Randomised controlled trials in pre-hospital trauma: a systematic mapping review

Epidemiology of patients assessed for trauma by Swedish ambulance services: a retrospective registry study

BACKGROUND

There is a lack of knowledge regarding the epidemiology of severe trauma assessed by Swedish emergency medical services (EMS).

AIM

To investigate the prevalence of trauma in Sweden assessed by EMS from a national perspective and describe patient demography, aetiology, trauma type, prehospital triage and clinical outcomes.

METHODS

Data from two national quality registries, the Swedish Ambulance Registry and the Swedish Trauma Registry (SweTrau) were collected from January 1 to December 31, 2019. Inclusion criteria were an Emergency Symptoms and Signs code equivalent to trauma in the Swedish Ambulance Registry and criteria fulfilled for SweTrau inclusion. Exclusion criteria were patients < 18 years old, those not transported to a hospital and those without a personal identification number.

RESULTS

In total, 53,120 patients with trauma were included (14% of primary EMS missions involving a personal identification number). Of those, 2,278 (4.3%) patients (median age: 45 years; 32% women) were reported in SweTrau to have severe or potentially severe trauma (penetrating: 7%, blunt: 93%). In terms of including all causes of trauma, the code for 'trauma alert activation' was most frequent (55%). The most frequent injury mechanism was an injury caused by a car (34%). Most (89%) cases were assigned Priority 1 (life-threatening condition) at the dispatch centre. 62% were regarded as potentially life threatening upon EMS arrival, whereas 29% were assessed as non-life-threatening. Overall, 25% of the patients had new injury severity scores > 15. 12% required invasive treatment, 11% were discharged with severe disability and the 30-day mortality rate was 3.6%.

CONCLUSION

In this cross-sectional study, 14% of the primary EMS missions for one year were caused by trauma. However, only a small proportion of these cases are severe injuries, and the risk of severe disabilities and death appears to be limited. The most frequent aetiology of a severe trauma is injury caused by a car, and most severe traumas are blunt. Severe traumas are given the highest priority at the dispatch centre in the vast majority of cases, but nearly one-third of these cases are considered a low priority by the EMS nurse. The latter leaves room for improvement.

The relationship between acute pain and other types of suffering in pre-hospital trauma victims: An observational study

BACKGROUND

Acute pain is an important complaint reported by trauma victims, however, the relationship between it and other types of discomfort, such as discomfort caused by cold, discomfort caused by immobilization, and psychological distress such as fear, anxiety, and sadness is limitedly studied and documented.

AIM

To assess the relationship between acute trauma pain and other types of suffering in pre-hospital trauma victims.

METHODS

This is a prospective multicentre cohort study conducted in Immediate Life Support Ambulances in Portugal. All adult trauma victims with a mechanism of blunt and penetrating injuries, falls, road accidents and explosions, were included.

RESULTS

605 trauma victims were included, mainly male, with a mean age of 53.4 years. Before the intervention of the rescue teams, 90.5 % of the victims reported some level of pain, 39.0 % reported discomfort caused by cold, while 15.7 % felt fear, 8.4 % sadness, 49.8 % anxiety and 4.5 % apathy. Victims with high discomfort caused by cold tend to have higher pain levels. Significantly higher pain intensity were observed in victims with fear and anxiety. Univariate and multivariate analysis indicates that immobilization is associated with increased pain levels.

CONCLUSIONS

There is a statistically significant relationship between acute trauma pain, anxiety, fear, cold and immobilization.

Challenges and opportunities for conducting pre-hospital trauma trials: a behavioural investigation

BACKGROUND

Trials in pre-hospital trauma care are relatively uncommon. There are logistical and methodological challenges related to designing and delivering trials in this setting. Previous studies have assessed challenges reported in individual trials rather than across the pre-hospital trial landscape to identify over-arching factors. The aim of this study was to investigate the challenges and opportunities related to the set-up, design and conduct of pre-hospital trauma trials from across the pre-hospital trial landscape and a specific pre-hospital trauma feasibility study.

METHODS

Semi-structured interviews were conducted with two cohorts of participants: research personnel who had experience of pre-hospital trials, either through direct involvement in conduct or through strategic oversight of national initiatives (n = 7), and clinical staff (n = 16) involved in recruitment to a pre-hospital trauma feasibility study. Thematic analyses were used to assess the barriers and enablers of conducting pre-hospital trauma trials. Two frameworks (The Capability Opportunity Motivation-Behaviour and the Theoretical Domains Framework) were used to guide analyses.

RESULTS

The barriers and enablers reported were relevant to several TDF domains and COM-B components. Across both cohorts, challenges associated with opportunities were reported and included the lack of research experience amongst pre-hospital staff, team dynamics within a rotating shift schedule, and the involvement of external organisations with diverse institutional priorities and infrastructures (e.g. Air Ambulances). The infrequency of eligible cases was also reported to affect the trial design, set-up, and conduct. Other barriers reported related to clinical equipoise amongst staff and institutional pressures, which affected motivation.

CONCLUSIONS

This study has highlighted that pre-hospital trials face many context-specific but also generic challenges. Pre-hospital trauma trial teams could consider the findings to develop targeted, behaviourally focused, solutions to the challenges identified in order to enhance the set-up and conduct of trials in this setting.

TRIAL REGISTRATION

NCT04145271. Trial registration date: October 30, 2019. Note that this paper does not report results from a specific trial but does include participants who were involved in the conduct of a registered pre-hospital feasibility study.

Accuracy of risk tools to predict critical bleeding in major trauma: A systematic review with meta-analysis

BACKGROUND

Early detection of critical bleeding by accurate tools can help ensure rapid delivery of blood products to improve outcomes in major trauma patients. We conducted a systematic review to evaluate the accuracy of risk tools to predict critical bleeding in patients with major trauma.

METHODS

PubMed, Embase, and CENTRAL were searched up to February 2021 for studies investigating risk tools to predict critical bleeding for major trauma people in prehospital and emergency department. We followed the Preferred Reporting Items for Systematic Review and Meta-Analysis of Diagnostic Test Accuracy study guidelines. Two independent authors included studies, extracted data, appraised the quality using the Quality Assessment of Diagnostic Accuracy Studies 2 and assessed the certainty of evidence (CoE) using the Grading of Recommendations Assessment, Development and Evaluation methodology. Sensitivity, specificity, and the receiver operating characteristics curve for all selected triage tools.

RESULTS

Eighty-nine observational studies for adults and 12 observational studies for children met our inclusion criteria. In adults, we found 23 externally validated and 28 unvalidated tools; in children, 3 externally validated tools and 5 unvalidated. In the externally validated tools, we identified those including clinical, laboratory, and ultrasound assessments. Among tools including only a clinical assessment, the Shock Index showed high sensitivity and specificity with the CoE ranging from very low to moderate in adults, as well as Shock Index Pediatric Age adjusted with a moderate CoE. We found that tools using clinical, laboratory, and ultrasound assessments were overall more accurate than those tools without all three components.

CONCLUSION

Clinicians should consider risk tools to predict critical bleeding in a time-sensitive setting like major life-threatening trauma. The Shock Index and Shock Index Pediatric Age adjusted are easy and handy tools to predict critical bleeding in the prehospital setting. In the emergency department, however, many other tools can be used, which include laboratory and ultrasound assessments, depending on staff experience and resources.

LEVEL OF EVIDENCE

Systematic Review and Meta-Analysis; Level III.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) in patients with major trauma and uncontrolled haemorrhagic shock: a systematic review with meta-analysis

Background

Multiple studies regarding the use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in patients with non-compressible torso injuries and uncontrolled haemorrhagic shock were recently published. To date, the clinical evidence of the efficacy of REBOA is still debated. We aimed to conduct a systematic review assessing the clinical efficacy and safety of REBOA in patients with major trauma and uncontrolled haemorrhagic shock.

Methods

We systematically searched MEDLINE (PubMed), EMBASE and CENTRAL up to June 2020. All randomized controlled trials and observational studies that investigated the use of REBOA compared to resuscitative thoracotomy (RT) with/without REBOA or no-REBOA were eligible.

We followed the PRISMA and MOOSE guidelines. Two authors independently extracted data and appraised the risk of bias of included studies. Effect sizes were pooled in a meta-analysis using random-effects models. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation methodology. Primary outcomes were mortality, volume of infused blood components, health-related quality of life, time to haemorrhage control and any adverse effects. Secondary outcomes were improvement in haemodynamic status and failure/success of REBOA technique.

Results

We included 11 studies (5866 participants) ranging from fair to good quality. REBOA was associated with lower mortality when compared to RT (aOR 0.38; 95% CI 0.20–0.74), whereas no difference was observed when REBOA was compared to no-REBOA (aOR 1.40; 95% CI 0.79–2.46). No significant difference in health-related quality of life between REBOA and RT (p = 0.766). The most commonly reported complications were amputation, haematoma and pseudoaneurysm. Sparse data and heterogeneity of reporting for all other outcomes prevented any estimate.

Conclusions

Our findings on overall mortality suggest a positive effect of REBOA among non-compressible torso injuries when compared to RT but no differences compared to no-REBOA. Variability in indications and patient characteristics prevents any conclusion deserving further investigation. REBOA should be promoted in specific training programs in an experimental setting in order to test its effectiveness and a randomized trial should be planned.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13017-021-00386-9.