Outcome for paediatric out-of-hospital cardiac arrest (OHCA) is generally poor, with survival reported as less than 10%. Those who do survive are likely to have an unfavourable neurological outcome. This retrospective observational analysis study examined the relationship between on-scene time and improved survival. The study also examined which pre-hospital interventions may lead to improved survival. The researchers had a focus on the length of time on scene, level of care (basic/advanced) and administration of fluids/medication.
The study used data from the Resuscitation Outcomes Consortium (ROC) database. This included data from eight American and three Canadian regions, with a mix of urban, suburban and rural populations. Patients aged 3 days to 19 years suffering a medical OHCA between December 2005 to December 2012 were included for analysis.
In total, 3 115 patients were identified, and after exclusion criteria were applied, the final sample size was 2 244. On-scene times were grouped into three categories: <10 minutes (n=486), 10–35 minutes (n=1542) and >35 minutes (n=216). The majority of patients (68.7%) had an on-scene time of between 10 and 35 minutes. For the <10 minute group, return of spontaneous circulation (ROSC) was achieved for 21/486 (4.3%) patients. For 10–35 minutes, ROSC was achieved for 299/1542 (19.4%) of patients. Lastly, the >35 minutes group had a ROSC rate of 76/216 (35.2%).
While ROSC was more likely in the >35 minute group, survival to hospital discharge was highest in the 10–35 minute group (158/1542, 10.2%). Survival to discharge for <10 was 5.3% and for >35 was 6.9%. Data were also separated by age, with the adolescent group (12–19 years) having the highest ROSC rate (221/644, 34.9%) and survival to hospital discharge (103/644, 16.3%). Children (1–12 years) had a ROSC rate of 102/594 (17.2%), with survival to discharge in 58/594 (9.8%).
Infants (3 days to 1 year) clearly had the highest incidence of OHCA in this data set (n=1 017), but lowest ROSC rate 73/1017 (7.2%) and lowest survival to discharge (38/1017, 3.7%). Over the study's duration, the authors noticed an increase in adolescent survival from 12.2% to 19.5%. Infants saw a slight increase over the period of study, but this was not observed in children.
The data is very clear on the scene time associated with survival (10–35 minutes), and there is trend towards the upper limit of 35 minutes being associated with increased survival to discharge. Attempts at circulatory access (IV and IO) were associated with increased survival. Interestingly, there was a negative association between resuscitation drug delivery and survival. Defibrillation and advanced airway techniques were also not associated with survival.
Limitations are openly discussed in this paper. Despite the prospective collection of data, causality could not be proven. The data set was also inconsistent in its completeness, which led to a number of records being excluded from the study. Aetiology of cardiac arrest and neurological outcome were not recorded for a number of subjects that limits analysis for these variables. A major confounding factor in this study was the difference in clinical practice between sites, including post-resuscitation care in the receiving hospital. Advanced life support providers attended the majority of patients and so no comparison could be made between the basic and advanced responder.
An important strength was a uniform definition of cardiac arrest applied to the data set, as well as the use of a large sample of patients for analysis. The authors recommend that a ‘scoop and run’ approach with a scene time of less than 10 minutes does allow sufficient time for interventions that may benefit the patient. The study also suggests more emphasis should be placed on circulatory access and fluid resuscitation over advanced airway management and resuscitation drugs. The significantly low ROSC and survival rates seen in the infant group may be explained by the incidence of sudden infant death syndrome; however, infants also had the shortest on-scene times and least interventions performed by emergency medical services.
The paper concludes that there is a significant association between scene time and survival for paediatric OHCA. We must now carefully consider how the recommendations of this paper may be implemented into clinical practice and how paediatric OHCA education may need to change to account for the lack of support for a ‘scoop and run’ approach.