title: An evaluation and comparison of intraventricular, intraparenchymal, and fluid-coupled techniques for intracranial pressure monitoring in patients with severe traumatic brain injury.
abstract: OBJECTIVE
  Intracranial pressure measurements have become one of the mainstays of traumatic brain injury management. Various technologies exist to monitor intracranial pressure from a variety of locations. Transducers are usually placed to assess pressure in the brain parenchyma and the intra-ventricular fluid, which are the two most widely accepted compartmental monitoring sites. The individual reliability and inter-reliability of these devices with and without cerebrospinal fluid diversion is not clear. The predictive capability of monitors in both of these sites to local, regional, and global changes also needs further clarification. The technique of monitoring intraventricular pressure with a fluid-coupled transducer system is also reviewed. There has been little investigation into the relationship among pressure measurements obtained from these two sources using these three techniques.
  
  
  METHODS
  Eleven consecutive patients with severe, closed traumatic brain injury not requiring intracranial mass lesion evacuation were admitted into this prospective study. Each patient underwent placement of a parenchymal and intraventricular pressure monitor. The ventricular catheter tubing was also connected to a sensor for fluid-coupled measurement. Pressure from all three sources was measured hourly with and without ventricular drainage.
  
  
  RESULTS
  Statistically significant correlation within each monitoring site was seen. No monitoring location was more predictive of global pressure changes or more responsive to pressure changes related to patient stimulation. However, the intraventricular pressure measurements were not reliable in the presence of cerebrospinal fluid drainage whereas the parenchymal measurements remained unaffected.
  
  
  CONCLUSIONS
  Intraparenchymal pressure monitoring provides equivalent, statistically similar pressure measurements when compared to intraventricular monitors in all care and clinical settings. This is particularly valuable when uninterrupted cerebrospinal fluid drainage is desirable.
authors.affiliation: Department of Neurosurgery, Medical College of Georgia, BI 3088, 1120 15th St, 30912, Augusta, Georgia. jvender@mail.mcg.edu
authors.forename: John
authors.initials: J
authors.lastname: Vender
authors.forename: Jennifer
authors.initials: J
authors.lastname: Waller
authors.forename: Krishnan
authors.initials: K
authors.lastname: Dhandapani
authors.forename: Dennis
authors.initials: D
authors.lastname: McDonnell
mesh_terms: D001930:Brain Injuries / Q000503:physiopathology*; D015170:Cerebrospinal Fluid Pressure; D006801:Humans; D007427:Intracranial Pressure; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012212:Rheology; D014160:Transducers, Pressure; D017725:Ventricular Pressure