title: Intracranial pressure variability predicts short-term outcome after intracerebral hemorrhage: a retrospective study.
abstract: BACKGROUND
  Elevated intracranial pressure (ICP) is generally observed in brain injury and intracerebral hemorrhage (ICH) patients and is consistently associated with poor neurological outcome. Intracranial pressure variability (IPV) is a better predictor of long-term neurological outcome than mean ICP in traumatic brain injury patients. However, whether IPV regulates functional outcome in ICH patients has not been investigated. In the present study, we investigated the relationship between IPV and functional outcome in ICH patients and determined whether IPV is a valid predictor of neurological outcome in ICH patients.
  
  
  METHODS
  A consecutive series of 56 patients with ICH were enrolled in this study. These patients underwent surgical treatments and were planted with an ICP monitor. The ICP was continuously recorded for 7 days at one-hour intervals. The mean arterial blood pressure (MAP) and cerebral perfusion pressure (CPP) were also calculated. We used successive variation (SV) to represent IPV, which was calculated by averaging the difference in ICP between successive parameters. The short-term outcome was dichotomized into improved and deteriorated groups based on the changes in their Glasgow Coma Scale (GCS) score between admission and 30 days after admission. The long-term outcome was evaluated by Glasgow Outcome Scale (GOS) at 12 months after discharge from the hospital, and the patients were dichotomized into independent and dependent groups.
  
  
  RESULTS
  The results showed that IPV was lower in the improved patient group and higher in patients with poorer outcome at 30 days after ICH. There was a significant positive correlation between SV and short-term neurological outcome. We also found the in-patient mortality was significantly increased in the high IPV patient group (P=0.02), which was divided by the cutoff point using receiver operating characteristic (ROC) curve analysis. The univariate correlation analysis demonstrated that the IPV levels were positively correlated with mean ICP (R(2)=0.652, P=0.000), while were negatively correlated with CPP (R(2)=0.426, P=0.000). Increases in SV of ICP were a predictor of 30-day poor short-term outcome, but not for 12-month long-term outcome after adjusting for the potential confounders in a multivariable logistic regression model.
  
  
  CONCLUSIONS
  The results suggest that high IPV is correlated with poorer outcome in ICH patients. Managing the ICP at an appropriate level during the early phase after ICH may improve functional outcome in ICH patients.
authors.affiliation: Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052, China. yetian1986@gmail.com
authors.forename: Ye
authors.initials: Y
authors.lastname: Tian
authors.forename: Zengguang
authors.initials: Z
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Jia
authors.forename: Shengjie
authors.initials: S
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Shizhao
authors.initials: S
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Sun
authors.forename: Jianning
authors.initials: J
authors.lastname: Zhang
authors.forename: Jieli
authors.initials: J
authors.lastname: Chen
authors.forename: Rongcai
authors.initials: R
authors.lastname: Jiang
mesh_terms: D000368:Aged; D000465:Algorithms; D001794:Blood Pressure / Q000502:physiology; D004558:Electric Stimulation; D005260:Female; D015600:Glasgow Coma Scale; D023261:Glasgow Outcome Scale; D006801:Humans; D020300:Intracranial Hemorrhages / Q000150:complications / Q000503:physiopathology*; D007427:Intracranial Pressure / Q000502:physiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009422:Nervous System Diseases / Q000209:etiology / Q000503:physiopathology; D012372:ROC Curve; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome