title: Outcomes and complications of intracranial pressure monitoring in acute liver failure: a retrospective cohort study.
abstract: OBJECTIVE
  To determine if intracranial pressure monitor placement in patients with acute liver failure is associated with significant clinical outcomes.
  
  
  METHODS
  Retrospective multicenter cohort study.
  
  
  METHODS
  Academic liver transplant centers comprising the U.S. Acute Liver Failure Study Group.
  
  
  METHODS
  Adult critically ill patients with acute liver failure presenting with grade III/IV hepatic encephalopathy (n = 629) prospectively enrolled between March 2004 and August 2011.
  
  
  METHODS
  Intracranial pressure monitored (n = 140) versus nonmonitored controls (n = 489).
  
  
  RESULTS
  Intracranial pressure monitored patients were younger than controls (35 vs 43 yr, p < 0.001) and more likely to be on renal replacement therapy (52% vs 38%, p = 0.003). Of 87 intracranial pressure monitored patients with detailed information, 44 (51%) had evidence of intracranial hypertension (intracranial pressure > 25 mm Hg) and overall 21-day mortality was higher in patients with intracranial hypertension (43% vs 23%, p = 0.05). During the first 7 days, intracranial pressure monitored patients received more intracranial hypertension-directed therapies (mannitol, 56% vs 21%; hypertonic saline, 14% vs 7%; hypothermia, 24% vs 10%; p < 0.03 for each). Forty-one percent of intracranial pressure monitored patients received liver transplant (vs 18% controls; p < 0.001). Overall 21-day mortality was similar (intracranial pressure monitored 33% vs controls 38%, p = 0.24). Where data were available, hemorrhagic complications were rare in intracranial pressure monitored patients (4 of 56 [7%]; three died). When stratifying by acetaminophen status and adjusting for confounders, intracranial pressure monitor placement did not impact 21-day mortality in acetaminophen patients (p = 0.89). However, intracranial pressure monitor was associated with increased 21-day mortality in nonacetaminophen patients (odds ratio, ~ 3.04; p = 0.014).
  
  
  CONCLUSIONS
  In intracranial pressure monitored patients with acute liver failure, intracranial hypertension is commonly observed. The use of intracranial pressure monitor in acetaminophen acute liver failure did not confer a significant 21-day mortality benefit, whereas in nonacetaminophen acute liver failure, it may be associated with worse outcomes. Hemorrhagic complications from intracranial pressure monitor placement were uncommon and cannot account for mortality trends. Although our results cannot conclusively confirm or refute the utility of intracranial pressure monitoring in patients with acute liver failure, patient selection and ancillary assessments of cerebral blood flow likely have a significant role. Prospective studies would be required to conclusively account for confounding by illness severity and transplant.
authors.affiliation: Divisions of Hepatology and Critical Care Medicine, University of Alberta, Edmonton, AB, Canada. 2Division of Gastroenterology, University of California, San Francisco, CA. 3Faculty of Medicine, Medical University of South Carolina, Charleston, SC. 4Division of Digestive and Liver Diseases, University of Texas Southwestern Medical Center, Dallas, TX.
authors.forename: Constantine J
authors.initials: CJ
authors.lastname: Karvellas
authors.forename: Oren K
authors.initials: OK
authors.lastname: Fix
authors.forename: Holly
authors.initials: H
authors.lastname: Battenhouse
authors.forename: Valerie
authors.initials: V
authors.lastname: Durkalski
authors.forename: Corron
authors.initials: C
authors.lastname: Sanders
authors.forename: William M
authors.initials: WM
authors.lastname: Lee
mesh_terms: D000082:Acetaminophen / Q000627:therapeutic use; D000328:Adult; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006501:Hepatic Encephalopathy / Q000401:mortality*; D006801:Humans; D019586:Intracranial Hypertension / Q000209:etiology* / Q000401:mortality / Q000628:therapy; D007427:Intracranial Pressure / Q000502:physiology*; D017114:Liver Failure, Acute / Q000401:mortality* / Q000628:therapy; D016031:Liver Transplantation / Q000401:mortality; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000009:adverse effects; D015999:Multivariate Analysis; D012042:Registries; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000082:Acetaminophen