Heart rate variability as a triage tool in patients with trauma during prehospital helicopter transport.

BACKGROUND Prehospital triage of patients with trauma is routinely challenging, but more so in mass casualty situations and military operations. The purpose of this study was to prospectively test whether heart rate variability (HRV) could be used as a triage tool during helicopter transport of civilian patients with trauma. METHODS After institutional review board approval and waiver of informed consent, 75 patients with trauma requiring prehospital helicopter transport to our level I center (from December 2007 to November 2008) were prospectively instrumented with a 2-Channel SEER Light recorder (GE Healthcare, Milwaukee, WI). HRV was analyzed with a Mars Holter monitor system and proprietary software. SDNN (standard deviation [SD] of the normal-to-normal R-R interval), as an index of HRV, was correlated with prehospital trauma triage criteria, base deficit, seriousness of injury, operative interventions, outcome, and other data extracted from the patients' medical records. There were no interventions or medical decisions based on HRV. Data were excluded only if there was measurement artifact or technical problems with the recordings. RESULTS The demographics were mean age 47 years, 63% men, 88% blunt, 25% traumatic brain injury, 9% mortality. Prehospital SDNN predicted patients with base excess < or = -6, those defined as seriously injured and benefiting from trauma center care, as well as patients requiring a life-saving procedure in the operating room. No other available data, including prehospital en-route vital signs, predicted any of these. The sensitivity, specificity, positive predictive value, and negative predictive value were 80%, 75%, 33%, 96%, respectively, with and an overall accuracy of 76% for predicting a life-saving intervention in the operating room. CONCLUSIONS This is the first demonstration that prehospital HRV (specifically SDNN) predicts base excess and operating room life-saving opportunities. HRV triages and discriminates severely injured patients better than routine trauma criteria or en-route prehospital vital signs. HRV may be a useful civilian or military triage tool to avoid unnecessary helicopter evacuation for minimally injured patients. A prospective, randomized trial in a larger patient population is indicated.

[1]  F. Veglio,et al.  Prolonged QT Interval and Reduced Heart Rate Variability in Patients with Uncomplicated Essential Hypertension , 2008, Hypertension Research.

[2]  Y. Park,et al.  Cardiovascular autonomic dysfunction predicts acute ischaemic stroke in patients with Type 2 diabetes mellitus: a 7‐year follow‐up study , 2008, Diabetic medicine : a journal of the British Diabetic Association.

[3]  José Salinas,et al.  Heart-rate complexity for prediction of prehospital lifesaving interventions in trauma patients. , 2008, The Journal of trauma.

[4]  Patrick R. Norris,et al.  HEART RATE MULTISCALE ENTROPY AT THREE HOURS PREDICTS HOSPITAL MORTALITY IN 3,154 TRAUMA PATIENTS , 2008, Shock.

[5]  S. Wedel,et al.  Helicopter Scene Response: Regional Variation in Compliance with Air Medical Triage Guidelines , 2008, Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors.

[6]  R. Swor,et al.  Do Outcome Measures for Trauma Triage Agree? , 2008, Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors.

[7]  E. Christensen,et al.  Evaluation of pre‐hospital trauma triage criteria: a prospective study at a Danish level I trauma centre , 2007, Acta anaesthesiologica Scandinavica.

[8]  Jose Salinas,et al.  Prehospital loss of R-to-R interval complexity is associated with mortality in trauma patients. , 2007, The Journal of trauma.

[9]  K. Proctor,et al.  Heart rate variability index in trauma patients. , 2007, The Journal of trauma.

[10]  Ashley C. Mull Cardiac uncoupling and heart rate variability stratify ICU patients by mortality: A study of 2088 trauma patients , 2007 .

[11]  Jose Salinas,et al.  Heart rate variability and its association with mortality in prehospital trauma patients. , 2006, The Journal of trauma.

[12]  Patrick R. Norris,et al.  Heart rate variability predicts trauma patient outcome as early as 12 h: implications for military and civilian triage. , 2005, The Journal of surgical research.

[13]  Benoit M Dawant,et al.  Reduced Heart Rate Volatility: An Early Predictor of Death in Trauma Patients , 2004, Annals of surgery.

[14]  Brahm Goldstein,et al.  Heart rate variability in critical illness and critical care , 2002, Current opinion in critical care.

[15]  R. O’Connor,et al.  Validation of new trauma triage rules for trauma attending response to the emergency department. , 2002, The Journal of trauma.

[16]  Timothy G. Buchman,et al.  Association between heart rate variability recorded on postoperative day 1 and length of stay in abdominal aortic surgery patients , 2001, Critical care medicine.

[17]  Y Cottin,et al.  Could Heart Rate Variability Predict Outcome In Patients With Severe Head Injury?: A Pilot Study , 2001, Journal of neurosurgical anesthesiology.

[18]  W. Scott,et al.  Heart rate variability after acute traumatic brain injury in children , 2000, Critical care medicine.

[19]  F. Lenfant,et al.  Could Heart Rate Variability Analysis Become an Early Predictor of Imminent Brain Death? A Pilot Study , 2000 .

[20]  D. Hoyt,et al.  Analysis of heart-rate variability: a noninvasive predictor of death and poor outcome in patients with severe head injury. , 1997, The Journal of trauma.

[21]  H. Thode,et al.  Incremental benefit of individual American College of Surgeons trauma triage criteria. , 1996, Academic emergency medicine : official journal of the Society for Academic Emergency Medicine.

[22]  T G Buchman,et al.  Uncoupling of biological oscillators: a complementary hypothesis concerning the pathogenesis of multiple organ dysfunction syndrome. , 1996, Critical care medicine.

[23]  M. H. Kempski,et al.  Autonomic control of heart rate after brain injury in children. , 1996, Critical care medicine.

[24]  D. Dries Reduced Heart Rate Variability: An Indicator of Cardiac Uncoupling and Diminished Physiologic Reserve in 1,425 Trauma Patients , 2008 .

[25]  Patrick R. Norris,et al.  Role of reduced heart rate volatility in predicting death in trauma patients. , 2005, Advances in surgery.

[26]  Patrick R. Norris,et al.  Volatility: a new vital sign identified using a novel bedside monitoring strategy. , 2005, The Journal of trauma.

[27]  D. Toweill,et al.  Uncoupling of the autonomic and cardiovascular systems in acute brain injury. , 1998, The American journal of physiology.

[28]  S. Lichtman,et al.  Heart-rate variability in chronic traumatic brain injury. , 1997, Brain injury.

[29]  B. Sayers,et al.  Analysis of heart rate variability. , 1973, Ergonomics.