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

Study objective

We determine the proportion of patients with increased emergency department (ED) blood pressure and no history of hypertension who have persistently increased blood pressure at home, describe characteristics associated with sustained blood pressure increase, and examine the relationship between pain and anxiety and the change in blood pressure after ED discharge.

Methods

This was a prospective cohort study. Patients with no history of hypertension and 2 blood pressure measurements of at least 140/90 mm Hg who were treated in an urban ED were enrolled, provided with home blood pressure monitors, and asked to take their blood pressure twice a day for 1 week. Outcome measures were increased mean home blood pressure (140/90 mm Hg or greater), and correlations between ED anxiety (Spielberger State Anxiety Scale) or pain (10-point scale) and the change in blood pressure after discharge. Potential relevant predictors were recorded and a multivariate model was constructed to assess the relationship between these predictors and increased home blood pressure.

Results

189 patients were enrolled and 156 returned the monitors and completed the protocol. Increased mean home blood pressure was present in 79 of 156 (51%) patients and was associated with older age and being black. Of patients with ED blood pressures meeting criteria for stage I hypertension, 6% had home blood pressures meeting stage II hypertension, 36% stage I, and 52% prehypertension, and 6% had normal blood pressure For patients with ED blood pressures meeting stage II criteria, the corresponding percentages were 28%, 31%, 33%, and 8%, respectively. The difference between home and ED systolic blood pressures was not associated with anxiety (r=–.03; P=.69) and showed a slight association with pain in the opposite direction from what was expected (r=.18; P=.03).

Conclusion

Patients without diagnosed hypertension and increased ED blood pressures often have persistently increased home blood pressures, which does not appear to be related to pain or anxiety in the ED.