REVIEW
Asymptomatically Elevated Blood Pressurein the Emergency Department:
A Finding Deserving of Attention by Emergency Physicians?
Matthew R. Lewin1, 2

Department of Emergency Medicine, University of California, San Francisco, USA
2
Department of Emergency Medicine, Novato Community Hospital, Novato, USA

1(Received for publication on December 10, 2007)(Revised for publication on August 30, 2008)(Accepted for publication on September 18, 2008)

Abstract
The Emergency Department (ED) may be an ideal place to screen and refer patients forblood pressure monitoring in the outpatient setting. Yet, little is known about the publichealth significance of asymptomatically elevated blood pressure measurements in the ED
and what to tell patients when these abnormal vital signs are recorded. Since the prevalence of hypertension and inadequately treated hypertension is so high, the incidental finding of elevated blood pressure in a previously undiagnosed patient may be a pivotal momentin that patient’s life. For those patients carrying the diagnosis of hypertension, it is the author’s opinion that the observation of elevated blood pressures should trigger advice to see
their physicians to consider medication adjustments or changes. Emergency Physicians andtheir staff are in a unique position to screen and refer large populations of patients to theircommunity physicians and help abort the long-term sequelae of unidentified or inadequately
managed hypertension. How best to advise physicians and their patients requires researchand innovative methods for transmitting important information to patients that may be unrelated to their primary complaint in the ED. (Keio J Med 58 (1) : 19－23, March 2009)

Keywords: blood pressure, emergency department, asymptomatic
Introduction

blood pressures in the ED who might benefit from medication adjustments (unpublished data). Now, we warn
all patients with elevated blood pressure measurements
to have their blood pressure checked as a matter of departmental policy. Nevertheless, reasonable people candisagree about the value and validity of this practice. The
following are my thoughts on the subject of whether asymptomatic elevated blood pressure is a finding worthyof attention by emergency physicians.
In Emergency Medicine, as in other specialties, we often focus on the acute complaints presented us by ourpatients. Yet, by doing so, we often lose the opportunity
to help our patients in ways perhaps more meaningful
than simply addressing the acute complaint. An exampleof this is the failure to warn patients about the presence

United States’ Emergency Departments have morethan 115 million visits each year (~40 visits/100 people)1
which may make them an ideal place to screen and referpatients for blood pressure monitoring in the outpatientsetting. EDs and their staff are in a unique position toscreen and refer large populations of patients to theircommunity physicians and help abort the long-term sequelae of unidentified or inadequately managed hypertension. In one year, one of our California University
EDs missed the opportunity to recommend follow-up
blood pressure checks on as many as 9,600 potentiallynew diagnoses of hypertension and more than 16,000 patients carrying the diagnosis but with uniformly elevated

Presented at the 1535th meeting of the Keio Medical Society in Tokyo, October 12, 2007
Reprint request to: Matthew R. Lewin, M.D., Ph.D., Box 0208, 505 Parnassus Ave, San Francisco, CA 94143, USA, Tel: +1-415-353-8309, Fax:
+1-415-353-1799, E-mail: aplysia99@yahoo.com Alternate Address: Novato Community Hospital, 180 Rowland way, Novato, CA 94945
19

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Lewin MR: Elevated Blood Pressure in the Emergency Department

Table 1 Abridged JNC-7 Classification and Management of Blood Pressure for Adults Aged 18 Years and Older.7
Blood Pressure (BP) classification

Systolic BP,
mm Hg
<120

Diastolic BP,
mm HG
<80

Prehypertension

120-139

80-89

Stage 1 Hypertension140-159

90-99

Stage 2 Hypertension

>160

>100

Normalof a potential killer: Hypertension.
Although the healthcare systems of Japan and theUnited States are significantly different in terms of prehospital care, emergency care, insurance and liability, thebasic goals and tenets of clinical medicine and its practitioners are similar: We strive as individuals, and as agroup to do what is in the best interest of our patients.
Even with the differences in style and content between
Japanese and U.S. medical care in mind, I ask you:
When was the last time you warned your patient with anacute exacerbation of chronic low back pain that, perhaps, those slightly elevated blood pressures in triage
and, prior to discharge might represent asymptomatic
hypertension? Did you suggest that the patient be seen inclinic or by his or her primary physician to have a recheck of these pressures when the patient is feeling better? If your patient with back pain already carries the diagnosis of hypertension and is taking medications…
could it be that those medications need to be adjusted? If
you did do this or asked your nurse to talk to the patientprior to discharge, how long did it take? Seconds or minutes? For a young man appearing in your ED with anankle sprain, your admonition to have his blood pressurechecked in clinic when he is feeling better could be apivotal moment in his life even if it is only to establish apersonal relationship with a physician, but especially if
this young man does in fact have hypertension or pre-hypertension.
In 2001 the cost of cardiovascular disease in Japanese
population 45-69 years old was 20.4% of total---greaterthan that of any other disease group.2, 3 This cost was directly proportional to the degree of hypertension withaverage ¥19,090,468/1000 persons/month during 10 year
follow-up period 1990-2001, with morbidity and mortality correlate directly with severity of disease.2 In the
United States, the estimated cost is upwards of USD$60,000,000,000 (or more than ¥6.6 x 1013) annually forthe treatment of hypertension related complications.2, 4-6
In the United States, the Joint National Committee on
Prevention, Detection, Evaluation and Treatment of High
Blood Pressure (JNC-7) reported that in individuals aged
40-70 years, each increment of 20 mm Hg in systolicpressure or 10 mm Hg in diastolic pressure doubles therisk of cardiovascular events.7 In addition, they reclassified the stages of hypertension to include “prehypertension” as an important and large group of patients (Table1). Except for those patients with symptomatic hypertension and evidence of end-organ damage, the committee made little comment about the management of hypertension in the acute care setting.
How to advise patients presenting to the emergency
department with an incidental finding of asymptomatically elevated blood pressure is a dilemma faced by every practicing emergency physician countless times eachday-but it is only a dilemma if the physician is awarethat there is a potential problem unrelated to the patient’s
chief complaint.
In recent years, some members of the U.S. emergency
medicine community have become actively interested in
the question of what to do when presented with patientsand one or more sets of vital signs containing asymptomatically elevated blood pressures.8, 9 One such group wasconvened by the American College of Emergency Physicians (ACEP). This working group formulated a policy
statement published by the College in 2006. This clinicalpolicy was developed to provide an analysis of the literature about asymptomatic hypertension in the ED.10
The critical questions asked by the committee were (a)whether the ED blood pressure readings are accurate andreliable for screening asymptomatic patients for hypertension? (b) How many blood pressure readings should
be obtained for screening purposes? (c) Do asymptomatic patients with elevated blood pressure benefit fromlowering of their blood pressure?
The American College of Emergency Physicians (ACEP)
Policy on Asymtomatically Elevated Blood Pressurein the Emergency Department9
The ACEP policy was created after a review and critical analysis of peer-reviewed literature published between 1992 and 2005. The guidelines were intended forphysicians working in the hospital-based ED and targeted toward patients over the age of 18 years. Exclusion
criteria included those patients with with acute stroke,
myocardial infarction, new onset renal dysfunction andKeio J Med 2009; 58 (1):19－23

other presentations suggestive of acute end-organ damage. As exist at the present time and at the time of the
ACEP recommendations, there were few compellingstudies to guide appropriate management of patients withasymptomatic hypertension in the ED. No literaturedemonstrates that patients who receive pharmacologic
intervention for asymptomatic hypertension in the ED
have better outcomes than those referred to their physicians or clinics for repeat evaluation and treatment.
Similarly, ambulatory blood pressure monitoring prescribed from the ED has yet to be tested on a large scale.
Below is a reiteration of the key question and recommendation of the ACEP advisory panel on asymptomatically elevated blood pressure in ED patients.
1. Patient Management Question: Are ED bloodpressure readings adequate for screening asymptomatic patients for hypertension?
Recommendation: Repeated measurements greaterthan 140 mmHg or diastolic pressure greater than
90 mmHg, the patient should be referred for follow
up for possible blood pressure reevaluation andmanagement
Relevance to Emergency
Medicine Other Specialty Practices
The appropriate steps for the evaluation and treatmentof asymptomatic hypertension in the non-primary caresetting remain controversial. What is not controversial isthat the correct interpretation and management of incipient or actually abnormal vital signs is a cornerstone of
medical care in any setting even when these vital signs
are not related to the patient’s primary complaint. I am
frequently reminding my students and residents that theword “vital” takes its origin from the Latin (vita) for“life”. Vital signs are the “signs of life.” We ignore themat the peril of our patients and our own mental and professional discipline.
Despite the importance of vital signs and their ease of
acquisition and study, at present, there is insufficient evidence to conclude that the various stressors related to an
ED visit are sufficient to attribute a diagnosable cause toa patient’s asymptomatically elevated blood pressure.
Given the extraordinarily high prevalence of the diseasein the general population, emergency physicians are
uniquely situated to inform their patients of a potentiallyinsidious killer. I find it surprising how scarce researchon this subject is in the current medical literature.
Given the extremely high prevalence of hypertension
in the population, it is certain that a significant percentage of patients will actually have the disease. Many authors have studied “white coat” hypertension in Japanand elsewhere.13-18 It hasn’t been studied in the ED, but

21

in my opinion, even if we accept that there is white coat
hypertension in the ED…its presence would most likely
increase the sensitivity of the test for asymptomatic hypertension at some expense to specificity.
Are ED blood pressure readings adequate for screening
asymptomatic patients for hypertension? The best available U.S. data are not from prospective, randomized
clinical trials. Nevertheless, the ACEP Clinical Policy
Committee has recommended that patients with repeatedly elevated readings should be referred for further
evaluation and outpatient screening for hypertension.
Interestingly, the emergency medicine community’s response to this new policy has been minimal, though thereasons for this lack of response are not clear.1 9-2 1 Recent studies have shown that emergency physicians in
the U.S. do not identify, diagnose or refer patients for asymptomatically elevated blood pressures in the ED. The
first, by Tilman and colleagues1 9 assessed the charts of1547 patients seen in their ED and meeting criteria for a
hypertensive state. Only 7% received any type of attention for this finding (e.g. referral or medication refill). Ina second study, Lehrman et al 2 1 asked a very simple
question: Would dissemination of the American Collegeof Emergency Physicians clinical policy on hypertension
to emergency physicians would lead to improvements inblood pressure reassessment and referral of ED patientswith elevated blood pressure? Knowledge of the policy
did not result in any improvement in referral rates…therates were actually lower (13% before the policy and 7%
afterwards) one year after publication. The authors did
not speculate about the cause of this “poor” performance,
but I suspect it has to do with lack of dissemination andthe strength of evidence to support ACEP’s recommendations.
Approach to Asymptomatic Elevated Blood Pressurein the ED and Missing Data
My personal approach to asymptomatically elevatedblood pressure in the ED is usually to do one of twothings in addition to verbally suggesting the patient havehis or her blood pressure checked (patients do not often
retain much of the information given to them verbally).22-24 I have printed cards on which I have hand-written the patient’s name, the date and their blood pressuresin the ED. When discharge instructions are printed froma computer, I type this suggestion into their standardized
discharge instructions. In our ED, we have recently automated our charts. The computer automatically prints out
a report to the patient and suggests they should havetheir blood pressure checked by their primary care physician or clinic to have the pressures evaluated for treatment or medication adjustment. The interventions I am
discussing, above, represent my personal views about
this topic and how I and my colleagues at the University

22

of California in San Francisco have decided to respondto this issue. We have implemented these changes inour emergency medicine practice realizing that manyquestions about asymptomatic elevated blood pressure in
the ED remain unanswered.
What are some of the missing data? From the standpoint of research and policy, it might be useful to study
the following questions, among many others before implementing standardized policies:
1. What is the true prevalence of hypertension in the
population presenting to the ED with asymptomaticallyelevated blood pressures? Should a single elevatedblood pressure reading be sufficient to trigger a referral?25 If not, how many? What values of systolic anddiastolic blood pressure should trigger a warning. If weare warning patients at 140mmHg systolic…what
about warnings for blood pressures in the range of prehypertension starting at 130mmHg?7, 10
2. What are the long-term outcomes of ED patients
identified, notified and referred for outpatient testing?
At present, there are no convincing data to suggest that
this advice for follow-up will lead to improved outcomes. Adults who get treatment in the ED but do nothave a primary physician and have not had prior hypertension screening may be a population that is at inherent risk of poor cardiovascular or health outcomesfor a variety of socioeconomic reasons. It should atleast be demonstrated that the proposed recommendation effectively encourages outpatient hypertension
screening for those to whom it is given.
3. What are the factors inhibiting emergency physiciansfrom acting on information readily available to themand potentially important to their patients? If it wereshown to be useful, what ED resources available could
be used to effectively communicate concern about elevated blood pressure to patients? Some possibilities
would be the use of nurses,26 electronic flagging, directreferral, discharge from the ED with ambulatory bloodpressure monitors--all of these interventions have been
widely studied in other settings, but not in the
ED.15, 18, 27-30
4. What are the parameters for identifying incipient or
actual hypertension in the pediatric ED population?31, 32
For advice to be effective and minimize potential anxiety for the patient, a considerable amount of time mayneed to be allocated by the physician or nurse to explain
the significance of the elevated blood pressure finding,including the uncertainties surrounding it. This timecommitment could conflict with other pressing ED
needs. Research is needed to factor the risks, benefits
and costs associated with seemingly simple recommendations. The cost in time and money to the patients mustalso be considered since many will end up being advised

Lewin MR: Elevated Blood Pressure in the Emergency Department

to undergo blood pressure screening in what may turnout to be multiple outpatient visits. These issues need to
be anticipated and considered before implementation ofa well-meaning, standardized intervention which may
have unintended, adverse consequences to individuals
and populations.21, 33
When the U.S. Department of Health and Human Services produced its document, “Healthy people 2010,”
one of the primary objectives was to lower the proportion of people over the age of twenty with unrecognizedhypertension. A second goal is to increase the proportionof people carrying the diagnosis of hypertension to haveadequate control.3 4- 3 6 Many U.S. emergency departments engage in point of care testing for HIV, provide
pneumococcal vaccines and give handouts with referrals
to help patients seek help for smoking cessation, substance abuse and domestic violence.2 1 These non-acuteservices have become integral to the practice of emergency medicine in the United States, but may not beneeded or may not be appropriate for the practice of
emergency medicine in other countries.
Concluding Remarks
There is a growing trend in medicine, world-wide, tomove quickly from collegial advice to expert recommendation and consensus then to policy and mandate in thename of quality of care--and at the expense of physician
autonomy. A very high burden of proof should be placedon any broad recommendation such as the one proposedby the ACEP to ensure that the physician-patient relationship is not hindered and medical care appropriately
individualized. Thus, while I agree with the spirit of the
ACEP policy and its value as an educational tool, I am
hesitant to endorse it a priori without having answered
the questions posed earlier.
As emergency medicine evolves in each country, it isprobably wise to be aware of the challenges faced bycomparable institutions in other countries with special
attention to their successes and failures. Screening for
hypertension, like so many diseases that do not recognize cultural or geographic boundaries is one that I believe deserves attention in emergency departments
around the globe and is an area ripe for research andimaginative problem solving by physicians and scientists
at any stage of training.
Acknowledgements
I thank Dr. Shingo Hori, Dr. Naoki Aikawa and the
Keio University Department of Emergency Medicine for
their interest and enthusiasm in the exchange of ideas
about the practice of emergency medicine. I also thankDr. Michel Accad for his critiques of my ideas and assumptions. This manuscript is based on my lecture spon-

Keio J Med 2009; 58 (1):19－23

sored by Keio University Hospital, School of Medicine
and the Keio Medical Society, October 12, 2007.
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