title: Transcranial doppler assessment of cerebral perfusion in critically ill septic patients: a pilot study.
abstract: BACKGROUND
  The aim of this study is to evaluate the feasibility and efficacy of Transcranial Doppler (TCD) in assessing cerebral perfusion changes in septic patients.
  
  
  METHODS
  Using TCD, we measured the mean velocity in the middle cerebral artery (VmMCA, cm/sec) and calculated the pulsatility index (PI), resistance index (RI) and cerebral blood flow index (CBFi = 10*MAP/1.47(PI)) on the first day of patients' admission or on the first day of sepsis development; measurements were repeated on the second day. Sepsis was defined according to standard criteria.
  
  
  RESULTS
  Forty-one patients without any known neurologic deficit treated in our 24-bed Critical Care Unit were assessed (Sepsis Group = 20, Control Group = 21). Examination was feasible in 91% of septic and 85% of non-septic patients (p = 0.89). No difference was found between the two groups in mean age, mean arterial pressure (MAP) or APACHE II score. The pCO2 values were higher in septic patients (46 ± 12 vs. 39 ± 4 mmHg p < 0.01). No statistically significant higher values of VmMCA were found in septic patients (110 ± 34 cm/sec vs. 99 ± 28 cm/sec p = 0.17). Higher values of PI and RI were found in septic patients (1.15 ± 0.25 vs. 0.98 ± 0.16 p < 0.01, 0.64 ± 0.08 vs. 0.59 ± 0.06 p < 0.01, respectively). No statistically significant lower values of CBFi were found in septic patients (497 ± 116 vs. 548 ± 110 p = 0.06).
  
  
  CONCLUSIONS
  Our results suggest cerebral vasoconstriction in septic compared to non-septic patients. TCD is an efficient and feasible exam to evaluate changes in cerebral perfusion during sepsis.
authors: Department of Intensive Care, Université Catholique de Louvain, Mont-Godinne University Hospital, Avenue Docteur G., Thérasse 1, Yvoir 5530, Belgium.
authors: Charalampos
authors: C
authors: Pierrakos
authors: Department of Intensive Care, Université Catholique de Louvain, Mont-Godinne University Hospital, Avenue Docteur G., Thérasse 1, Yvoir 5530, Belgium.
authors: Aurélie
authors: A
authors: Antoine
authors: Department of Internal Medicine, University Hospital of Patras, Patras Rio 26504, Greece.
authors: Dimitrios
authors: D
authors: Velissaris
authors: Department of Intensive Care, Université Catholique de Louvain, Mont-Godinne University Hospital, Avenue Docteur G., Thérasse 1, Yvoir 5530, Belgium.
authors: Isabelle
authors: I
authors: Michaux
authors: Department of Intensive Care, Université Catholique de Louvain, Mont-Godinne University Hospital, Avenue Docteur G., Thérasse 1, Yvoir 5530, Belgium.
authors: Pierre
authors: P
authors: Bulpa
authors: Department of Intensive Care, Université Catholique de Louvain, Mont-Godinne University Hospital, Avenue Docteur G., Thérasse 1, Yvoir 5530, Belgium.
authors: Patrick
authors: P
authors: Evrard
authors: Department of Neurology, Université Catholique de Louvain, Mont-Godinne University Hospital, Avenue Docteur G., Thérasse 1, Yvoir 5530, Belgium.
authors: Michel
authors: M
authors: Ossemann
authors: Department of Intensive Care, Université Catholique de Louvain, Mont-Godinne University Hospital, Avenue Docteur G., Thérasse 1, Yvoir 5530, Belgium.
authors: Alain
authors: A
authors: Dive
keywords: Cerebral microcirculation; Cerebral vasoconstriction; Encephalopathy; Pulsatility index; Resistance index; Sepsis
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