Approximately 5000 to 10,000 children suffer an in-hospital cardiac arrest requiring cardiopulmonary resuscitation (CPR) each year in the United States. Importantly, 2% to 6% of all children admitted to pediatric intensive care units (ICUs) receive CPR, as do 4% to 6% of children admitted to pediatric cardiac ICUs. Survival from pediatric ICU cardiac arrest has improved substantially during the past 20 years presumably due to improved training methods, CPR quality, and post–resuscitation care. Extracorporeal life support CPR remains an important treatment option for both cardiac and noncardiac ICU patients.
Key points
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Survival outcomes after pediatric intensive care unit (ICU) cardiac arrest have been improving.
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Most in-hospital cardiopulmonary resuscitation (CPR) occurs in highly monitored patients in ICUs.
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The quality of CPR is associated with pediatric survival outcomes.
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Patient physiology can be used to monitor the resuscitation effort.
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Postarrest care is a key component of resuscitation care.
Introduction
In-hospital pediatric cardiac arrest (p-IHCA) affects approximately 5000 to 10,000 children per year in the United States. Although survival outcomes have improved substantially over the past 20 years, more work is needed. Nearly half of these children will not live to hospital discharge, and in those that do survive, new morbidity is common. Cardiopulmonary resuscitation (CPR) delivered in compliance with recommended targets for chest compression rate and depth has been associated with improved event survival in children, with the latest research highlighting physiologic-directed CPR as a promising CPR method to improve outcomes further. In this article, the authors review the latest epidemiologic data regarding p-IHCA, highlight CPR quality and postarrest care as targets to improve survival outcomes, and discuss the use of patient physiology to guide resuscitation quality and potential areas of clinical care and research that may be targeted in the future to improve outcomes further.
Introduction
In-hospital pediatric cardiac arrest (p-IHCA) affects approximately 5000 to 10,000 children per year in the United States. Although survival outcomes have improved substantially over the past 20 years, more work is needed. Nearly half of these children will not live to hospital discharge, and in those that do survive, new morbidity is common. Cardiopulmonary resuscitation (CPR) delivered in compliance with recommended targets for chest compression rate and depth has been associated with improved event survival in children, with the latest research highlighting physiologic-directed CPR as a promising CPR method to improve outcomes further. In this article, the authors review the latest epidemiologic data regarding p-IHCA, highlight CPR quality and postarrest care as targets to improve survival outcomes, and discuss the use of patient physiology to guide resuscitation quality and potential areas of clinical care and research that may be targeted in the future to improve outcomes further.
Discussion
Epidemiology of Pediatric Cardiac Arrest
p-IHCA is an important public health problem. Best estimates reveal that approximately 5000–10,000 children per year will be treated with CPR for a cardiac arrest at some point during their hospitalization. More than half of these children will not live to hospital discharge, and in those who do survive, new morbidity is common. Assuming a pediatric cardiac arrest survival rate of 40%, an average age at arrest of 6 years, and a life expectancy of 78 years, p-IHCA accounts for the loss of up to 400,000 quality-of-life years annually in the United States .
Although the newest evidence still suggests that more than half of children will not live to hospital discharge after p-IHCA, this is a substantial improvement over the past 20 years. Of the pediatric patients who survive to hospital discharge, nearly three-quarters will have good neurologic outcome, and more than 90% who survive to discharge are alive 1 year later. Factors that influence outcome after p-IHCA include the following: (1) the preexisting condition of the child ; (2) the initial electrocardiographic (ECG) rhythm detected (ie, shockable rhythms have better outcomes ); (3) the quality of CPR provided during the resuscitation ; and (4) the quality-of-life supporting therapies during post–resuscitation care.
Early warning scores and rapid response teams have successfully decreased the number p-IHCAs that occur on general medical wards outside of the intensive care unit (ICU). In a large study using the American Heart Association’s (AHA) Get with the Guidelines-Resuscitation (GWTG-R) registry, more than 95% of pediatric intensive care unit (PICU) and ward CPR events in the United States occurred in an ICU between 2005 and 2010. Many of these ICU patients have invasive monitoring in place at the time of arrest to guide resuscitation quality. Nearly half of the children in the aforementioned GWTG-R study had arterial blood pressure monitoring in place at the time of the event. These data have substantial implications for CPR training that will be discussed in more detail later.
As this article intends to focus on ICU CPR, it is important to note that ICU CPR is common, affecting 1.4% to 1.8% of children in 2 large prospective studies. This percentage has remained relatively constant over the past 20 to 30 years despite the growing proportion of p-IHCA occurring in ICUs, likely due to rapid increases in the size and number of PICUs. Similar to p-IHCA that occurs outside of an ICU, hypotension and acute respiratory insufficiency are the most common immediate causes of arrest. Fortunately, over time, outcomes have improved substantially in the ICU CPR population as well ( Table 1 ). In the most recent study published in 2016 by the Collaborative Pediatric Critical Care Research Network (CPCCRN; a National Institute of Child Health and Human Development–funded clinical network of 7 leading pediatric institutions ), nearly 80% of children who received ICU CPR attained return of circulation (ROC), 45% survived to hospital discharge, and 89% of survivors had favorable neurologic outcome defined by the Pediatric Cerebral Performance Category Scale. However, substantial new morbidity defined by the Functional Status Scale affected almost 30% of survivors, suggesting neurologic changes may be underestimated in the literature. This study affirmed previous work that demonstrated a higher incidence of p-IHCA in cardiac patients compared with noncardiac patients. However, in contrast to previous single-center and registry studies, this prospective trial demonstrated that survival outcomes were similar between these groups. Although shorter duration of CPR was associated with better outcome, 89% of children who survived after more than 30 minutes of CPR had a favorable neurologic outcome, indicating that long durations of CPR do not necessarily translate into a universally poor outcome for the child.
| Author, Year | Setting | Patients | ROSC | Survival to Discharge, % |
|---|---|---|---|---|
| Berg et al, 2016 | All ICUs | 139 | 78% | 45 |
| Berg et al, 2013 | All ICUs | 5477 | 72% | 38 |
| Meaney et al, 2006 | All ICUs | 464 | 50% | 22 |
| Slonim et al, 1997 | PICU | 205 | Not reported | 14 |
High-Quality Cardiopulmonary Resuscitation
One potential explanation of improved outcomes following p-IHCA may be related to a growing understanding of the effect of CPR quality on outcomes. High-quality CPR is best described by the AHA catch-phrase “PUSH HARD and PUSH FAST.” Additional aspects of high-quality CPR include minimizing interruptions in chest compressions, allowing full chest recoil between compressions, and avoiding excessive ventilation. There is a focus on delivery of chest compressions over ventilations, even in pediatrics where most events have a respiratory cause. This algorithm was best exemplified in the acronym change from Airway-Breathing-Circulation, or ABC, to Circulation-Airway-Breathing, or CAB in the 2010 iteration of the pediatric advanced life support (PALS) Guidelines. If compressions are delivered at an adequate rate, initiation of ventilation will theoretically be delayed by only about 18 seconds if a pediatric rescuer starts with chest compressions for children without an artificial airway. Table 2 shows the most recent evidence-supported pediatric CPR targets.
| Metric | Evidence-Based Target |
|---|---|
| Depth: infant/children |
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| Depth: adolescents a |
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| Rate |
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| CPR fraction |
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| Ventilation rate |
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| Chest recoil | FULL chest recoil between all compressions |
Intra-Arrest Cardiopulmonary Resuscitation Quality Monitoring Technology
Innovative technology primarily using force transducers and accelerometers has allowed resuscitation scientists to quantitatively measure the quality of CPR performed during actual resuscitation attempts. This technology has provided important additions to the pediatric resuscitation knowledge base. First, providing high-quality CPR is difficult. Professional pediatric rescuers frequently fail to deliver the recommended chest compression depth and rate, to avoid long pauses in CPR, and to allow full chest recoil during compressions. Second, when high-quality pediatric CPR is provided to patients, outcomes improve. Specifically, when rescuers achieve AHA guideline recommendations for CPR, patients are almost twice as likely to have excellent blood pressure during CPR and 10 times as likely to survive for at least 24 hours after the event. Finally, incorporation of CPR quality data into education and patient care is a vital component of any comprehensive resuscitation quality improvement program. In a single-center study, the combination of focused bedside training with audiovisual feedback before the resuscitation, automated defibrillator CPR feedback during the resuscitation, and post–cardiac arrest debriefing after the resuscitation improved guideline compliance and survival outcomes. In this study, favorable neurologic survival after PICU arrest improved from 29% to 50% with this approach. Currently, a National Heart, Lung, and Blood Institute-funded clinical trial in the CPCCRN network is evaluating this resuscitation bundle of care to improve outcomes across 18 ICUs in the United States (ICU-RESUS: R01HL131544).
Point-of-Care Bedside Training
Traditional CPR training programs function under a high-intensity, low-frequency training paradigm. As such, trainees attend a lengthy CPR instruction class offered every 2 years to maintain their certification. Unfortunately, there is a substantial body of evidence showing decline of CPR skills as early as 3 months after conventional training. In response, resuscitation scientists have evaluated an alternative CPR training approached termed “Rolling Refreshers”: a point-of-care educational program that functions under a low-intensity, but high-frequency paradigm. Rooted in adult educational theory, this new approach allows trainees to practice their CPR skills “on the job” in a brief (<2 minute) instruction. Studies have demonstrated this approach to improve initial skill acquisition and retention of both ICU and non-ICU providers alike during simulated resuscitation. The AHA now offers Basic Life Support recertification through this transformational approach: http://cpr.heart.org/AHAECC/CPRAndECC/Training/RQI/UCM_476470_RQI.jsp .
Physiologic Monitoring During Cardiopulmonary Resuscitation
Traditionally, CPR training has focused on treatment of out-of-hospital cardiac arrests (OHCAs), mostly because the magnitude of OHCA was previously thought to be much greater than IHCA, and therefore, training was appropriately designed for a wide range of skill levels across both trained and untrained rescuers. As a result, the paradigm for optimal resuscitation was more “rescuer-centric” in that the rescuer was coached to provide a specific rate and depth of compression and to provide vasopressors at a fixed dosing interval across all patients, irrespective of the patient’s underlying physiologic response to the resuscitation. However, newer data have suggested that in-hospital professional CPR is as common as out-of-hospital professional CPR, and more importantly, that most IHCA occurs in ICUs where physiologic data are available to guide the resuscitation. This statement is particularly true in pediatrics, where more than 95% of arrests now occur in ICUs compared with general wards. In response, both in a recent 2013 CPR Quality Consensus Statement released by the AHA and in the 2015 PALS Guidelines, physiologic monitoring during CPR was recommended with invasive hemodynamic targets favored over exhaled end tidal carbon dioxide (ETCO 2 ).
Arterial blood pressure
Achieving adequate coronary perfusion pressure (CPP), the mathematical difference between aortic and right atrial diastolic pressures, is an important determinant of successful resuscitation. In preclinical models of p-IHCA, titration of vasopressor administration to CPP and adjustment of compression depth to systolic blood pressure resulted in improved survival. Although CPP monitoring requires simultaneous measurement of diastolic blood pressure (DBP) and central venous pressure, DBP alone is a more clinically feasible surrogate marker of CPR quality. Therefore, in the most recent 2015 PALS Guidelines, use of the arterial waveform as a feedback device to evaluate chest compression quality was recommended in patients with an indwelling arterial catheter in place at the time of arrest. This recommendation acknowledges the substantial risk of interrupting CPR to place an arterial line for CPR quality monitoring. Specific target values in children have not been identified; however, a large multicenter trial in the CPCCRN network is ongoing to establish these targets (expected publication, 2017).
End tidal carbon dioxide
ETCO 2 reflects pulmonary blood flow and is thereby a marker of cardiac output ( Fig. 1 ). ETCO 2 values <10 mm Hg during cardiac arrest are associated with mortality, but higher ETCO 2 values do not always correspond to a successful resuscitation (ie, ETCO 2 is a good negative predictor). ETCO 2 can also be used to detect return of spontaneous circulation (ROSC), because abrupt increases in ETCO 2 result from the increased pulmonary blood flow at ROSC. In adult studies, ETCO 2 values correlate with chest compression depth and ventilation rates. Similar to arterial blood pressure–guided CPR described above, recent animal work has also demonstrated that ETCO 2 -guided chest compressions are as effective as standard CPR optimized with other feedback modalities (eg, visual depth marker, video, verbal cues). Although specific cutoff values are not known, monitoring of ETCO 2 may be considered to guide CPR quality (2015 PALS Guidelines).
