title: The Effect of Positive End-Expiratory Pressure on Intracranial Pressure and Cerebral Hemodynamics.
abstract: Lung protective ventilation has not been evaluated in patients with brain injury. It is unclear whether applying positive end-expiratory pressure (PEEP) adversely affects intracranial pressure (ICP) and cerebral perfusion pressure (CPP). We aimed to evaluate the effect of PEEP on ICP and CPP in a large population of patients with acute brain injury and varying categories of acute lung injury, defined by PaO2/FiO2.
  
  
  
  Retrospective data were collected from 341 patients with severe acute brain injury admitted to the ICU between 2008 and 2015. These patients experienced a total of 28,644 paired PEEP and ICP observations. Demographic, hemodynamic, physiologic, and ventilator data at the time of the paired PEEP and ICP observations were recorded.
  
  
  
  In the adjusted analysis, a statistically significant relationship between PEEP and ICP and PEEP and CPP was found only among observations occurring during periods of severe lung injury. For every centimeter H2O increase in PEEP, there was a 0.31 mmHg increase in ICP (p = 0.04; 95 % CI [0.07, 0.54]) and a 0.85 mmHg decrease in CPP (p = 0.02; 95 % CI [-1.48, -0.22]).
  
  
  
  Our results suggest that PEEP can be applied safely in patients with acute brain injury as it does not have a clinically significant effect on ICP or CPP. Further prospective studies are required to assess the safety of applying a lung protective ventilation strategy in brain-injured patients with lung injury.
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, MA, 02215, USA. mboone@bidmc.harvard.edu.
authors.forename: Myles D
authors.initials: MD
authors.lastname: Boone
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, MA, 02215, USA.
authors.forename: Sayuri P
authors.initials: SP
authors.lastname: Jinadasa
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, MA, 02215, USA.
authors.forename: Ariel
authors.initials: A
authors.lastname: Mueller
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, MA, 02215, USA.
authors.forename: Shahzad
authors.initials: S
authors.lastname: Shaefi
authors.affiliation: Department of Surgery, Division of Neurosurgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: Ekkehard M
authors.initials: EM
authors.lastname: Kasper
authors.affiliation: Department of Neurology, Division of Neurocritical Care, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: Khalid A
authors.initials: KA
authors.lastname: Hanafy
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, MA, 02215, USA.
authors.forename: Brian P
authors.initials: BP
authors.lastname: O'Gara
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, MA, 02215, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Talmor
mesh_terms: D000328:Adult; D000368:Aged; D062186:Arterial Pressure / Q000502:physiology*; D001930:Brain Injuries / Q000628:therapy*; D000070642:Brain Injuries, Traumatic / Q000628:therapy*; D002543:Cerebral Hemorrhage / Q000628:therapy*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration / Q000379:methods*; D013345:Subarachnoid Hemorrhage / Q000628:therapy; D016896:Treatment Outcome
keywords: Acute brain injury; Acute respiratory distress syndrome; Cerebral perfusion pressure; Intracranial hypertension; Intracranial pressure; Mechanical ventilation