title: Acute traumatic intraparenchymal hemorrhage: risk factors for progression in the early post-injury period.
abstract: OBJECTIVE
  To characterize the natural course of traumatic intraparenchymal contusions and hematomas (IPHs) and to identify risk factors for IPH progression in the acute post-injury period.
  
  
  METHODS
  A retrospective analysis was performed on a prospective observational database containing 113 head trauma patients exhibiting 229 initially nonoperated acute IPHs. The main outcome variable was radiographic evidence of IPH progression on serially obtained head computed tomographic (CT) scans. Secondary outcomes included the actual amount of IPH growth and later surgical evacuation. Univariate and multivariate analyses (using a generalized estimate equation) were applied to both demographic and initial radiographic features to identify risk factors for IPH progression and surgery.
  
  
  RESULTS
  Overall, 10 IPHs (4%) shrank, 133 (58%) remained unchanged, and 86 (38%) grew between the first and second head CT scan. IPH progression was independently associated with the presence of subarachnoid hemorrhage (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.12-2.3), presence of a subdural hematoma (OR, 1.94; 95% CI, 1.1-3.43), and initial size (OR, 1.11; 95% CI, 1.02-1.21, for each cm volume). Size of initial IPH proportionately correlated with the amount of subsequent growth (linear regression, P < 0.001). Worsened Glasgow Coma Score between initial and follow-up head CT scan (OR, 8.6; 95% CI, 1.5-50), IPH growth greater than 5 cm (OR, 7.3; 95% CI, 1.6-34), and effacement of basal cisterns on initial CT scan (OR, 9.0; 95% CI, 1.5-52) were strongly associated with late surgical evacuation.
  
  
  CONCLUSIONS
  A large proportion of IPHs progress in the acute post-injury period. IPHs associated with subarachnoid hemorrhage, a subdural hematoma, or large initial size should be monitored carefully for progression with repeat head CT imaging. Effacement of cisterns on the initial head CT scan was strongly predictive of failure of nonoperative management, thereby leading to surgical evacuation. These findings should be important factors in the understanding and management of IPH.
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco General Hospital, San Francisco, California, USA. echang@itsa.ucsf.edu
authors.forename: Edward F
authors.initials: EF
authors.lastname: Chang
authors.forename: Michele
authors.initials: M
authors.lastname: Meeker
authors.forename: Martin C
authors.initials: MC
authors.lastname: Holland