Increased Blood Pressure in the Emergency Department: Pain, Anxiety,

or Undiagnosed Hypertension

AHRQ Annual Meeting 2008

Paula Tanabe, PhD, MPH, RN

Northwestern University, Feinberg School of MedicineDepartment of Emergency Medicine and the

Institute for Healthcare Studies

Acknowledgements

Funded by the Agency for Healthcare Research and Quality, RO3 -HSO15619-01

Background

• Approximately 29% of adults in the US have HTN• 33.5% of these adults are undiagnosed1,2

• HTN leads to cardiac disease, strokes and renal failure3,4

• Adults from low socioeconomic backgrounds and African Americans have a higher morbidity and mortality5,6

• 2003 JNC 7 guidelines re-defined hypertension as 2 or more SBP >140 mm Hg or DBP > 90 mm Hg

• Guidelines advocate improvement in recognition and treatment of HTN7

Emergency Department Opportunity

• Many patients use the ED as their primary health care provider

• Other patients with physicians do not routinely visit their physician

• 2006 American College of Emergency Physicians Clinical Policy recommends: “If BP measurements are persistently elevated with a SBP >140 mm Hg or DBP > 90 mm Hg, the patient should be referred for follow-up of possible HTN and BP management”8

• ACEP policy acknowledges the meaning of elevated ED blood pressures is unclear and often these elevated BPs are attributed to pain or anxiety; data is needed

Study Aims1. Determine proportion of patients with no history

of HTN and two ED blood pressure readings >140/90 who have sustained blood pressure elevations measured at home after ED discharge

2. Describe characteristics associated with sustained BP increase

3. Examine the relationship between pain and anxiety and the change in BP after ED discharge

MethodsDesign, Setting

Prospective cohort of ED patients Large urban, academic medical center with an

EM residency program

Sample Inclusion Criteria

Initial ED SBP >140 or DBP >90 mm Hg No history of HTN Repeat ED SBP >140 or DBP >90 mm Hg

Exclusion Criteria

Non-English speaking Admitted to the hospital Unable to operate home BP monitor Pregnant Medical or psychiatric instability Inadequate contact information Discharged with anti-HTN prescription

Study Protocol

RAs enrolled subjects Mon.-Thurs. 9A-9P, Fri. and Sat 9A-5P Brief patient interview Instructed subjects on use of home BP monitor

Home BP monitor: UA 787EJ Home BP monitor (British Hypertension Society approved) – Monitor stored up to 30 readings

Patients were asked to record home BP twice daily for 1 week

Methods of Return

• Triage desk• Post office, postage

paid envelope• Dominick’s pharmacy

Study Variables

• Sustained blood pressure elevation Highest and lowest SBP and DBP deleted Mean monitor SBP and DBP calculated Classified as sustained elevation if SBP

>140 or DBP >90 mm Hg

Pain and Anxiety

• ED Pain score (0-10 verbal descriptor scale)

• ED Anxiety score – Spielberger State Anxiety Scale– Scoring patient report: 20-80, low to high

anxiety

Analysis

• Chi-square and Fisher’s exact test (categorical variables), t test (continuous variables)

• Standard logistic regression• Pearson correlation coefficients to determine the

correlations between the – Change from ED to home SBP and DBP with the

ED mean pain score and anxiety score

– If elevated ED BP is due to pain or anxiety, we anticipated a negative correlation

Results

189 subjects enrolled 171 (90%) returned monitor 156/171 (91%) had adequate BP data Mean (SD) age = 47 (13) 50% Female 35% Black, 60% White, 7 (n) Hispanic

Results

54% had sustained HTN 40% prehypertension 6% patients had a “normal” JNC7

BP

Prevalence of Home Sustained HTN Based on ED Blood Pressures

Home JNC Classification

Stage I ED BP

No. (%)

Stage II ED BP

No. (%)

Normal

(<120, <80)

5(6) 6(8)

Pre-hypertension

(120-139, 80-90)

41(52) 24(33)

Stage I

(140-159, 90-99)

29(36) 31(23)

Stage II

(>160, >100)

5(6) 21(28)

Demographic Characteristics

Sustained HTN

N(%)

Normal BP

N(%)

Female 52(64) 29(36)

Male 32(43) 43(57)

Black 36(69) 16(31)

White 44(45) 53(55)

Patient Characteristics Associated with Elevated Home Blood Pressure

Characteristic Adjusted Odds Ratio

95% CI

Age / 10 years 1.39 1.03-1.88

Black race vs. white (ref.)

2.50 1.16-5.40

Female vs. male (ref.)

1.94 0.95-3.96

ED SBP, (per 10 mm Hg)

1.03 0.99-1.05

Relationship between self-reported anxiety and pain and the difference between patients’ home and ED systolic blood

pressure (SBP)

604020

Emergency Department Spielberger Anxiety Score

20

0

-20

-40

-60

Cha

nge

in M

ean

SBP

(ho

me-

ED

)

1086420

Emergency Department Mean Pain Score

20

0

-20

-40

-60

Cha

nge

in M

ean

SBP

(ho

me-

ED

)

Limitations

Single site English-speaking only patients Most patients had insurance Home vs. office BP measurements We believe our study under-estimates the

findings based on these limitations

Conclusions

A high proportion of ED patients with elevated BPs were found to have sustained BP elevation at home

ED patients with 2 or more blood pressures >140/90 should not be assumed to be anxious or in pain and are at risk for undiagnosed HTN

Conclusions

The ED is an important setting for identifying patients with undetected HTN

Mechanisms to standardize and automate BP re-assessment orders and prompt discharge instructions are needed

Future research is needed to determine referral mechanisms and brief interventions to motivate patients to follow-up

Acknowledgments, Study Team

• Stephen D. Persell, MD, MPH2 • James G. Adams, MD1 • Jennifer McCormick, BS1 • Zoran Martinovich, PhD3

• David W. Baker, MD, MPH2

• Lori McGee, Steve Gorman and Alexis Bergan-Guzman for their assistance with patient enrollment

• Northwestern University, Feinberg School of Medicine• 1Emergency Medicine, 2General Internal Medicine, 3Psychiatry

References

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2. Chobabanian AV, Bakris GL, Black HR, et al. Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: The JNC 7 Report. JAMA. 2003;289:2560-2571.

3. Almgren T, Persson B, Wilhelmsen L, et al. Stroke and coronary heart disease in treated hypertension -- a prospective cohort study over three decades. J Intern Med. Jun 2005;257(6):496-502.

4. Hsia J, Margolis KL, Eaton CB, et al. Prehypertension and cardiovascular disease risk in the Women's Health Initiative. Circulation. Feb 20 2007;115(7):855-860.

5. Mensah GA, Mokdad AH, Ford ES, et al. State of disparities in cardiovascular health in the United States. Circulation. Mar 15 2005;111(10):1233-1241.

6. Dennison CR, Post WS, Kim MT, et al. Underserved urban african american men: hypertension trial outcomes and mortality during 5 years. Am J Hypertens. Feb 2007;20(2):164-171.

7. Chobabanian AV, Bakris GL, Black HR, et al. Seventh report of the joint national committee on prevention, detection, evaluation, and treatment of high blood pressure. Hypertension. 2003;42:1206-1252.

8. Decker WW, Godwin SA, Hess EP, et al. Clinical policy: critical issues in the evaluation and management of adult patients with asymptomatic hypertension in the emergency department. Ann Emerg Med. 2006;47:237-249.