title: Cerebral hemodynamics in sepsis assessed by transcranial Doppler: a systematic review and meta-analysis.
abstract: Cerebral microcirculation is gradually compromised during sepsis, with significant reductions in the function of capillaries and blood perfusion in small vessels. Transcranial Doppler ultrasound (TCD) has been used to assess cerebral circulation in a typical clinical setting. This study was to systematically review TCD studies, assess their methodological quality, and identify trends that can be associated with the temporal evolution of sepsis and its clinical outcome. A meta-analysis of systematic reviews was conducted according to the PRISMA statement. Articles were searched from 1982 until the conclusion of this review in December 2015. Twelve prospective and observational studies were selected. Evaluations of cerebral blood flow, cerebral autoregulation, and carbon dioxide (CO2) vasoreactivity were summarized. A temporal pattern of the evolution of the illness was found. In early sepsis, the median blood flow velocity (Vm) and pulsatility index (PI) increased, and the cerebral autoregulation (CA) remained unchanged. In contrast, Vm normalization, PI reduction and CA impairment were found in later sepsis (patients with severe sepsis or septic shock). Cerebral haemodynamic is impaired in sepsis. Modifications in cerebral blood flow may be consequence to the endothelial dysfunction of the microvasculature induced by the release of inflammatory mediators. A better understanding of cerebral hemodynamics may improve the clinical management of patients with sepsis and, consequently, improve clinical outcomes.
authors.affiliation: Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, Avenida Doutor Arnaldo, 455, Cerqueira César, São Paulo, SP, CEP 01246-904, Brazil.
authors.forename: Daniel Silva
authors.initials: DS
authors.lastname: de Azevedo
authors.affiliation: Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, Avenida Doutor Arnaldo, 455, Cerqueira César, São Paulo, SP, CEP 01246-904, Brazil.
authors.forename: Angela Salomao Macedo
authors.initials: ASM
authors.lastname: Salinet
authors.affiliation: Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, Avenida Doutor Arnaldo, 455, Cerqueira César, São Paulo, SP, CEP 01246-904, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: de Lima Oliveira
authors.affiliation: Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, Avenida Doutor Arnaldo, 455, Cerqueira César, São Paulo, SP, CEP 01246-904, Brazil.
authors.forename: Manoel Jacobsen
authors.initials: MJ
authors.lastname: Teixeira
authors.affiliation: Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, Avenida Doutor Arnaldo, 455, Cerqueira César, São Paulo, SP, CEP 01246-904, Brazil. edsonshu@gmail.com.
authors.forename: Edson
authors.initials: E
authors.lastname: Bor-Seng-Shu
authors.affiliation: Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, Avenida Doutor Arnaldo, 455, Cerqueira César, São Paulo, SP, CEP 01246-904, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: de Carvalho Nogueira
mesh_terms: D001783:Blood Flow Velocity; D001921:Brain / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D006439:Hemodynamics; D006801:Humans; D007249:Inflammation; D008833:Microcirculation; D064887:Observational Studies as Topic; D011446:Prospective Studies; D018805:Sepsis / Q000503:physiopathology; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial; D014665:Vasodilator Agents / Q000737:chemistry
chemical_list: D014665:Vasodilator Agents
keywords: Cerebral autoregulation in sepsis; Cerebral hemodinamycs in sespsis; Transcranial Doppler in sepsis