Neuromonitoring after Pediatric Cardiac Arrest: Cerebral Physiology and Injury Stratification

Comprehensive Brain-wide Mapping of Afferent and Efferent Nuclei Associated with the Heart in the Mouse

Normal heart function depends on complex regulation by the brain, and abnormalities in the brain‒heart axis affect various diseases, such as myocardial infarction and anxiety disorders. However, systematic tracking of the brain regions associated with the input and output of the heart is lacking. In this study, we injected retrograde transsynaptic pseudorabies virus (PRV) and anterograde transsynaptic herpes simplex virus (HSV) into the left ventricular wall of mice to identify the whole-brain regions associated with the input to and output from the heart. We successfully detected PRV and HSV expression in at least 170 brain subregions in both male and female mice. Sex differences were discovered mainly in the hypothalamus and medulla, with male mice exhibiting greater correlation and hierarchical clustering than female mice, indicating reduced similarity and increased modularity of virus expression patterns in male mice. Further graph theory and multiple linear regression analysis of different injection timelines revealed that hub regions of PRV had highly similar clusters, with different brain levels, suggesting a top-down, hierarchically transmitted neural control pattern of the heart. Hub regions of HSV had scattered clusters, with brain regions gathered in the cortex and brainstem, suggesting a bottom-up, leapfrog, multipoint neural sensing pattern of the heart. Both patterns contain many hub brain regions that have been previously overlooked in brain‒heart axis studies. These results provide brain targets for future research and will lead to deeper insight into the brain mechanisms involved in specific heart conditions.

Evaluating post-cardiac arrest blood pressure thresholds associated with neurologic outcome in children: Insights from the pediRES-Q database

BACKGROUND

Current Pediatric Advanced Life Support Guidelines recommend maintaining blood pressure (BP) above the 5th percentile for age following return of spontaneous circulation (ROSC) after cardiac arrest (CA). Emerging evidence suggests that targeting higher thresholds, such as the 10th or 25th percentiles, may improve neurologic outcomes. We aimed to evaluate the association between post-ROSC BP thresholds and neurologic outcome, hypothesizing that maintaining mean arterial pressure (MAP) and systolic blood pressure (SBP) above these thresholds would be associated with improved outcomes at hospital discharge.

METHODS

This retrospective, multi-center, observational study analyzed data from the Pediatric Resuscitation Quality Collaborative (pediRES-Q). Children (<18 years) who achieved ROSC following index in-hospital or out-of-hospital cardiac arrest and survived ≥ 6 h were included. Multivariable logistic regression was preformed to analyze the association between the pre-defined BP thresholds (5th, 10th, and 25th percentiles) and favorable neurologic outcome, controlling for illness category (surgical-cardiac), initial rhythm (shockable), arrest time (weekend or night), age, CPR duration, and clustering by site.

RESULTS

There were 787 patients with evaluable MAP data and 711 patients with evaluable SBP data. Fifty-four percent (N = 424) of subjects with MAP data and 53 % (N = 380) with SBP data survived to hospital discharge with favorable neurologic outcome. MAP above the 5th, 10th, and 25th percentile thresholds was associated with significantly greater odds of favorable outcome compared to patients with MAP below target (aOR, 1.81 [95 % CI, 1.32, 2.50]; 1.50 [95 % CI, 1.10, 2.05]; 1.40 [95 % CI, 1.01, 1.94], respectively). Subjects with lowest SBP above the 5th percentile also had greater odds of favorable outcome (aOR, 1.44 [95 % CI, 1.04, 2.01]). Associations between lowest SBP above the 10th percentile and 25th percentile did not reach statistical significance (aOR 1.33 [95 % CI, 0.96, 1.86]; 1.23 [95 % CI, 0.87, 1.75], respectively).

CONCLUSION

After pediatric CA, maintaining MAP above the 5th, 10th, and 25th percentiles and SBP above the 5th percentile during the first 6 h following ROSC was significantly associated with improved neurologic outcomes.

Prediction of Survival After Pediatric Cardiac Arrest Using Quantitative EEG and Machine Learning Techniques

BACKGROUND AND OBJECTIVES

Early neuroprognostication in children with reduced consciousness after cardiac arrest (CA) is a major clinical challenge. EEG is frequently used for neuroprognostication in adults, but has not been sufficiently validated for this indication in children. Using machine learning techniques, we studied the predictive value of quantitative EEG (qEEG) features for survival 12 months after CA, based on EEG recordings obtained 24 hours after CA in children. The results were confirmed through visual analysis of EEG background patterns.

METHODS

This is a retrospective single-center study including children (0-17 years) with CA, who were subsequently admitted to the pediatric intensive care unit (PICU) of a tertiary care hospital between 2012 and 2021 after return of circulation (ROC) and were monitored using EEG at 24 hours after ROC. Signal features were extracted from a 30-minute EEG segment 24 hours after CA and used to train a random forest model. The background pattern from the same EEG fragment was visually classified. The primary outcome was survival or death 12 months after CA. Analysis of the prognostic accuracy of the model included calculation of receiver-operating characteristic and predictive values. Feature contribution to the model was analyzed using Shapley values.

RESULTS

Eighty-six children were included (in-hospital CA 27%, out-of-hospital CA 73%). The median age at CA was 2.6 years; 53 (62%) were male. Mortality at 12 months was 56%; main causes of death on the PICU were withdrawal of life-sustaining therapies because of poor neurologic prognosis (52%) and brain death (31%). The random forest model was able to predict death at 12 months with an accuracy of 0.77 and positive predictive value of 1.0. Continuity and amplitude of the EEG signal were the signal parameters most contributing to the model classification. Visual analysis showed that no patients with a background pattern other than continuous with amplitudes exceeding 20 μV were alive after 12 months.

DISCUSSION

Both qEEG and visual EEG background classification for registrations obtained 24 hours after ROC form a strong predictor of nonsurvival 12 months after CA in children.

Post-resuscitation care in the NICU

Post-cardiac arrest syndrome is a unique pathophysiologic condition that is well-described in adult and pediatric populations. Early, goal-directed care after cardiac arrest can mitigate ongoing injury, improve clinical outcomes, and prevent re-arrest. There is a paucity of evidence about post-cardiac arrest care in the NICU, however, pediatric principles and guidelines can be applied in the NICU in the appropriate clinical context.

Association of blood pressure with neurologic outcome at hospital discharge after pediatric cardiac arrest resuscitation

BACKGROUND

Poor outcomes are associated with post cardiac arrest blood pressures <5th percentile for age. We aimed to study the relationship of mean arterial pressure (MAP) with favorable neurologic outcome following cardiac arrest and return of spontaneous circulation (ROSC).

METHODS

This retrospective, multi-center, observational study analyzed data from the Pediatric Resuscitation Quality Collaborative (pediRES-Q). Children (<18 years) who achieved ROSC following index in-hospital or out-of-hospital cardiac arrest and survived ≥6 hours were included. Lowest documented MAP within the first 6 hours of ROSC was percentile adjusted for age and categorized into six groups - Group I: <5th, II: 5-24th, III: 25-49th, IV: 50-74th, V: 75-94th; and VI: 95-100th percentile. Primary outcome was favorable neurologic status at hospital discharge, defined as PCPC score 1, 2, or no change from pre-arrest baseline. Multivariable logistic regression was performed to analyze the association of MAP group with favorable outcome, controlling for illness category (surgical-cardiac), initial rhythm (shockable), arrest time (weekend or overnight), age, CPR duration, and clustering by site.

RESULTS

787 patients were included: median [Q1,Q3] age 17.9 [4.8,90.6] months; male 58%; OHCA 21%; shockable rhythm 13%; CPR duration 7 [3,16] min; favorable neurologic outcome 54%. Median lowest documented MAP percentile for the favorable outcome group was 13 [3,43] versus 8 [1,37] for the unfavorable group. The distribution of blood pressures by MAP group was I: 37%, II: 28%, III: 13%, IV: 11%, V: 7%, and VI: 4%. Compared with patients in Group I (<5%ile), Groups II, III, and IV had higher odds of favorable outcome (aOR, 1.84 [95% CI, 1.24, 2.73]; 2.20 [95% CI, 1.32, 3.68]; 1.90 [95% CI, 1.12, 3.25]). There was no association between Groups V or VI and favorable outcome (aOR, 1.44 [95% CI, 0.75, 2.80]; 1.11 [95% CI, 0.47, 2.59]).

CONCLUSION

In the first 6-hours post-ROSC, a lowest documented MAP between the 5th-74th percentile for age was associated with favorable neurologic outcome compared to MAP <5th percentile for age.