Prehospital Blood Transfusion in New South Wales, Australia: A Retrospective Cohort Study

The shock index predicts in-flight blood transfusion in aeromedical trauma patients

OBJECTIVE

To define the utility of the Triage Revised Trauma Score (TRTS), GCS/Age/arterial Pressure (GAP) score, and shock index (SI) in predicting the need for in-flight blood product administration in civilian trauma patients transported by an aeromedical platform.

METHODS

A retrospective chart review of 3582 aeromedical trauma cases was conducted. An initial TRTS, GAP score and SI were calculated for each patient, and the administration of in-flight blood products was also recorded. Receiver operating characteristic (ROC) curves were used to quantify the predictive discrimination of the TRTS, GAP score and SI on the need for in-flight blood product administration.

RESULTS

The SI showed a superior predictive value compared to the TRTS and GAP score. The SI showed an area under the curve on the ROC curve of 0.85 in both primary and inter-hospital transfer cases, indicating reasonable predictive value.

CONCLUSION

The SI demonstrates favourable test characteristics for predicting the need for in-flight blood product administration. Prospective validation of these results is warranted.

Blood Product Administration in the Prehospital Setting: A Scoping Review

OBJECTIVES

Implementing prehospital blood products for treating hemorrhagic shock has been utilized globally in military and civilian settings. This review aims to compare various guidelines for using blood products, including the types of blood products, injuries, biomarkers (hemodynamic measurement) to indicate use, associated treatments and risks, and the logistical concerns of storage and wastage in the prehospital setting. Furthermore, it explores whether prehospital blood transfusions are beneficial and a safe treatment option.

METHODS

Data were collected using a systematic search and screening process of online databases CINAHL, Medline, and Scopus, as well as by creating a PRISMA flow diagram to screen articles using inclusion and exclusion criteria. Forty-five articles were screened, with twenty-five excluded, resulting in twenty articles in this scoping review.

RESULTS

The most frequently used blood product used was red blood cells, with twelve studies using either red blood cells alone or in combination with other products. Indications for blood use varied across services, but all aimed to address hemodynamic instability as a primary indication for blood transfusion. Eleven studies recorded no adverse reactions. Only one study reported chills and shivers; however, it was unclear if blood products were the cause. Nine studies avoided logistical issues of storage and wastage to create a feasible rotation system.

CONCLUSIONS

Prehospital blood was used in medical, trauma, and maternity-related hemorrhage. Many types of blood products are in use, ranging from component therapy to whole blood, with each protocol having different indications of use and treatment guidelines aimed at improving hemodynamic stability.

Hypocalcaemia upon arrival (HUA) in trauma patients who did and did not receive prehospital blood products: a systematic review and meta-analysis

PURPOSE

Hypocalcaemia upon arrival (HUA) to hospital is associated with morbidity and mortality in the trauma patient. It has been hypothesised that there is an increased incidence of HUA in patients receiving prehospital transfusion as a result of citrated blood products. This research aimed to determine if there was a difference in arrival ionised calcium (iCa) levels in trauma patients who did and did not receive prehospital transfusion.

METHODS

We conducted a systematic review and meta-analysis of patients with an Injury Severity Score (ISS) > / = 15 and an iCa measured on hospital arrival. We then derived mean iCa levels and attempted to compare between-group variables across multiple study cohorts.

RESULTS

Nine studies reported iCa on arrival to ED, with a mean of 1.08 mmol/L (95% CI 1.02-1.13; I2 = 99%; 2087 patients). Subgroup analysis of patients who did not receive prehospital transfusion had a mean iCa of 1.07 mmol/L (95% CI 1.01-1.14; I2 = 99%, 1661 patients). Transfused patients in the 3 comparative studies had a slightly lower iCa on arrival compared to those who did not receive transfusion (mean difference - 0.03 mmol/L, 95% CI - 0.04 to - 0.03, I2 = 0%, p = 0.001, 561 patients).

CONCLUSION

HUA is common amongst trauma patients irrespective of transfusion. Transfused patients had a slightly lower initial iCa than those without transfusion, though the clinical impact of this remains to be clarified. These findings question the paradigm of citrate-induced hypocalcaemia alone in trauma. There is a need for consensus for the definition of hypocalcaemia to provide a basis for future research into the role of calcium supplementation in trauma.

Prehospital Blood Transfusion: A Cross-Sectional Study of Prehospital and Retrieval Medicine Services across Australia & Aotearoa-New Zealand

BACKGROUND

The frequency and type of prehospital blood product delivery across Australia and Aotearoa-New Zealand is unknown. This study aims to describe transfusion practice across different services in the two nations, as well as identifying potential barriers to the carriage of blood products.

METHODOLOGY

Prehospital and retrieval medicine services operating teams of doctors, specialist paramedics, and/or flight nurses out of specialty bases across Australia and Aotearoa-New Zealand were sent a standardized questionnaire regarding their base characteristics and their current blood transfusion practice. Bases that only performed inter-hospital transfers or search & rescue operations were excluded. Bases were queried on personnel, equipment, transport times, type and volume of blood products carried, frequency of use, and barriers to implementation for those without prehospital blood transfusion programs.

RESULTS

64 bases were identified and contacted, of which 5 were excluded and 45 of the remaining 59 (76.3%) responded. 62% (28/45) of respondents routinely carry prehospital blood products. 78.6% (22/28) carried packed red blood cells (PRBC) only, 14.3% (4/28) carried both PRBC and plasma, and 1 service (3.6%) carried whole blood. The mean number of units of blood product carried was 3.3 (SD 0.82). 2 bases (7.1%) carried fibrinogen concentrate. All services carried tranexamic acid and calcium. 734 patients received a blood transfusion in 2021, with trauma being the most common indication (552, 75.2%). Base characteristics varied significantly in staffing, vehicle platform and transfer times. The median transfer time from scene to hospital was 65 min (IQR of 40-92). Services without access to prehospital blood products identified multiple barriers to implementation, including training and supply chain.

CONCLUSION

Approximately two-thirds of prehospital services operating advanced teams across Australia and Aotearoa-New Zealand carried blood products and there was wide variation both in the type and number of blood products carried by each base. Multiple barriers to the carriage of blood by all bases were reported, which have implications for service equity. Transfer times are generally long in Australia and Aotearoa-New Zealand, which may impact the generalizability of overseas research performed in prehospital systems with significantly shorter transfer times to services operating in Australia and Aotearoa-New Zealand.

Midwives' perspectives of intravenous fluid management and fluid balance documentation in labour: A qualitative reflexive thematic analysis study

AIM

To describe current practice, examine the influences and explore barriers and facilitators to accurate documentation, for the administration of intravenous fluids during labour.

DESIGN

A descriptive qualitative study was performed.

METHODS

Qualitative semi-structured interviews were conducted with Registered Midwives working across Australia. Midwives were recruited via email and social media advertisements. A maximum variation sampling strategy was used to identify potential participants. Interview questions explored four main areas: (i) understanding of indications for IV fluids in labour; (ii) identification of current practice; (iii) barriers to documentation and (iv) benefits and complications of IV fluid administration. Reflexive thematic analysis of recorded-transcribed interviews was conducted.

RESULTS

Eleven midwives were interviewed. Clinical practice variation across Australia was recognized. Midwives reported a potential risk of harm for women and babies and a current lack of evidence, education and clinical guidance contributing to uncertainty around the use of IV fluids in labour. Overall, eight major themes were identified: (i) A variable clinical practice; (ii) Triggers and habits; (iii) Workplace and professional culture; (iv) Foundational knowledge; (v) Perception of risk; (vi) Professional standards and regulations; (vii) The importance of monitoring maternal fluid balance and (viii) barriers and facilitators to fluid balance documentation.

CONCLUSION

There was widespread clinical variation identified and midwives reported a potential risk of harm. The major themes identified will inform future quantitative research examining the impact of IV fluids in labour.

IMPACT

The implications of this research are important and potentially far-reaching. The administration of IV fluids to women in labour is a common clinical intervention. However, there is limited evidence available to guide practice. This study highlights the need for greater education and evidence examining maternal and neonatal outcomes to provide improved clinical guidance.

A Service Evaluation of Prehospital Blood Transfusion by Critical Care Paramedics in British Columbia, Canada

Early administration of blood products is emerging as best practice in selected trauma and medical patients. Blood products carried by critical care transport (CCT) teams are sometimes the first available to critically ill and injured patients. The purpose of this research was to evaluate the introduction of prehospital transfusion into a paramedic-led CCT program in Canada. A retrospective review of electronic patient care records for all patients who received a prehospital transfusion of uncrossmatched group O packed red blood cells between February 10, 2019, and September 30, 2020, was conducted. Forty-eight patients received a prehospital transfusion. The median age of the patients was 44 years, 81.3% were male, and most patients were victims of blunt trauma. Packed red blood cells were associated with a significant increase in systolic blood pressure (P < .001) and mean arterial pressure (P < .001), a decrease in shock index (P < .001), and a reduction in the time to first transfusion, with minimal waste, no patient-related adverse events, and complete traceability. The results of this service evaluation demonstrate the successful introduction of prehospital transfusion into a paramedic-led CCT program. Further prospective research is needed to assess the impact of such a protocol in this patient population.

Survival outcomes in emergency medical services witnessed traumatic out-of-hospital cardiac arrest after the introduction of a trauma-based resuscitation protocol

AIM

In this study, we examine the impact of a trauma-based resuscitation protocol on survival outcomes following emergency medical services (EMS) witnessed traumatic out-of-hospital cardiac arrest (OHCA).

METHODS

We included EMS-witnessed OHCAs arising from trauma and occurring between 2008 and 2019. In December 2016, a new resuscitation protocol for traumatic OHCA was introduced prioritising the treatment of potentially reversible causes before conventional cardiopulmonary resuscitation. The effect of the new protocol on survival outcomes was assessed using adjusted multivariable logistic regression models.

RESULTS

Paramedics attempted resuscitation on 490 patients, with 341 (69.6%) and 149 (30.4%) occurring during the control and intervention periods, respectively. A reduction in the proportion of cases receiving cardiopulmonary resuscitation and epinephrine administration were found in the intervention period compared to the control period, whereas trauma-based interventions increased significantly, including blood administration (pre-arrest: 17.9% vs 3.7%; intra-arrest: 24.1% vs 2.7%), splinting (pre-arrest: 38.6% vs 17.1%; intra-arrest: 20.7% vs 5.2%), and finger thoracostomy (pre-arrest: 13.1% vs 0.6%; intra-arrest: 22.8% vs 0.9%), respectively, with p-values < 0.001 for all comparisons. After adjustment, the trauma-based resuscitation protocol was not associated with an improvement in survival to hospital discharge (AOR 1.29, 95% CI: 0.51-3.23), event survival (AOR 0.72, 95% CI: 0.41-1.28) or prehospital return of spontaneous circulation (AOR 0.63, 95% CI: 0.39-1.03).

CONCLUSION

In our region, the introduction of a trauma-based resuscitation protocol led to an increase in the delivery of almost all trauma interventions; however, this did not translate into better survival outcomes following EMS-witnessed traumatic OHCA.

Characteristics of Nontrauma Patients Receiving Prehospital Blood Transfusion with the Same Triggers as Trauma Patients: A Retrospective Observational Cohort Study

Objective: While prehospital blood transfusion (PHBT) for trauma patients has been established in many services, the literature on PHBT use for nontrauma patients is limited. We aimed to describe and compare nontrauma and trauma patients receiving PHBT who had similar hemodynamic triggers. Methods: We analyzed 3.5 years of registry data from a single prehospital critical care unit. The PHBT protocol included two packed red blood cell units and was later completed with two freeze-dried plasma units. The transfusion triggers were a strong clinical suspicion of massive hemorrhage and systolic blood pressure below 90 mmHg or absent radial pulse. Results: Thirty-six nontrauma patients and 96 trauma patients received PHBT. The nontrauma group had elderly patients (median 65 [interquartile range, IQR, 56-73] vs 37 [IQR 25-57] years, p < 0.0001) and included patients with gastrointestinal bleeding (n = 15; 42%), vascular catastrophes (n = 9; 25%), postoperative bleeding (n = 6; 17%), obstetrical bleeding (n = 4; 11%) and other (n = 2; 6%). Cardiac arrest occurred in nine (25%) nontrauma and in 15 (16%) trauma patients. Of these, 5 (56%) and 10 (67%) survived to hospital admission and 3 (33%) and 2 (13%) to hospital discharge. On admission, the nontrauma patients had lower hemoglobin (median 95 [84-119] vs 124 [108-133], p < 0.0001), higher pH (median 7.40 [7.27-7.44] vs 7.30 [7.19-7.36], p = 0.0015) and lower plasma thromboplastin time (median 55 [45-81] vs 72 [58-86], p = 0.0261) than the trauma patients. Conclusions: We identified four nontrauma patient groups in need of PHBT, and the patients appeared to be seriously ill. Efficacy of prehospital transfusion in nontrauma patients should be evaluated futher in becoming studies.

Retrieval transfusion protocol in New South Wales, Australia: A retrospective review of the first 5 years

BACKGROUND

Ambulance service blood transfusion is an area of rapid development. In New South Wales, Australia, the blood products carried by ambulance medical teams are often the first available to patients with critical bleeding. In addition to the blood products routinely carried by these teams, the Service created and implemented a method of initiating large-volume, mixed-product transfusions using existing blood banks: the Retrieval Transfusion Procedure (RTP). This article describes the trends and characteristics of New South Wales Ambulance RTP activations.

MATERIALS AND METHODS

This retrospective database review examines the patient records for all RTP activations. Key areas of investigation include logistics, product requests, population demographics, etiologies, physiology, mission timings, and transfusions.

RESULTS

Ambulance medical teams attended 27 531 missions in the reviewed period, 1573 patients received transfusion, and there were 138 RTP activations. Blood products were sourced from 40 banks and transported by police (46.7%), ambulance (27.1%), and helicopter (13.0%) to refueling stops (39.2%), prehospital scenes (24.2%) and hospitals (15.8%). The median time engaged on each mission was 189 minutes for metropolitan and 222 minutes for rural locations. Seventy-eight patients were transfused with RTP blood products; 83.3% were traumas, of which 63.1% were motor vehicle collisions. Up to 18 units of blood products were administered before hospital arrival. There was significant (P < .001) improvement in the mean shock index of transfused patients between the first and final observations recorded.

CONCLUSIONS

Ambulance service extended blood product transfusion is logistically achievable and facilitates emergency transfusions throughout the state with minimal additional infrastructure.