Earlier Detection of Brain Injury Using Optical Brain Pulse Monitoring in Critically Ill Patients Following Cardiac Arrest

IMPORTANCEPoint-of-care, non-invasive brain monitoring in critically ill patients following cardiac arrest could provide earlier detection of neurological injury and, when combined with earlier treatments, limit brain injury. Point-of-care monitoring could also enable better neuro-prognostication. OBJECTIVESThe study assessed the time to detection of brain injury using optical brain pulse monitoring (OBPM) compared to routine brain monitoring. The association of OBPM signals with more severe forms of brain injury was also assessed. DESIGNRetrospective analysis of patients enrolled in an observational study. SETTINGCritical care unit of a tertiary academic hospital. PARTICIPANTSAdult patients requiring mechanical ventilation in a critical care unit following a cardiac arrest. MAIN OUTCOMES AND MEASURESOBPM uses red and infrared light to capture brain pulse waveforms whose morphology reflects the relative arteriole and venous pressure levels driving microvascular blood flow in the brain. The OBPM sensors were placed bilaterally on the anterior temporal region of the scalp, over the middle cerebral artery territories. Time to brain injury detection was defined as the period from cardiac arrest to the first detection of brain injury by OBPM or routine monitoring. RESULTSTwelve patients were enrolled, three required veno-arterial extra-corporeal membrane oxygenator support. In-hospital mortality was 83% and eight patients developed global hypoxic-ischemic brain injury. The median time to detection of brain injury was 57 hours earlier using OBPM compared to routine monitoring (P < 0.01). In brain injured patients OBPM brain pulse morphologies changed over time and were often different between hemispheres, high amplitude respiratory waves were also present. Known poor prognostic brain pulse waveform morphologies were present in some patients with severe brain injury. CONCLUSIONS AND RELEVANCEOBPM detected brain injury earlier compared to routine brain monitoring. Earlier detection of neurological injury could improve patient outcomes through earlier treatment and better neuro-prognostication. KEY POINTSO_ST_ABSQuestionC_ST_ABSCan point-of-care non-invasive optical brain pulse monitoring (OBPM) in critically ill patients following cardiac arrest provide earlier detection of brain injury compared to routine monitoring? FindingsIn this observational study of 12 patients the median time to detection of brain injury was 57 hours earlier using OBPM compared to routine monitoring. MeaningEarlier detection of brain injury could improve patient outcomes through earlier treatment and better neuro-prognostication.