title: Prehospital shock index and pulse pressure/heart rate ratio to predict massive transfusion after severe trauma: Retrospective analysis of a large regional trauma database.
abstract: Early and accurate detection of severe hemorrhage is critical for a timely trigger of massive transfusion (MT). Hemodynamic indices combining heart rate (HR) and either systolic (shock index [SI]) or pulse pressure (PP) (PP/HR ratio) have been shown to track blood loss during hemorrhage. The present study assessed the accuracy of prehospital SI and PP/HR ratio to predict subsequent MT, using the gray-zone approach.
  
  
  
  This was a retrospective analysis (January 1, 2009, to December 31, 2011) of a prospectively developed trauma registry (TRENAU), in which the triage scheme combines patient severity and hospital facilities. Thresholds for MT were defined as either classic (≥10 red blood cell units within the first 24 hours [MT1]) or critical (≥3 red blood cells within the first hour [MT2]). The receiver operating characteristic curves and gray zones were defined for SI and PP/HR ratio to predict MT1 and MT2 and faced with initial triage scheme.
  
  
  
  The TRENAU registry included 3,689 trauma patients, of which 2,557 had complete chart recovery and 176 (6.9%) required MT. In the whole population, PP/HR ratio and SI moderately and similarly predicted MT1 (area under the receiver operating characteristic curve, 0.77 [95% confidence interval {CI}, 0.70-0.84] and 0.80 [95% CI, 0.74-0.87], respectively, p = 0.064) and MT2 (0.71 [95% CI, 0.67-0.76] and 0.72 [95% CI, 0.68-0.77], respectively, p = 0.48). The proportions of patients in the gray zone for PP/HR ratio and SI were 61% versus 40%, respectively, to predict MT1 (p < 0.001) and 62% versus 71%, respectively, to predict MT2 (p < 0.001). In the least severe patient, both indices had fair accuracy to predict MT1 (0.91 [95% CI, 0.82-1.00] vs. 0.87 [95% CI, 0.79-1.00]; p = 0.638), and PP/HR ratio outperformed SI to predict MT2 (0.72 [95% CI, 0.59-0.84] vs. 0.54 [95% CI, 0.33-0.74]; p < 0.015).
  
  
  
  In an unselected trauma population, prehospital SI and PP/HR ratio were moderately accurate in predicting MT. In the seemingly least severe patients, an improvement of prehospital undertriage for MT may be gained by using the PP/HR ratio.
  
  
  
  Epidemiolgic study, level III.
authors.affiliation: From the Hôpitaux Universitaires de Strasbourg, Pôle d'Anesthésie-Réanimation SAMU-SMUR, Hôpital de Hautepierre, Service d'Anesthésie-Réanimation Chirurgicale; and Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), EA 3072, Institut de Physiologie, Faculté de Médecine, Strasbourg, France (J.P., E.N.); Centre Hospitalier Annecy Genevois, Pôle Urgences-SAMU, Pôle Santé Publique-Réseau Nord Alpin des Urgences, Annecy, France (F.-X.A.); Centre Hospitalier Universitaire de Grenoble, Hôpital Michallon, Pôle d'Anesthésie Réanimation, Grenoble, France (C.F., J.-F.P., P.B.); AP-HP, Hôpitaux Universitaires Paris-Sud, Hôpital de Bicêtre, Département de Physiologie-Université Paris Sud, INSERM U999, Le Kremlin-Bicêtre, France (D.C.); AP-HP, Hôpitaux Universitaires Paris-Sud, Université Paris-Sud, Hôpital de Bicêtre, Service d'Anesthésie-Réanimation, Le Kremlin-Bicêtre; and Laboratoire d'Etude de la Microcirculation, "Bio-CANVAS: Biomarqueurs in CardiaNeuroVascular Diseases" UMRS 942, Paris, France (J.D.); Centre Hospitalier Albertville Moutiers, Service des Urgences-SMUR, Albertville, France (L.C.); Université Grenoble Alpes, Grenoble Institut des Neurosciences, and INSERM U836, Chemin Fortuné Ferrini, Grenoble F-38042, France (J.-F.P, P.B.).
authors.forename: Julien
authors.initials: J
authors.lastname: Pottecher
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Ageron
authors.forename: Clémence
authors.initials: C
authors.lastname: Fauché
authors.forename: Denis
authors.initials: D
authors.lastname: Chemla
authors.forename: Eric
authors.initials: E
authors.lastname: Noll
authors.forename: Jacques
authors.initials: J
authors.lastname: Duranteau
authors.forename: Laurent
authors.initials: L
authors.lastname: Chapiteau
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Payen
authors.forename: Pierre
authors.initials: P
authors.lastname: Bouzat
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D001803:Blood Transfusion / Q000706:statistics & numerical data*; D004632:Emergency Medical Services; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D011237:Predictive Value of Tests; D012042:Registries; D012189:Retrospective Studies; D012771:Shock, Hemorrhagic / Q000503:physiopathology* / Q000628:therapy*