title: Bedside cerebral microdialysis monitoring of delayed cerebral hypoperfusion in comatose patients with poor grade aneurysmal subarachnoid haemorrhage.
abstract: BACKGROUND
  Delayed cerebral ischaemia (DCI) is frequent after poor grade aneurysmal subarachnoid haemorrhage (SAH). Owing to the limited accuracy of clinical examination, DCI diagnosis is often based on multimodal monitoring. We examined the value of cerebral microdialysis (CMD) in this setting.
  
  
  METHODS
  20 comatose SAH participants underwent CMD monitoring-for hourly sampling of cerebral extracellular lactate/pyruvate ratio (LPR) and glucose-and brain perfusion CT (PCT). Patients were categorised as DCI when PCT (8±3 days after SAH) showed cerebral hypoperfusion, defined as cerebral blood flow <32.5 mL/100 g/min with a mean transit time >5.7 s. Clinicians were blinded to CMD data; for the purpose of the study, only patients who developed cerebral hypoperfusion in anterior and/or middle cerebral arteries were analysed.
  
  
  RESULTS
  DCI (n=9/20 patients) was associated with higher CMD LPR (51±36 vs 31±10 in patients without DCI, p=0.0007) and lower CMD glucose (0.64±0.34 vs 1.22±1.05, p=0.0005). In patients with DCI, CMD changes over the 18 hours preceding PCT diagnosis revealed a pattern of CMD LPR increase (coefficient +2.96 (95% CI 0.13 to 5.79), p=0.04) with simultaneous CMD glucose decrease (coefficient -0.06 (95% CI -0.08 to -0.01), p=0.03, mixed-effects multilevel regression model). No significant CMD changes were noted in patients without DCI.
  
  
  CONCLUSIONS
  In comatose patients with SAH, delayed cerebral hypoperfusion correlates with a CMD pattern of lactate increase and simultaneous glucose decrease. CMD abnormalities became apparent in the hours preceding PCT, thereby suggesting that CMD monitoring may anticipate targeted therapeutic interventions.
authors.affiliation: Neuroscience Critical Care Research Group, Departments of Intensive Care Medicine, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Camille
authors.initials: C
authors.lastname: Patet
authors.affiliation: Neuroscience Critical Care Research Group, Departments of Intensive Care Medicine, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.|Department of Anesthesia and Critical Care, University Hospital, Nice, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Quintard
authors.affiliation: Department of Radiology, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Zerlauth
authors.affiliation: University of Lausanne, Lausanne, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Maibach
authors.affiliation: Neuroscience Critical Care Research Group, Departments of Intensive Care Medicine, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Laurent
authors.initials: L
authors.lastname: Carteron
authors.affiliation: Neuroscience Critical Care Research Group, Departments of Intensive Care Medicine, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Tamarah
authors.initials: T
authors.lastname: Suys
authors.affiliation: Department of Anesthesia and Critical Care, University Hospital, Grenoble, France.|Neuroscience Institute, Grenoble, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bouzat
authors.affiliation: Division of Neurosurgery, Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Bervini
authors.affiliation: Division of Neurosurgery, Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Levivier
authors.affiliation: Division of Neurosurgery, Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Roy T
authors.initials: RT
authors.lastname: Daniel
authors.affiliation: Neuroscience Critical Care Research Group, Departments of Intensive Care Medicine, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Eckert
authors.affiliation: Department of Radiology, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Reto
authors.initials: R
authors.lastname: Meuli
authors.affiliation: Neuroscience Critical Care Research Group, Departments of Intensive Care Medicine, Centre Hospitalier Universitaire Vaudois (CHUV)-Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Mauro
authors.initials: M
authors.lastname: Oddo
mesh_terms: D000328:Adult; D000368:Aged; D017542:Aneurysm, Ruptured / Q000175:diagnosis* / Q000503:physiopathology; D001786:Blood Glucose / Q000378:metabolism; D001921:Brain / Q000503:physiopathology; D002545:Brain Ischemia / Q000175:diagnosis* / Q000503:physiopathology; D015331:Cohort Studies; D003128:Coma / Q000175:diagnosis* / Q000503:physiopathology; D003422:Critical Care; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000503:physiopathology; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010101:Oxygen Consumption / Q000502:physiology; D000067716:Point-of-Care Testing; D011446:Prospective Studies; D019289:Pyruvic Acid / Q000378:metabolism; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed
chemical_list: D001786:Blood Glucose; D019344:Lactic Acid; D019289:Pyruvic Acid