Orthostatic blood pressure and heart rate responses within hypovolemic and normovolemic populations.

Abstract

A descriptive study was conducted comparing the blood pressure and heart rate responses to position change among hypovolemic and normovolemic subjects. A convenience sample of 32 men and women from an emergency room with complaints of diarrhea, vomiting, vaginal or rectal bleeding for $\ge$12 hours duration were recruited. The normovolemic group consisted of a convenience sample of 30 men and women from the community. Data analysis included a mixed design analysis of variance. Compared to supine baseline measurements, between group changes in the systolic, diastolic, and mean arterial blood pressure were not statistically significant (p $>$.05). Once the subject stood, heart rate increased statistically significant in both groups (p $<$.05). The data suggest orthostatic hypotension can be considered when the supine resting heart rate is $\ge$87 beats per minute, and if upon standing, heart rate increases by $\ge$19.33 or is $\ge$110 beats per minute. Heart rate measurements should be taken at one minute after standing.