In this Prehospital Journal Club Recap, let us take a deep dive into the use of blood products, as well as the adjunct use of automated controlled elevation in CPR.
Resuscitation with blood products in patients with trauma-related hemorrhagic shock receiving prehospital care (RePHILL): a multicentre, open-label, randomized, controlled, phase 3 trial
Background
The use of early transfusion in the context of traumatic hemorrhagic shock has widely been used in the military. However, its use in a civilian setting is limited by a lack of evidence supporting the use of blood products at first point of contact in the prehospital environment. The two most recent RCTs investigating the use of prehospital plasma transfusion – COMBAT and PAMPer – have yielded conflicting results.
- COMBAT, published in The Lancet in 2018, was a pragmatic RCT involving 144 eligible patients. It compared the administration of 250mL of AB plasma versus an equivalent volume of normal saline (placebo). It demonstrated no significant difference in mortality at 28 days between the two groups. Secondary analysis suggested a potential benefit for circumstances for which longer transport times were expected.
- PAMPer, published in NEJM in 2018, was a phase 3 multi-center cluster-randomized trial involving 564 eligible patients. This trial compared plasma transfusion with crystalloid-based resuscitation and revealed a significantly lower 30-day mortality (9.8% difference) in the plasma group when compared to the control.
The above trials focused on plasma transfusion in the prehospital setting, however, the use of pRBC in this environment is even more sparse.
Clinical Question
Is prehospital transfusion of packed red blood cells (PRBCs) and lyophilized plasma (LyoPlas) superior to 0.9% normal saline solution for trauma-related hemorrhagic shock?
Methods
This study was a multicenter, open-label, parallel-group, randomized, controlled, phase 3 trial, which was conducted across four prehospital critical care services in the UK.
Results
- Primary Outcome:A composite outcome of mortality between time of injury and hospital discharge or a failure to reach lactate clearance (<20% per hour in the first 2 hours after randomization).
- Key Secondary Outcomes:
- All-cause Mortality within 30 days of injury, and;
- Mortality within 3 hours of injury.
Key results are summarized in the infographics below.
Authors’ Conclusion
There is no demonstrable benefit for a composite outcome of mortality and lactate clearance in trauma patients with hemorrhagic shock receiving PRBC-LyoPlas compared with 0.9% saline.
Limitations
- The study’s composite outcome combined both patient-oriented and lab-oriented parameters, making results not fully patient-centred.
- The projected sample size of 490 participants was never achieved due to funding issues, and the challenging nature of the COVID-19 pandemic.
- The study focused on a civilian setting within an established major trauma network where prehospital teams included critical care paramedics and physicians. A model which is not easily applied to all prehospital settings.
- The time from randomization to hospitalization, was quite short, bringing into question the true impact of the prehospital intervention.
Bottom Line
The use of pRBC/plasma in the prehospital context in this study did not yield favourable patient-centred outcomes. Although, it’s benefit for more specific remote settings has yet to be clarified.
Citation
Head and Thorax elevation during cardiopulmonary resuscitation using circulatory adjuncts is associated with improved survival.
Background
There is a new kid on the block when it comes to adjuncts to high-quality CPR. In particular, the emergence of Head Up CPR (HUP CPR). This particular technique involves raising the head and thorax during compressions, in an effort to enhance cerebral perfusion pressure (CPP) to minimize hypoxic brain injuries and their resulting neurologic outcomes. Despite encouraging results from animal studies, human data remains limited.
- Head Up CPR in Animal Models: Ryu et al. conducted a randomized study in pigs comparing HUP CPR with conventional CPR. The addition of circulation adjuncts like active compression-decompression and impedance threshold device (ACD + ITD) with HUP CPR showed significant improvement in CPP.
- Clinical Safety and Feasibility of HUP CPR: Pepe et al. conducted an observational trial in a prehospital setting, demonstrating the feasibility and safety of HUP CPR. It resulted in a doubled successful delivery of resuscitated patients to the emergency department (ED).
Clinical Question
Does automated controlled elevation CPR (ACE-CPR) used in conjunction with mechanical CPR + Impedance Threshold Device improve survival to hospital discharge compared to traditional CPR in OHCA?
Methods
Prospective observational study with historic controls and propensity score matching analysis.
- Intervention: Mechanical CPR with a commercially available device and automated controlled elevation of the head and thorax + Impedance threshold device application.
- Control: Standard CPR
Results
- Primary Outcome: Survival to hospital discharge
- ACE-CPR 9.5% vs. C-CPR 6.7%, OR 1.44 (95% CI, 0.86–2.44).
- Subgroup analysis of those treated from 911 call to ACE-CPR had an improved odds ratio of survival when initiated in <11 min (OR 3.28, 95% CI, 1.55–6.92) and < 18 min (OR 1.88, 95% CI, 1.03–3.44).
- Secondary Outcomes:
- ROSC at any time: ACE-CPR 33% vs. C-CPR 33%, OR 1.02 (95% CI, 0.75–1.49).
- Survival to hospital discharge with favorable neurological status: ACE-CPR vs C-CPR 5.9% vs 4.1%, OR 1.47(95% CI, 0.76–2.82).
|
ACE-CPR |
C-CPR |
Odds Ratio (95% CI) |
|
|
Survival to hospital discharge |
9.5% (21/222) |
6.7% (58/860) |
1.44 (0.86–2.44) |
|
Survival when CPR initiated in <11 min |
————— |
————— |
3.28 (1.55–6.92) |
|
Survival when CPR initiated in <18 min |
————— |
————— |
1.88 (1.03–3.44) |
|
ROSC at any time |
33% (74/222) |
33% (282/860) |
1.02 (0.75–1.49) |
|
Survival to hospital discharge with favorable neurological status |
5.9% (13/222) |
4.1% (35/860) |
1.47(0.76–2.82) |
Authors Conclusion
“Compared with C-CPR controls, rapid initiation of ACE-CPR was associated with a higher likelihood of survival to hospital discharge after OHCA.”
Limitations
- Selection bias due to exclusion of EMS systems.
- Lack of blinding and randomization.
- Historical control comparison which introduces confounding variables.
- Propensity score matching cannot fully eliminate all confounders.
- Complexity and equipment involved may introduce delays and require significant training.
- Association is not causation: This is a prospective observational study, cannot be used to conclude causation
Bottom Line
While the concept behind HUP CPR is intriguing, current evidence suggests it is not yet ready for widespread adoption. Future research may provide more conclusive results. For the time being, it is crucial to maintain a focus on interventions that have demonstrated efficacy and positive outcomes.
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