We aimed to investigate whether a bystander’s emotional stress state affects DA-CPR in OHCA. The primary outcome was initiation of chest compressions (Yes/No). Secondarily we analysed time until chest compressions were initiated and assessed how the dispatcher instructed CPR.
We found no significant difference in initiation of chest compressions according to the caller’s emotional stress state. There was a longer time until initiation of chest compressions in cases with an emotionally stressed caller compared to cases with a not emotionally stressed caller, however, non-significant. We found that the dispatchers were significantly more likely to be encouraging and motivating, and to instruct on speed and depth of chest compressions during resuscitation attempt, in cases with an emotionally stressed caller compared to cases with a not emotionally stressed caller.
There was a higher incidence of ROSC in the cases where the caller was emotionally stressed. Even though there was a non-significantly longer time until chest compressions were initiated, the outcome of OHCA was better in the cases with an emotionally stressed caller. This could imply that being an emotionally stressed bystander, somewhat might be favorable in OHCA. However, one could imagine that reaching a certain level of emotional stress might not be beneficial. The Yerkes-Dodson law states that moderate arousal can actually enhance performance, although high levels of arousal can decrease performance [18]. However, the patients were generally younger in the cases where the caller was emotionally stressed, which would, expectedly, improve the probability of OHCA outcome.
Although only 32.2% of the callers were emotionally stressed, many of them actually presented symptoms such as crying, screaming, or not paying attention, implying that some callers were in fact severely emotionally stressed. Previous studies have primarily used an ECCS score of the original five groups, but without specified symptoms [11,21]. To investigate whether the symptoms used in this study have an impact on OHCA variables, further research in the area is needed.
Many of the not emotionally stressed callers consisted of healthcare professionals, who would be expected to be less stressed. Alfsen et. Al. analyzed emergency calls regarding OHCA and found that when the caller is a healthcare professional, the roles were reversed, and the responsibility was given to the caller. This resulted in a longer time until recognition of OHCA due to the CA algorithm being abandoned [19]. The emotionally stressed callers were primarily relatives to the patient. This could result in a higher emotional stress state. Studies have found that relatives less often provide CPR, even though they received instructions from the dispatcher [20]. We found that the caller cases with an emotionally stressed caller, were more often alone, which could also be an important factor in the higher emotional stress state.
The longer time until chest compressions were initiated could be explained by the emotional stress causing confusion or delayed actions taken. However, a similar study evaluating emergency call recordings regarding OHCA by Chien et al. found a shorter median time until recognition of OHCA and first chest compression in caller’s registered as ECCS 4–5 compared to ECCS 1–3 [11]. Our study only evaluated the caller’s emotional stress state in two categories, and more elaborate classification might explore further differences.
Dispatchers were significantly more likely to be encouraging and motivating, to instruct on speed and depth of chest compressions during resuscitation attempt, in cases with an emotionally stressed caller compared to cases with a not emotionally stressed caller. This might be due to the medical dispatcher sensing that the caller was emotionally stressed and therefore tried to provide more precise and encouraging instructions. Twenty-seven percent of callers were characterized as “Emotionally stressed”, meaning the vast majority of the callers were calm (ECCS 1–2) (73%). Various studies on the impact of stress coping strategy during simulated CPR and real OHCA audio recordings also found 90% of the callers to be cooperative (ECCS 1–3) [21,22].
Furthermore, we found that emotionally stressed callers more often reported barriers to DA-CPR. The most frequent barrier was “Could not move the patient”. Wah Ho et al., also found this to be the most prevalent barrier [9]. Others have found the most prevalent barrier to be “Caller refused” [11]. An emotionally stressed caller could access the situation under the influence of their emotional stress and report a barrier that might be manageable to eliminate. Furthermore, Wah Ho et al. suggested that barriers to DA-CPR are related to a longer time until chest compressions initiated and to be related to lower proportions of chest compressions eventually being performed [9]. Lewis et al. found that the factors delaying recognition of OHCA were related to the dispatcher asking unnecessary questions, and the caller’s emotional stress state [23]. A study by Calle et al. on the effect of training medical dispatchers showed a 20% increase in collecting relevant information before vs. after training [24].
4.1 LIMITATIONS
The study only analyzed the dispatcher assisted resuscitation and not the recognition of cardiac arrest, which might also be affected by a bystander’s emotional stress. Unfortunately, many of the calls did not have registered times until chest compressions were initiated. This might be due to difficulty determining this through audio recordings. Previous studies have shown a thorough insight to OHCA cases using live video streaming from bystander’s smartphones, which might give a more precise timestamp until any of the abovementioned events [25].
Additionally, even though an overall kappa score of 0.72 was reached, suggesting substantial agreement amongst observers, rating the callers is a case of individual assessment. The assessment depends on the individual observers’ evaluation, which provides a degree of unintended subjectivity.
Being assertive, motivating and encouraging is in this study presented as being a positive factor when performing DA-CPR. Dispatchers in Denmark follow a criteria-based protocol termed the Danish Index for Emergency Care, helping the dispatcher assess the severity of the call [26]. However, this protocol does not instruct the dispatcher to be encouraging or assertive, etc. In a study of qualitative interviews of 11 medical dispatchers, Møller et al. suggested that non-technical skills training of medical dispatchers should be implemented along with the medical expertise skills [27].
The study cannot determine the quality of DA-CPR, since we only registered whether the dispatchers were being assertive or passive, encouraging and motivating, instructed on speed and depth of chest compressions, and addressed an AED. The amount of guidance and quality of this would be difficult using this binary method (Yes/No) when registering data. A qualitative study design might address this in a more precise manner.