title: Continuous noninvasive monitoring of cardiac performance and tissue perfusion in pediatric trauma patients.
abstract: OBJECTIVE
  The aim of this study was to assess the accuracy of a continuous survival probability prediction using noninvasive measures of cardiac performance and tissue perfusion in severely injured pediatric patients.
  
  
  METHODS
  Review of all patients entered into a prospective noninvasive monitoring protocol. Cardiac index (CI) was measured using a thoracic bioimpedance device and tissue perfusion was assessed by transcutaneous carbon dioxide (Ptcco(2)) tension and oxygen tension indexed to the fraction of inspired oxygen (Ptco(2)/Fio(2)). Survival probability (SP) was continuously calculated using a stochastic analysis program.
  
  
  RESULTS
  There were 45 patients with a total of 953 data sets. The mean age was 11 years (range, 1-16 years) with a mean Injury Severity Score of 24 (+/-16). There was no difference between survivors (n = 32) and nonsurvivors (n = 13) at study entry for heart rate, blood pressure, CI, or pulse oximetry (all P > .05). However, survivors demonstrated higher Ptcco(2) (45 vs 35), higher Ptco(2)/Fio(2) (236 vs 156), and higher predicted SP (89% vs 62%) compared with nonsurvivors at study entry and throughout the monitoring period (all P < .01). For the entire data set, the strongest independent predictors of survival were Ptco(2)/Fio(2) and SP. The area under the receiver operating characteristic curve for mortality prediction was 0.83 for SP and 0.71 for Ptco(2)/Fio(2), compared with 0.6 for heart rate, 0.51 for blood pressure, and 0.53 for CI. Similar hemodynamic patterns were observed for all injury patterns with the exception of those with severe brain injury.
  
  
  CONCLUSIONS
  Thoracic bioimpedance and transcutaneous monitoring give critical real-time hemodynamic and tissue perfusion data that can provide early identification of pathologic flow patterns and accurately predict survival.
authors.affiliation: Division of Trauma and Surgical Critical Care, Los Angeles County Hospital + USC Medical Center, Los Angeles, CA 90033, USA. docmartin2@yahoo.com
authors.forename: Matthew
authors.initials: M
authors.lastname: Martin
authors.forename: Carlos
authors.initials: C
authors.lastname: Brown
authors.forename: David
authors.initials: D
authors.lastname: Bayard
authors.forename: Demetrios
authors.initials: D
authors.lastname: Demetriades
authors.forename: Ali
authors.initials: A
authors.lastname: Salim
authors.forename: Ryan
authors.initials: R
authors.lastname: Gertz
authors.forename: Kenneth
authors.initials: K
authors.lastname: Azarow
authors.forename: Charles C J
authors.initials: CC
authors.lastname: Wo
authors.forename: William
authors.initials: W
authors.lastname: Shoemaker
mesh_terms: D000293:Adolescent; D001775:Blood Circulation; D002245:Carbon Dioxide / Q000032:analysis; D002302:Cardiac Output; D002648:Child; D002675:Child, Preschool; D017097:Electric Impedance; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007223:Infant; D008297:Male; D008991:Monitoring, Physiologic; D010092:Oximetry; D010100:Oxygen / Q000032:analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D012039:Regional Blood Flow; D012129:Respiratory Function Tests; D012720:Severity of Illness Index; D016019:Survival Analysis; D014947:Wounds and Injuries
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen