Acute neurological complications in adult patients with cardiogenic shock on veno-arterial extracorporeal membrane oxygenation support
Authors: Laimoud Mohamed , Ahmed Walid 
Published: May 2020

Abstract
Background
Extracorporeal life support has markedly progressed over the recent years to support patients with severe cardiac and pulmonary dysfunction refractory to conventional management. Many patients developed acute neurological complications while being supported with extracorporeal membrane oxygenation (ECMO). Our objectives were to study the frequencies and outcomes of CNS complications in adult patients with cardiogenic shock on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and to study the risk factors of these CNS complications. We conducted a retrospective study including adult patients admitted to the cardiac critical care unit with cardiopulmonary instability and supported with VA-ECMO from January 2016 until December 2018 in a tertiary care hospital.

Results
After reviewing 231 patients with ECMO, 67 patients with cardiogenic shock supported with VA-ECMO were included. About 65.7% of the studied patients were supported after cardiothoracic surgeries. About 56.7% of the patients developed acute CNS events. According to brain CT imaging, ischaemic stroke was diagnosed in 14.9% and intracerebral haemorrhage (ICH) was diagnosed in 11.9% of patients while 16.4% of patients with CNS events had negative brain CT imaging. The SOFA score was significantly higher in the group with CNS events at ICU admission and after 48 hours . As compared to patients with ischaemic strokes, patients with ICH were younger with lesser BMI, had higher SOFA scores at admission and at 48 hours of ICU admission, had longer cardiopulmonary bypass and aortic cross clamping times and had more support with central than peripheral VA-ECMO. AF was more frequent in the group with CNS events especially in the ischaemic stroke subgroup. Presence of intracardiac thrombi was more frequent in the ischaemic stroke subgroup. There was no statistically significant difference between both groups regarding ECMO circuit thrombi. The use of IABP and presence of DM were more frequent in the ischaemic stroke subgroup. Patients with neurological events had hypoalbuminaemia and higher blood glucose and serum creatinine levels compared to those without CNS events. The peak lactate level and lactate after 24 hours of ECMO support were significantly higher in those with CNS events. Patients with ICH had significant thrombocytopenia and higher INR with more prolonged aPTT and PTT ratio than those with ischaemic stroke. Patients with neurological events had significant hospital mortality, more mechanical ventilation days and tracheostomy, AKI and haemodialysis compared to those without CNS events, but there were no significant differences between both groups regarding ECMO duration, ICU or post ICU stays nor 1 year mortality.

Conclusion
Acute neurological events are frequent in patients supported with VA-ECMO and associated with significant morbidity and hospital mortality. As compared to ischaemic stroke, ICH is more frequent in younger patients with lesser BMI, central VA-ECMO after cardiothoracic surgeries, thrombocytopenia, and coagulopathy. Our findings may have major implications for the care of patients requiring VA-ECMO.