Patterns and Predictors of Extra-Corporeal Membrane Oxygenation Related Cerebral Microbleeds

Prognostic Factors Associated With Intracranial Hemorrhage and Ischemic Stroke During Venovenous Extracorporeal Membrane Oxygenation: A Systematic Review

OBJECTIVES

Venovenous extracorporeal membrane oxygenation (ECMO) is a life-preserving intervention for patients with respiratory failure refractory to conventional mechanical ventilation. Intracranial hemorrhage (ICH) and ischemic stroke are life-threatening complications associated with venovenous ECMO. Despite this, little is known regarding the prognostic factors associated with these adverse neurologic events. We conducted a systematic review that characterizes these predictors of ICH and ischemic stroke during venovenous ECMO.

DATA SOURCES

We conducted a comprehensive search of MEDLINE and Embase via the Ovid interface.

STUDY SELECTION

We developed and performed a literature search to identify articles that evaluated ICH and ischemic stroke in adult patients undergoing venovenous ECMO. We excluded studies based on design, target population, and outcomes.

DATA EXTRACTION

Data were extracted manually by one reviewer. Risk of bias assessment was completed using the Quality in Prognostic Studies approach for each included study. Prognostic factors associated with ICH and ischemic stroke that were identified in two or more included studies were evaluated through the Grading of Recommendations, Assessment, Development, and Evaluation approach.

DATA SYNTHESIS

Three hundred thirty-three studies met criteria for screening. Seventeen studies met final inclusion criteria. Seventeen studies addressed predictors of ICH. Five studies demonstrated an increased risk of ICH with lower pH before venovenous ECMO (moderate certainty). Five studies demonstrated an increased risk of ICH with greater decreases in Pa co2 pre- to post-venovenous ECMO cannulation (moderate certainty). Four studies addressed predictors of ischemic stroke; however, there were no predictors of ischemic stroke identified in two or more of the included studies.

CONCLUSIONS

This systematic review demonstrates that abnormalities and changes in blood gas parameters from pre- to post-venovenous ECMO cannulation are probably associated with increased risk of ICH. Additional high-quality studies dedicated to probable predictors of these adverse neurologic events are crucial to understanding the pathophysiology of ICH and ischemic stroke in this population and informing clinical practice to mitigate the risk of these life-threatening events.

Association Between Cerebral Microbleeds and Neurological Outcomes in Patients Who Underwent Extracorporeal Membrane Oxygenation

BACKGROUND

Cerebral microbleeds (CMBs) are common and varied in patients receiving extracorporeal membrane oxygenation (ECMO). Here, the authors describe CMB findings in patients receiving ECMO and their association with clinical factors.

METHODS AND RESULTS

A total of 138 patients receiving ECMO were enrolled and categorized as venovenous and venoarterial. Blood coagulation profiles during ECMO support and Glasgow Coma Scale (GCS) scores within 7 days were recorded. Patients with CMBs exhibited prolonged activated clotting time (P<0.001), decreased fibrinogen levels (P<0.001), reduced platelet counts (P<0.001), and extended prothrombin time (P<0.001). A significant correlation (P<0.05) was observed between the presence of CMBs and most coagulation parameters among all patients. Patients with venoarterial ECMO had significantly higher activated partial thromboplastin time, activated clotting time, and prothrombin time compared with those with venovenous ECMO (all P<0.05). Patients with a less severe CMB burden exhibited higher GCS scores and better neurological injury outcomes at both 7 and 90 days. CMB burden in all patients with ECMO was significantly correlated (P<0.05) with most blood coagulation profiles and neurological injury.

CONCLUSIONS

CMB burdens after ECMO are common, varied, and associated with a variety of clinical conditions. These findings may guide ECMO management.

Critical illness-associated cerebral microbleeds involving the corpus callosum following cardiac arrest: A case report

RATIONALE

Critical illness-associated cerebral microbleeds (CI-aCMBs) are emerging as significant radiographic findings in patients with hypoxic ischemic injuries. Their occurrence, particularly in the corpus callosum, warrants a closer examination due to the potential implications for neurological outcomes in critically ill patients. We aim to describe a rare case of CI-aCMBs within the corpus callosum following cardiac arrest with the goal of bolstering the scientific literature on this topic.

PATIENT CONCERNS

A 34-year-old man with a history of polysubstance abuse was found unconscious and experienced a pulseless electrical activity (PEA) cardiac arrest after a suspected drug overdose. Post-resuscitation, the patient exhibited severe respiratory distress, acute kidney injury, and profound neurological deficits.

DIAGNOSES

Initial magnetic resonance imaging scans post-cardiac arrest showed no acute brain abnormalities. However, subsequent imaging revealed extensive cerebral microbleeds predominantly in the corpus callosum, diagnosed as CI-aCMBs. These findings were made in the absence of high signal intensity on T2-weighted images, suggesting a unique pathophysiological profile of microhemorrhages.

INTERVENTIONS

The patient underwent targeted temperature management (TTM) and supportive care in the intensive care unit after cardiac arrest.

OUTCOMES

He was subsequently extubated and had significant recovery without any neurological deficits.

LESSONS

CI-aCMBs is a rare radiographic finding after cardiac arrest. These lesions may be confined to the corpus callosum and the long-term clinical and radiographic sequelae are still largely unknown.

Brain magnetic resonance imaging findings six months after critical COVID-19: A prospective cohort study

BACKGROUND

COVID-19 patients suffered from neurological symptoms in the acute phase. Whether this led to long-term consequences was unknown. We studied long-term brain MRI findings in ICU-treated COVID-19 patients and compared them with findings in groups with less severe acute disease.

MATERIALS AND METHODS

In this prospective cohort study, 69 ICU-treated, 46 ward-treated, and 46 home-isolated patients, as well as 53 non-COVID-19 controls, underwent brain MRI six months after acute COVID-19. Plasma neurofilament light chain (NfL), a biomarker of neuroaxonal injury, was measured simultaneously.

RESULTS

Ischaemic infarctions existed in 5.8% of ICU-treated patients. Cerebral microbleeds (CMBs) existed in 27 (39.1%) ICU-treated, 13 (28.3%) ward-treated, 8 (17.4%) home-isolated COVID-19 patients, and 12 (22.6%) non-COVID controls. Patients with CMBs were older (p < 0.001), had a higher level of plasma NfL (p = 0.003), and higher supplementary oxygen days (p < 0.001). In multivariable analysis, age (OR 1.06, 95% CI 1.02-1.09) and supplementary oxygen days (OR 1.07, 95% CI 1.02-1.13) were associated with CMBs. The ICU group showed prevalent distribution of CMBs in deep regions.

CONCLUSION

Age and supplementary oxygen days were independently associated with CMBs; COVID-19 status showed no association. Accumulation of risk factors in the ICU group may explain the higher prevalence of CMBs.

TRIAL REGISTRATION

ClinicalTrials.govNCT04864938, registered February 9, 2021.