Paramedic administration of blood products to improve outcomes for trauma patients

LEARNING OUTCOMES

After completing this module, the paramedic will be able to:

Haemorrhage is responsible for up to 40% of trauma mortality, and between 33% and 56% of these deaths occur in the out-of-hospital setting (Kauvar et al, 2006). Inadequate resuscitation in a patient experiencing major haemorrhage is an important cause of avoidable death and, there is consensus that if circulating volume is restored and blood components are transfused early, patients have a better chance of survival (Mahambrey et al, 2013).

However, since then, Guyette et al (2021) suggested that fluid resuscitation is no longer appropriate as large amounts of fluids can cause more harm than good. Kaur et al (2011) stated that although transfusion support is vital for a trauma patient experiencing a major haemorrhage, it comes with many concerns such as those around the availability of blood components, cost, storage, shelf life and religious prohibitions.

Thompson et al (2019) found that clinical decisions are often influenced by a paramedic's experience and previous exposure to trauma rather than evidence.

This review aims to explore whether paramedics who are able to administer blood products could improve outcomes and mortality rates.

Methodology

A focused question was used using a population, issue, outcome method with searches of databases—CINAHL, Medline and AMED—to find relevant literature, with limiters added to ensure the literature was recent and appropriate (Table 1).

Study selection

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework (Page et al, 2021) was used to record the search results found at each stage to ensure robustness. The final selection comprised four papers which were then assessed for their eligibility for the study: Bodnar et al (2014a); Heschl et al (2018); Rehn et al (2019); and Sayre et al (2022) (Table 2). These studies were all quantitative and were analysed using the McMaster critical review (Law et al, 2005).

The data from each paper were put together so the results could be compared. Data included sample sizes, average age, participant sex, design method, location, mortality rates and P values (if used). The sample sizes were over a wide range (39–623). All papers used the same study design methods.

The results of each study noted the numbers of participants who survived or did not survive or whether this was not known as data were missing.

Study outcomes reflected the outcome of the patients as well as other factors, such as the cost and feasibility of out-of-hospital blood transfusions.

Results and discussion

Clumpner et al (2020) acknowledged that while there have been advances in out-of-hospital treatment, trauma patients still die from potentially preventable causes such as major haemorrhage. Intravenous fluid therapy is the go-to treatment for a patient experiencing major haemorrhage in the out-of-hospital setting to maintain circulating volume. However, this can increase on-scene time with little benefit to the patient, resulting in poorer outcomes and mortality rates (Clumpner et al, 2020).

Grossman and Porth (2014) stated that blood is a specialised connective tissue that has significantly more benefits than fluid alone. Kaur (2011) further argued that the transfusion of blood should be the treatment of choice as it is the ideal resuscitation tool for maintaining circulating volume, has oxygen-carrying capacity and clotting functions. Where blood is not available, crystalloid fluids can be administered; however, they pose a significant risk of over-infusion.

Eastridge et al (2019) found many potentially preventable deaths after trauma are related to haemorrhage and occur soon after injury and usually before the patient arrives at hospital. Interventions in haemorrhagic injuries, such as blood transfusions, have been shown to decrease mortality. Eastridge et al (2019) also believed advancing these strategies in the out-of-hospital setting may prove beneficial to patient outcomes.

Rehn et al (2019) found that, although there was no significant improvement in overall survival if patients were given out-of-hospital blood products, there was a significant improvement in the survival rates of those within the out-of-hospital setting and on arrival to hospital. This suggests that receiving out-of-hospital blood products reduced mortality. Rehn et al's study (2019) was of a fair quality, scoring 9/15 on the quality assessment table (Table 3).

Bodnar et al (2014a) found similar outcomes and came to a similar conclusion in their study, finding there is a potential role for red blood cell administration in the out-of-hospital environment and it is beneficial for trauma patients to receive blood transfusions as early as possible to decrease mortality rates. However, this study has a small sample size of only 71 patients. Nonetheless, it was of fair quality as it scored 10/15, similar to Rehn et al (2019).

Heschl et al (2018) did not reach the same conclusions as Rehn et al (2019) and Bodnar et al (2014a). They reported that, although out-of-hospital blood transfusions resulted in improvements in patients' vital signs, more research was needed before positive effects on mortality could be proved.

Sayre et al (2022) scored low in the quality assessment (6/15) and had a small sample size. Although this study involved a similar intervention as the other three papers, it did not report on how it affected participant outcomes or mortality.

Although most of the papers in this systematic review reported an increase in patient survival in the out-of-hospital setting, overall survival was not significantly better. However, as Rehn et al (2019) stated, once patients have been transported to hospital, results may be biased as hospitals and trauma centres may provide different interventions. Heschl et al (2018) also acknowledged that further research, such as randomised control trials with bigger sample sizes needed to be carried out to determine the effect of out-of-hospital blood transfusions on mortality rates.

Blood use efficiency

The cost, storage and waste of blood are related issues, along with logistics as vehicles carrying blood products require cooling equipment. McCullagh (2021) also noted that blood from donations are in short supply. Raitt et al (2020) offered a solution to the problem of wastage for ambulances, suggesting a paramedic vehicle could carry two units of blood for a period of up to 24–48 hours and, if the blood is not used within that time, it is returned to a blood bank to be used for in hospital transfusions.

Sayre et al (2022) noted it is possible for paramedics to provide whole blood products to patients with efficient blood use, minimal blood wastage and low cost. They reported it cost $867 for each unit of blood to be administered, which did not include the cost of paramedic training. Training costs were not included in the study as they were viewed as part of the ‘wider mission’; however, for the initial provision of blood transfusions in the out-of-hospital setting, expenditure would be needed on training paramedics to ensure they were competent in delivering the intervention. While Sayre et al's (2022) study is of poor quality, scoring 6/15, Heschl et al (2018), which agrees with some of Sayre et al's (2022) findings, scored the highest (Table 3).

In Heschl et al's (2018) study, blood components were changed every 7–14 days; if they had not been used in the out-of-hospital setting, they were rotated back to the blood bank to be used in hospitals to minimise waste. An audit was carried out to assess the amount of blood wasted during the study; this found 2255 units were delivered to be used in the out-of-hospital setting, 11 of which were wasted because of breakages and a power cut. All the other units were used or returned to the blood bank; the percentage of waste reported was 0.5%.

Although several papers highlighted that although it may be costly for ambulance services to set up so all paramedics can provide blood products for trauma patients, as training is needed and fridges and other equipment would have to be installed on vehicles, the overall cost is not higher.

Blood waste can be minimised if policies are put in place, as reported in the studies in this review.

Bodnar et al (2014b) stated that the proportion of wastage in emergency departments and the out-of-hospital setting are similar. Although Rehn et al (2019) and Bodnar et al (2014a) were silent on these issues, neither Heschl et al (2018) and Sayre et al (2022) reported that out-of-hospital blood transfusions were too costly or there was too much wastage.

Implications for practice

Bodnar et al (2014b) said it is feasible and practical to provide out-of-hospital blood transfusions if there is equipment to keep blood cool, then warm it before transfusion. Vuorinen et al (2020) agreed, noting that minimal additional equipment would be needed and that emergency services already carry the tubing needed for blood transfusions. However, they acknowledged that providing out-of-hospital blood transfusions can delay the arrival of the patient to hospital by up to 7 minutes. Nonetheless, in most cases, even with this delay, starting a transfusion earlier outweighs this risk (Vuorinen et al, 2020).

None of the papers reviewed said giving blood transfusions in the out-of hospital setting would not be feasible. Rehn et al (2019) concluded that it would be logical to provide blood transfusions and that research investigations into this intervention and patient outcomes are warranted. Heschl et al (2018) agreed that out-of-hospital blood transfusions by paramedics are feasible but are not without risks. Blood transfusions can cause complications such as the transmission of pathogens, although no complications were found throughout the study period (Heschl et al, 2018). As Bodnar et al (2014a) expressed, an integrated trauma system with highly skilled paramedics and access to blood in the out-of-hospital setting is feasible and would be capable of providing blood transfusions.

Although Sayre et al's (2022) received a poor quality score, its results match those of the other papers in this systematic review. Sayre et al (2022) concluded: ‘It is possible to provide whole blood to an urban paramedical ambulance system.’ The study acknowledged, however, that what had worked for them might not work in all areas.

Bodnar et al (2014a) also mentioned that many logistical obstacles had prevented out-of-hospital blood transfusions in the past. However, this study, along with the other three, concluded it was possible and feasible for paramedics to give blood transfusions in the out-of-hospital setting. Bodnar et al (2014b) summarised that this would be feasible if the equipment and training were provided and, overall, the benefits outweigh the risks.

Conclusion

Patient outcomes do not significantly improve overall after an out-of-hospital blood transfusion. However, patients' outcomes on arrival at hospital and vital signs show significant improvement after an out-of-hospital blood transfusion.

Prehospital blood transfusions are feasible and systems can be put in place to minimise the cost and waste of blood products.

Further research is needed to determine whether out-of-hospital blood transfusions improve the outcomes of trauma patients. However, randomised control trials would have limitations as there would have ethical and logistical issues. Retrospective studies with larger sample sizes and over longer periods may be a better vehicle.

Blood transfusion for a trauma patient experiencing a major haemorrhage significantly improves their chance of survival before they reach hospital. Out-of-hospital blood transfusions are feasible and benefit trauma patients in this setting. Blood should be available and training and systems put in place to mitigate cost and blood wastage.