Cerebral perfusion in sepsis-associated delirium.
BACKGROUND
The pathophysiology of sepsis-associated delirium is not completely understood and the data on cerebral perfusion in sepsis are conflicting. We tested the hypothesis that cerebral perfusion and selected serum markers of inflammation and delirium differ in septic patients with and without sepsis-associated delirium.


METHODS
We investigated 23 adult patients with sepsis, severe sepsis, or septic shock with an extracranial focus of infection and no history of intracranial pathology. Patients were investigated after stabilisation within 48 hours after admission to the intensive care unit. Sepsis-associated delirium was diagnosed using the confusion assessment method for the intensive care unit. Mean arterial pressure (MAP), blood flow velocity (FV) in the middle cerebral artery using transcranial Doppler, and cerebral tissue oxygenation using near-infrared spectroscopy were monitored for 1 hour. An index of cerebrovascular autoregulation was calculated from MAP and FV data. C-reactive protein (CRP), interleukin-6 (IL-6), S-100beta, and cortisol were measured during each data acquisition.


RESULTS
Data from 16 patients, of whom 12 had sepsis-associated delirium, were analysed. There were no significant correlations or associations between MAP, cerebral blood FV, or tissue oxygenation and sepsis-associated delirium. However, we found a significant association between sepsis-associated delirium and disturbed autoregulation (P = 0.015). IL-6 did not differ between patients with and without sepsis-associated delirium, but we found a significant association between elevated CRP (P = 0.008), S-100beta (P = 0.029), and cortisol (P = 0.011) and sepsis-associated delirium. Elevated CRP was significantly correlated with disturbed autoregulation (Spearman rho = 0.62, P = 0.010).


CONCLUSIONS
In this small group of patients, cerebral perfusion assessed with transcranial Doppler and near-infrared spectroscopy did not differ between patients with and without sepsis-associated delirium. However, the state of autoregulation differed between the two groups. This may be due to inflammation impeding cerebrovascular endothelial function. Further investigations defining the role of S-100beta and cortisol in the diagnosis of sepsis-associated delirium are warranted.


BACKGROUND
ClinicalTrials.gov NCT00410111.
Pfister
David
D
Department of Anaesthesia, Operative Intensive Care Unit, University Hospital Basel, Spitalstrasse 21, CH-4031 Basel, Switzerland.
Siegemund
Martin
M
Dell-Kuster
Salome
S
Smielewski
Peter
P
Rüegg
Stephan
S
Strebel
Stephan P
SP
Marsch
Stephan C U
SC
Pargger
Hans
H
Steiner
Luzius A
LA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D001921:Brain / Q000378:metabolism; D002097:C-Reactive Protein / Q000032:analysis; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003693:Delirium / Q000503:physiopathology*; D005260:Female; D006706:Homeostasis; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007362:Intensive Care Units; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000502:physiology; D009414:Nerve Growth Factors / Q000097:blood; D010100:Oxygen / Q000378:metabolism; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood; D018805:Sepsis / Q000503:physiopathology*; D019265:Spectroscopy, Near-Infrared; D017585:Ultrasonography, Doppler, Transcranial
D015415:Biomarkers; D015850:Interleukin-6; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D002097:C-Reactive Protein; D010100:Oxygen; D006854:Hydrocortisone