Increased Blood Pressure in the Emergency Department: Pain, Anxiety, or Undiagnosed Hypertension

Slide Presentation from the AHRQ 2008 Annual Conference

On September 8, 2008, Paula Tanabe, Ph.D., M.P.H., R.N., made this presentation at the 2008 Annual Conference. Select to access the PowerPoint® presentation (1 MB).

Slide 1

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 Medicine
Department of Emergency Medicine and the Institute for Healthcare Studies

Slide 2

Acknowledgements

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

Slide 3

Background

• Approximately 29% of adults in the U.S. have hypertension (HTN).
• 33.5% of these adults are undiagnosed.^1-2
• HTN leads to cardiac disease, strokes and renal failure.^3-4
• Adults from low socioeconomic backgrounds and African Americans have a higher morbidity and mortality.^5-6
• 2003 Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) guidelines re-defined hypertension as 2 or more systolic blood pressure (SBP) ≥140 mm Hg or diastolic blood pressure (DBP) ≥90 mm Hg.
• Guidelines advocate improvement in recognition and treatment of HTN.⁷

Slide 4

Emergency Department (ED) 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 (ACEP) 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 blood pressure (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.

Slide 5

Study Aims

1. 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.

Slide 6

Methods, Design, Setting

• Prospective cohort of ED patients.
• Large urban, academic medical center with an emergency medicine (EM) residency program.

Slide 7

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.

Slide 8

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.

Slide 9

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.

Slide 10

Methods of Return

• Triage desk.
• Post office, postage paid envelope.
• Dominick's pharmacy.

On the left side of the slide is a color photograph of a man hooked up to a blood pressure monitor while holding up a Priority Mail envelope in the other hand.

Slide 11

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.

Slide 12

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.

Slide 13

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.

Slide 14

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.

Slide 15

Results (continued)

• 54% had sustained HTN.
• 40% prehypertension.
• 6% patients had a "normal" JNC 7 BP.

Slide 16

Prevalence of Home Sustained HTN Based on ED Blood Pressures

The table shows the results for "Home JNC Classification," "Stage I ED BP No. (%)," and Stage II ED BP No. (%)".

Slide 17

Demographic Characteristics

The table shows the results for "Sustained HTN" and "Normal BP".

Slide 18

Patient Characteristics Associated with Elevated Home Blood Pressure

The table shows the results for "Characteristic," "Adjusted Odds Ratio," and "95% CI".

Slide 19

Relationship between self-reported anxiety and pain and the difference between patients' home and ED systolic blood pressure (SBP)

The slide shows two graphs. The first graph shows the vertical axis going from -60 to 20, Change in Mean SBP (home-ED), and the horizontal axis going from 20 to 60, Emergency Department Spielberger Anxiety Score. The majority of the dots lie in the area between 20 and 40, and -40 and 0. The second graph shows the vertical axis going from -60 to 20, Change in Mean SBP (home ED), and the horizontal axis going from 0 to 10, Emergency Department Mean Pain Score. The dots lie evenly from 0-10, but are more heavily concentrated between -40 and 0.

Slide 20

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.

Slide 21

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.

Slide 22

Conclusions (continued)

• 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.

Slide 23

Acknowledgments, Study Team

• Stephen D. Persell, MD, MPH^b
• James G. Adams, MD^a
• Jennifer McCormick, BS^a
• Zoran Martinovich, PhD^c
• David W. Baker, MD, MPH^b
• Lori McGee, Steve Gorman and Alexis Bergan-Guzman for their assistance with patient enrollment.

^a Northwestern University, Feinberg School of Medicine, Dept. of Emergency Medicine
^b Northwestern University, Feinberg School of Medicine, Dept. of General Internal Medicine
^c Northwestern University, Feinberg School of Medicine, Dept. of Psychiatry

Slide 24

References

1. Lewington S, Clarke R, Qizilbash N, et al. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet Dec 14 2002;360(9349):1903-1913.

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.