title: Observation of Autoregulation Indices During Ventricular CSF Drainage After Aneurysmal Subarachnoid Hemorrhage: A Pilot Study.
abstract: BACKGROUND
  Cerebral autoregulation is increasingly recognized as a factor that requires evaluation when managing poor grade aneurysmal subarachnoidal hemorrhage (aSAH) patients. In this single center pilot study, we investigated whether intraventricular intracranial pressure (ICP) derived when extraventricular drain (EVD) is open can be used to calculate dynamic autoregulation estimates in ICU aSAH patients.
  
  
  METHODS
  Ten patients with the diagnosis of aSAH as confirmed by computed tomography (CT) and CT-angiography were enrolled. ICP was monitored via a transducer connected to the most proximal side exit of the EVD catheter. From at least 30 min periods of brain monitoring before, during, and after temporarily EVD closure, commonly used indexes of dynamic cerebral autoregulation were calculated.
  
  
  RESULTS
  Preserved pulsatile ICP signals were seen with open EVD. There were no significant changes in parameters describing cerebral autoregulation between EVD open and closed conditions. Power spectra of ABP and ICP showed no significant changes for the selected frequency ranges. There was a small significant increase in absolute ICP [2.4 (3.8) mmHg, p < 0.001] upon short-term EVD closure. Cerebral spinal reserve capacity (RAP index) worsened significantly by short-term EVD closure.
  
  
  CONCLUSIONS
  Due to preserved slow fluctuations in the ICP signal, an open EVD system can be used to calculate dynamic autoregulation indices in aSAH patients requiring intensive care monitoring with the pressure measurement from the most proximal part of drain. If these results are confirmed in larger study, this technique can open the way for investigating the role of autoregulation disturbance in aSAH patients.
authors: Department of Critical Care Groningen, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. m.j.h.aries@umcg.nl.|Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. m.j.h.aries@umcg.nl.
authors: Marcel J H
authors: MJ
authors: Aries
authors: Department of Critical Care Groningen, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.|Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors: Sytse F
authors: SF
authors: de Jong
authors: Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors: J Marc C
authors: JM
authors: van Dijk
authors: Department of Critical Care Groningen, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors: Joost
authors: J
authors: Regtien
authors: Department of Neurosurgery, University of Leuven, Louvain, Belgium.
authors: Bart
authors: B
authors: Depreitere
authors: Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
authors: Marek
authors: M
authors: Czosnyka
authors: Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
authors: Peter
authors: P
authors: Smielewski
authors: Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors: Jan Willem J
authors: JW
authors: Elting
mesh_terms: D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications*; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods*; D010865:Pilot Projects; D013345:Subarachnoid Hemorrhage / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery; D014696:Ventriculostomy
keywords: Aneurysmal subarachnoïdal hemorrhage; Autoregulation; Cerebrospinal fluid drainage; Cerebrovascular pressure reactivity