title: Lack of correlation among intracerebral cytokines, intracranial pressure, and brain tissue oxygenation in patients with traumatic brain injury and diffuse lesions.
abstract: OBJECTIVE
  To determine the evolution of cytokine patterns using microdialysis in patients with traumatic brain injury with diffuse lesions and to study the relationship between cytokines and intracranial pressure, brain tissue oxygenation and lesion type on the computed cranial tomography scan (patients with and without brain swelling).
  
  
  METHODS
  Prospective and observational study.
  
  
  METHODS
  Third-level university hospital.
  
  
  METHODS
  Patients between 15 and 65 yrs with severe traumatic brain injury and a diffuse lesion requiring intracranial pressure and brain tissue oxygenation monitoring were eligible.
  
  
  METHODS
  Microdialysis catheters with a high-cutoff membrane of 100 kDa were inserted.
  
  
  RESULTS
  Sixteen patients were included in the analysis. There was a substantial interindividual variability between cytokine values. The highest concentrations for the interleukin-1β, interleukin-6, and interleukin-8 were measured during the first 24 hrs followed by a gradual decline. The average concentration for interleukin-10 did not vary over time. This pattern is the most frequent in patients with traumatic brain injury with diffuse lesions. The intracranial pressure-cytokines correlation coefficients for the 16 patients varied substantially: interleukin-1β-intracranial pressure (-0.76 to 0.63); interleukin-6-intracranial pressure (-0.83 to 0.78); interleukin-8-intracranial pressure (-0.86 to 0.84); and interleukin-10-intracranial pressure (-0.36 to 0.65). The brain tissue oxygenation-cytokine correlation coefficients, like with intracranial pressure, also varied between patients: interleukin-1β-brain tissue oxygenation (-0.49 to 0.68), interleukin-6-brain tissue oxygenation (-0.99 to 0.84); interleukin-8-brain tissue oxygenation (-0.65 to 0.74); and interleukin-10-brain tissue oxygenation (-0.34 to 0.52). Similarly, we found no difference in the cytokine values inpatient microdialysis with and without swelling in the computed tomographic scan.
  
  
  CONCLUSIONS
  No clear relationship was found between the temporal pattern of cytokines and the behavior of the intracranial pressure, brain tissue oxygenation, and the presence or absence of swelling in the computed tomography scan. This study demonstrates the feasibility of microdialysis in recovering cytokines for a prolonged time, although there may be some nonresolved methodologic problems with this technique when we try to study the inflammation during traumatic brain injury that could affect the results and make interpretation of microdialysis data prone to difficulties.
authors.affiliation: Intensive Care Unit Department, and the Investigation Unit, Son Dureta University Hospital, Palma de Mallorca, Spain. juan.perez@ssib.es
authors.forename: Jon
authors.initials: J
authors.lastname: Perez-Barcena
authors.forename: Javier
authors.initials: J
authors.lastname: Ibáñez
authors.forename: Marta
authors.initials: M
authors.lastname: Brell
authors.forename: Catalina
authors.initials: C
authors.lastname: Crespí
authors.forename: Guiem
authors.initials: G
authors.lastname: Frontera
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Llompart-Pou
authors.forename: Javier
authors.initials: J
authors.lastname: Homar
authors.forename: Josep María
authors.initials: JM
authors.lastname: Abadal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000378:metabolism* / Q000503:physiopathology; D001923:Brain Chemistry; D001930:Brain Injuries / Q000378:metabolism / Q000503:physiopathology*; D016207:Cytokines / Q000032:analysis*; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000032:analysis; D053583:Interleukin-1beta / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D016209:Interleukin-8 / Q000032:analysis; D007427:Intracranial Pressure; D008297:Male; D017551:Microdialysis; D008875:Middle Aged; D010084:Oxidation-Reduction; D011446:Prospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D055815:Young Adult
chemical_list: D016207:Cytokines; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10