In this assessment of the BLS and AED skills in the cohort of EMS providers in a local low-volume Scandinavian ambulance setting, 70% of the maximal achievable score according to the Cardiff test was reached. There is, however, room for improvements. Compressions were given at a higher rate than recommended in the guidelines but compression depth was adequate in a majority of cases. Ventilation was successful but tidal volume was significantly higher than the maximum recommended value. All managed to deliver a defibrillation shock, but the safety checks in relation to AED managing were not satisfactory in all subjects.

The strengths of our study include that the study population comprised 91% of the entire cohort of EMS providers ‘level 2’ in the community and thus gives a realistic assessment of the available resuscitation skills. The ordinal data was registered by one doctor only, thus avoiding inter observer variability. Given that the study was performed with a manikin and not actual cardiac arrest victims, one could argue that this dummy setting does not extrapolates to real life. On the other hand, this design enabled us to study variables, which has not been studied in real life settings, like the recognition of cardiac arrest and safety checks related to the AED deployment. Also our measurements of variables such as ventilation volume and compression depth might be more consistent. A limitation is that the EMS providers knew that they were to participate in a research project regarding resuscitation skills. Another limitation is that it would have been beneficial to create a specific course where the identified skills needing improvement could have been trained systematically and afterwards re-assessed. Unfortunately, for logistics and economic reasons this was not possible. One could argue that our emphasis on safety checks is rather large, since the EMS providers often are performing resuscitation alone in the vehicle during transport. But in the patients home they are working together and likely with relatives present.

Throughout the ERC guidelines for resuscitation 2005 and 2010 [14, 15] there is increased emphasis on minimally interrupted high-quality chest compressions and both human [16] and animal [17, 18] studies have shown that even short interruptions in chest compressions are associated with worse outcome.

Previously the quality of real life EMS CPR has been found to be poor with no compressions being given 48% of the time (38% when subtracting time for defibrillation) [6] and 57% of the time, respectively [8]. More recent studies have shown improvements in the hands-off ratios following the Guidelines 2005 for resuscitation, from 23% to 14% [19], and 49% to 34% [20], respectively.

The hands-off ratio in our study was 40%. Some time without chest compressions is unavoidable (e.g. for recognition of cardiac arrest and defibrillation) but the above mentioned clinical studies do not take this into account. Therefore, the hands-off ratio in our study is high, especially since it was a manikin study with no interruptions due to placement of i.v. lines or loading of the patient into the EMS vehicle. In a recent Danish study exactly the loading of the patient was found to be a major contributor to hands-off time [21]. Thus, one of the very important aspects of the guidelines (minimizing the hands-off time) was not performed well by the EMS providers.

Another important parameter discussed in the guidelines is the quality of chest compressions. In our study 55% achieved a compression depth of 40–50 mm, which was the recommended depth in guidelines 2005 [12]. The average compression depth was not significantly too shallow, but still 30% provided compressions that were too shallow. One study has shown that shallow compressions were associated with defibrillation failure [16] and other studies have shown that increasing compression depth was correlated with increasing short-term survival [22, 23]. Clinical studies have documented prevalence of too shallow compressions [6, 7, 24] whereas EMS manikin studies have reported that up to 50% of the compressions were too deep [25, 26]. Thus our study is not concurrent with other manikin studies and points out a skill that needs improvement. The mean compression rate was 123 (±15)/min, which was too high but in accordance with other studies [19, 23, 24]. Only 35% changed the person providing chest compressions every 2 minutes, which is emphasized in the guidelines and only 45% had a correct hand position.

In our study the mean tidal volume was 745 (±221) ml, and significantly exceeding the recommended maximum of 600 ml. Only 10% reached the recommended ventilation volume (500–600 ml) and 75% hyperventilated the manikin. In porcine models hyperventilation has resulted in increased intrathoracic pressure, decreased coronary perfusion pressure and survival rate [27].

A fundamental rule in all first aid is ‘safety first’ and therefore it is surprising that more than half of the EMS providers did not perform any hands-off checks during rhythm analysis and only 30% performed both a visual and a verbal hands-off safety check before pushing the shock button. During training, safety checks in relation to the AED should be reinforced.

With regard to recognition of cardiac arrest it is recommended in the guidelines that looking for signs of life should take no more than 10 sec [14]. In our study the delay from start of the scenario to the first compression or ventilation was 35 (±9) sec. Studies with trained laypersons have reported similar excessive times (29–40 sec) for recognition of cardiac arrest [28–30]. When recognizing cardiac arrest 25% did not make any attempt at opening the airway which is higher than the reported 11% in a manikin study with trained emergency healthcare professionals [25]. After recognizing the unwitnessed cardiac arrest, only half performed BLS for 2 min, which was the current guideline. With regard to correct compression/ventilation ratio (30:2) is it surprising that only 80% were able to recall this, 3½ years after the guidelines changed. An explanation could be that the island’s ambulance company (Falck a/s) had a delay of at least 1½ year in implementing the guidelines 2005 [31]. All the issues mentioned in this paragraph are simple cognitive skills and one could speculate if enough attention has been paid to maintenance of EMS providers’ resuscitation skills.

When evaluating the BLS/AED skills in the cohort of EMS providers in a rural low-volume Scandinavian community, 70% of the maximal achievable score according to the Cardiff test was reached. These are the health care professionals who are on duty with the responsibility of taking care of a real cardiac arrest and one could expect a better performance, especially given the inoffensive training scenario. The study took place on a rural island with only approximately 50 cardiac arrests annually, calling for frequent training in BLS/AED. Our findings suggest that this training most likely has been too moderate and in that way our results might extrapolate to the rest of the country as the island’s EMS operator covers approximately 85% of the population in Denmark. In addition, our findings might be generalizable to other similar rural settings in Scandinavia.

Identifying suboptimal performance demands action. The EMS providers should be trained at regular intervals in realistic settings and with qualified instructors. Personnel employed in rural areas might benefit from a rotation system with shifts in more busy areas. This study points out specific difficulties to which training should be targeted. For instance, the recognition of cardiac arrest probably deserves more attention in resuscitation training, including stressing the importance of checking the airways. The manikin was ventilated successfully, but with high tidal volumes. In addition, the tidal volumes were given with very large variability, indicating that this is another skill that should be trained carefully.