title: Rapid unexpected brain herniation in association with renal replacement therapy in acute brain injury: caution in the neurocritical care unit.
abstract: BACKGROUND
  We aim to raise awareness for the potential for rapid brain edema and herniation in acutely brain-injured patients undergoing renal replacement therapy (RRT), including one case undergoing continuous veno-venous hemofiltration. Dialysis disequilibrium syndrome (DDS) may have been a possible cause for the brain edema.
  
  
  METHODS
  We retrospectively reviewed four consecutive neurocritically ill patients in acute renal failure undergoing RRT between 2011 and 2013. Imaging, blood pressure, and laboratory data pre-, during, and post-RRT are presented in graphical form. We performed an extensive literature review.
  
  
  RESULTS
  All patients suffered rapidly progressive herniation and death from global brain edema closely related in time to RRT, without other identifiable causes even after detailed review by three neurointensivists. Common clinical symptoms included sudden onset fixed and dilated pupils with apnea, consistent with brain stem compression. Herniation was not reversed by high-dose osmotherapy, and all patients died. Our detailed literature review provides plausible mechanisms for DDS as the most likely cause for our patients' brain edema.
  
  
  CONCLUSIONS
  Even today, sudden brain edema and herniation may occur in association with RRT in neurocritically ill patients. We call for the establishment of RRT guidelines in patients with acute neurological injuries.
authors.affiliation: Department of Neurology (Neurocritical Care), University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA, 01655, USA.
authors.forename: Marcey
authors.initials: M
authors.lastname: Osgood
authors.forename: Rebecca
authors.initials: R
authors.lastname: Compton
authors.forename: Raphael
authors.initials: R
authors.lastname: Carandang
authors.forename: Wiley
authors.initials: W
authors.lastname: Hall
authors.forename: Glenn
authors.initials: G
authors.lastname: Kershaw
authors.forename: Susanne
authors.initials: S
authors.lastname: Muehlschlegel
mesh_terms: D058186:Acute Kidney Injury / Q000628:therapy*; D000293:Adolescent; D001929:Brain Edema / Q000209:etiology*; D001930:Brain Injuries / Q000628:therapy*; D004677:Encephalocele / Q000209:etiology*; D017809:Fatal Outcome; D005260:Female; D006440:Hemofiltration / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017582:Renal Replacement Therapy / Q000009:adverse effects*