Marie-Hélène Masse1,2, Marie Anne Richard3, Frédérick D'Aragon1,2,4, Charles St-Arnaud1,5, Michael Mayette1,5, Neill K J Adhikari6,7, William Fraser2,8, André Carpentier2,9, Steven Palanchuck5, David Gauthier4, Luc Lanthier5, Matthieu Touchette5, Albert Lamontagne10, Jean Chénard11, Sangeeta Mehta12, Yanick Sansoucy4, Etienne Croteau2,3, Martin Lepage2,3, François Lamontagne1,2,5. 1. Department of Medicine/Division of Critical Care Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada. 2. Centre de recherche du CHUS, Sherbrooke, QC, Canada. 3. Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, QC, Canada. 4. Department of Anesthesiology, Université de Sherbrooke, Sherbrooke, QC, Canada. 5. Department of Medicine/Division of Internal Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada. 6. Department of Critical Care Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada. 7. Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada. 8. Department of Gynecology/Obstetrics, Université de Sherbrooke, Sherbrooke, QC, Canada. 9. Department of Medicine/Division of Endocrinology, Université de Sherbrooke, Sherbrooke, QC, Canada. 10. Department of Medicine/Division of Neurology, Université de Sherbrooke, Sherbrooke, QC, Canada. 11. Department of Diagnostic Radiology, Université de Sherbrooke, Sherbrooke, QC, Canada. 12. Interdepartmental Division of Critical Care Medicine, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada.
Abstract
OBJECTIVES: Mechanisms underlying sepsis-associated encephalopathy remain unclear, but reduced cerebral blood flow, alone or in conjunction with altered autoregulation, is reported as a potential contributor. We compared cerebral blood flow of control subjects and vasopressor-dependent septic patients. DESIGN: Randomized crossover study. SETTING: MRI with arterial spin labeling. PATIENTS: Ten sedated septic patients on mechanical ventilation (four with controlled chronic hypertension) and 12 control subjects (six with controlled chronic hypertension) were enrolled. Mean ± SD ages were 61.4 ± 10.2 and 44.2 ± 12.8 years, respectively (p = 0.003). Mean Acute Physiology and Chronic Health Evaluation II score of septic patients at ICU admission was 27.7 ± 6.6. INTERVENTIONS: To assess the potential confounding effects of sedation and mean arterial pressure, we measured cerebral blood flow with and without sedation with propofol in control subjects and at a targetmean arterial pressure of 65 mm Hg and greater than or equal to 75 mm Hg in septic patients. The sequence of sedation versus no sedation and mean arterial pressure targets were randomized. MEASUREMENTS AND MAIN RESULTS: In septic patients, cerebral blood flow measured at a mean arterial pressure target of 65 mm Hg (40.4 ± 10.9 mL/100 g/min) was not different from cerebral blood flow measured at a mean arterial pressure target of greater than or equal to 75 mm Hg (41.3 ± 9.8 mL/100 g/min; p = 0.65). In control subjects, we observed no difference in cerebral blood flow measured without and with sedation (24.8 ± 4.2 vs 24.9 ± 5.9 mL/100 g/min; p = 0.93). We found no interaction between chronic hypertension and the effect of sedation or mean arterial pressure targets. Cerebral blood flow measured in sedated septic patients (mean arterial pressure target 65 mm Hg) was 62% higher than in sedated control subjects (p = 0.001). CONCLUSIONS: In septic patients, cerebral blood flow was higher than in sedated control subjects and did not vary with mean arterial pressure targets. Further research is required to understand the clinical significance of cerebral hyperperfusion in septic patients on vasopressors and to reassess the neurologic effects of current mean arterial pressure targets in sepsis.
RCT Entities:
OBJECTIVES: Mechanisms underlying sepsis-associatedencephalopathy remain unclear, but reduced cerebral blood flow, alone or in conjunction with altered autoregulation, is reported as a potential contributor. We compared cerebral blood flow of control subjects and vasopressor-dependent septic patients. DESIGN: Randomized crossover study. SETTING: MRI with arterial spin labeling. PATIENTS: Ten sedated septic patients on mechanical ventilation (four with controlled chronic hypertension) and 12 control subjects (six with controlled chronic hypertension) were enrolled. Mean ± SD ages were 61.4 ± 10.2 and 44.2 ± 12.8 years, respectively (p = 0.003). Mean Acute Physiology and Chronic Health Evaluation II score of septic patients at ICU admission was 27.7 ± 6.6. INTERVENTIONS: To assess the potential confounding effects of sedation and mean arterial pressure, we measured cerebral blood flow with and without sedation with propofol in control subjects and at a target mean arterial pressure of 65 mm Hg and greater than or equal to 75 mm Hg in septic patients. The sequence of sedation versus no sedation and mean arterial pressure targets were randomized. MEASUREMENTS AND MAIN RESULTS: In septic patients, cerebral blood flow measured at a mean arterial pressure target of 65 mm Hg (40.4 ± 10.9 mL/100 g/min) was not different from cerebral blood flow measured at a mean arterial pressure target of greater than or equal to 75 mm Hg (41.3 ± 9.8 mL/100 g/min; p = 0.65). In control subjects, we observed no difference in cerebral blood flow measured without and with sedation (24.8 ± 4.2 vs 24.9 ± 5.9 mL/100 g/min; p = 0.93). We found no interaction between chronic hypertension and the effect of sedation or mean arterial pressure targets. Cerebral blood flow measured in sedated septic patients (mean arterial pressure target 65 mm Hg) was 62% higher than in sedated control subjects (p = 0.001). CONCLUSIONS: In septic patients, cerebral blood flow was higher than in sedated control subjects and did not vary with mean arterial pressure targets. Further research is required to understand the clinical significance of cerebral hyperperfusion in septic patients on vasopressors and to reassess the neurologic effects of current mean arterial pressure targets in sepsis.
Authors: Tamas Csipo; Benjamin R Cassidy; Priya Balasubramanian; Douglas A Drevets; Zoltan I Ungvari; Andriy Yabluchanskiy Journal: Front Aging Neurosci Date: 2021-05-14 Impact factor: 5.750
Authors: Michael D Wood; J Gordon Boyd; Nicole Wood; James Frank; Timothy D Girard; Amanda Ross-White; Akash Chopra; Denise Foster; Donald E G Griesdale Journal: J Intensive Care Med Date: 2021-03-09 Impact factor: 3.510