Skip Navigation LinksHome > June 2011 - Volume 70 - Issue 6 > Heart Rate Variability Is an Independent Predictor of Morbid...
Journal of Trauma-Injury Infection & Critical Care:
doi: 10.1097/TA.0b013e31821858e6
Original Article

Heart Rate Variability Is an Independent Predictor of Morbidity and Mortality in Hemodynamically Stable Trauma Patients

Ryan, Mark L. MD; Ogilvie, Michael P. MD, MBA; Pereira, Bruno M. T. MD, FCCM; Gomez-Rodriguez, Juan Carlos MD; Manning, Ronald J. RN, MPH; Vargas, Paola A.; Duncan, Robert C. PhD; Proctor, Kenneth G. PhD

Collapse Box

Abstract

Background: Reduced heart rate variability (HRV) reflects autonomic dysfunction and can triage patients better than routine trauma criteria or vital signs. However, there is questionable specificity and no consensus measurement technique. The purpose of this study was to analyze whether factors that alter autonomic function affect the specificity of HRV for assessing traumatic injury.

Methods: We evaluated 216 hemodynamically stable adults (3:1 M:F; 97:3 blunt:penetrating; age 49 years ± 1 year, mean ± standard error) undergoing computed axial tomography (CT) scan to rule out traumatic brain injury (TBI). All were prospectively instrumented with a Mars Holter system (GE Healthcare, Milwaukee, WI). HRV was determined offline using time domain (standard deviation of normal–normal intervals, root-mean-square successive difference) and frequency domain (very low frequency [VLF], LF, wideband frequency, high frequency [HF], low to HF index ratio) calculations from 15-minute electrocardiogram and correlated with routine vital signs, mortality, TBI, morbidity, length of stay (LOS), and comorbidities. Significance (p ≤ 0.05) was determined using nonparametric analysis, Student's t test, analysis of variance, or multiple logistic regression.

Results: VLF alone predicted survival, severity of TBI, intensive care unit LOS, and hospital LOS (all p < 0.05). Beta-blockers or diabetes had no effect, whereas age, sedation, mechanical ventilation, spinal cord injury, and intoxication influenced one or more of the variables with age being the most powerful confounder (all p < 0.05). Except for the Glasgow Coma Scale, no other routine trauma or hemodynamic criteria correlated with any of these outcomes.

Conclusions: Decreased VLF is an independent predictor of mortality and morbidity in hemodynamically stable trauma patients. Other time and other frequency domain variables correlated with some, but not all, outcomes. All were heavily influenced by factors that alter autonomic function, especially patient age.

© 2011 Lippincott Williams & Wilkins, Inc.

Follow Us


Login

Article Tools

Share

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.