title: Brain tissue oxygen tension monitoring in pediatric severe traumatic brain injury. Part 2: Relationship with clinical, physiological, and treatment factors.
abstract: BACKGROUND
  Brain tissue oxygen tension (PbtO(2)) monitoring is used increasingly in adult severe traumatic brain injury (TBI) management. Several factors are known to influence PbtO(2) in adults, but the variables that affect PbtO(2) in pediatric TBI are not well described. This study examines the relationships between PbtO(2) and (1) physiological markers of potential secondary insults commonly used in pediatric TBI, in particular intracranial pressure (ICP), cerebral perfusion pressure (CPP), and systemic hypoxia, and (2) other clinical factors and treatment received that may influence PbtO(2).
  
  
  METHODS
  In this prospective observational study, 52 children (mean age, 6.5 +/- 3.4 years; range, 9 months to 14 years old) with severe TBI and a median post-resuscitation Glasgow Coma Score (GCS) of 5 were managed with continuous PbtO(2) monitoring. The relationships between PbtO(2) parameters (Pbt)(2)(low), PbtO(2) < 5, PbtO(2) < 10, and mPbtAO(2)(24)) and clinical, physiological, and treatment factors were explored using time-linked data and Spearman's correlation coefficients.
  
  
  RESULTS
  No clinical, physiological, or treatment variable was significantly associated with all PbtO(2) parameters, but individual associations were found with initial GCS (PbtO(2) < 5, p = 0.0113), admission Pediatric Trauma Score (PbtO(2) < 10, 0.0175), mICP > 20 (mPbtO(2)(24), p = 0.0377), CPP(low) (PbtO(2)(low), p = 0.0065), CPP < 40 (PbtO(2)(low), p = 0.0269; PbtO(2) < 5, p = 0.0212), P(a)O(2) < 60 (mPbtO(2)(24), p = 0.0037), S(a)O(2) < 90 (PbtO(2)(low), p = 0.0438), and use of inotropes during ICU care (PbtO(2)(low), p = 0.0276; PbtO(2) < 10, p = 0.0277; p = mPbtO(2)(24)).
  
  
  CONCLUSIONS
  Delivery of oxygen to the brain is important to limit secondary neuronal injury after severe TBI. Our data show that PbtO(2) is poorly predicted by clinical and physiological factors commonly measured in the pediatric ICU. Multimodality monitoring may be needed to detect all secondary cerebral insults in pediatric TBI.
authors.affiliation: Divisions of Neurosurgery, School of Child and Adolescent Health, University of Cape Town, Red Cross Children's Hospital, Cape Town, South Africa. Anthony.Figaji@uct.ac.za
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Figaji
authors.forename: Eugene
authors.initials: E
authors.lastname: Zwane
authors.forename: Crispin
authors.initials: C
authors.lastname: Thompson
authors.forename: A Graham
authors.initials: AG
authors.lastname: Fieggen
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Argent
authors.forename: Peter D
authors.initials: PD
authors.lastname: Le Roux
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Peter
mesh_terms: D000293:Adolescent; D001921:Brain / Q000378:metabolism*; D001930:Brain Injuries / Q000378:metabolism* / Q000401:mortality / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007427:Intracranial Pressure; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D010100:Oxygen / Q000378:metabolism*; D011446:Prospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D010100:Oxygen