title: Optimal Cerebral Perfusion Pressure Management at Bedside: A Single-Center Pilot Study.
abstract: BACKGROUND
  Guidelines recommend cerebral perfusion pressure (CPP) values of 50-70 mmHg and intracranial pressure lower than 20 mmHg for the management of acute traumatic brain injury (TBI). However, adequate individual targets are still poorly addressed, since patients have different perfusion thresholds. Bedside assessment of cerebral autoregulation may help to optimize individual CPP-guided treatment.
  
  
  OBJECTIVE
  To assess staff compliance and outcome impact of a new method of autoregulation-guided treatment (CPPopt) based on continuous evaluation of cerebrovascular reactivity (PRx).
  
  
  METHODS
  Prospective pilot study of severe TBI adult patients managed with continuous multimodal brain monitoring in a single Neurocritical Care Unit (NCCU). Every minute CPPopt was automatically estimated, based on the previous 4-h window, as the CPP with the lowest PRx indicating the best cerebrovascular pressure reactivity. Patients were managed with CPPopt targets whenever possible and otherwise CPP was managed following general/international guidelines. In addition, other offline CPPopt estimates were calculated using cerebral oximetry (COx-CPPopt), brain tissue oxygenation (ORxs-CPPopt), and cerebral blood flow (CBFx-CPPopt).
  
  
  RESULTS
  Eighteen patients with a total multimodal brain monitoring time of 5,520 h were enrolled. During the total monitoring period, 11 patients (61 %) had a CPPopt U-shaped curve, 5 patients (28 %) had either ascending or descending curves, and only 2 patients (11 %) had no fitted curve. Real CPP correlated significantly with calculated CPPopt (r = 0.83, p < 0.0001). Preserved autoregulation was associated with greater Glasgow coma score on admission (p = 0.01) and better outcome (p = 0.01). We demonstrated that patients with the larger discrepancy (>10 mm Hg) between real CPP and CPPopt more likely have had adverse outcome (p = 0.04). Comparison between CPPopt and the other estimates revealed similar limits of precision. The lowest bias (-0.1 mmHg) was obtained with COx-CPPopt (NIRS).
  
  
  CONCLUSIONS
  Targeted individual CPP management at the bedside using cerebrovascular pressure reactivity seems feasible. Large deviation from CPPopt seems to be associated with adverse outcome. The COx-CPPopt methodology using non-invasive CO (NIRS) warrants further evaluation.
authors.affiliation: Neurocritical Care Unit, Intensive Care Department, Hospital Sao Joao, Porto, Portugal, mceleste.dias@gmail.com.
authors.forename: Celeste
authors.initials: C
authors.lastname: Dias
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Silva
authors.forename: Eduarda
authors.initials: E
authors.lastname: Pereira
authors.forename: Elisabete
authors.initials: E
authors.lastname: Monteiro
authors.forename: Isabel
authors.initials: I
authors.lastname: Maia
authors.forename: Silvina
authors.initials: S
authors.lastname: Barbosa
authors.forename: Sofia
authors.initials: S
authors.lastname: Silva
authors.forename: Teresa
authors.initials: T
authors.lastname: Honrado
authors.forename: António
authors.initials: A
authors.lastname: Cerejo
authors.forename: Marcel J H
authors.initials: MJ
authors.lastname: Aries
authors.forename: Peter
authors.initials: P
authors.lastname: Smielewski
authors.forename: José-Artur
authors.initials: JA
authors.lastname: Paiva
authors.forename: Marek
authors.initials: M
authors.lastname: Czosnyka
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D001930:Brain Injuries / Q000175:diagnosis* / Q000628:therapy; D002560:Cerebrovascular Circulation / Q000502:physiology*; D019468:Disease Management; D005260:Female; D019983:Guideline Adherence / Q000592:standards*; D006706:Homeostasis; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000592:standards*; D017063:Outcome Assessment, Health Care; D010865:Pilot Projects