Cerebral microbleeds in critically ill patients with respiratory failure or sepsis: a scoping review

Abstract

BackgroundCerebral microbleeds (CMB) have been described in critically ill patients with respiratory failure, acute respiratory distress syndrome (ARDS), or sepsis. This scoping review aimed to systematically summarize existing literature on critical illness-associated CMBs.MethodsStudies reporting on adults admitted to the intensive care unit for respiratory failure, ARDS or sepsis with evidence of CMBs on magnetic resonance imaging were included for review following a systematic search across five databases (MEDLINE, Embase, CENTRAL, Scopus, and Web of Science) and a two-stage screening process. Studies were excluded if patients’ CMBs were clearly explained by another process of neurological injury.ResultsForty-eight studies reporting on 216 critically ill patients (mean age 57.9, 18.4% female) with CMBs were included. Of 216, 197 (91.2%) patients developed respiratory failure or ARDS, 5 (2.3%) developed sepsis, and 14 (6.5%) developed both respiratory failure and sepsis. Of 211 with respiratory failure, 160 (75.8%) patients had Coronavirus Disease 2019 (COVID-19). The prevalence of CMBs among critically ill patients with respiratory failure or ARDS was 30.0% (111 of 370 patients in cohort studies). The corpus callosum and juxtacortical area were the most frequently involved sites for CMBs (64.8% and 41.7% of all 216 patients, respectively).Functional outcomes were only reported in 48 patients, among whom 31 (64.6%) were independent at discharge, 4 (8.3%) were dependent at discharge, and 13 (27.1%) did not survive until discharge. Cognitive outcomes were only reported in 11 of 216 patients (5.1%), all of which showed cognitive deficits (9 patients with executive dysfunction, 2 patients with memory deficits).ConclusionsCMBs are commonly reported in patients with critical illness due to respiratory failure, ARDS, or sepsis. CMBs had a predilection for the corpus callosum and juxtacortical area, which may be specific to critical illness-associated CMBs. Functional and cognitive outcomes of these lesions are largely unknown.