Alterations in regional brain microcirculation have not been well studied in patients with sepsis. Regional brain microcirculation can be studied using contrast-enhanced brain ultrasound (CEUS) with microbubble administration.
CEUS was used to assess alterations in regional brain microcirculation on 3 consecutive days in 58 patients with sepsis and within 24 h of intensive care unit admission in 10 aged-matched nonseptic postoperative patients. Time-intensity perfusion curve variables (time-to-peak and peak intensity) were measured in different regions of interest of the brain parenchyma. The mean arterial pressure, cardiac index (using transthoracic echocardiography), global cerebral blood flow (using echo-color Doppler of the carotid and vertebral arteries), mean flow velocities of the middle cerebral arteries, and brain autoregulation (using transcranial echo-color Doppler) were measured simultaneously. The presence of structural brain injury in patients with sepsis was confirmed on computed tomography imaging, and encephalopathy, including coma and delirium, was evaluated using the Glasgow Coma Scale and the Confusion Assessment Method in the Intensive Care Unit.
Of the 58 patients with sepsis, 42 (72%) developed acute encephalopathy and 11 (19%) had some form of structural brain injury. Brain autoregulation was impaired in 23 (40%) of the patients with sepsis. Brain microcirculation alterations were observed in the left lentiform nucleus and left white matter of the temporoparietal region of the middle cerebral artery in the sepsis nonsurvivors but not in the survivors or postoperative patients. The alterations were characterized by prolonged time-to-peak (p < 0.01) and decreased peak intensity (p < 0.01) on the time-intensity perfusion curve. Prolonged time-to-peak but not decreased peak intensity was independently associated with worse outcome (p = 0.03) but not with the development of encephalopathy (p = 0.77).
Alterations in regional brain microcirculation are present in critically ill patients with sepsis and are associated with poor outcome. Trial registration Registered retrospectively on December 19, 2019.