title: Heart rate: is it truly a vital sign?
abstract: BACKGROUND
  Tachycardia, often defined as heart rate >100 bpm, has been utilized as a physical sign of hypovolemic shock among the injured for decades without evidence to support its use as a predictor of injury or significant hypovolemia. We sought to determine whether admission heart rate is a valid predictor of hemodynamically significant injuries.
  
  
  METHODS
  Trauma registry data from 1998 to 2004 were analyzed with logistic regression to determine whether heart rate was associated with need for emergent intervention for bleeding (laparotomy, thoracotomy, or angiography), need for packed red blood cell (pRBC) transfusion in the first 24 hours, or severe injury (ISS >25) after blunt or penetrating trauma.
  
  
  RESULTS
  Records of 10,825 patients were analyzed. Overall, heart rate was neither sensitive nor specific in determining the need for emergent intervention, pRBCs in the first 24 hours or severe injury. This was not altered by the presence of hypotension (systolic blood pressure <90 mm Hg) or age in the blunt cohort.
  
  
  CONCLUSIONS
  Heart rate alone is not sufficient to determine the need for emergent interventions for hemorrhage. Although tachycardia may still indicate need for emergent intervention in the trauma patient, its absence should not allay such concern.
authors.affiliation: Department of Surgery, Medical College of Wisconsin, Wisconsin 53226, USA. kbrasel@mcw.edu
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Brasel
authors.forename: Clare
authors.initials: C
authors.lastname: Guse
authors.forename: Larry M
authors.initials: LM
authors.lastname: Gentilello
authors.forename: Ram
authors.initials: R
authors.lastname: Nirula
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001794:Blood Pressure / Q000502:physiology; D001803:Blood Transfusion; D003935:Diagnostic Techniques, Cardiovascular; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D020896:Hypovolemia / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D007362:Intensive Care Units; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013610:Tachycardia / Q000209:etiology*; D014947:Wounds and Injuries / Q000503:physiopathology* / Q000628:therapy