Blood component therapy: Which, when and how much

Blood usage and wastage at an academic teaching hospital before the initial wave of COVID-19 and during and after its quarantine periods

BACKGROUND

Transfusion services aim to maintain sufficient blood inventory to support patients, even with challenges introduced by COVID-19.

OBJECTIVES

To review blood usage and wastage before, during, and after COVID-19 surges, and to evaluate effects on inventory.

METHODS

In a retrospective review, we evaluated the association between time periods corresponding to the initial wave of COVID-19 (pre-COVID-19, quarantine, and postquarantine) and blood usage/wastage. Data were stratified by period, and χ2 testing was used to examine the association between these time periods and blood usage/wastage.

RESULTS

In the period before COVID-19, the transfusion service used more units, and in the period after quarantine, more units went to waste. Across all time periods, the most-used product was RBCs, and the most wasted product was plasma. A statistically significant association existed between usage (χ2 [6/3209 (0.2%)]) = 24.534; P ≤.001; Cramer V = 0.62), wastage (χ2 [6/775 (0.8%)]) = 21.673; P = .001; Cramer V = 0.118), and time period. The postquarantine period displayed the highest wastage costs ($51,032.35), compared with the pre-COVID-19 period ($29,734.45).

CONCLUSION

Changes in blood inventory use and waste are significantly associated with the onset and continuation of COVID-19.

Implementation of Indian National plasma policy at blood bank of a tertiary care hospital: A step towards strengthening of blood transfusion services

INTRODUCTION

The World Health Organization has advocated that every country should make its own policy for ensuring safe and adequate supply of plasma derived medicinal products through mobilization and usage of locally collected plasma. The National Plasma Policy (NPP) of India was published in 2014 with a dual objective to achieve self sufficiency in the production of plasma derived medicinal products and at the same time to augment the component preparation facilities in India and overall upliftment of blood transfusion services in the country. Thus the present study was done to access the impact of implementation of NPP in our blood bank on the blood transfusion services in our hospital.

MATERIALS AND METHODS

The present study was a retrospective observational study conducted in the department of transfusion medicine of a tertiary care hospital in India involving analysis of data from 1st January 2019 till 31st December 2022. For the purpose of data analysis the time period was divided into 2 periods: (i) Pre-NPP implementation period from 1st January 2019 till 31st December 2020; (ii) Post-NPP period from 1st January 2021 till 31st December 2022. The following parameters were compared for the two periods: (i) component preparation rate; (ii) percentage of component therapy; (iii) total number of FFP transferred to plasma fractionation centers; (iv) total amount of exchange amount generated in lieu of transferred FFP to plasma fractionation centers.

RESULTS

The component preparation rate after NPP implementation was significantly higher as compared to the pre NPP implementation period (93.81% vs 56.70%; p = 0.007). The percentage of component therapy in the patients was also significantly higher as compared to the pre-NPP implementation period (97.9% vs 73.6%; p = 0.005). The total amount of exchange amount generation in Indian rupee (INR) after NPP implementation was INR 1419462 (15835€) while it was INR 636898 (7105€) in the pre NPP implementation period. This amount was utilized for procurement of various blood bank equipment, in addition 2 lab technicians were also hired for the blood bank.

CONCLUSIONS

The implementation of NPP resulted in upliftment of blood transfusion services in our hospital. Other low and middle income countries can benefit from implementation of similar plasma policy in their countries.

Improvement in Platelet Product Wastage and Reduction of Costs through Implementation of the Pan Genera Detection Test

OBJECTIVE

The aim of this study was to evaluate the effects of Pan Genera Detection (PGD) testing on reducing platelet product wastage and transfusion service costs.

METHODS

We conducted a retrospective cross-sectional study comparing the number of platelet apheresis units wasted before (March 2017 to February 2019) and after (March 2019 to February 2021) PGD implementation. The PGD testing was performed before transfusion on days 6 and 7. Cost analysis considered the costs of platelet units wasted ($500.00/unit) and PGD test supplies and performance (estimated $26.50 per test). Paired samples t-test was used to compare platelet wastage pre- and post-PGD implementation.

RESULTS

The number of wasted platelet units decreased from pre-PGD (419) to post-PGD (195), representing a significant decrease in platelet wastage from 17.5% to 9.2% (P < .0001). During the post-PGD period, 366 and 133 units were tested on days 6 and 7, with 28 and 36 units discarded each day, allowing transfusion of an additional 302 platelet units. Costs from platelet wastage decreased from $209,500.00 pre-PGD to $97,500.00 post-PGD.

CONCLUSION

Our results showed that PGD testing effectively reduced platelet wastage, extended platelet availability, and reduced transfusion service costs.

Use of Cryoprecipitate in Newborn Infants

Cryoprecipitate is a transfusion blood product derived from fresh-frozen plasma (FFP), comprised mainly of the insoluble precipitate that gravitates to the bottom of the container when plasma is thawed and refrozen. It is highly enriched in coagulation factors I (fibrinogen), VIII, and XIII; von Willebrand factor (vWF); and fibronectin. In this article, we have reviewed currently available information on the preparation, properties, and clinical importance of cryoprecipitate in treating critically ill neonates. We have searched extensively in the databases PubMed, Embase, and Scopus after short-listing keywords to describe the current relevance of cryoprecipitate.

Practice patterns of ABO-matching for cryoprecipitate and patient outcomes after ABO-compatible versus incompatible cryoprecipitate

BACKGROUND AND OBJECTIVES

This sub-study of the FIBRES trial sought to examine the patterns of ABO-compatible cryoprecipitate administration and to identify adverse consequences of ABO-incompatible cryoprecipitate.

MATERIALS AND METHODS

This was a post hoc analysis of data collected from the FIBRES randomized clinical trial comparing fibrinogen concentrate with cryoprecipitate in the treatment of bleeding related to hypofibrinogenemia after cardiac surgery. The primary outcome was the percentage of administered cryoprecipitate that was ABO-compatible. Secondary outcomes were adverse events at 28 days. A follow-up survey was distributed to the FIBRES participating sites to examine the rationale behind the identified cryoprecipitate ABO-matching practice patterns.

RESULTS

A total of 363 patients were included: 53 (15%) received ABO-incompatible cryoprecipitate and 310 (85%) received ABO-compatible cryoprecipitate. There was an increased incidence of post-operative anaemia in the ABO-incompatible group (15; 28.3%) in comparison to the ABO-compatible (44; 14.2%) group (p = 0.01) at 28 days, which was unrelated to haemolysis, without a significant difference in transfusion requirement. In the multivariable logistic regression models accounting for clustering by site, there was no observed statistically significant association between the administration of ABO-incompatible cryoprecipitate and any other adverse outcomes. Nine out of 11 sites did not have a policy requiring ABO-matched cryoprecipitate.

CONCLUSION

This sub-study demonstrated that most cryoprecipitate administered in practice is ABO-compatible, despite the absence of guidelines or blood bank policies to support this practice. A signal towards increased risk of post-operative anaemia may be explained by higher rates of urgent surgery (vs. elective) in the ABO-incompatible group. Future studies should prospectively examine the impact of ABO-compatible versus incompatible cryoprecipitate to conclusively establish if there is a meaningful clinical impact associated with the administration of ABO-incompatible cryoprecipitate.

An insight to the internal quality control of blood components separated using the latest whole blood collection and processing systems: Experience from a tertiary care hospital blood transfusion service in Eastern India

BACKGROUND

With blood component therapy becoming the standard of care in transfusion medicine globally, the quality control (QC) of these components has become a routine and mandatory program in all blood centers. Extensive utilization of blood components has been observed in our multidisciplinary tertiary care hospital. We use quadruple bag systems and automated component extraction facilities for collection and processing of whole blood (WB). In this study, we analyzed our data relating to QC of all blood components which we prepare and issue for transfusion.

MATERIALS AND METHODS

The retrospective 5-year study comprised 47,430 WB collections which were separated into blood components using quadruple bags and automated component extraction machine. A total of 90 units of WB were processed into blood components for the machine calibration and validation. Routine use of the system was started once the calibration and validation results were acceptable. At least 1% of each component prepared was subjected to QC as per departmental standard operating procedures. Statistical analysis was done using the SPSS statistical package.

RESULTS

The mean volume, hematocrit (Hct), platelet (PLT), and white blood cell (WBC) in 350 and 450 mL WB units were 394.63 mL, 39.43%, 0.93 × 1011, and 3.12 × 109 and 507.75 mL, 40.72%, 1.13 × 1011, and 3.45 × 109, respectively, with mean recovery of PLT and WBC in buffy coat being 95.54% and 68.63% and 97.87% and 74.51%, respectively. As high as 89.91% RBC recovery was noted in the packed red blood cell units which were subjected to QC. QC of random donor platelets was performed in 979 (2.36%) units with acceptable results. The mean fibrinogen and FVIII values were estimated to be 469.17 mg and 217.34 IU (1.07 IU/mL) and 600.21 mg and 273.39 IU (1.11 IU/mL) in fresh frozen plasma units prepared from 350 and 450 mL WB, respectively. A total of 578 (1.62%) units of cryoprecipitate were investigated for QC with favorable results.

CONCLUSION

We conclude that QC data generated in this study will provide invaluable information about the performance of the latest blood collection systems. QC of all blood components under study complied with both national and international standards. We opine that all blood centers should establish a complete QC program and adhere to departmental protocols and manufacturer's instructions for its execution and effective outcome.

The clinical demand and supply of blood in India: A National level estimation study

Background

Estimating the clinical demand for blood and components arising in a health facility is crucial to ensure timely availability of blood. This study aims to estimate disease-specific clinical demand, supply and utilization of whole blood and components in India.

Methods

We conducted a national level cross-sectional study in five randomly selected states from five regions of the country. We included 251 public and private facilities representing primary, secondary and tertiary care facilities. We collected annual disease-specific demand, supply and utilization of blood and components using a structured tool. We estimated the national demand by extrapolating the study data (demand and beds) to the total number of estimated beds in the country.

Findings

According to the study, the total clinical demand of 251 health facilities with 51,562 beds was 474,627 whole blood units. Based on this, the clinical demand for India was estimated at 14·6 million whole blood units (95 CI: 14·59–14·62), an equivalent of 36·3 donations per 1,000 eligible populations, which will address whole blood and component requirement. The medicine specialty accounted for 6·0 million units (41·2%), followed by surgery 4·1 million (27·9%), obstetrics and gynecology 3·3 million (22·4%) and pediatrics 1·2 million (8·5%) units. The supply was 93% which is equivalent to 33·8 donations against the demand.

Conclusion

The study indicated a demand and supply gap of 2.5 donations per 1,000 eligible persons which is around one million units. The gap emphasises the need for sustained and concerted efforts from all stakeholders and for increasing the awareness about repeat voluntary non-remunerated blood donation (VNRBD); optimizing the availability of blood components through efficient blood component separation units; promoting modern principles of patient blood management and strengthening capacities of human resources in the blood transfusion system in India.

The effect of perioperative blood transfusion thresholds on patient outcomes in orthopaedic surgery: a literature review

Blood transfusions are one of the most common interventions required perioperatively in orthopaedic patients. There exist two main schools of thought in relation to perioperative blood transfusion - transfusing at a haemoglobin level of 70 g/L or below (termed 'restrictive protocol' in the literature), versus transfusing at a haemoglobin threshold of 100 g/L (which the literature terms 'liberal'). Few reviews of the literature exist comparing the impact of different transfusion strategies on the postoperative outcomes of these orthopaedic patients. This review analyses the 11 currently available studies on transfusion protocols in orthopaedics and associated findings related to patient outcomes. The literature showed no clear consensus on whether one transfusion protocol is superior in the orthopaedic patient. There was strong evidence for reduced transfusion rates among groups receiving transfusion at <70 g/L, and hence a reduction in complication directly related to transfusions. Despite this, other measured patient outcomes, including length of stay, postoperative complication rate, and mortality rate, were unchanged between the groups. Some evidence exists that a Hb threshold of 100 g/L results in earlier postoperative ambulation in hip surgery patients. One study suggests using preoperative haemoglobin as a preoperative risk factor to aid in determining whether patients are more suited to one approach over the other. Further high-quality clinical trials in orthopaedic cohorts must become available to determine whether a haemoglobin threshold of 70 g/L can safely be adopted to reduce transfusion rates without adversely impacting patient outcomes.

Thrombocytopenia in malaria patients from an arid region of Western Rajasthan (India)

Context

The arid climate of Western Rajasthan is challenging for malaria transmission, with the number of cases correlating directly with the annual rainfall pattern. Moreover, >90% of the cases in this region are caused by Plasmodium vivax, which has recently been shown to cause a similar degree of thrombocytopenia as Plasmodium falciparum.

Aims and Objectives

The aim of the study was to determine the degree of thrombocytopenia in malaria patients and its association with different species of malaria in this region with an unstable malaria epidemiology.

Materials and Methods

This retrospective study was conducted on all microbiologically confirmed malaria patients with documented platelet counts from August 2017 to October 2018. Microbiological diagnosis was established by rapid diagnostic tests and peripheral blood film examination. Platelet counts were used to assess the degree of thrombocytopenia.

Results

A total of 130 cases were included in the study, of which 118 (91%) were caused by P. vivax, while the rest 12 (9%) were caused by P. falciparum. Thrombocytopenia was present in 108 (83%) cases, and the mean values of platelets in thrombocytopenic patients with P. vivax and P. falciparum infection were 72600/μL and 48500/μL, respectively. Although P. falciparum infection was significantly associated with severe thrombocytopenia (odds ratio: 4.7, [95% confidence interval 1.3-16.1]), extremely low platelet counts (n = 5) warranting platelet transfusions (n = 1) were seen only in P. vivax cases. Only one patient required platelet transfusions in these patients suggesting good tolerance to thrombocytopenia.

Conclusions

Avoiding unnecessary transfusions in febrile thrombocytopenic patients with an established malaria diagnosis can help in reducing transfusion-transmitted infections.

Whole blood haemostatic function throughout a 28-day cold storage period: an in vitro study

BACKGROUND

In recent years, there has been renewed interest in whole blood (WB) transfusion, particularly in damage control resuscitation, in part due to the ability to provide the adequate ratio of blood components in a single transfusion. However, there is insufficient evidence to suggest that WB units maintain their haemostatic function during storage, which could compromise their quality and efficacy if transfused. Here, we evaluate the in vitro haemostatic function of stored WB units over a 28-day refrigeration period.

METHODS

Standard WB units were collected from healthy volunteers and stored at 4°C for 28 days. Samples were collected from each unit on several days throughout the storage period and tested for complete blood count (CBC), WB aggregation, clot kinetics as measured by thromboelastography (TEG), closure time and plasma-free haemoglobin.

RESULTS

Throughout the storage period, there were gradual, significant decreases in platelet count and function, including WB aggregation in response to collagen (P < 0·05) and closure time with epinephrine (P < 0·0005). Plasma-free haemoglobin increased substantially (by 163%) throughout the storage period. However, TEG results remained relatively stable for 3 weeks, indicating possible preservation of haemostatic function during that time.

CONCLUSION

This study shows that clot kinetics (as measured by TEG) in WB units stored at 4°C are preserved for up to 21 days. However, high levels of free haemoglobin raise concern for the potential risks of transfusing stored WB. Clinical studies are required to evaluate optimal storage times and outcomes of patients resuscitated with WB as compared to blood components.

Influence of AS-7 on the storage lesion in young and old circulating erythrocytes

Blood and its components are stored to meet the demands of blood transfusion. Erythrocytes undergo progressive modifications during storage known as storage lesions. Storage solutions were developed to improve shelf life and extend red cell viability. Therefore, the objective of this study is to analyze the effects of AS-7 on young and old erythrocytes during storage. Blood was collected from the blood bank at Kempegowda Institute of Medical Sciences (KIMS) hospital, Bengaluru. Erythrocytes were isolated from whole blood and separated based on its age using Percoll density gradient. The young and old erythrocytes were stored in AS-7 for 35 days and every 5th day, oxidative stress markers - Hemoglobin (Hb), Oxidative Hemolysis, Mechanical Fragility, Sialic Acid, Superoxides, Glucose, Lactate Dehydrogenase (LDH), Glutathione, antioxidant capacity (TAC_CUPRAC), Plasma Membrane Redox System (PMRS), antioxidant enzymes, lipid peroxidation, and protein oxidation products were assessed. Hb, glucose, TAC_CUPRAC, and superoxide dismutase reduced, while oxidative hemolysis, mechanical fragility, protein oxidation, and lipid peroxidation products increased in young and old cells over storage. LDH, PMRS, catalase, advanced oxidation protein products, and conjugate dienes were significant in old cells from day 5 itself, whereas in young cells towards the end of storage (from day 25). Oxidative insult was higher in old cells compared to young cells. AS-7 was beneficial to young erythrocytes during storage and thus laying the foundation for the possibilities of utilizing young cells as models for storage studies.

Recent advances in use of fresh frozen plasma, cryoprecipitate, immunoglobulins, and clotting factors for transfusion support in patients with hematologic disease

Hematologic diseases include a broad range of acquired and congenital disorders, many of which affect plasma proteins that control hemostasis and immune responses. Therapeutic interventions for these disorders include transfusion of plasma, cryoprecipitate, immunoglobulins, or convalescent plasma-containing therapeutic antibodies from patients recovering from infectious diseases, as well as concentrated pro- or anticoagulant factors. This review will focus on recent advances in the uses of plasma and its derivatives for patients with acquired and congenital hematologic disorders.

Whole Blood Transfusion

Whole blood is the preferred product for resuscitation of severe traumatic hemorrhage. It contains all the elements of blood that are necessary for oxygen delivery and hemostasis, in nearly physiologic ratios and concentrations. Group O whole blood that contains low titers of anti-A and anti-B antibodies (low titer group O whole blood) can be safely transfused as a universal blood product to patients of unknown blood group, facilitating rapid treatment of exsanguinating patients. Whole blood can be stored under refrigeration for up to 35 days, during which it retains acceptable hemostatic function, though supplementation with specific blood components, coagulation factors or other adjuncts may be necessary in some patients. Fresh whole blood can be collected from pre-screened donors in a walking blood bank to provide effective resuscitation when fully tested stored whole blood or blood components are unavailable and the need for transfusion is urgent. Available clinical data suggest that whole blood is at least equivalent if not superior to component therapy in the resuscitation of life-threatening hemorrhage. Low titer group O whole blood can be considered the standard of care in resuscitation of major hemorrhage.

Reversibility of platelet P2Y12 inhibition by platelet supplementation: ex vivo and in vitro comparisons of prasugrel, clopidogrel and ticagrelor

Essentials Successful outcome of platelet transfusion depends on specific antiplatelet therapy in use. We assessed if ticagrelor, clopidogrel or prasugrel impacts on donor platelet activity ex vivo. Ticagrelor and/or its active metabolite in plasma or bound to platelets can inhibit donor platelets. This might compromise the effectiveness of platelet transfusion therapy.

SUMMARY

Background Platelet transfusion is the conventional approach to restore platelet function during acute bleeds or surgery, but successful outcome depends on the specific antiplatelet therapy. Notably ticagrelor is associated with inadequate recovery of platelet function after platelet transfusion. We examined whether plasma and/or platelets from ticagrelor-treated patients influence donor platelet function, in comparison with clopidogrel and prasugrel. Methods Platelet transfusion was mimicked ex vivo by mixing naïve donor platelet-rich plasma (PRP) or gel-filtered platelets (GFP) in defined proportions with PRP, plasma or GFP from cardiovascular patients receiving standard care including medication with prasugrel, clopidogrel or ticagrelor (n = 20 each). Blood was taken 4 h after the previous dose. HLA2/HLA28 haplotyping let us distinguish net (all platelet) and individual patient/donor platelet reactivity in mixtures of patient/donor platelets, measured by flow cytometry analysis of ADP-induced fibrinogen binding and CD62P expression. Results ADP responsiveness of donor platelets was dramatically reduced by even low (10%) concentrations of PRP or plasma from ticagrelor-treated patients. Clopidogrel and prasugrel were associated with more modest donor platelet inhibition. GFP from ticagrelor-treated patients but not patients receiving clopidogrel or prasugrel also suppressed donor GFP function upon mixing, suggesting the transfer of ticagrelor from patient platelets to donor platelets. This transfer did not lead to recovery of ADP responsiveness of patient's platelets. Conclusion Collectively, these observations support the concept that ticagrelor and/or its active metabolite in plasma or bound to platelets can inhibit donor platelets, which might compromise the effectiveness of platelet transfusion therapy.

Biomaterials and Advanced Technologies for Hemostatic Management of Bleeding

Bleeding complications arising from trauma, surgery, and as congenital, disease-associated, or drug-induced blood disorders can cause significant morbidities and mortalities in civilian and military populations. Therefore, stoppage of bleeding (hemostasis) is of paramount clinical significance in prophylactic, surgical, and emergency scenarios. For externally accessible injuries, a variety of natural and synthetic biomaterials have undergone robust research, leading to hemostatic technologies including glues, bandages, tamponades, tourniquets, dressings, and procoagulant powders. In contrast, treatment of internal noncompressible hemorrhage still heavily depends on transfusion of whole blood or blood's hemostatic components (platelets, fibrinogen, and coagulation factors). Transfusion of platelets poses significant challenges of limited availability, high cost, contamination risks, short shelf-life, low portability, performance variability, and immunological side effects, while use of fibrinogen or coagulation factors provides only partial mechanisms for hemostasis. With such considerations, significant interdisciplinary research endeavors have been focused on developing materials and technologies that can be manufactured conveniently, sterilized to minimize contamination and enhance shelf-life, and administered intravenously to mimic, leverage, and amplify physiological hemostatic mechanisms. Here, a comprehensive review regarding the various topical, intracavitary, and intravenous hemostatic technologies in terms of materials, mechanisms, and state-of-art is provided, and challenges and opportunities to help advancement of the field are discussed.

Red Blood Cell Transfusion and Surgical Site Infection After Colon Resection Surgery: A Cohort Study

BACKGROUND

Surgical site infections (SSIs) after colon surgery remain a critical safety issue. Patients with an SSI have an increased risk of death, prolonged hospitalization, and increased costs of care. Red blood cell (RBC) transfusion is given during the perioperative period to increase blood oxygen delivery, but it is associated with complications, including infection. We hypothesized that RBC transfusion would be associated with increased SSI risk in patients undergoing colon resection surgery.

METHODS

A retrospective cohort study was performed using the 2014 National Surgical Quality Improvement Program participant use file. Patients who had colon resection surgery were identified using current procedural terminology codes. The association between perioperative RBC transfusion and superficial and deep incisional SSIs, organ space SSIs, and postoperative septic shock was modeled using logistic regression with propensity score analysis.

RESULTS

Of 23,388 patients who had colon resection surgery, 1845 (7.9%) received perioperative RBC transfusion. After controlling for confounders with propensity score analysis and inverse probability of treatment weighting, RBC transfusion had no apparent association with superficial incisional SSI (odds ratio [OR], 1.18; 99% confidence interval [CI], 0.48-2.88) or deep incisional SSI (OR, 1.47; 99% CI, 0.23-9.43). However, RBC transfusion appeared to be associated with increased risk of organ space SSI (OR, 2.93; 99% CI, 1.43-6.01) and septic shock (OR, 9.23; 99% CI, 3.53-24.09).

CONCLUSIONS

RBC transfusion has no apparent association with increased risk for incisional SSIs, but may be associated with increased risk for organ space SSI and septic shock after colon resection surgery.

Quality Assessment of Established and Emerging Blood Components for Transfusion

Blood is donated either as whole blood, with subsequent component processing, or through the use of apheresis devices that extract one or more components and return the rest of the donation to the donor. Blood component therapy supplanted whole blood transfusion in industrialized countries in the middle of the twentieth century and remains the standard of care for the majority of patients receiving a transfusion. Traditionally, blood has been processed into three main blood products: red blood cell concentrates; platelet concentrates; and transfusable plasma. Ensuring that these products are of high quality and that they deliver their intended benefits to patients throughout their shelf-life is a complex task. Further complexity has been added with the development of products stored under nonstandard conditions or subjected to additional manufacturing steps (e.g., cryopreserved platelets, irradiated red cells, and lyophilized plasma). Here we review established and emerging methodologies for assessing blood product quality and address controversies and uncertainties in this thriving and active field of investigation.

A Correlation of the Platelet Count with D-Dimer Levels as an Indicator for Component Therapy in Children with Dengue Hemorrhagic Fever

Dengue Fever (DF) may evolve into two life threatening forms-Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS). DHF is associated with increased vascular permeability and plasma leakage causing thrombocytopenia and loss of clotting factors into the third space and may result in bleeding initially due to thrombocytopenia and later due to disseminated intravascular coagulation (DIC), often as a terminal event. Prompt recognition and treatment of minor bleeds in DF children with incipient DIC with component therapy may be associated with improved survival while failure to do so is usually catastrophic. A sensitive marker for early DIC is the presence of D-dimer (DD) in the blood. To determine the correlation between the severity of thrombocytopenia and early DIC in children with DHF. The impact of additional factors like age and shock will also be evaluated. Case control prospective study of 60 DHF sero -positive children (1-15 years) with thrombocytopenia. After clinical evaluation they were divided into two equal groups based on the degree of thrombocytopenia (more than/less than 30,000/mm³). PT/APTT and DD levels were estimated in all children of both groups and statistical correlation was done. There was no significant difference in the DD levels between the two groups. However, children in either group, presenting with clinical features of shock and thrombocytopenia had significantly higher DD levels. Empirical component therapy in children with DHF based purely on their low platelet counts may not be justified. However, in DHF children with thrombocytopenia and features of shock, aggressive component therapy may prevent subsequent bleeding and may be justified.

Never-frozen liquid plasma blocks endothelial permeability as effectively as thawed fresh frozen plasma

BACKGROUND

Thawed fresh frozen plasma (TP) is a preferred plasma product for resuscitation but can only be used for up to 5 days after thawing. Never-frozen, liquid plasma (LQP) is approved for up to 26 days when stored at 1°C to 6°C. We have previously shown that TP repairs tumor necrosis factor α (TNF-α)-induced permeability in human endothelial cells (ECs). We hypothesized that stored LQP repairs permeability as effectively as TP.

METHODS

Three single-donor LQP units were pooled. Aliquots were frozen, and samples were thawed on Day 0 (TP0) then refrigerated for 5 days (TP5). The remaining LQP was kept refrigerated for 28 days, and aliquots were analyzed every 7 days. The EC monolayer was stimulated with TNF-α (10 ng/mL), inducing permeability, followed by a treatment with TP0, TP5, or LQP aged 0, 7, 14, 21, and 28 days. Permeability was measured by leakage of fluorescein isothiocyanate-dextran through the EC monolayer. Hemostatic profiles of samples were evaluated by thrombogram and thromboelastogram. Statistical analysis was performed using two-way analysis of variance, with p < 0.05 deemed significant.

RESULTS

TNF-α increased permeability of the EC monolayer twofold compared with medium control. There was a significant decrease in permeability at 0, 7, 14, 21, and 28 days when LQP was used to treat TNF-α-induced EC monolayers (p < 0.001). LQP was as effective as TP0 and TP5 at reducing permeability. Stored LQP retained the capacity to generate thrombin and form a clot.

CONCLUSION

LQP corrected TNF-α-induced EC permeability and preserved hemostatic potential after 28 days of storage, similar to TP stored for 5 days. The significant logistical benefit (fivefold) of prolonged LQP storage improves the immediate availability of plasma as a primary resuscitative fluid for bleeding patients.

Theoretical modelling of fibrinogen supplementation with therapeutic plasma, cryoprecipitate, or fibrinogen concentrate

Background

We aimed to create a theoretical tool to model the effect of three haemostatic agents containing fibrinogen (therapeutic plasma, cryoprecipitate, and fibrinogen concentrate) on the patient's plasma fibrinogen level.

Methods

A mathematical model was developed step-wise. The relationship between the amount of haemostatic agent and plasma fibrinogen level was plotted for each agent. A fibrinogen concentration simulator (FCS_amount) was developed, where the amount of haemostatic agent was calculated from patient characteristics, agent characteristics, and target plasma fibrinogen level. Refinements were introduced so that (i) FCS_amount would account for in vivo fibrinogen recovery, (ii) circulatory volume would not increase ad infinitum with increasing amounts, and (iii) red blood cells would be included in the simulation if haematocrit decreased below a certain level. A second FCS (FCS_level) was created to calculate fibrinogen levels resulting from specified amounts of haemostatic agents.

Results

Fibrinogen concentration in haemostatic agents has a critical impact on their ability to increase patients' fibrinogen levels. If the target plasma fibrinogen level approaches the concentration of the fibrinogen source, the required amounts increase exponentially; it is impossible to achieve a target above the concentration of the fibrinogen source.

Conclusions

We successfully developed two theoretical tools answering the questions: ‘How much therapeutic plasma, cryoprecipitate, or fibrinogen concentrate would be needed to achieve a specified target fibrinogen level?’ and ‘What would be the resultant fibrinogen level for a specified amount of haemostatic agent?’ The current tools are not intended for clinical application, but they are potentially useful for educational purposes.