Research Review By Dr. Joshua Plener©

Audio:

Download MP3

Date Posted:

January 2021

Study Title:

Blood Pressure Screening by Outpatient Physical Therapists: A Call to Action and Clinical Recommendations

Authors:

Severin R, Sabbahi A, Albarrati A et al.

Author's Affiliations:

Department of Physical Therapy, College of Applied Health Sciences, University of Illinois; College of Applied Medical Sciences, King Saud University, Saudi Arabia.

Publication Information:

Physical Therapy 2020; 100: 1008-19.

Background Information:

Cardiovascular disease remains the leading cause of mortality for both men and women, despite improved medical interventions (1). Specifically, hypertension, which is a modifiable risk factor for cardiovascular disease, is the elevation of blood pressure above a predetermined cut-off point (2). Hypertension affects approximately 34% of the population in the USA and is a leading cause of mortality. One reason for this is the fact that hypertension can be asymptomatic, even as numbers reach critical levels (> 180/120 mmHg) (3). However, when hypertension is known to the individual, the Center for Disease Control and Prevention reports that only approximately 50% of cases are effectively controlled (3). To illustrate, it has been reported that one-half of patients stop taking their medications within 1 year of starting (4). Even in patients who adhere to their medication, significant blood pressure increases during exercise may occur (5), which is associated with risks of major cardiovascular events and mortality (2, 6, 7). Other factors that impair effective hypertension screening and management include the presence of white coat hypertension, masked hypertension and measurement error.

Hypertension is more prevalent in individuals with disabilities compared to those without disabilities, especially individuals with mobility limitations (8). One study reported that 75% of outpatient orthopedic physical therapists reported at least 25% of their current case load included patients with diagnosed cardiovascular disease or at a moderate or severe risk for its development (9). An effective management strategy for hypertension is early detection which can reduce mortality, morbidity and health care costs (10-12). Studies have demonstrated that screening by non-physician health care providers can improve the detection and management of hypertension (12-14).

It is uncertain what the data may show about chiropractic practices, but it has been demonstrated that outpatient physical therapy practices seldomly measure blood pressure, with only 10-15% of therapists measuring resting blood pressure on all new patients (9, 15). Rationales for the lack of screening include a lack of perceived importance, lack of clinic policy and time constraints (9, 15, 16). Therefore, a change in clinician perceptions regarding the importance of blood pressure screening may be required in order to facilitate screening at outpatient clinics. This article is a call to action for routine blood pressure measurement by outpatient physical therapists (and chiropractors!) through establishing the importance of screening, providing evidence-based recommendations on screening, and discussing potential future directions regarding screening and clinical management.

Although this paper was written from a physical therapy perspective, this information is also highly relevant to chiropractors, who often act in a primary care capacity.

Summary:

Ethical Duty to Screen:

Several physical therapy organizations suggest that physical therapists have a duty to protect the safety and optimize the overall health of patients (the same could be said for chiropractors). Following this mandate, the implementation of routine blood pressure screening in outpatient physical therapy practices seems appropriate in order to ensure the overall health of patients is assessed. It is likely that physical therapists see a significant number of patients without a prior physician referral and therefore, this may be the only opportunity for early detection of elevated blood pressure.

Equipment Requirements:

The following equipment recommendations for outpatient practice settings include 1 stethoscope per therapist, 1 standard aneroid (manual) blood pressure cuff for every 2 therapists, 1 small and 1 large blood pressure cuff per clinic and 1 child cuff for clinics providing care to patients younger than 12 years of age (15). Additionally, 1 thigh cuff would be warranted to examine the lower extremity. It is important to ensure enough equipment is at the clinic in order to have the appropriate cuff sizes available.

Instrumentation:

The two most popular ways to measure blood pressure in clinic are aneroid devices, which are manually measured, and oscillometric devices which are used for automatic measurements. Both approaches measure blood pressure accurately (17, 18).
<br/ /> Manual auscultatory blood pressure measurements are based on the identification of sounds resulting from the return of arterial blood flow following a period of temporary occlusion, known as Korotkoff sounds. The systolic pressure is detected as the cuff deflates allowing blood to return to the artery in a turbulent fashion, causing vibration along the arterial wall making a tapping sound which can be heard. The diastolic pressure is determined once the cuff pressure falls below the diastolic pressure, blood flow is restored to the artery and the arterial wall no longer vibrates, resulting in the tapping sound disappearing, with silence heard when auscultating.

Automatic oscillometric devices operate on the principle of vibrations in the arterial wall which are detected and transduced into electrical signals. The devices inflate the blood pressure cuff to about 20mmHg above the patient’s systolic blood pressure and as the cuff deflates, the arterial wall vibrations transfer through the air inside the cuff into a transducer in the monitor. The point of maximal oscillation (vibration) is identified by the device and corresponds to the mean intra-arterial pressure. Systolic and diastolic pressures are estimated based on the maximal point of oscillation by the device.

There are advantages and disadvantages to both blood pressure techniques. Automatic oscillometric devices reduce the white coat response compared to manual measurements (19, 20), as blood pressure can be taken with the clinician outside of the patient’s room. In addition, automatic devices are less susceptible to what is referred to as an auscultatory gap, which is a period of diminished or absent Korotkoff sounds, resulting in an underestimation of systolic blood pressure (21). However, automatic devices measure blood pressure by detecting vibration, therefore they cannot be used to measure blood pressure during exercise (20, 22) whereas manual devices can.

A new method to measure blood pressure is wrist monitors. This may be more useful for obese patients where cuff sizing options are limited (23). However, the accuracy of these devices has been demonstrated to overestimate blood pressure (22, 23).

Automatic auscultatory devices have been proposed as an alternative to manual and oscillometric devices (24, 25). These devices combine the best features of manual and oscillometric options, however this may be too costly for routine outpatient physical therapy practices.

Equipment Function and Calibration:

Routine equipment checks and maintenance are essential to ensure accurate readings are taken. Prior studies demonstrated 22% of aneroid gauges used in physical therapist practices are not adequately calibrated (26, 27). Therefore, maintenance and regular calibration ranging from 6 months to 2 years is essential to measure blood pressure accurately. Standardized calibration protocols exist such as the one recommended by the European Society of Hypertension (18). This procedure involves connecting a Y-tube connector allowing for a synchronized comparison of the mercury and aneroid gauges at 50 mmHg increments to ensure proper readings throughout the entire range. As opposed to mercury sphygmomanometers, the use of digital pressure gauges could be used to conduct these inspections.

BP Cuff Size Selection:

Not selecting the appropriate cuff size can result in significant blood pressure measurement error (22). Therefore, having proper cuff sizes is vital to ensure accurate readings. It is recommended that the cuff should have a bladder length that is 80% and a width that is at least 40% of the arm circumference (22). The bladder refers to the plastic inflatable piece inside the outer cuff wrap. Two methods to ensure proper sizing is to determine the radius of the blood pressure measurement site or use the index line and reference range printed on the blood pressure cuff. If the index line falls outside the refence range, a different sized cuff is required.

Standardized Measurement Technique:

The standard measurement position includes having the individual in a seated position resting for 5 minutes prior to obtaining the measurement (28, 17). Their feet should be flat on the floor and uncrossed with their back supported. Their arm should be positioned with the shoulder in a mid-point of flexion and the elbow fully extended and pronated. If the arm is above or below the right atrium level, readings may be underestimated or overestimated respectively. During the initial exam, blood pressure measurement of both arms is recommended, and the side of the higher reading should be used for future readings. Additional controls should be employed for speaking, sneezing, coughing and isometric contraction of the surrounding musculature during measurement (29). Any deviation from the standard position can impact the blood pressure readings. Some positioning errors such as the patient talking and a full urinary bladder can impact blood pressure by as much as 10-15 mmHg (22).

Forearm, Thigh and Calf Blood Pressure Measurement:

For situations where upper arm measurements are not possible, a forearm measurement may be indicated. As well, if an upper extremity measurement is not possible, a calf or thigh measurement would be indicated.

Measurements using alternative locations follow the same standard measurement procedures with a few exceptions. First, the auscultation of the Kortokoff sounds would take place at the artery below the site of cuff inflation. Second, a supine position would be the best option to limit muscular contraction of the lower extremity. Third, bony structures of the ankle or wrist may interfere with sound transmission through the stethoscope and therefore manual palpation or use of a Doppler to obtain the systolic blood pressure may be indicated. Finally, the established values for blood pressure classification are for an upper arm measurement and variability may exist in different parts of the arterial tree (22). In these circumstances, more regular measurements are required. For example, distal arteries may have an increased systolic blood pressure whereas diastolic blood pressure may be decreased (22).
 
Standing Blood Pressure and Response to Position Change:
 
Some increases in blood pressure are expected when going from supine to sitting and standing. For example, diastolic pressure in sitting can be 5 mmHg higher than supine (30). An orthostatic response would be considered abnormal if the systolic blood pressure decreases by 20 mmHg or greater or the diastolic pressure decreases by 10 mmHg or greater as the individual moves to a more upright position. It is recommended to take the measurements at 1 and/or 3-minute time frames after the position change (31). A condition known as initial orthostatic hypotension is defined as no decrease in systolic pressure and/or a decrease in diastolic pressure of > 20 mmHg within the first 15 seconds of standing but correcting within 30-60 seconds (32). If there is an abnormal response to positional changes, appropriate referrals are required.

Blood Pressure Response to Exercise:

Blood pressure measurement during exercise may provide a more robust assessment of a patient’s hemodynamic stability and clinical prognosis (33-35). The cardiovascular system is expected to increase cardiac output in order to match the increase in metabolic demand of working muscles. A normal response to dynamic exercise is blood pressure increasing in systolic pressure and no change or a slight drop in diastolic pressure. A failure of the systolic pressure to increase with increased workloads indicates inadequate cardiac output, while a rapid increase in systolic blood pressure with a minimal increase in workload would indicate high total peripheral resistance and thus impaired vascular function such as arterial stiffness (7).

During exercise, an increase of 8-12 mmHg of systolic blood pressure per metabolic equivalent with a plateau at peak exercise is expected (36). The normal increase from rest is 55 to 65 mmHg for systolic blood pressure in men and 45 to 60 mmHg in women, however depending on the individual’s age, these are variable (37). Diastolic blood pressure values change to a greater degree in women with values increasing across their lifespan (37).

Blood Pressure Screening During Exercise:

From a safety standpoint, it is important for physical therapists to monitor blood pressure responses to exercise during treatment sessions. It has even been demonstrated that blood pressure response to exercise serves as a valuable prognostic marker for future cardiovascular events, independent of resting blood pressure levels (29). However, measurements during and following exercise are underutilized. Exercise hypertension is an exaggerated response to exercise, defined as a reading greater than or equal to the 90th percentile relative to normative data (65, 68). Those with exercise hypertension have a 1.4-3.0 increased relative risk for cardiovascular events compared to normal blood pressure individuals (38).

In addition to issues surrounding elevated blood pressure during exercise, an abnormally low blood pressure response to exercise has been demonstrated to be a strong prognostic factor of cardiovascular events and all-cause mortality, independent of clinical presentation or exercise intensity (33). During an exercise test, if a persistent decrease in systolic blood pressure of 10 mmHg or greater is noted with increased workload, the test should be terminated (36, 39).

Measurement of Blood Pressure During Exercise:

In the absence of automated blood pressure devices, clinicians should rely on manual auscultatory methods. During low to moderate intensity exercise, accurate measure using manual methods are possible (7). However, as exercise intensity increases, blood pressure measurements may become increasingly difficult to auscultate. Blood pressure should be measured at rest, during exercise and post exercise. If blood pressure can’t be measured during exercise, measuring immediately after exercise in the same exercise position can occur. This would be referred to post-exercise blood pressure and not exercise blood pressure. Within 6 minutes after exercise, the systolic blood pressure should return to pre-exercise levels and in some cases, a post exercise hypotensive response may be present (40).

Exercise Management for Hypertension:

Exercise has been demonstrated to be as effective as pharmacologic therapy in terms of treatment effectiveness for hypertension (40, 41). Although the benefits of exercise therapy have been well-established, only 15% of American adults with hypertension have been reported to meet the exercise recommendations (42). An aerobic exercise program for 90 to 150 minutes per week at 65 – 75% of the patient’s heart rate reserve can result in a systolic blood pressure reduction of about 5-8 mmHg in hypertension individuals and 2-4 mmHg in normotensive individuals (43, 44). Decreases of this amount have been shown to reduce the risk of stroke by 14%, coronary artery disease by 9% and total mortality by 7% (40, 45).

Clinical Application & Conclusions:

Hypertension is a serious medical condition that affects a significant portion of the population. In order to effectively manage this condition, communication between all health care professionals needs to occur. With the large body of literature demonstrating the need for physical therapists, and other clinical professionals (i.e. chiropractors) to consistently measure blood pressure in patients, it is only logical this is carried out in outpatient clinics. Simple blood pressure measures performed in outpatient clinics have the ability to reduce burden on the health care system and identify hypertensive patients early before a serious medical emergency occurs.

Rehabilitation professionals are uniquely situated to not only screen for hypertension, but also to provide effective evidence-based exercise interventions to help manage these patients.

Study Methods:

This was a “Perspective” article. Therefore, no statistical analysis was conducted nor was a specific description of their methodology provided.

Study Strengths / Weaknesses:

Strengths:
  • The authors discuss a broad range of topics in order to effectively make their arguments.
Weaknesses:
  • This article is a perspective piece and therefore doesn’t follow the same rigor as a systematic review. This could result in a biased look at the literature on this topic.

Additional References:

  1. Forouzanfar MH, Liu P, Roth GA, et al. Global burden of hypertension and systolic blood pressure of at least 110 to 115 mm hg, 1990–2015. JAMA 2017; 317: 165.
  2. Benjamin EJ, Virani SS, Callaway CW, et al. Heart disease and stroke statistics–2018 update: a report from the American Heart Association. Circulation 2018; 137: e67–e492.
  3. Kessler CS, Joudeh Y. Evaluation and treatment of severe asymptomatic hypertension. Am Fam Physician 2010; 81: 470–476.
  4. Vrijens B, Antoniou S, Burnier M, et al. Current situation of medication adherence in hypertension. Front Pharmacol 2017; 8: 100.
  5. Chant B, Bakali M, Hinton T, et al. Antihypertensive treatment fails to control blood pressure during exercise. Hypertension 2018; 72: 102–109.
  6. Schultz MG, Otahal P, Cleland VJ, et al. Exercise-induced hypertension, cardiovascular events, and mortality in patients undergoing exercise stress testing: a systematic review and meta-analysis. Am J Hypertens 2013; 26: 357–366.
  7. Sharman JE, LaGerche A. Exercise blood pressure: clinical relevance and correct measurement. J Hum Hypertens 2015; 29: 351–358.
  8. Stevens A, Courtney-Long E, Gillespie C, et al. Hypertension among US adults by disability status and type, National Health and Nutrition Examination Survey, 2001–2010. Prev Chronic Dis. 2014; 11: E139.
  9. Severin R, Wang E, Wielechowski A, et al. Outpatient physical therapist attitudes toward and behaviors in cardiovascular disease screening: a national survey. Phys Ther 2019; 99: 833–848.
  10. Bromfield S. High blood pressure: the leading global burden of disease risk factor and the need for worldwide prevention programs. Curr Hypertens Rep 2014; 15: 134–136.
  11. Danaei G, Ding EL, Mozaffarian D, et al. The preventable causes of death in the United States: comparative risk assessment of dietary, lifestyle, and metabolic risk factors. PLoS Med 2009; 6.
  12. Engström S, Berne C, Gahnberg L, et al. Efficacy of screening for high blood pressure in 1 dental health care. BMC Public Health 2011; 11: 194.
  13. Fleming S, Atherton H, Mccartney D, et al. Self-screening and non-physician screening for hypertension in communities: a systematic review. Am J Hypertens 2015; 28: 1316–1324.
  14. Community Preventive Services Task Force. Cardiovascular disease prevention and control: team-based care to improve blood pressure control. 2016. Available from: https://www. thecommunityguide.org/findings/cardiovascular-diseaseteam-based-care-improve-blood-pressure-control. Accessed May 14, 2020.
  15. Arena SK, Reyes A, Rolf M, et al. Blood pressure attitudes, practice behaviors, and knowledge of outpatient physical therapists. Cardiopulm Phys Ther J 2018; 29: 3–12.
  16. Albarrati AM. Outpatient physical therapy cardiovascular assessment: physical therapist perspective and experience. Physiother Theory Pract 2018; 29: 1–8.
  17. Muntner P, Shimbo D, Carey RM, et al. Measurement of blood pressure in humans: a scientific statement from the American Heart Association. Hypertension 2019; 73: e35–e66.
  18. O’Brien E, Asmar R, Beilin L, et al. European Society of Hypertension recommendations for conventional, ambulatory and home blood pressure measurement. J Hypertens 2003; 21: 821–848.
  19. Roerecke M, Kaczorowski J, Myers MG. Comparing automated office blood pressure readings with other methods of blood pressure measurement for identifying patients with possible hypertension: a systematic review and meta-analysis. JAMA Intern Med 2019; 179: 351–362.
  20. Myers MG, McInnis NH, Fodor GJ, et al. Comparison between an automated and manual sphygmomanometer in a population survey. Am J Hypertens 2008; 21: 280–283.
  21. Ogedegbe G, Pickering T. Principles and techniques of blood pressure measurement. Cardiol Clin 2010; 28: 571–586.
  22. Pickering TG, Hall JE, Appel LJ, et al. Recommendations for blood pressure measurement in humans and experimental animals. Part 1: blood pressure measurement in humans: a statement for professionals from the subcommittee of professional and public education of the American Heart Association Council on high blood pressure research. Hypertension 2005; 45: 142–161.
  23. De Senarclens O, Feihl F, Giusti V, et al. Brachial or wrist blood pressure in obese patients: which is the best? Blood Pressure Monitoring 2008; 13: 149–151.
  24. Cameron JD, Stevenson I, Reed E, McGrath BP, Dart AM, Kingwell BA. Accuracy of automated auscultatory blood pressure measurement during supine exercise and treadmill stress electrocardiogram-testing. Blood Press Monit 2004; 9: 269–275.
  25. Parati G, Ochoa JE. Automated-auscultatory (hybrid) sphygmomanometers for clinic blood pressure measurement: a suitable substitute to mercury sphygmomanometer as reference standard. J Hum Hypertens 2012; 26: 211–213.
  26. Arena SK, Simon L, Peterson EL. Aneroid blood pressure manometer calibration rates in physical therapy curricula: a descriptive study. Cardiopulm Phys Ther J 2016; 27: 56–61.
  27. Arena SK, Bacyinski A, Simon L, et al. Aneroid blood pressure manometer calibration rates of devices used in home health. Home Healthc Now 2016; 34: 23–82.
  28. Frese EM, Fick A, Sadowsky HS. Blood pressure measurement guidelines for physical therapists. Cardiopulm Phys Ther J 2011; 22: 5–12.
  29. Schultz MG, Otahal P, Cleland VJ, et al. Exercise-induced hypertension, cardiovascular events, and mortality in patients undergoing exercise stress testing: a systematic review and meta-analysis. Am J Hypertens 2013; 26: 357–366.
  30. Netea RT, Lenders JWM, Smits P, et al. Both body and arm position significantly influence blood pressure measurement. J Hum Hypertens 2003; 17: 459–462.
  31. Centers for Disease Control and Prevention. Stopping elderly accidents deaths and injuries (STEADI): measuring orthostatic blood pressure. 2017. Available from https://www.cdc.gov/ steadi/pdf/STEADI-Assessment-Measuring BP-508.pdf. Accessed January 6, 2020.
  32. McJunkin B, Rose B, Amin O, et al. Detecting initial orthostatic hypotension: a novel approach. J Am Soc Hypertens 2015; 9: 365–369.
  33. Barlow PA, Otahal P, Schultz MG, Shing CM, Sharman JE. Low exercise blood pressure and risk of cardiovascular events and all-cause mortality: systematic review and meta-analysis. Atherosclerosis 2014; 237: 13–22.
  34. Schultz MG, Sharman JE. Exercise hypertension. Pulse 2013; 1: 161–176.
  35. Weiss SA, Blumenthal RS, Sharrett AR, et al. Exercise blood pressure and future cardiovascular death in asymptomatic individuals. Circulation 2010; 121: 2109–2116.
  36. Pescatello LS, Arena R, Riebe D, et al. ACSM’s Guidelines for Exercise Testing and Prescription. 9th ed. Philadelphia, PA, USA: Wolters Kluwer/Lippincott Williams & Wilkins Health; 2014.
  37. Sabbahi A, Arena R, Kaminsky LA, et al. Peak blood pressure responses during maximum cardiopulmonary exercise testing. Hypertension 2018; 71: 229–236.
  38. Keller K, Stelzer K, Ostad MA, et al. Impact of exaggerated blood pressure response in normotensive individuals on future hypertension and prognosis: systematic review according to PRISMA guideline. Adv Med Sci 2017; 62: 317–329.
  39. Fletcher GF, Ades PA, Kligfield P, et al. Exercise standards for testing and training: a scientific statement from the American Heart Association. Circulation 2013; 128: 873–934.
  40. Sabbahi A, Arena R, Elokda A, et al. Exercise and hypertension: uncovering the mechanisms of vascular control. Prog Cardiovasc Dis 2016; 59: 226–234.
  41. Green DJ. Exercise training as vascular medicine: direct impacts on the vasculature in humans. Exerc Sport Sci Rev. 2009;37:196–202.
  42. Mu L, Cohen AJ, Mukamal KJ. Prevalence and predictors of resistance and aerobic exercise among hypertensive adults in the United States. J Hum Hypertens 2015; 29: 394–395.
  43. Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/ AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol 2018; 71: e127–e248.
  44. Pescatello LS, Buchner DM, Jakicic JM, et al. Physical activity to prevent and treat hypertension. Med Sci Sport Exerc 2019; 51: 1314–1323.
  45. Whelton PK, He J, Appel LJ, et al. Primary prevention of hypertension: clinical and public health advisory from the National High Blood Pressure Education program. JAMA 2002; 288:1882–1888.

Contact Tech Support  Contact Dr. Shawn Thistle
 
RRS Education on Facebook Dr. Shawn Thistle on Twitter Dr. Shawn Thistle on LinkedIn Find RRS Education on Instagram RRS Education (Research Review Service)