Establishing Standards of Orthostatic Measurements in Normovolemic Adolescents

OBJECTIVE: To determine normal orthostatic heart rate and blood pressure changes in healthy adolescents. DESIGN: Survey. SETTING: General adolescent clinic at a military teaching medical center in Honolulu, Hawaii. PARTICIPANTS: One hundred healthy normovolemic patients aged 12 to 19 years representing a cross section of individuals from a diverse military population during a 5-month study period. SELECTION PROCEDURE: Convenience sample. INTERVENTIONS: None. MEASUREMENTS/MAIN RESULTS: The mean (+/- 2 SDs) orthostatic heart rate change in beats per minute was 21.5 +/- 21.2, with a range of 50 to -3 beats per minute. The mean (+/- 2 SDs) systolic blood pressure change was -0.9 +/- 15.7 mm Hg, with a range of 19 to -17 mm Hg. Orthostatic measurements in a normal adolescent population may result in a heart rate increase of 40 to 50 beats per minute and a systolic blood pressure decrease of 15 mm Hg. There were no significant differences between individuals with respect to age, race, sex, and body habitus. CONCLUSIONS: Healthy adolescents display wide variation in orthostatic measurements that exceed previously accepted standards. Further study is required to determine if sensitivity and specificity values exist for orthostatic measurements that can identify individuals with intravascular volume depletion.