Cardiac arrest is an immediate medical emergency, which can be effectively managed if effective cardiopulmonary resuscitation is commenced promptly. Recent studies show that bystander cardiopulmonary resuscitation (CPR) is the key factor for determining out of hospital cardiac arrest survival.^1,2 It is, therefore, critical to educate young people in CPR as a long-term strategy for the community. Training school children to perform cardiopulmonary resuscitation is one possible method of increasing bystander CPR rates. Evidence shows that cardiopulmonary training, delivered in various ways, is successful in a wide age range of children.^3-16 Studies performed over a wide period and looking at a variety of approaches to training schoolchildren in CPR and associated skills show that all training interventions are successful within a short time scale in increasing knowledge and skills of children when tested.¹⁷ While older children perform more successfully on testing, younger children can perform basic tasks well, including the use of automated external defibrillator. The most efficient method is however not well established.¹⁷

A fundamental problem in learning and performing CPR manoeuvres is the loss of acquired knowledge over time. In one study looking at the retention of CPR skills of successfully trained adults, after 12 months only 47% demonstrated correct hand placement on the manikin; 44% adequately performed the depth of compressions and compression rate was adequate in just 59%.¹⁸

One of the methods used in the training of bystanders in CPR is student participation in training courses. A Norwegian study demonstrated that CPR training can be disseminated in a population by distributing personal resuscitation manikins among children in primary schools.¹⁹ The teachers felt able to easily facilitate CPR training although the incidence of bystander CPR did not increase significantly in the months following the project.  In a study by Jones et al,¹⁴only children from 13 to 14 and older performed chest compressions as well as adults. In order to achieve the depth of chest compressions for adult in cardiac arrest, it requires the application of about 50_kg. Therefore, it seems reasonable to limit the practice of skills for compressing the chest to children over 13 years.

Chest compression depth correlates with physical factors such as increasing weight, body mass index and height. Instruction must include hands-on practice to enable children to perform physical tasks. Repeated training improves performance and retention, but the optimal form and frequency of repeated training are yet to be fully determined. Training interventions should be age-appropriate and practical and should both reinforce core ideas and sequentially introduce skills of greater complexity. Brevity, diversity of format and attention to cost and efficiency will promote interest from children and schools. Types of training that may reduce the main obstacles to the implementation of such training in schools include the use of self-instruction kits, computer-based learning and use of teacher and peer tutor trainers, but again, further exploration is required.¹⁹

This study assessed the basic life support knowledge and performance of secondary school students before and after CPR training with a song and video that was specifically created for this purpose by local authors, with special focus on compressions and easy to remember.

The study included a total of 370 students in the intervention group and 128 in the control group. A single representative random sample of 87 from the intervention group and 35 students from the control group were obtained, students who had not done any of the three questionnaires were not included.

The score in pre-test workshops had a homogeneous score since the intervention group had an average score of 4.48 (95% CI: 4.08 to 4.88), similar to the control group average score 4.19 (95% CI: 3.56 to 4.82). With regard to the assessment of knowledge at one and eight months, students in the control group went to an average score of 5.9 (95% CI: 5.38 to 6.43) to 5.33 (95% CI: 4.75 to 5.92) compared to students in the intervention group that increased from 6.44 (95% CI: 6.10 to 6.77) to 6.76 (95% CI: 6.39-7.13) (Table 1).

Both the pre-intervention questionnaire and the questionnaire performed one month after the intervention showed no significant differences between the two groups; however, at 8 months significant difference was shown with a value of p = 0.000 (Intervention 95% CI: 6.39 to 7.13 vs control 95% CI: 4.75 to 5.92), (F _(1,120)=16.644, p= 0.000), Figure 1.

Taking into account the recommendations of prioritizing compressions in bystander-only CPR, answers were rated regarding the quality of chest compressions, relationship to ventilations and the hand position. Table 2 shows the results. We can see that although average scores are very similar pre-intervention, there are marked differences between groups at one month and eight months. In Figure 2, the differences are significant (F _{(1, 120} = 15.561, p= 0.000), Figure 2.

The aim of the study was to examine the effectiveness of a CPR song in improving the secondary grade students skills in BLS. After eight months, a significant difference was obtained in the group of secondary grade students that were trained with the CPR song and video.

Studies assessing the success of training courses demonstrate significant improvements in performance after training, compared to baseline, in children of all ages, from 4 to 20 years.¹⁷ Increasing the percentage of the population trained in CPR is an integral part of an overall strategy to improve community response to the Out-of-hospital cardiac arrest. Schools provide excellent access to a large part of the community. Over time, a significant percentage of the overall community will receive training. Programs in which students can share materials used in school-based programs at home with family members can further increase the program’s yield regarding the total number of members of the community trained per unit of class time expended.^19,22 In this work we demonstrate that use of a song related to basic CPR is capable of reducing the loss of acquired theoretical knowledge compared to methods using only the traditional basic CPR training. Taking into account the ILCOR recommendation to prioritize thoracic compressions,²⁰ we can see the effectiveness of this new tool to embed knowledge, as the lyrics and choreography used encouraged learning in a fun manner, fulfilling the premise that it is easier to remember the lyrics of a song that the theory learned in a workshop.²³  Previous studies have used popular songs like “Macarena” by Los del Río, Staying Alive and Nellie the elephant to improve the quality of compressions, especially the frequency of compressions. Unlike them, the song “You can” has a content based not only on chest compressions but on the entire sequence of basic CPR. Further work is needed to check if the song is effective in preserving acquired skills in the performance of CPR, in addition to improving the quality of compressions.

The results demonstrate the effectiveness of a new tool to reinforce the theoretical knowledge acquired on CPR, using a song whose lyrics facilitates learning by school adolescents. An advantage of this study is the limited geographical mobility of the group, a difficult obstacle to overcome in large cities that has affected monitoring in other studies.

CPR instruction including the use of automatic external defibrillators has shown to be feasible even for young schoolchildren; earlier training may lead to better results.

The programme 'Kids Save Lives' recently endorsed by the WHO aims to help promote schools-based BLS training worldwide, requiring education on CPR for all pupils starting at least at age 12. We believe that the use of different teaching methods similar to the exposed in our work may encourage students to retain knowledge in CPR.

We may conclude that this method of basic life support training in secondary schools students seems highly effective.  We observed significant improvement and a good retention rate eight months after training in the intervention group. Our study showed that incorporating the song component in the CPR education increases its effectiveness. The use of a song and a video may show promise in the teaching of CPR in secondary school students and should be considered in the future training of this group.