Changing Risk of In-Hospital Cardiac Arrest in Children Following Cardiac Surgery in Victoria, Australia, 2007-2016

Cardiac arrest and cardiopulmonary resuscitation in pediatric patients with cardiac disease: a narrative review

Children with cardiac disease are at a higher risk of cardiac arrest as compared to healthy children. Delivering adequate cardiopulmonary resuscitation (CPR) can be challenging due to anatomic characteristics, risk profiles, and physiologies. We aimed to review the physiological aspects of resuscitation in different cardiac physiologies, summarize the current recommendations, provide un update of current literature, and highlight knowledge gaps to guide research efforts. We specifically reviewed current knowledge on resuscitation strategies for high-risk categories of patients including patients with single-ventricle physiology, right-sided lesions, right ventricle restrictive physiology, left-sided lesions, myocarditis, cardiomyopathy, pulmonary arterial hypertension, and arrhythmias. Cardiac arrest occurs in about 1% of hospitalized children with cardiac disease, and in 5% of those admitted to an intensive care unit. Mortality after cardiac arrest in this population remains high, ranging from 30 to 65%. The neurologic outcome varies widely among studies, with a favorable neurologic outcome at discharge observed in 64%-95% of the survivors. Risk factors for cardiac arrest and associated mortality include younger age, lower weight, prematurity, genetic syndrome, single-ventricle physiology, arrhythmias, pulmonary arterial hypertension, comorbidities, mechanical ventilation preceding cardiac arrest, surgical complexity, higher vasoactive-inotropic score, and factors related to resources and institutional characteristics. Recent data suggest that Extracorporeal membrane oxygenation CPR (ECPR) may be a valid strategy in centers with expertise. Overall, knowledge on resuscitation strategies based on physiology remains limited, with a crucial need for further research in this field. Collaborative and interprofessional studies are highly needed to improve care and outcomes for this high-risk population. What is Known: • Children with cardiac disease are at high risk of cardiac arrest, and cardiopulmonary resuscitation may be challenging due to unique characteristics and different physiologies. • Mortality after cardiac arrest remains high and neurologic outcomes suboptimal. What is New: • We reviewed the unique resuscitation challenges, current knowledge, and recommendations for different cardiac physiologies. • We highlighted knowledge gaps to guide research efforts aimed to improve care and outcomes in this high-risk population.

Machine learning predicts blood lactate levels in children after cardiac surgery in paediatric ICU

BACKGROUND

Although serum lactate levels are widely accepted markers of haemodynamic instability, an alternative method to evaluate haemodynamic stability/instability continuously and non-invasively may assist in improving the standard of patient care. We hypothesise that blood lactate in paediatric ICU patients can be predicted using machine learning applied to arterial waveforms and perioperative characteristics.

METHODS

Forty-eight post-operative children, median age 4 months (2.9-11.8 interquartile range), mean baseline heart rate of 131 beats per minute (range 33-197), mean lactate level at admission of 22.3 mg/dL (range 6.3-71.1), were included. Morphological arterial waveform characteristics were acquired and analysed. Predicting lactate levels was accomplished using regression-based supervised learning algorithms, evaluated with hold-out cross-validation, including, basing prediction on the currently acquired physiological measurements along with those acquired at admission, as well as adding the most recent lactate measurement and the time since that measurement as prediction parameters. Algorithms were assessed with mean absolute error, the average of the absolute differences between actual and predicted lactate concentrations. Low values represent superior model performance.

RESULTS

The best performing algorithm was the tuned random forest, which yielded a mean absolute error of 3.38 mg/dL when predicting blood lactate with updated ground truth from the most recent blood draw.

CONCLUSIONS

The random forest is capable of predicting serum lactate levels by analysing perioperative variables, including the arterial pressure waveform. Thus, machine learning can predict patient blood lactate levels, a proxy for haemodynamic instability, non-invasively, continuously and with accuracy that may demonstrate clinical utility.

Trends in In-Hospital Cardiac Arrest and Mortality Among Children With Cardiac Disease in the Intensive Care Unit: A Systematic Review and Meta-analysis

IMPORTANCE

Data on trends in incidence and mortality for in-hospital cardiac arrest (IHCA) in children with cardiac disease in the intensive care unit (ICU) are lacking. Additionally, there is limited information on factors associated with IHCA and mortality in this population.

OBJECTIVE

To investigate incidence, trends, and factors associated with IHCA and mortality in children with cardiac disease in the ICU.

DATA SOURCES

A systematic review was conducted using PubMed, Web of Science, EMBASE, and CINAHL, from inception to September 2021.

STUDY SELECTION

Observational studies on IHCA in pediatric ICU patients with cardiac disease were selected (age cutoffs in studies varied from age ≤18 y to age ≤21 y).

DATA EXTRACTION AND SYNTHESIS

Quality of studies was assessed using the National Institutes of Health Quality Assessment Tools. Data on incidence, mortality, and factors associated with IHCA or mortality were extracted by 2 independent observers. Random-effects meta-analysis was used to compute pooled proportions and pooled ORs. Metaregression, adjusted for type of study and diagnostic category, was used to evaluate trends in incidence and mortality.

MAIN OUTCOMES AND MEASURES

Primary outcomes were incidence of IHCA and in-hospital mortality. Secondary outcomes were proportions of patients who underwent extracorporeal membrane oxygenation (ECMO) cardiopulmonary resuscitation (ECPR) and those who did not achieve return of spontaneous circulation (ROSC).

RESULTS

Of the 2574 studies identified, 25 were included in the systematic review (131 724 patients) and 18 in the meta-analysis. Five percent (95% CI, 4%-6%) of children with cardiac disease in the ICU experienced IHCA. The pooled in-hospital mortality among children who experienced IHCA was 51% (95% CI, 42%-59%). Thirty-nine percent (95% CI, 29%-51%) did not achieve ROSC; in centers with ECMO, 22% (95% CI, 14%-33%) underwent ECPR, whereas 22% (95% CI, 12%-38%) were unable to be resuscitated. Both incidence of IHCA and associated in-hospital mortality decreased significantly in the last 20 years (both P for trend < .001), whereas the proportion of patients not achieving ROSC did not significantly change (P for trend = .90). Neonatal age, prematurity, comorbidities, univentricular physiology, arrhythmias, prearrest mechanical ventilation or ECMO, and higher surgical complexity were associated with increased incidence of IHCA and mortality odds.

CONCLUSIONS AND RELEVANCE

This systematic review and meta-analysis found that 5% of children with cardiac disease in the ICU experienced IHCA. Decreasing trends in IHCA incidence and mortality suggest that education on preventive interventions, use of ECMO, and post-arrest care may have been effective; however, there remains a crucial need for developing resuscitation strategies specific to children with cardiac disease.

Hemodynamic assessment in children after cardiac surgery: A pilot study on the value of infrared thermography

Introduction

Low cardiac output syndrome in the postoperative period after cardiac surgery leads to an increase in tissue oxygen extraction, assessed by the oxygen extraction ratio. Measurement of the oxygen extraction ratio requires blood gases to be taken. However, the temperature of the skin and various parts of the body is a direct result of blood flow distribution and can be monitored using infrared thermography. Thus, we conducted a prospective clinical study to evaluate the correlation between the thermal gradient obtained by infrared thermography and the oxygen extraction ratio in children at risk for low cardiac output after cardiac surgery.

Methods

Children aged 0 to 18 years, having undergone cardiac surgery with cardio-pulmonary bypass in a pediatric intensive care unit were included in the study. One to 4 thermal photos were taken per patient using the FLIR One Pro thermal imaging camera. The thermal gradient between the central temperature of the inner canthus of the eye and the peripheral temperature was compared to the concomitant oxygen extraction ratio calculated from blood gases.

Results

41 patients were included with a median age of 6 months (IQR 3-48) with median Risk Adjustment for Congenital Heart Surgery-1 score was 2 (IQR 2-3). Eighty nine thermal photos were analyzed. The median thermal gradient was 2.5 °C (IQR 1,01-4.04). The median oxygen extraction ratio was 35% (IQR 26-42). Nine patients had an oxygen extraction ratio ≥ 50%. A significant but weak correlation was found between the thermal gradient and the oxygen extraction ratio (Spearman's test p = 0.25, p = 0.016). Thermal gradient was not correlated with any other clinical or biologic markers of low cardiac output. Only young age was an independent factor associated with an increase in the thermal gradient.

Conclusion

In this pilot study, which included mainly children without severe cardiac output decrease, a significant but weak correlation between thermal gradient by infrared thermography and oxygen extraction ratio after pediatric cardiac surgery was observed. Infrared thermography is a promising non-invasive technology that could be included in multimodal monitoring of postoperative cardiac surgery patients. However, a clinical trial including more severe children is needed.

Cardiac Arrest in Children Following Cardiac Surgery: A Scoping Review of Contributing Factors

Nearly half of children experiencing cardiac arrest following cardiac surgery do not survive hospital discharge and patients who survive often experience significant neurological impairment. Additionally, increased resource utilization following cardiac arrest translates into adverse logistical and financial consequences. Although some studies have identified patient characteristics that increase the risk of cardiac arrest after pediatric cardiac surgery, modifiable risk factors, which could provide a foundation for effective prevention strategies, have been elusive. This scoping review explores the current knowledge surrounding risk factors associated with cardiac arrest in children following cardiac surgery and provides recommendations for future research.

Global mortality of children after perioperative cardiac arrest: A systematic review, meta-analysis, and meta-regression

Background

The body of evidence showed that perioperative cardiac arrest and mortality trends varied globally over time particularly in low and middle-income nations. However, the survival of children after cardiac arrest and its independent predictors are still uncertain and a topic of debate. This study was designed to investigate the mortality of children after a perioperative cardiac arrest based on a systematic review of published peer-reviewed literature.

Methods

A comprehensive search was conducted in PubMed/Medline; Science direct, CINHAL, and LILACS from December 2000 to August 2021. All observational studies reporting the rate of perioperative CA among children were included. The data were extracted with two independent authors in a customized format. The methodological quality of the included studies was evaluated using the Newcastle-Ottawa appraisal tool.

Results

A total of 397 articles were identified from different databases. Thirty-eight studies with 3.35 million participants were included. The meta-analysis revealed that the global incidence of perioperative cardiac arrest was 2.54(95% CI: 2.23 to 2.84) per 1000 anesthetics. The global incidence of perioperative mortality was 41.18 (95% CI: 35.68 to 46.68) per 1000 anesthetics.

Conclusion

The incidence of anesthesia-related pediatric cardiac arrest and mortality is persistently high in the last twenty years in low and middle-income countries. This probes an investment in continuous medical education of the perioperative staff and adhering with the international standard operating protocols for common procedures and critical situations.

Registration

This systematic review and meta-analysis is registered in the research registry (UIN: researchregistry6932).

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The incidence of anesthesia-related cardiac arrest and mortality is persistently high in low and middle-income countries.

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The review also showed that anesthesia-related cardiac arrest was very high among younger children with congenital heart disease.

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The overall perioperative cardiac arrest among children has decreased in the last 20 years in high-income countries.

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The Meta-analysis strongly recommends continuous medical education of the perioperative staff, and adherence to the international standard operating protocols.

Temperature Management and Health-Related Quality of Life in Children 3 Years After Cardiac Arrest

OBJECTIVES

Therapeutic hypothermia minimizes neuronal injury in animal models of hypoxic-ischemic encephalopathy with greater effect when used sooner after the insult. Clinical trials generally showed limited benefit but are difficult to perform in a timely manner. In this clinical study, we evaluated the association between the use of hypothermia (or not) and health-related quality of life among survivors of pediatric cardiac arrest as well as overall mortality.

DESIGN

Single-center, retrospectively identified cohort with prospective assessment of health-related quality of life.

SETTING

PICU of a pediatric hospital.

PATIENTS

Children with either out-of-hospital or in-hospital cardiac arrest from January 2012 to December 2017.

INTERVENTIONS

Patients were assigned into two groups: those who received therapeutic hypothermia at less than or equal to 35°C and those who did not receive therapeutic hypothermia but who had normothermia targeted (36-36.5°C). The primary outcome was health-related quality of life assessment and the secondary outcome was PICU mortality.

MEASUREMENTS AND MAIN RESULTS

We studied 239 children, 112 (47%) in the therapeutic hypothermia group. The median (interquartile range) of lowest temperature reached in the 48 hours post cardiac arrest in the therapeutic hypothermia group was 33°C (32.6-33.6°C) compared with 35.4°C (34.7-36.2°C) in the no therapeutic hypothermia group (p < 0.001). At follow-up, 152 (64%) were alive and health-related quality of life assessments were completed in 128. Use of therapeutic hypothermia was associated with higher lactate and lower pH at baseline. After regression adjustment, therapeutic hypothermia (as opposed to no therapeutic hypothermia) was associated with higher physical (mean difference, 15.8; 95% CI, 3.5-27.9) and psychosocial scores (13.6 [5.8-21.5]). These observations remained even when patients with a temperature greater than 37.5°C were excluded. We failed to find an association between therapeutic hypothermia and lower mortality.

CONCLUSIONS

Out-of-hospital or in-hospital cardiac arrest treated with therapeutic hypothermia was associated with higher health-related quality of life scores despite having association with higher lactate and lower pH after resuscitation. We failed to identify an association between use of therapeutic hypothermia and lower mortality.