Adult and Pediatric Resuscitation: Title and subTitle BreakFinding Common Ground

In this issue of JAMA, Nadkarni and colleagues¹ compare the outcomes of pediatric and adult in-hospital cardiac arrests in the National Registry of Cardiopulmonary Resuscitation (NRCPR). In this largest pediatric inpatient cohort reported, the survival rate for children (27%) was higher than for adults (18%), with similar neurological outcomes for survivors, primarily due to better outcome in those patients with asystole. The initial pulseless rhythm proved the independent predictor of the outcome. Why compare adult and pediatric arrests? For decades, pediatric resuscitation has focused on the etiology of the arrest, which in children is most commonly respiratory. Adult resuscitation has focused on cardiac rhythm, which often is ventricular fibrillation (VF). This difference has formed the basis of 2 very different approaches to cardiac arrest care, training emphasis, and development and use of technologies. The results of Nadkarni et al raise the issue as to whether approaches for pediatric and adult resuscitation should differ.

The prevalence (14%) of pediatric VF in the NRCPR data set was a surprise. Once considered a rare pediatric condition, VF is a pediatric problem worth reckoning. Pediatric VF prevalence could increase as pediatric cardiac surgery and improved survival among children with cardiac disease increase the prevalence of patients at risk for VF. Moreover, Nadkarni et al showed VF was more successfully treated, with higher survival rates for both pediatric (29%) and adult (36%) patients compared with survival rates of 24% and 11%, respectively, for asystole and pulseless electrical activity. Because the treatment of adult VF has been extensively evaluated, the adult experience could be a benchmark for the pediatric experience. Although survival rates from VF did not differ significantly between children and adults, individuals involved with pediatric resuscitation interventions and research should not be complacent with these outcomes. Instead, they should reexamine the chain of survival.

Cardiac arrest care is about systems, which are best expressed as the chain of survival. Initially designed to delineate the key steps in resuscitation of VF, the adult chain consists of early access, early cardiopulmonary resuscitation (CPR), early defibrillation, and early advanced care.² In out-of-hospital adult resuscitations, survival is almost only achieved in patients with VF. Early defibrillation of VF is critical to outcome, with survival decreasing for every minute of delay to defibrillation.³ This is reflected in the survival chain whereby early access (the emergency services call to obtain defibrillator capability) precedes initiation of CPR by the lone rescuer. Subsequently, major technological advances, including the automated external defibrillator (AED), enabled early defibrillation and proved remarkably simple to use and effective in out-of-hospital settings.⁴

The pediatric chain of survival, which consists of prevention of injury/cardiac arrest, early CPR, early access, and early advanced care, was conceived differently from the adult chain of survival because of the epidemiology of pediatric cardiac arrest.⁵ Prevention, and specifically injury prevention, was the initial link in the chain because injury is the major cause of death in children in the United States.⁶ Also, because most pediatric arrests are respiratory in origin, the final common pathway of respiratory distress and failure, early CPR to ventilate and reverse anoxia precedes early access.

However, this approach came into question as studies showed that out-of-hospital VF was observed in 9% to 22% of pediatric cardiac arrests,^{7 - 9} and occurring secondary to respiratory and other conditions as well as cardiac conditions. Similar to VF in adults, VF in children has far better survival rates (30%) than asystole or pulseless electrical activity (0%-5%).^{7 - 9} Now that Nadkarni et al confirm this finding based on data from in-hospital arrests, the pediatric chain of survival should be more like the adult chain of survival (ie, advising the lone rescuer to call first [early access] before initiating CPR to shorten the time to defibrillation if VF is likely to be present).

CPR remains essential in adult resuscitation as studies show that CPR provided by emergency medical services or bystanders before defibrillation improves survival rates in both witnessed and unwitnessed arrests.^{10 - 12} The findings of Nadkarni et al suggest the pediatric emphasis on airway and respirations may contribute to survival even for the patient who is asystolic. The dilemma is how to achieve both early CPR and early defibrillation especially for the lone rescuer. The trade-off between the time interval of collapse to CPR vs collapse to defibrillation has not been evaluated. How long should CPR be provided and defibrillation delayed for maximal outcomes? How many minutes are actually lost calling first? Can bystanders provide 5 sequences of CPR and assessment within 2 minutes before calling for help? In this age of cell phones and rapid communication, will bystanders or family initiate CPR and delay calling first? Do the answers apply to both adult and pediatric patients?

These dilemmas are resolved in the new American Heart Association's CPR Guidelines.¹³ According to these guidelines, the lone rescuer must decide if the unresponsive patient, regardless of age, has had a VF arrest or an asphyxial arrest. For any age individual who collapses suddenly, the lone rescuer should call first for an AED and then initiate CPR. For the unresponsive person of any age with an asphyxial arrest, the rescuer should provide 5 cycles of CPR before calling emergency services.¹³ No longer is there an adult or pediatric chain, but a chain with 2 branches (one for the unresponsive patient whose arrest was most likely respiratory and one for the patient in arrest with VF).

The in-hospital chain of survival is essentially the adult chain of survival (call for help, CPR, defibrillation, and advanced life support). A separate pediatric chain has not been drawn. An additional link—prevention of cardiac arrest—has been suggested to start the chain.¹⁴ This link is based on increasing data that show early recognition of prearrest states can prevent arrests or improve outcome of arrest states.¹⁵ The NRCPR study results suggest a role for greater use of patient monitoring.

Although hospitals are thought of as places of rapid resuscitation response (faster is achievable and better), the study by Sandroni et al¹⁶ reported that adult survival in nonmonitored areas was greater when response teams responded in less than 3 minutes. Improved survival of in-hospital VF may also be achieved with use of AEDs. The study by Cusnir et al¹⁷ showed that use of an AED significantly decreased time to recognize VF (76 seconds for staff recognition vs 7.6 seconds for AED recognition) and time to defibrillation (169 seconds for staff vs 38 seconds for AED). Following institution of an AED program, the study by Hanefeld et al¹⁸ reported 56% survival of adults with VF. Alternatively, without using AEDs but decreasing the time to defibrillation to less than 3 minutes, the study by Herlitz et al¹⁹ reported a 3-fold increased survival to hospital discharge rate (66%) compared with those defibrillated more than 3 minutes postcollapse (20%). Such gains should be sought throughout adult and pediatric hospital settings.

Both early recognition of VF and rapid defibrillation pose challenges for the treatment of pediatric patients. Recognition of VF may be impaired in pediatric arrests for several reasons. Disturbingly, children in the NRCPR data set were significantly less likely than adults (78% vs 90%) to have their first pulseless arrest rhythms documented. Was this a function of poor documentation or difficulty with recognition or inattentiveness as teams focused on respiratory care? The pediatric patient usually does not have the benefit of early recognition of VF that an AED can provide as AEDs are less commonly used in pediatric hospital settings.

Once the need for defibrillation is recognized, pediatric defibrillation is problematic. Requirements for different defibrillator paddle sizes, chest placement, and energy dosing can contribute to delay. Dosing guidelines, based on 1 small study,²⁰ have recommended a narrow dosing range (2-4 J/kg). The correct range for monophasic or biphasic dosing is unknown. Patients with short periods of VF, which more likely occur in-hospital, may require less than 2 J/kg, whereas much larger doses may be required for out-of-hospital defibrillation.^{21 - 22} Rapid response teams, AEDs, or both, with pediatric capabilities that result in quicker defibrillation, might result in pediatric VF outcomes surpassing those of adult patients with VF.

In addition, the surprisingly high, although discrepant, survival rates for pediatric and adult asystole in the NRCPR study should prompt reevaluation of asystole. Does quick response explain survival from asystole as it does for VF? Is there opportunity for improvement in asystole care besides better monitoring in adults? Does the pediatric heart possess greater resiliency than the adult heart? Although no study has evaluated pediatric and adult outcomes together, it is reasonable to believe that age is not an independent factor in outcome. In studies evaluating patients aged 0 to 21 years and in several adult studies, after adjustment, age has not been associated with survival.^{10 ,16 ,23 - 24}

The NRCPR data set reveals the need for better outcome evaluation following pediatric cardiac arrest.¹ That the neurological status at hospital discharge was “unknown” for 59 of 236 (25%) of surviving pediatric patients in this NRCPR data set is unconscionable. Others have called for adding an additional link to the chain of survival—postresuscitation care—to make physicians attend to more than just the cardiac arrest.¹⁴ Certainly, the chain of survival is meaningless without outcome evaluations.

In the study by Nadkarni et al, adult and pediatric resuscitation find common ground and, furthermore, one informs the other. Although the underlying diseases and the degrees of illness are very different for adult and pediatric patients with cardiac arrest, the tenets of care appear the same. By recognizing the need for prevention of cardiac arrest, recognition of respiratory deterioration, early CPR, and early defibrillation, the chain of survival and its treatment implications appear applicable to all patients. The 2 pillars of resuscitation, CPR and defibrillation, are intertwined, interlocked, and now ageless. The pediatric and adult in-hospital and out-of-hospital chain of survival appear one and the same. What a great relief it would be to say to those individuals involved in resuscitation care, regardless of the arrest patient's age and setting, there is a universal approach. What is good for the goose is also good for the gosling.