# Evaluation of mean arterial pressure as a risk factor for missed ophthalmoscopic findings in the emergency department Open Access

## Bruce, Beau Benjamin (2010)

Permanent URL: https://etd.library.emory.edu/concern/etds/kh04dq21b?locale=en
Published

## Abstract

Background: The objective of this study was to examine risk factors for the failure
to diagnose acute ophthalmoscopic findings in patients presenting to the emergency
department (ED).
Methods: Consecutive, adult patients presenting to the Emory University ED with
a chief complaint of headache, acute focal neurologic deficit, visual changes, or a diastolic blood pressure ≥120 were included. Photographs of the ocular fundus (optic
disc and macula) were obtained from both eyes using a commercially available non-
mydriatic ocular fundus camera. ED physicians were masked to the results of the
photographs during their care of these patients and were asked to proceed with their
routine evaluation of patients. Photographs were reviewed by experts for the presence or absence of ocular fundus abnormalities. The outcome of interest was missed findings defined as the presence of relevant findings not identified during routine care of patients. Presenting complaints, systolic and diastolic blood pressure, heart rate, height, weight, age, race, gender, and the patients ED diagnoses were recorded. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR)
were used to calculate mean arterial pressure (MAP). MAP≥125 was the exposure of
interest. Univariate, stratified, and logistic regression analyses were performed.
Results: 350 were enrolled in the study. Forty-four patients (13%) had an relevant
abnormality and 27 (61%) of these were missed. Stratified analyses indicated evidence
of interaction between MAP and age, BMI, black race, and sex. Logistic regression
analyses showed that MAP≥125 was the primary, independent risk factor for missed
fundus abnormalities after controlling for age, BMI, race, and sex.
Conclusions: There is a substantial burden of relevant ophthalmoscopic findings in
the ED and the majority of these findings are missed. Mean arterial pressure was the
most important determinant of whether a patient would have a missed ophthalmoscopic finding during the ED evaluation, and our findings suggest that defining the
blood pressure threshold for hypertensive emergency as DBP≥120 is too high to be
used as a screening criteria for end organ damage and that a lower threshold may be
more appropriate.

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Hypothesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Study Conduct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24