title: Effects of the neurological wake-up test on clinical examination, intracranial pressure, brain metabolism and brain tissue oxygenation in severely brain-injured patients.
abstract: BACKGROUND
  Daily interruption of sedation (IS) has been implemented in 30 to 40% of intensive care units worldwide and may improve outcome in medical intensive care patients. Little is known about the benefit of IS in acutely brain-injured patients.
  
  
  METHODS
  This prospective observational study was performed in a neuroscience intensive care unit in a tertiary-care academic center. Twenty consecutive severely brain-injured patients with multimodal neuromonitoring were analyzed for levels of brain lactate, pyruvate and glucose, intracranial pressure (ICP), cerebral perfusion pressure (CPP) and brain tissue oxygen tension (PbtO2) during IS trials.
  
  
  RESULTS
  Of the 82 trial days, 54 IS-trials were performed as interruption of sedation and analgesics were not considered safe on 28 days (34%). An increase in the FOUR Score (Full Outline of UnResponsiveness score) was observed in 50% of IS-trials by a median of three (two to four) points. Detection of a new neurologic deficit occurred in one trial (2%), and in one-third of IS-trials the trial had to be stopped due to an ICP-crisis (> 20 mmHg), agitation or systemic desaturation. In IS-trials that had to be aborted, a significant increase in ICP and decrease in PbtO2 (P < 0.05), including 67% with critical values of PbtO2 < 20 mmHg, a tendency to brain metabolic distress (P < 0.07) was observed.
  
  
  CONCLUSIONS
  Interruption of sedation revealed new relevant clinical information in only one trial and a large number of trials could not be performed or had to be stopped due to safety issues. Weighing pros and cons of IS-trials in patients with acute brain injury seems important as related side effects may overcome the clinical benefit.
authors.forename: Raimund
authors.initials: R
authors.lastname: Helbok
authors.forename: Pedro
authors.initials: P
authors.lastname: Kurtz
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Schmidt
authors.forename: Morgan R
authors.initials: MR
authors.lastname: Stuart
authors.forename: Luis
authors.initials: L
authors.lastname: Fernandez
authors.forename: Sander E
authors.initials: SE
authors.lastname: Connolly
authors.forename: Kiwon
authors.initials: K
authors.lastname: Lee
authors.forename: Erich
authors.initials: E
authors.lastname: Schmutzhard
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Mayer
authors.forename: Jan
authors.initials: J
authors.lastname: Claassen
authors.forename: Neeraj
authors.initials: N
authors.lastname: Badjatia
mesh_terms: D000328:Adult; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D001930:Brain Injuries / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D054810:Deep Sedation / Q000379:methods*; D005260:Female; D005947:Glucose / Q000032:analysis; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology*; D019344:Lactic Acid / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000379:methods*; D010043:Outcome and Process Assessment, Health Care; D010100:Oxygen / Q000032:analysis; D011446:Prospective Studies; D019289:Pyruvic Acid / Q000032:analysis; D014851:Wakefulness / Q000502:physiology
chemical_list: D019344:Lactic Acid; D019289:Pyruvic Acid; D005947:Glucose; D010100:Oxygen