Orthostatic Vital Signs in Healthy Young Male Marines

Orthostatic vital signs are routine in emergency and ambulatory care settings. This crosssectional, quasi-experimental, time-series study investigated orthostatic vital signs, including patient positioning and timing, and identified normal vital sign changes that occur with postural changes, in conditioned, healthy, young, males.

A convenience sample of 326 healthy, male Marines (18-22 years old) was enrolled. Heart rate and blood pressure were measured 2 mornings per week for 6-months, before and after participants stood upright from a supine position; data went directly into a database, eliminating entry and transcription error.

Participants rested supine for 5.5 minutes and 4 sets of blood pressure and heart rate data were obtained, the first at 60 seconds, then every 90 seconds. Participants stood upright and vital signs were retaken.

Multifactor ANOVA was run on vital signs and demographic factors. Correlation coefficients were calculated against the independent variables of physical fitness testing (PFT) scores and 3-mile run times.

The range of heart rate means differed significantly by age group and race. PFT score and run time were highly negatively correlated. Both mean systolic and diastolic blood pressures differed significantly by race.

Supine measurement time was when clinical stability was reached, 2┬╜ minutes after assuming the position. Tilt time was when the largest differences were attained, about 4 minutes after standing.

A healthy participant has a "positive tilt test" if blood pressure difference is below a critical value or if the heart rate difference lies above a critical value. Orthostatic responses varied widely despite the homogeneous sample, making "normal" orthostatic vital sign changes difficult to define and raising concerns about orthostatic testing to identify hypovolemia. If orthostatic testing is used, the client should lie supine at least 2┬╜ minutes before vital signs are obtained and stand for 4 minutes before the second set is taken.

Final Report is available on NTRL at: https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/PB2007107...