# Presentation: 544576

## 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

## 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 Aims

- 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
- Describe characteristics associated with sustained BP increase
- Examine the relationship between pain and anxiety and the change in BP after ED discharge

## MethodsDesign, 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) 

## 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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- 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.
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- 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.