In the present study, it was shown for the first time on the basis of a large patient cohort of severely injured children that the criteria from the German S3 polytrauma guidelines for prehospital intubation can also be applied to children. Thus, a general transferability from adults to children seems to be possible in principle. However, it must always be kept in mind that intubation per se is not the goal-directed measure, but is a possible form of therapy for the restoration of normoxia, normoventalation and normotension.
Examining the descriptive data, it is not surprising that the majority of severely injured children are male. This finding reflects the previous data situation regarding severely injured patients in the TR-DGU and the current literature [1]. Thus, Ilie et al. came to a comparable conclusion in their study [28]. Interestingly, however, the distribution of gender in children, especially the younger that they are, is somewhat more balanced than that in the adult collective. In addition, blunt trauma represents the largest proportion, with a mean greater than 94.3%, as would be expected. This injury remains the leading injury entity in German-speaking countries and in Europe as a whole. Injury severity measured with the ISS or NISS showed little variation between groups. However, infants up to 2 years of age were more severely injured and more comparable to the adult group. In a retrospective registry study, it remained speculative, of course, why the infants in particular appeared to be more severely injured. Here, one explanation could lie in the causes of accidents. Due to falls, both from low (< 3 m) and very high (> 3 m) heights, there was a high prevalence of falls in Group 1. Correspondingly, severe head injuries with an AIS ≥3 in comparison also occurred most frequently in this group. In contrast, both in the current literature and in the present study, traffic accidents and their consequences (e.g., increased severe limb injuries with an AIS of ≥3) increase with increasing age of children [29, 30].
The association between severe head injuries and very young children has been well described in the current literature. For example, Haarbauer-Krupa et al. showed in their study, analogous to the present results, that falls are the leading cause of accidents in children up to 4 years of age and, in this context, severe TBI occurs disproportionately [31]. Prehospital measures also emphasize these findings. Thus, it seems initially conclusive that prehospital resuscitation, prehospital administration of catecholamines, and initial lower GCS scores were also most common in the group of youngest children, in contrast to the other groups. Interestingly, prehospital rescue time was shorter in children than in adults. This outcome was also demonstrated by Ashburn et al. in their study [32]. One reason could be the cause of the accident itself. As already mentioned, falls in particular represent a leading cause, so potentially complex rescues of trapped patients, e.g., from cars, occurred less often.
It is clear from both the present study and the current literature that severe TBI in particular is by far the most common cause of death in children [33]. Accordingly, in this study, the proportion of children dying with an initial GCS score < 9 was more than 30%. Thus, based on these results, as well as a review of current studies, it is completely indisputable that a major focus in the treatment of severely injured children must be the prehospital securing of the airway and breathing or ventilation. In this context, prehospital securing of the airway and maintenance of at least adequate oxygenation play crucial roles due to severe TBI [34]. These roles are illustrated not least by the high prioritization of the airway in internationally recognized treatment concepts, such as the ATLS® [6].
Therefore, the most remarkable finding of this study is that the intubation criteria listed in the German S3 polytrauma guideline are apparently also applied in practice in pediatric patients. Approximately 30% of all patients fulfilled at least one intubation criterion, and of these patients, more than 70% were actually intubated, both adults and children. Transferability of the guideline from the adult to the severely injured child thus seems to have been actually applied in practice. It should be mentioned once again that absolute causality cannot be readily deduced on the basis of retrospective registry data. Thus, it remains unclear why intubation was not performed in the remaining 30% of severely injured children despite an intubation criterion. It must be noted here that the prehospital decision for or against an intervention, e.g., intubation, must be made individually by the acting emergency team and cannot be conclusively clarified in a retrospective analysis with pseudonymized data. Previous studies have shown that intubation is also associated with risks and can negatively influence the outcome if the indication is not clear [35]. When examining the results of the adult cohort, it is also notable that the prehospital decision for intubation was also not made in approximately 30%, although an intubation criterion according to the S3 polytrauma guideline existed in these cases as well. Thus, there were no statistically significant differences and in practice between the adult and pediatric populations in this regard. Similar results were obtained by Laurer et al. in their study [29]. With the help of a matched pairs analysis, they were also able to show that the prehospital treatment of severely injured children is comparable in principle to that of adults and that there are only differences in the causes of accidents and previous illnesses.
Interestingly, it could be shown that children who were not intubated, despite an existing intubation criterion, died in only approximately 4.1% of cases. Thus, the proportion was significantly lower than in adults, with 6.6% of nonintubated casualties having an existing intubation criterion. Almost 30% who met an intubation criterion and were intubated died. This finding suggests that children with an existing intubation criterion might have been more severely injured, but the prehospital individual decision not to intubate despite an existing intubation criterion did not necessarily worsen the outcome. In this context, the current literature by von Elm et al. and Emami et al. even critically questions in principle whether intubation in severe TBI, for example, improves outcomes [36, 37]. Both conclude that there is insufficient evidence to date to support the absolute benefit of intubation in TBI. In current practice, therefore, the infrequent use of severely injured children seems to indicate that intubation is most appropriate only after all alternative treatments have been exhausted. A possible explanation for why children and adults were not intubated emerges from consideration of the multivariate regression analysis. Of all the intubation criteria, prehospital low systolic blood pressure < 90 mmHg and associated hemorrhagic shock, although significant, still emerged as the weakest parameters leading to intubation. Unlike severe TBI with a GCS < 9, alternative treatment to intubation and ventilatory therapy for hemorrhagic shock seem at least conceivable. Hudson et al. also concluded in their review that uncritical prehospital intubation for hemorrhagic shock should be reconsidered and alternative therapies should be considered [38]. In their study, Chou et al. even observed an increase in mortality with prehospital intubation due to hemorrhagic shock [39]. However, it remains completely undisputed that intubation is also of substantial importance in hemorrhagic shock to ensure adequate oxygenation. Furthermore, the most severe injuries are often associated with TBI and a GCS score < 9. In these cases, according to current studies, intubation should be performed anyway [34]. Another reason why low systolic pressure has not been used as the most important parameter for intubation in children could be due to physiologically low blood pressure values, especially in infants. However, it was shown in the present study that, for example, in Group 1 of the smallest children or babies, the prehospital blood pressure tended to be even higher on average than in the slightly older children in Group 2. Another argument against an explanation based purely on the physiology of children due to physiologically low blood pressure values is that prehospital hemorrhagic shock with a systolic pressure < 90 mmHg was also the weakest independent parameter for intubation in adults.
Overall, the respective specialization of the physician on site could also have a fundamental influence on prehospital measures. Gaessler et al. came to a similar conclusion in their study [40]. The collective here referred to patients who were transported by helicopter, regardless of whether they were children or adults. However, this relationship cannot be fully elucidated with a retrospective analysis because data on individual decision-making are simply lacking. Nevertheless, because the basic decision to intubate or not intubate was similarly distributed between children and adults in the present study, the inference that children were intubated less or more prehospital is not supported by the data presented here. As a therapy for respiratory failure, endotracheal intubation seems to be preferred over an alternative airway in both children and adults. Why this relationship exists cannot be conclusively determined based on retrospective data. It is surprising only insofar as an alternative airway would have been expected, especially in very young children, for example, out of concern that endotracheal intubation would damage vulnerable airways. However, it is also possible that the use of, e.g., a laryngeal mask as an alternative airway, is not sufficiently widespread and therefore not practiced often enough by emergency teams. This is remarkable, as the current S2k guideline Polytrauma in Children and Adolescents points out that tracheal intubation as a standard airway management procedure must be critically reflected in the pre-hospital context [9].
In summary, guidelines are an important pillar in the treatment of severely injured patients, regardless of whether they are children or adults. For example, a study by van Rein et al. demonstrated that the existence of triage protocols or checklists simplifies decision-making in the field, potentially improving outcomes [41]. A basis for such protocols should always be scientific guidelines.
Limitations
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1.
In a retrospective analysis based on pseudonymized data, it is not possible to clarify the individual decisions of the hospital teams involved. Additionally, access to the patient records for further analysis was not possible due to pseudonymization.
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2.
Only possible links with conclusions can be described in the examined data, not absolute causalities.
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3.
Only patients who could be transferred to a hospital/emergency room are included in the TR-DGU. Patients who died at the scene of the accident are not documented and therefore were not evaluated.
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4.
All patients were treated on site by a physician. However, it remains unclear in this analysis what specialization the physician had (e.g., anesthesiologist, surgeon, etc.).
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5.
Particularly in children, the determination of circulatory parameters, for example, can falsify values through the use of blood pressure cuffs that do not correspond to the size. Psychological states such as anxiousness or agitation can also alter the values measured, for example, respiratory rate. However, due to the group size, these influencing factors should not have a statistical impact.