Freeze‐dried plasma stability under prehospital field conditions

An experimental comparison and user evaluation of three different dried plasma products

BACKGROUND AND OBJECTIVES

Access to blood components in pre-hospital bleeding resuscitation is challenging. Dried plasma is a logistically superior alternative, and new products are emerging. Therefore, we aimed to evaluate laboratory and practical differences in three differently produced dried plasma products.

MATERIALS AND METHODS

Single-donor lyophilized LyoPlas®, pooled-donor, lyophilized and pathogen-reduced OctaplasLG Powder®, and single-donor sprayed-dried FrontlineODP™ along with fresh plasma (in-house, pre-FrontlineODP and OctaplasLG) as controls were analysed (n = 8). Laboratory tests included measurements of various coagulation factors and thromboelastography. The practical evaluation of the dried plasma products included preparation time, time to dissolve the dried plasma and total time, together with subjective opinions from eight clinical users.

RESULTS

The coagulation factor content was within human reference ranges for all dried plasma, with approximately 10%-20% loss compared with fresh plasma. More variations were observed in the single-donor products compared with the pooled products. Clot formation analysed by thromboelastography showed normal graphs. Reconstitution time was similar, ranging from on average 7-9 min. In the user evaluation, the reconstitution time and the possibility of using a plastic bag for the transfusion were emphasized as important, the latter fulfilled by two of the products.

CONCLUSION

The study supports that dried plasma may be produced with lyophilization or spray-drying technique, as well as with the addition of pathogen reduction, with preserved coagulation capability. The products were reconstituted in acceptable time and deemed feasible for pre-hospital use by eighth test users.

[Prehospital blood transfusion : Opportunities and challenges for the German emergency medical services]

BACKGROUND

Exsanguination is the leading cause of preventable death in severe trauma. Immediate hemorrhage control and transfusion of blood products are critical to maintain oxygen delivery and address trauma-induced coagulopathy. While prehospital blood product transfusion (PHBT) is established in neighboring countries, the fragmented configuration of Germany's emergency medical service (EMS) infrastructure has delayed the adoption of widespread PHBT programmes. This review aims to provide an updated perspective on the evolution, international practices and research needs of PHBT within the German context.

METHODS

This narrative review is based on a PubMed search using the search terms "prehospital" and "blood*". From an initial 4738 articles, 333 were directly related to PHBT and were subjected to further detailed examination. The literature, including referenced studies, was categorized into areas such as history, rationale, international practices, and evidence, and analyzed for quality.

RESULTS

The benefit of early blood transfusion in major trauma has been established since WW1, explaining the efforts to initiate this lifesaving intervention as early as possible in the care pathway, including the prehospital field. Recent randomized trials have faced design and recruitment challenges, reflecting the complexity of the research question. These trials have yielded inconclusive results regarding the survival benefits of PHBT in civilian settings. This scenario raises doubts about the capability of randomized trials to resolve questions concerning survival advantages. Despite these difficulties, there is a discernible trend indicating potential improvements in patient outcomes. In Germany, the incidence of trauma-associated shock stands at 38 per 100,000 individuals per year. It is estimated that between 300 and 1800 patients annually possibly benefit from PHBT.

CONCLUSION

Prehospital Blood Transfusion appears to be promising but identifying patient groups most likely to benefit as well as the most suitable blood products remain unresolved issues. In Germany PHBT programs are not yet widely established. Paradoxically, this situation, paired with the extensive German Trauma Registry, provides a prime opportunity for comprehensive prospective cohort studies, addressing the balance between PHBT benefits, logistical feasibility, and implementation strategies. Such studies are essential for establishing guidelines and integrating PHBT efficiently into German trauma care protocols.

Dried Plasma for Major Trauma: Past, Present, and Future

Uncontrollable bleeding is recognized as the leading cause of preventable death among trauma patients. Early transfusion of blood products, especially plasma replacing crystalloid and colloid solutions, has been shown to increase survival of severely injured patients. However, the requirements for cold storage and thawing processes prior to transfusion present significant logistical challenges in prehospital and remote areas, resulting in a considerable delay in receiving thawed or liquid plasma, even in hospitals. In contrast, freeze- or spray-dried plasma, which can be massively produced, stockpiled, and stored at room temperature, is easily carried and can be reconstituted for transfusion in minutes, provides a promising alternative. Drawn from history, this paper provides a review of different forms of dried plasma with a focus on in vitro characterization of hemostatic properties, to assess the effects of the drying process, storage conditions in dry form and after reconstitution, their distinct safety and/or efficacy profiles currently in different phases of development, and to discuss the current expectations of these products in the context of recent preclinical and clinical trials. Future research directions are presented as well.

Post-Reconstitution Hemostatic Stability Profiles of Canadian and German Freeze-Dried Plasma

Despite the importance of the hemostatic properties of reconstituted freeze-dried plasma (FDP) for trauma resuscitation, few studies have been conducted to determine its post-reconstitution hemostatic stability. This study aimed to assess the short- (≤24 h) and long-term (≥168 h) hemostatic stabilities of Canadian and German freeze-dried plasma (CFDP and LyoPlas) after reconstitution and storage under different conditions. Post-reconstitution hemostatic profiles were determined using rotational thromboelastometry (ROTEM) and a Stago analyzer, as both are widely used as standard methods for assessing the quality of plasma. When compared to the initial reconstituted CFDP, there were no changes in ROTEM measurements for INTEM maximum clot firmness (MCF), EXTEM clotting time (CT) and MCF, and Stago measurements for prothrombin time (PT), partial thromboplastin time (PTT), D-dimer concentration, plasminogen, and protein C activities after storage at 4 °C for 24 h and room temperature (RT) (22-25 °C) for 4 h. However, an increase in INTEM CT and decreases in fibrinogen concentration, factors V and VIII, and protein S activities were observed after storage at 4 °C for 24 h, while an increase in factor V and decreases in antithrombin and protein S activities were seen after storage at RT for 4 h. Evaluation of the long-term stability of reconstituted LyoPlas showed decreased stability in both global and specific hemostatic profiles with increasing storage temperatures, particularly at 35 °C, where progressive changes in CT and MCF, PT, PTT, fibrinogen concentration, factor V, antithrombin, protein C, and protein S activities were seen even after storage for 4 h. We confirmed the short-term stability of CFDP in global hemostatic properties after reconstitution and storage at RT, consistent with the shelf life of reconstituted LyoPlas. The long-term stability analyses suggest that the post-reconstitution hemostatic stability of FDP products would decrease over time with increasing storage temperature, with a significant loss of hemostatic functions at 35 °C compared to 22 °C or below. Therefore, the shelf life of reconstituted FDP should be recommended according to the storage temperature.

Prehospital Freeze-Dried Plasma in Trauma: A Critical Review

Major traumatic hemorrhage is now frequently treated by early hemostatic resuscitation on hospital arrival. Prehospital hemostatic resuscitation could therefore improve outcomes for bleeding trauma patients, but there are logistical challenges. Freeze-dried plasma (FDP) offers indisputable logistical advantages over conventional blood products, such as long shelf life, stability at ambient temperature, and rapid reconstitution without specialized equipment. We sought high level, randomized, controlled evidence of FDP clinical efficacy in trauma. A structured systematic search of MEDLINE/PubMed was carried out and identified 52 relevant English language publications. Three studies involving 607 patients met our criteria: Resuscitation with Blood Products in Patients with Trauma-related Hemorrhagic Shock receiving Prehospital Care (RePHILL, n = 501); Prehospital Lyophilized Plasma Transfusion for Trauma-Induced Coagulopathy in Patients at Risk for Hemorrhagic Shock (PREHO-PLYO, n = 150); and a pilot Australian trial (n = 25). RePHILL found no effect of FDP plus packed red blood cells (PRBC) concentrate transfusion versus saline on mortality. PREHO-PLYO found no effect of FDP versus saline on International Normalized Ratio (INR) at hospital arrival. The pilot trial found that study of PRBC versus PRBC plus FDP was feasible during long air transport times to an Australian trauma centre. Further research is required to determine under what conditions FDP might provide prehospital benefit to trauma patients.

Frozen and freeze-dried solvent/detergent treated plasma: Two different pharmaceutical formulations with comparable quality

BACKGROUND

OctaplasLG is a frozen solvent/detergent-treated plasma product used for treating complex coagulation factor deficiencies or as substitution therapy in emergency situations where specific factor concentrates are not available. A new freeze-dried (also known as lyophilized) form of OctaplasLG, referred as OctaplasLG Lyo (Octapharma AG, Switzerland) offers rapid reconstitution and more flexible storage conditions, improving logistics and utilization. This study compared the biochemical quality of OctaplasLG Lyo with OctaplasLG and single-donor fresh frozen plasma units.

STUDY DESIGN AND METHODS

Three batches of OctaplasLG Lyo, manufactured for production process qualification, and 12 batches of OctaplasLG were provided by Octapharma AB (Sweden). Twelve units of fresh frozen plasma were collected by the local FDA-licensed blood provider. All plasma samples were assessed for global coagulation parameters, coagulation factors and protease inhibitors, activation markers of coagulation and fibrinolysis, and important plasma proteins. Quality control assays were conducted in accordance with European Pharmacopeia requirements.

RESULTS

Frozen and freeze-dried OctaplasLG demonstrated comparable quality profiles upon thawing or reconstitution. All coagulation factor and protease inhibitor activity parameters were in line with levels mandated by the European Pharmacopeia. Fresh frozen plasma units showed comparable coagulation factor activities, with higher protein S and plasmin inhibitor levels than the OctaplasLG products. Fresh frozen plasma parameters showed high lot-to-lot variations.

DISCUSSION

The two pharmaceutical forms of OctaplasLG (frozen and freeze-dried) have comparable biochemical quality. Key features of OctaplasLG Lyo are rapid reconstitution time and storage flexibility, which may improve logistics and utilization, and have particular advantages in emergency situations and pre-hospital settings.

Charles M, Markstrom L, Atkinson AJ, King MR, Snyder M, Burgess D, Murto J, Valiyaveettil MK, C. Pehta J, Penegor SA. Characterization and first-in-human clinical dose-escalation safety evaluation of a next-gen human freeze-dried plasma

BACKGROUND

Early plasma transfusion is life-saving for bleeding trauma patients. Freeze-dried plasma (FDP) provides unique formulation advantages for infusion in the prehospital setting. We describe characterization and clinical safety data of the first, next-generation FDP stored in plastic bags with rapid reconstitution.

STUDY DESIGN AND METHODS

Coagulation and chemistry parameters on 155 pairs of fresh frozen plasma (FFP) and their derivative FDP units were compared. Next, a first-in-human, dose-escalation safety evaluation of FDP, involving 24 healthy volunteers who donated either whole blood or apheresis plasma to create autologous FDP, was performed in three dose cohorts (270, 540, and 810 ml) and adverse events (AEs) were monitored. Cohort 3 was randomized, double-blind with a cross-over arm that compared FDP versus FFP using descriptive analysis for AEs, coagulation, hematology, and chemistry parameters.

RESULTS

FDP coagulation factors, clotting times, and product quality (pH, total protein, and osmolality) post-lyophilization were preserved. FDP infusions, of up to 810 ml per subject, were found to be safe and with no serious AEs (SAEs) related to FDP. The average time to reconstitute FDP was 67 s (range: 43-106). No differences in coagulation parameters or thrombin activation were detected in subjects infused with 810 ml of FDP compared with FFP.

CONCLUSION

This first next-generation FDP product preserves the potency and safety of FFP in a novel rugged, compressible, plastic container, for rapid transfusion, allowing rapid access to plasma in resuscitation protocols for therapy in acute traumatic hemorrhage.

Use of Dried Plasma in Prehospital and Austere Environments

More than 1,000,000 units of lyophilized plasma have been used in France, Germany, and South Africa. Recently, numerous other countries have adopted lyophilized plasma for patients with severe bleeding in prehospital and austere settings.

Retention of hemostatic and immunological properties of frozen plasma and COVID-19 convalescent apheresis fresh-frozen plasma produced and freeze-dried in Canada

BACKGROUND

Randomized clinical trial data show that early plasma transfusion may save lives among trauma patients. Supplying plasma in remote environments is logistically challenging. Freeze-dried plasma (FDP) offers a possible solution.

STUDY DESIGN AND METHODS

A Terumo BCT plasma freeze-drying system was evaluated. We compared pooled frozen plasma (FP) units with derived Terumo BCT FDP (TFDP) units and pooled COVID-19 convalescent apheresis fresh-frozen plasma (CC-AFFP) with derived CC-TFDP units. Parameters measured were: coagulation factors (F) II; V; VII; VIII; IX; XI; XIII; fibrinogen; Proteins C (PC) and S (PS); antithrombin (AT); α₂ -antiplasmin (α₂ AP); ADAMTS13; von Willebrand Factor (vWF); thrombin-antithrombin (TAT); D-dimer; activated complement factors 3 (C3a) and 5 (C5a); pH; osmolality; prothrombin time (PT); and activated partial thromboplastin time (aPTT). Antibodies to SARS-CoV-2 in CC-AFFP and CC-TFDP units were compared by plaque reduction assays and viral protein immunoassays.

RESULTS

Most parameters were unchanged in TFDP versus FP or differed ≤15%. Mean aPTT, PT, C3a, and pH were elevated 5.9%, 6.9%, 64%, and 0.28 units, respectively, versus FP. CC-TFDP showed no loss of SARS-CoV-2 neutralization titer versus CC-AFFP and no mean signal loss in most pools by viral protein immunoassays.

CONCLUSION

Changes in protein activities or clotting times arising from freeze-drying were <15%. Although C3a levels in TFDP were elevated, they were less than literature values for transfusable plasma. SARS-CoV-2-neutralizing antibody titers and viral protein binding levels were largely unaffected by freeze-drying. In vitro characteristics of TFDP or CC-TFDP were comparable to their originating plasma, making future clinical studies appropriate.

Ex vivo hemostatic and immuno-inflammatory profiles of freeze-dried plasma

BACKGROUND

Hemorrhage is a leading cause of preventable death in civilian and military trauma. Freeze-dried plasma is promising for hemostatic resuscitation in remote prehospital settings, given its potential benefits in reducing blood loss and mortality, long storage at ambient temperatures, high portability, and rapid reconstitution for transfusion in austere environments. Here we assess the ex vivo characteristics of a novel Terumo's freeze-dried plasma product (TFDP).

STUDY DESIGN AND METHODS

Rotational thromboelastometry (ROTEM) tests (INTEM, EXTEM, and FIBTEM) were conducted on plasma samples at 37°C with a ROTEM delta-machine using standard reagents and procedures. The following samples were analyzed: pooled plasma to produce TFDP, TFDP reconstituted, and stored immediately at -80°C, reconstituted TFDP stored at 4°C for 24 h and room temperature (RT) for 4 h before freezing at -80°C. Analysis of plasma concentrations of selected cytokines, chemokines, and vascular molecules was performed using a multiplex immunoassay system. One-way ANOVA with post hoc tests assessed differences in hemostatic and inflammatory properties.

RESULTS

No significant differences in ROTEM variables (coagulation time [CT], clot formation time, α-angle, maximum clot firmness, and lysis index 30) between the TFDP-producing plasma and reconstituted TFDP samples were observed. Compared to control plasma, reconstituted TFDP stored at 4°C for 24 h or RT for 4 h showed a longer INTEM CT. Levels of immuno-inflammatory mediators were similar between frozen plasma and TFDP.

CONCLUSIONS

TFDP is equivalent to frozen plasma with respect to global hemostatic and immuno-inflammatory mediator profiles. Further investigations of TFDP in trauma-induced coagulopathy models and bleeding patients are warranted.

Temperature mapping in an air ambulance helicopter: Implications for the delivery of pre-hospital transfusion

BACKGROUND

Pre-hospital blood products, including freeze-dried plasma, are increasingly carried on air ambulance helicopters. The purpose of this study was to map the temperatures within a civilian air ambulance and consider the implications for pre-hospital transfusion.

MATERIALS AND METHODS

We conducted a single-site prospective observational study in the United Kingdom. Tinytag temperature data-loggers (Gemini, UK) were secured on to three locations throughout an air ambulance, and one was placed inside an insulated drug-pouch. Temperatures were monitored at 5-min intervals. Data were downloaded monthly and processed using R and MKT software to collate maximum, minimum, and day/night mean kinetic temperatures (MKTs). Blood was transported in Crēdo ProMed 4 containers (Peli Products, S.L.U) and monitored with QTA data-loggers (Tridentify, Sweden).

RESULTS

A total of 344,844 temperature recordings were made on 302 days during a 12-month period from January 2019. The external ambient temperatures varied seasonally from -7.1°C to 31.2°C, whereas internal temperatures ranged from -0.3°C to 60.6°C. The warmest area was alongside the left front-crew position (range 1.9-60.6°C, MKT 24.8°C). The lowest daytime MKT (16.9°C) and range (1.7°C-36.4°C) were recorded next to the patient stretcher. Temperatures ranged from 4.2°C to 40.1°C inside the insulated drugs-pouch, exceeding 25°C on 47 days (15%) and falling below 15°C on 192 days (63%) In contrast, thermally packed blood maintained a range of 2-6°C.

CONCLUSION

The temperatures within an air ambulance varied throughout the cabin and often exceeded the external ambient temperature. Appropriately selected thermal protection and monitoring is required for the successful delivery of pre-hospital transfusion, even in a temperate climate.

Post-expiry stability of freeze-dried plasma under field conditions - Can shelf life be extended?

BACKGROUND

This prospective study evaluated the effect of routine, uncontrolled, Israeli field storage conditions on the safety and efficacy of Lyo-Plas N Freeze-Dried Plasma (FDP) at the end of the manufacturer's shelf life, and up to 24 months post expiry. Clotting factors V, VIII and XI, proteins S, C, fibrinogen, PTT, ATIII, VWF, and INR as well as TEG, DDM, residual moisture, pH, and sterility of FDP returned from field units after uncontrolled storage were evaluated.

STUDY DESIGN AND METHODS

Parameters measured at the end of manufacturer shelf life, as well as 6, 12, 18, and 24 months after expiry, were compared to those of freshly supplied FDP doses.

RESULTS

Changes were found when comparing freshly supplied FDP to all field-stored groups in INR, PT, PTT, pH, fibrinogen, and factor VIII. A significant change was also seen in Factor XI in the 12, 18, and 24 months post-expiry samples, Factor V and R in the 24 months post-expiry samples, MA in the 12, 24 months post-expiry group, and Protein C in the 18 months post-expiry group. An increase in the residual moisture from 0.90% in freshly supplied FDP to 1.35% in 24 months post-expiry FDP.; all p < .05. No growth was found in sterility analysis.

CONCLUSION

Despite uncontrolled field storage conditions, the findings demonstrate that the safety and efficacy of FDP units, stored in uncontrolled conditions are only slightly affected, even beyond their expiration date. This information allows consideration of possibly extending the shelf life.

Increasing storage stability of freeze-dried plasma using trehalose

Preservation of blood plasma in the dried state would facilitate long-term storage and transport at ambient temperatures, without the need of to use liquid nitrogen tanks or freezers. The aim of this study was to investigate the feasibility of dry preservation of human plasma, using sugars as lyoprotectants, and evaluate macromolecular stability of plasma components during storage. Blood plasma from healthy donors was freeze dried using 0-10% glucose, sucrose, or trehalose, and stored at various temperatures. Differential scanning calorimetry was used to measure the glass transition temperatures of freeze-dried samples. Protein aggregation, the overall protein secondary structure, and oxidative damage were studied under different storage conditions. Differential scanning calorimetry measurements showed that plasma freeze-dried with glucose, sucrose and trehalose have glass transition temperatures of respectively 72±3.4°C, 46±11°C, 15±2.4°C. It was found that sugars diminish freeze-drying induced protein aggregation in a dose-dependent manner, and that a 10% (w/v) sugar concentration almost entirely prevents protein aggregation. Protein aggregation after rehydration coincided with relatively high contents of β-sheet structures in the dried state. Trehalose reduced the rate of protein aggregation during storage at elevated temperatures, and plasma that is freeze- dried plasma with trehalose showed a reduced accumulation of reactive oxygen species and protein oxidation products during storage. In conclusion, freeze-drying plasma with trehalose provides an attractive alternative to traditional cryogenic preservation.