of recent clinical trials, it is estimated that for a patient with stage I hypertension and additionally cardiovascular risk factors, lowering the SBP by 12mm Hg over 10 years would prevent 1 death for every 11 patients treated. As the patient s risk factors increase, the benefit to lowering blood pressure also increases. Previous studies have demonstrated that clinical uncertainty regarding blood pressure measurements play a prominent role in therapeutic inertia. In the study by Kerr et. al in May of 2008, it was found that uncertainty at the time of the visit about the true blood pressure value was the most prominent predictor of whether a change was made in blood pressure management. Primary care providers often re-checked and recorded lower repeat blood pressure values or considered patient reports of lower home blood pressure values. However, as there is typically not a standardized method for obtaining blood pressure measurements in either triage or on repeat, this re-check may be subject to bias. Bias is of particular concern with measurements using the auscultatory method. This concept of bias was divided into three main components in the Kerr et. al article: terminal digit preference (rounding to the nearest ten), threshold bias (rounding below a treatment threshold), and treatment bias (expecting a lower blood pressure in those receiving treatment). Blood pressure measurement variation between physicians is also of concern and studies have previously demonstrated a significant difference between both physicians using the auscultatory method and the electronic method. During the NCQA diabetes review of 200 DM patients we found that providers often rechecked blood pressure. On recheck, patients who were originally not at blood pressure goal were frequently at goal when using the second value. Based on this information, reducing clinical uncertainty regarding blood pressure measurements may result in a decrease in therapeutic inertia in regards to blood pressure treatment. Amy PDSA worksheet.doc page 1 of 7 1/16/2009
PLAN: Aim/Objective for this cycle (What you hope to learn): Our goal is to determine whether our blood pressure measurements as taken typically in the clinic are accurate and whether taking blood pressure in the manner described in JNC VII is likely to make a difference in our clinical decision making. Specifically, we will address: 1. Is there a difference between blood pressure measurements taken immediately on arrival and blood pressure measurements taken according to JNC 7 guidelines? 2. Is this difference clinically (and statistically) significant? 3. What are barriers to appropriate measurement of blood pressure in our clinic? Predictions/Hypotheses (What do you think will happen when test is done?) It is likely that blood pressure measurements taken with a standardized instrument according to JNC guidelines will be lower than BP measurements taken as they normally are in clinic. Plan for data collection: who, what, when, how and how long Who: Amy Auerbach, nursing staff (Robin Wofford, Stephanie Degraffenreid) What: BP measurements taken When: Tuesdays and Thursdays during Dr. Chelminski s clinic Data collection: According to JNC 7 guidelines for BP monitoring: Pt should be seated for at least 5 minutes in a chair with feet on the floor, arm supported at heart level (avoid caffeine, smoking, exercise 30 minutes prior to BP reading). At least 2 measurements should be made and the average should be recorded. The initial blood pressure measurement and then the subsequent 2 blood pressure measurements and average of the later two measurements will be recorded. Our data collection: Blood pressure taken as soon as patient sits down in room (as nurse typically takes blood pressure) with the research protocol blood pressure cuff. Dial on machine is switched to single and then the initial measurement taken by pressing the start button. Dial then switched to average and start pressed again. Blood pressure then re-taken 5 minutes after the initial reading (taken automatically by blood pressure cuff). Another reading taken one minute later and average recorded. Patients also asked if they have diabetes or end stage renal disease. DO: Carry out the change/test. Collect data. Note when completed, observations, problems encountered, and special circumstances: Pilot: Patient is brought back into room by nurse. Blood pressure cuff (OMRON digital blood pressure monitor) immediately placed on arm (with patient sitting on chair, arm at heart level) and initial reading recorded as blood pressure. Dial then switched to average and start button pressed by nurse. Reading recorded at 5 minutes and then at 6 minutes and these two measurements are averaged (by the blood pressure cuff). Readings are all recorded on data sheet and then transcribed to an electronic excel database. Pilot of study 11/13: A few difficulties noted- CQI difficult to carry out in resident s clinic because of multiple rooms being used and difficulty in gathering data. Feel that it would be Amy PDSA worksheet.doc page 2 of 7 1/16/2009
burdensome on the nurses to expect them to record the readings of blood pressure after 5 minutes, 6 minutes and average. Stephanie and Robin participated in first days of study- felt that the blood pressure cuff was easier to use than the automatic cuff currently used. Pros of the automated blood pressure cuff: Easier to use, blood pressure measurement can be obtained more quickly. Cons of this automated blood pressure cuff: Cuff size too big for some patients. Nurses feel that they cannot collect data at 5 minutes because they are typically not still in the room and the physicians are anxious to see the patient themselves to keep clinic flow going. (cuff size issue resolved by providing the smaller cuff size). Amy PDSA worksheet.doc page 3 of 7 1/16/2009
STUDY: Analyze data (quantitative and qualitative). Data Summary: In 10 out of 27 patients in whom blood pressure was measured initially and then 5 and 6 minutes after patient arrival, the average of the later blood pressure measurements was lower and represented a clinically significant change. Out of the 27 patients, 4 had a goal BP 130/80 (secondary to a diagnosis of DM or ESRD) and 23 had a goal BP of 140/90. 14 of these 27 patients were hypertensive according to the initial reading and 6 out of 27 were hypertensive according to the average later reading. Mean BP First Reading: 134/83 Mean BP Average later Reading: 125/78 Graph 1: Changes in Blood Pressure Category from Original Reading to Reading after Five Minutes 25% 20% 5% 10% 40% Hypertensive-Hypertensive Hypertensive-Pre-Hypertensive Hypertensive-Normotensive Pre-hypertensive-Normotensive Normotensive-Normotensive Indicates clinically significant change (i.e. change that would produce medication change) Amy PDSA worksheet.doc page 4 of 7 1/16/2009
27 patients blood pressures measured according to protocol 4 out of 27 patients with goal BP of 130/80 23 out of 27 patients with goal BP of 140/90 2 patients with average later readings higher than initial reading 20 patients with average later readings lower than initial reading 5 patients with the same average later reading as compared to initial reading 1 originally hypertensive and average later reading also hypertensive 8 originally hypertensive and average later reading pre-hypertensive 2 originally hypertensive and average later reading normotensive 4 originally prehypertensive and changed to normotensive 5 originally normotensive and remained normotensive Distribution of Patients and Changes in Blood Pressure Readings Amy PDSA worksheet.doc page 5 of 7 1/16/2009
Graph 2: Distribution of Patient s Blood Pressure Change when Measured after 5 Minutes 19% 7% 74% Pt's with average later readings lower Pt's with average later readings the same Pt's with average later readings higher ACT: Document what was learned. Are you confident that you should expand size/scope of test or implement? Mean BP is lower for blood pressures taken after 5 minutes of patient arrival (as according to JNC VII guidelines) and this change seems to be clinically significant. The difference in the mean blood pressures (9 points systolic and 5 points diastolic) is the amount that one blood pressure medication can typically affect. For this reason, it seems that it is important to implement this change into our clinic. What changes are needed for the next cycle? The cycle could be expanded to collect more data, particularly data involving resident s clinic patients (thus more patients with lower blood pressure goals). The next cycle should likely include more information about the patients- their comorbidities and perhaps a limited chart review as opposed to the very basic information collected this cycle (whether or not the patient had diabetes or ESRD). Implementation of this change into the clinic may be somewhat difficult. Robin and Stephanie were surveyed as to their thoughts and opinions on this matter. While they both feel that this is an important change, it is difficult given the clinic structure. The following issues were brought up: 1) Who is going to record the blood pressure reading after 5 minutes and where will it be recorded? (Physicians and nurses feel that clinic is better served by having the physician take the second measurement so as not to interrupt clinic flow. In the final presentation, it was felt that it was only needed in patients who are hypertensive. Additionally, the use of an automated cuff is needed for both blood pressure measurements in order to eliminate provider bias in blood pressure measurement) 2) If a first and second measurement is recorded, which will be the official measurement? How will people outside of ACC clinic know which measurement to use? (It may be difficult to get WebCis changed so that a second measurement can be entered- for now we will just enter the second measurement into our WebCis note. This will, however, pose a difficulty for future research) Amy PDSA worksheet.doc page 6 of 7 1/16/2009
Proposed Changes for Next Cycle: 1) Use blood pressure protocol to measure blood pressure in clinic 2) Consider acquiring more automated cuffs (to eliminate provider bias when measuring blood pressure) Proposed Blood Pressure Protocol: Internal Medicine Blood Pressure Measurement Algorithm Initial Measurement of Blood Pressure using automated cuff Nurse records initial blood pressure in WebCis and leaves automated cuff on Assessment of Comorbid Conditions: Diagnosis of diabetes End Stage Renal Disease Current BP <140/90 or <130/80 with above risk factors Current BP >140/90 or > 130/80 with above risk factors Physician to re-check BP with automated cuff in 5 minutes No further action warranted Record repeat BP in WebCis note in vital signs section Amy PDSA worksheet.doc page 7 of 7 1/16/2009