Non-invasive cerebral perfusion monitoring in cardiac arrest patients: a prospective cohort study

Neuromonitoring after Pediatric Cardiac Arrest: Cerebral Physiology and Injury Stratification

BACKGROUND

Significant long-term neurologic disability occurs in survivors of pediatric cardiac arrest, primarily due to hypoxic-ischemic brain injury. Postresuscitation care focuses on preventing secondary injury and the pathophysiologic cascade that leads to neuronal cell death. These injury processes include reperfusion injury, perturbations in cerebral blood flow, disturbed oxygen metabolism, impaired autoregulation, cerebral edema, and hyperthermia. Postresuscitation care also focuses on early injury stratification to allow clinicians to identify patients who could benefit from neuroprotective interventions in clinical trials and enable targeted therapeutics.

METHODS

In this review, we provide an overview of postcardiac arrest pathophysiology, explore the role of neuromonitoring in understanding postcardiac arrest cerebral physiology, and summarize the evidence supporting the use of neuromonitoring devices to guide pediatric postcardiac arrest care. We provide an in-depth review of the neuromonitoring modalities that measure cerebral perfusion, oxygenation, and function, as well as neuroimaging, serum biomarkers, and the implications of targeted temperature management.

RESULTS

For each modality, we provide an in-depth review of its impact on treatment, its ability to stratify hypoxic-ischemic brain injury severity, and its role in neuroprognostication.

CONCLUSION

Potential therapeutic targets and future directions are discussed, with the hope that multimodality monitoring can shift postarrest care from a one-size-fits-all model to an individualized model that uses cerebrovascular physiology to reduce secondary brain injury, increase accuracy of neuroprognostication, and improve outcomes.

Advanced Neuromonitoring Modalities on the Horizon: Detection and Management of Acute Brain Injury in Children

Timely detection and monitoring of acute brain injury in children is essential to mitigate causes of injury and prevent secondary insults. Increasing survival in critically ill children has emphasized the importance of neuroprotective management strategies for long-term quality of life. In emergent and critical care settings, traditional neuroimaging modalities, such as computed tomography and magnetic resonance imaging (MRI), remain frontline diagnostic techniques to detect acute brain injury. Although detection of structural and anatomical abnormalities remains crucial, advanced MRI sequences assessing functional alterations in cerebral physiology provide unique diagnostic utility. Head ultrasound has emerged as a portable neuroimaging modality for point-of-care diagnosis via assessments of anatomical and perfusion abnormalities. Application of electroencephalography and near-infrared spectroscopy provides the opportunity for real-time detection and goal-directed management of neurological abnormalities at the bedside. In this review, we describe recent technological advancements in these neurodiagnostic modalities and elaborate on their current and potential utility in the detection and management of acute brain injury.

The success rate of cardiopulmonary resuscitation and its correlated factors in patients with emergency prehospital cardiac arrest

To assess the initial success rate and its correlated factors on cardiopulmonary resuscitation (CPR) in emergency prehospital cardiac arrest patients. The clinical information of 429 patients with cardiac arrest who underwent prehospital CPR in the fourth hospital of Hebei Medical University from Jan 2020 to Apr 2022 were evaluated. The patients were divided into the successful group (ROSC, n = 25) and the unsuccessful group (non-ROSC, n = 404) according to whether the autonomous circulation (ROSC) was resumed. The univariate analysis was performed to evaluate the differences in age, the start time of CPR, the application of electric defibrillation, and other related data between the two groups. The multivariate analysis evaluated protective factors affecting CPR's success in prehospital cardiac arrest patients. Patients with cardiogenic causes had the highest success rate of cardiopulmonary resuscitation. The causes of traffic accidents and drowning account for a low proportion. Furthermore, the median CPR length was 25.0 min, alternating from 1.5 to 64 mi. The univariate analysis revealed that age, the start time of CPR, application of electric defibrillation, and adrenaline dosage were correlated with CPR attempts (p < 0.05). Multivariate logistic regression analysis showed that the age of patients with prehospital CA, the location of prehospital CA, etiology, bystander CPR, CPR start time, defibrillation start time, tracheal intubation time, type of rhythm before resuscitation, adrenaline dosage <5 mg, and adrenaline administration time were all the influencing factors of prehospital CPR success (p < 0.01). The factors affecting CPR's success rate in prehospital CA patients are complicated. Establishing a few procedures to diminish the incidence of these risk factors is crucial.

Low frequency power in cerebral blood flow is a biomarker of neurologic injury in the acute period after cardiac arrest

AIM

Cardiac arrest often results in severe neurologic injury. Improving care for these patients is difficult as few noninvasive biomarkers exist that allow physicians to monitor neurologic health. The amount of low-frequency power (LFP, 0.01-0.1 Hz) in cerebral haemodynamics has been used in functional magnetic resonance imaging as a marker of neuronal activity. Our hypothesis was that increased LFP in cerebral blood flow (CBF) would be correlated with improvements in invasive measures of neurologic health.

METHODS

We adapted the use of LFP for to monitoring of CBF with diffuse correlation spectroscopy. We asked whether LFP (or other optical biomarkers) correlated with invasive microdialysis biomarkers (lactate-pyruvate ratio - LPR - and glycerol concentration) of neuronal injury in the 4 h after return of spontaneous circulation in a swine model of paediatric cardiac arrest (Sus scrofa domestica, 8-11 kg, 51% female). Associations were tested using a mixed linear effects model.

RESULTS

We found that higher LFP was associated with higher LPR and higher glycerol concentration. No other biomarkers were associated with LPR; cerebral haemoglobin concentration, oxygen extraction fraction, and one EEG metric were associated with glycerol concentration.

CONCLUSION

Contrary to expectations, higher LFP in CBF was correlated with worse invasive biomarkers. Higher LFP may represent higher neurologic activity, or disruptions in neurovascular coupling. Either effect may be harmful in the acute period after cardiac arrest. Thus, these results suggest our methodology holds promise for development of new, clinically relevant biomarkers than can guide resuscitation and post-resuscitation care. Institutional protocol number: 19-001327.