While once considered a rare event,1 out-of-hospital cardiac arrest (CA) in the pediatric population currently holds a relevant place in this type of disease.2,3 Nevertheless, in comparison with CA in the adult population, the available information referred to pediatric patients is scarce. Some series have presented a significant number of patients, analyzing the incidence of the disease at population level and the outcomes referred to survival and neurological status at hospital discharge.4 However, there is controversy regarding the long-term outcomes in terms of pediatric patient recovery. This situation is due to the few data available on neurological recovery in periods late after discharge from hospital. The most important series do not explore beyond neurological status one month after the event.5,6 On the other hand, pediatric age has not been clearly defined in the literature on CA, and in this regard the incidence and final outcomes vary greatly according to the different age intervals considered. The age range involved therefore needs to be specified.5,7

The present study describes the long-term outcomes in terms of survival and neurological status in patients between 0 and 15 years who suffer out-of-hospital CA.

A retrospective observational study was made between January 2008 and December 2012, based on data obtained from the Andalusian Out-of-Hospital Cardiac Arrest Registry (Registro Andaluz de Parada Cardíaca Extrahospitalaria), the protocols of which have been described elsewhere.8 In brief, this is a continuous registry of cases of out-of-hospital CA assisted by the emergency care teams (ECTs) of the Public Company of Healthcare Emergencies of Andalusia (Spain)(Empresa Pública de Emergencias Sanitarias de Andalucía, EPES).

The registry comprised a total of 5069 patients subjected to advanced life support care. Of these individuals, 125 (2.5%) were 15 years old or younger (Fig. 1). A total of 113 CA events (90.4%) occurred before arrival of the ECT. The exact timing of the event could not be established in 50 cases (44.2%), i.e., the interval could only be calculated in 63 (55.8%). The general characteristics of the patients are reported in Table 1. The details referred to pre-hospital care and the outcomes following such care are described in Table 2. None of the patients admitted to hospital received treatment involving hypothermia.

Figure 1.

Diagram showing the inclusion of patients and final outcome. EAWP: electrical activity without a pulse; CPC: Cerebral Performance Category; CPR: cardiopulmonary resuscitation; RSC: recovery of spontaneous circulation.

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Of the 9 patients (7.2%) alive at hospital discharge, 5 experienced full recovery (CPC1), while four suffered severe neurological sequelae (CPC3–4).

The following results were recorded over follow-up: the 5 patients with CPC1 maintained this status 18, 22, 42, 58 and 62 months after the event, respectively. The four patients with CPC3–4 neurological impairment were alive and presented discrete improvement of their neurological status (all four corresponded to CPC3) after a period of 6, 8, 24 and 45 months, respectively. The characteristics of these patients are described in Table 3.

The present study describes the results of the largest series of out-of-hospital CA episodes in the pediatric population in Spain. The proportion of pediatric/adult CA in our series is similar to that published by other registries, taking into account the differences in defining the age groups.3,6 Likewise, overall survival was consistent with the data from other similar series,13 and lower than in our adult population.8 Most of the CA episodes occurred outside the home, though close to 50% were not witnessed. Despite these data, resuscitation maneuvers were started in two-thirds of the cases before the arrival of the ECT–probably because a proportion of arrests occurred in primary care centers and others were directly referred to these centers before the ECT arrived. One-half of the patient reached the hospital, though one out of every 5 of these individuals did so without a spontaneous pulse and under conditions of ongoing resuscitation maneuvering–this being known to imply a poor prognosis.14,15 This circumstance, which greatly exceeds what is seen in adults, is probably related to the known difficulty of deciding resuscitation cessation in children.16 Although the time of death cannot be established, the fact is that none of the patients with ongoing resuscitation maneuvering received hospital discharge.

In the same way as in other series from different countries, an initial defibrillable rhythm is infrequent,5,17,18 and this undoubtedly exerts an influence upon the low general survival rates observed at this age. In fact, asystolia was not the initial condition in any of the cases with a favorable neurological outcome.

All the survivors underwent life support maneuvering before arrival of the ECT, and CA was witnessed in the 5 cases resulting in full recuperation. One arrest of traumatic origin was also witnessed by the ECT. Although this patient survived, long-term sequelae resulted (CPC3)–this being expected, considering the poor general prognosis of CA of this kind.19

An important number of cases were classified as being of unknown cause, and although in adults CA is usually attributed to cardiac causes, the same does not apply to pediatric patients, where a low diagnostic correlation has been evidenced in the absence of an apparent cause of CA.20 There was moreover important uncertainty in estimating the time of arrest – this reflecting the difficulty of establishing the time of the event when CA is not witnessed.

Survival among out-of-hospital CA victims is low. Although a significant percentage of patients reach hospital, the long-term outcome is disappointing, independently of adherence of the pre-hospital basic, airway and drug measures (Table 2) to the international recommendations.21 The results are probably influenced by the difficulty of treating the cause of CA, e.g., percutaneous coronary intervention in the case of CA of cardiac origin in adults,22 and uncertainty regarding the efficacy of therapeutic hypothermia in pediatric CA.23,24 In fact, in none of the patients in our series was hypothermia used, despite the fact that during the first years of this type of practice there were fewer negative data to feed such controversy.24

A very notorious observation is the marked difference in outcome between pediatric out-of-hospital CA and CA occurring in hospital,25 with percentage results that currently give the impression of being beyond reach. Nevertheless, considering that the data are referred to a single emergency care service (albeit assisting the most populated region in Spain), there might be some variability, as occurs with other general series published in this country.26

A key issue in intervention would be not only to increase the percentage of prior resuscitation maneuvering but also its quality – specifically, performing chest compression with ventilation versus compression alone. This aspect should be stressed when telephone recommendations and instructions are provided from the coordination centers.27,28

Despite the abovementioned data, the neurological status of the pediatric patients that survived out-of-hospital CA was maintained over the long term. The patients discharged from hospital with full recovery maintained that condition. In comparison, although the patients with neurological sequelae showed discrete improvement, they all remained dependent for daily life activities.

Our study has a number of limitations. Although patients are entered prospectively in the registry, in chronological order, the data were analyzed on a retrospective basis. Certain variables with missing information in turn can condition the results. In this regard, missing information referred to the time of arrest limits analysis of the influence of the time interval between collapse and the start of resuscitation. Although this is a common limitation in most registries, it constitutes a key variable in relation to the outcome of CA. On the other hand, the registry is characterized by an automatic case inclusion system, and although quality control measures have been implemented, it is not possible to discard errors attributable to defective case coding, which would result in the non-inclusion of some patients.

Although the study series was very large considering the age group involved, the small number of patients who finally survived did not advise any correlating analysis between variables and outcome. Lastly, this is a general CA registry, not a specific registry of pediatric CA, and is moreover confined to a regional setting. The results obtained therefore might not be extendable to the rest of Spain.

Our results demonstrate the need to maintain follow-up and to analyze the evolution of pediatric patients with out-of-hospital CA, in order to incorporate improvements in their integral care. Research focusing on measures capable of guaranteeing previous resuscitation of better quality could increase the chances for success of a series of hospital care measures which, at least for the time being, lack protocols specifically targeted to patients of this age.

The Andalusian Out-of-Hospital Cardiac Arrest Registry (Registro Andaluz de Parada Cardíaca Extrahospitalaria) was implemented through a research grant from the Fondo de Investigaciones Sanitarias, Instituto Carlos III, and is maintained through proprietary funding from the EPES.

The authors declare that they have no conflicts of interest.