The Relationship Between Fibrinogen Levels After Cardiopulmonary Bypass and Large Volume Red Cell Transfusion in Cardiac Surgery

Amplitude at 10 min in thromboelastography predicts maximum amplitude: a single-center observational study

Thromboelastography is a quantitative test widely used to measure the efficiency of blood clotting. However, awaiting the results of maximum amplitude (MA) is necessary for determining the need for platelet- and fibrinogen-containing products. A more rapid prediction of MA could facilitate faster preparation and administration of blood transfusion products, thereby resulting in coagulation improvement. In this retrospective study, we hypothesized that early amplitude at 10 min (A10) could be a predictor of MA. Therefore, we investigated whether MA can be rapidly inferred from thromboelastographic 6 s (TEG6s) measurements and evaluated its correlation with A10. We extracted TEG6s measurements obtained in operating rooms and intensive care units of our hospital between January 2018 and December 2022. The correlation of MA with display items of TEG6s results, including reaction time, kinetics, α angle, activated clotting time, and A10, was evaluated. The relationship between citrated rapid TEG (CRT)-A10 and CRT-MA, as well as between citrated functional fibrinogen (CFF)-A10 and CFF-MA, were evaluated if A10 and MA showed a good correlation. The results showed good correlations between CRT-A10 and CRT-MA, as well as between CFF-A10 and CFF-MA. Therefore, evaluating A10 using TEG6s could predict MA.

CG02N Analyzer Accurately Measures Fibrinogen Level in Whole Blood in the Presence of Low- or High-Dose Heparin

Rapid fibrinogen (Fbg) evaluation is important in patients with massive bleeding during severe trauma and those undergoing major surgery. However, there are only a few studies on the point-of-care Fbg analyzer. In this study, we aimed to investigate the accuracy of Fbg level measured using CG02N, with whole blood contained in lithium-heparinized syringes with two different concentrations of heparin. Blood samples were collected in lithium-heparinized tubes, namely PREZA-PAK®II (low-dose heparin group [LG], 7 IU/mL) and Pro-Vent® Plus (high-dose heparin group [HG], 70.5 IU/mL). The Fbg levels in LG and HG were compared with those of citrated plasma Fbg (standard-Fbg). Strong correlations with respect to the Fbg level were observed between standard-Fbg and LG or HG (r = 0.968, p < 0.0001; r = 0.970, p < 0.0001, respectively). We demonstrated that the Fbg level in whole-blood samples was accurately assessed by CG02N and not affected by low- or high-dose heparin.

Standardized in vitro bleeding tests in a non-coated novel hybrid prosthesis for frozen elephant trunk demonstrates minimal oozing during full heparinization, supported by clinical data

Introduction

Recent reports have questioned the blood impermeability of the novel frozen elephant trunk (FET) device E-vita Open NEO© (EO-NEO). Therefore, standardized in vitro bleeding tests using porcine heparinized blood were performed, as well as stress testing on the blood tightness of the collar suture line, to investigate this observation.

Material and methods

EO-NEO prostheses were examined in vitro for blood permeability in three test series. Initially, antegrade perfusion with heparinized porcine blood [activated clotting time (ACT) of 500 s, with a 60 min duration] was performed, followed by ante/retrograde testing via the EO-NEO side port. Testing of the collar suture line under a tension of 10 Newton (N) within a suspension device (blood pressure 120 mmHg, ACT of 560 s, 1 min duration) was carried out with the suture material force fiber white (FFWs) yarn, using standard fixation (5 stitches/cm), FFWh yarn in hemostatic fixation (15 stitches/cm), and flow weave yarn (FWYh).

Results

Blood permeability testing of EO-NEO through the prosthetic lumen or via the side port demonstrated minor leakage without statistical difference between the standard and hemostatic suture lines or suture materials used, or positioning on the crimped or tapered portion (p > 0.05). The specific collar anastomosis testing demonstrated leakage volumes of 140 ml/min for FFWs vs. 16 ml/min for FFWh (p = 0.02), vs. 9 ml/min with the FWYh (p = 0.01).

Conclusion

Different blood leakage tests showed minimal oozing and no difference in blood loss through the fabric and different collar suture lines, but unphysiological pressurized retrograde perfusion of the collar region showed significantly less leakage using FWYh and FFWh, prompting production modification of EO-NEO. Clinical results confirmed low blood loss using this novel FET device.

Preoperative fibrinogen level and blood transfusions in liver transplantation: A systematic review

BACKGROUND

Orthotopic liver transplantation (OLT) is a major surgery often associated with significant bleeding. We conducted a systematic review to explore the association between preoperative fibrinogen level and intraoperative blood products transfusion, blood loss and clinical outcomes in patients undergoing OLT.

METHODS

We included observational studies conducted in patients undergoing an OLT mostly for end-stage liver disease that reported an association between the preoperative fibrinogen level and our outcomes of interest. Our primary outcome was the intraoperative red blood cell (RBC) transfusion requirements. Our secondary outcomes were intraoperative blood loss, intraoperative transfusion of any blood product, postoperative RBC transfusion, postoperative thrombotic or hemorrhagic complications, and mortality. We used a standardized search strategy. We reported our results mostly descriptively but conducted meta-analyses using random-effect models when judged feasible.

RESULTS

We selected 24 cohort studies reporting at least one of our outcomes. We found that a high preoperative fibrinogen level was associated with fewer intraoperative RBC and other blood products transfusions, and lower blood loss. We also found a lower overall survival in patients with a higher fibrinogen level (pooled hazard ratio [95% CI] of 1.50 [1.23 to 1.84]; 5 studies, n = 1012, I2 = 48%). Only one study formally explored a fibrinogen level threshold effect. Overall, reporting was heterogeneous, and risk of bias was variable mostly because of uncontrolled confounding.

CONCLUSION

A higher preoperative fibrinogen level was associated with fewer intraoperative RBC and other blood products transfusions, lower blood loss, and higher mortality. Further studies may help clarify observed associations and inform guidelines.

Basic Principles of Rotational Thromboelastometry (ROTEM®) and the Role of ROTEM-Guided Fibrinogen Replacement Therapy in the Management of Coagulopathies

Rotational thromboelastometry (ROTEM) is a viscoelastic method, which provides a graphical and numerical representation of induced hemostasis in whole blood samples. Its ability to quickly assess the state of hemostasis is used in the management of bleeding from a variety of causes. The separate activation of particular parts of hemocoagulation in INTEM, EXTEM, and FIBTEM tests allows for a more comprehensive and faster evaluation of the missing component of hemostasis followed by targeted therapy. One of the most common cause of coagulopathy is trauma-induced coagulopathy. Fibrinogen replacement therapy by ROTEM allows for the use of a standard dosage of fibrinogen, which has been shown to be successful in preventing dilutional coagulopathy following colloid and crystalloid replacement and excessive amount of allogeneic blood transfusions. The best reflection of fibrinogen activity is observed in the FIBTEM assay, where fibrinogen replacement therapy is recommended at an MCF (maximum clot firmness) of FIBTEM < 10 mm and FIBTEM A10 < 7 mm. ROTEM also plays an important role in the diagnostic and management of inherited fibrinogen disorders. These can be manifested by bleeding complications, where changes in the MCF parameter are the most useful tool for assessing the effectiveness of fibrinogen replacement therapy. ROTEM-guided bleeding management algorithms effectively reduce the number of transfusions, healthcare costs, and complications, leading to the improvement of patient safety and overall health.

Guided blood transfusion of trauma patients with rotational thromboelastometry: a single-center cohort study

BACKGROUND

Rotational thromboelastometry (ROTEM) is a blood test used to measure in vitro clot strength as a surrogate for a patient's ability to form clots in vivo. This provides information about induction, formation, and clot lysis, allowing goal-directed transfusion therapy for specific hemostatic needs. We sought to evaluate the effect of ROTEM-guided transfusion on blood product usage and in-hospital mortality among patients with a traumatic injury.

METHODS

This was a single-center observational cohort analysis of emergency department patients in a Level 1 trauma center. We compared blood usage in trauma patients in whom ratio-based massive hemorrhage protocols were activated in the twelve months before the introduction of ROTEM (pre-ROTEM group) to the twelve months following the introduction of ROTEM (ROTEM-period group). ROTEM was implemented in this center in November 2016. The ROTEM device allowed clinicians to make real-time decisions about blood product therapy in resuscitation for trauma.

RESULTS

The pre-ROTEM group contained 21 patients. Forty-three patients were included from the ROTEM-period, of whom 35 patients received ROTEM-guided resuscitation (81% compliance). The use of fibrinogen concentrate was significantly higher in the ROTEM-period group (pre-ROTEM mean 0.2 vs. ROTEM-period mean 0.8; p = 0.006). There was no significant difference in the number of units of red blood cells, platelets, cryoprecipitate, or fresh frozen plasma transfused between these groups. There was no significant difference in the mortality rate between the pre-ROTEM and ROTEM-period groups (33% vs. 19%; p = 0.22).

CONCLUSIONS

The introduction of ROTEM-guided transfusion at this institution was associated with increased fibrinogen usage, but this did not impact mortality rates. There was no difference in the administration of red blood cell, fresh frozen plasma, platelet, and cryoprecipitate. Future research should focus on increased ROTEM compliance and optimizing ROTEM-guided transfusion to prevent blood product overuse among trauma patients.

Hemostatic effects of a dextran-based priming solution for cardiopulmonary bypass: A secondary analysis of a randomized clinical trial

INTRODUCTION

Intravascular fluids administered to patients may influence hemostasis. In patients undergoing cardiac surgery with cardiopulmonary bypass, the heart-lung machine is primed with 1300 ml of fluid. We assessed postoperative coagulation and platelet function in patients randomized to two different priming solutions, one colloid-based (dextran 40) and one crystalloid-based.

MATERIALS AND METHODS

Eighty-four elective cardiac surgery patients were randomized to either a dextran-based prime or Ringer's acetate with added mannitol. Blood samples were collected before, and 2 and 24 h after cardiopulmonary bypass. Coagulation was assessed by standard coagulation tests and rotational thromboelastometry. Platelet function was assessed with impedance aggregometry. Bleeding volumes and transfusion requirements were recorded.

RESULTS

Comparing the groups 2 h after bypass, the dextran group showed lower hemoglobin concentration, hematocrit, platelet count, and fibrinogen concentration, and higher INR and aPTT, as well as longer clot formation time (+41 ± 21 % vs. +8 ± 18 %, p < 0.001) and a larger reduction in fibrinogen-dependent clot strength (-37 ± 12 % vs. -7 ± 20 %, p < 0.001). Adenosine diphosphate-dependent platelet activation was reduced in the dextran group but not in the crystalloid group 2 h after bypass (-14 ± 29 % vs. -1 ± 41 %, p = 0.041). No significant between-group differences in hemostatic variables remained after 24 h, and no significant differences in perioperative bleeding volumes, re-explorations for bleeding, or transfusion rates were observed.

CONCLUSIONS

Compared to a crystalloid solution, a dextran-based prime had measurable negative impact on hemostatic variables but no detectable increase in bleeding volume or transfusion requirements in cardiac surgery patients.

Point-of-Care Viscoelastic Hemostatic Assays in Cardiac Surgery Patients: Comparison of Thromboelastography 6S, Thromboelastometry Sigma, and Quantra

OBJECTIVES

Viscoelastic tests allow a reduction in blood product transfusion. Three modern devices are currently available (rotational thromboelastometry [ROTEM] sigma, thromboelastography [TEG] 6S, and Quantra). No study has compared the performances of these 3 devices simultaneously.

DESIGN

An observational, nonrandomized cohort study.

SETTING

A single-center of cardiac surgery in a university hospital.

PARTICIPANTS

A total of 30 consecutive measurements from at least 10 adult patients presenting significant bleeding in the intensive care unit after cardiac surgery INTERVENTION: Viscoelastic tests using ROTEM sigma, TEG 6S, and Quantra were performed concomitantly with conventional coagulation measurements MEASUREMENTS AND MAIN RESULTS: The authors included 16 patients with 31 blood samples. After the exclusion of missing values, 27 samples were analyzed. Correlation with platelet count was as follows: ROTEM, r = 0.84 [0.66-0.93], p < 0.0001; Quantra, r = 0.83 [0.64-0.92], p < 0.0001; TEG 6S, r = 0.64 [0.29-0.83], p = 0.001. Correlation with fibrinogen (Clauss assay) was as follows: ROTEM, r = 0.85 [0.68-0.93], p < 0.0001; Quantra, r = 0.88 [0.74-0.95], p < 0.0001; TEG 6S, r = 0.79 [0.55-0.91], p < 0.0001. No difference was observed for the detection of residual circulating heparin (anti-Xa activity >0.1), with 87% of correct identification for Quantra and 80% for both ROTEM and TEG 6S (p = 0.3). Time to first results after the beginning of the test was shorter for Quantra than ROTEM and TEG 6S (136 [126-152] seconds v 205 [176-221] seconds, p = 0.003 and v 450 [372-516] seconds, p < 0.0001 respectively).

CONCLUSION

ROTEM sigma, TEG 6S, and Quantra performed similarly for exploring platelet count or residual circulating heparin. Thromboelastography 6S presented a weaker correlation with fibrinogen Clauss.

Evaluation of fibrinogen concentration by clot firmness using a dielectric blood coagulation test system

PURPOSE

To determine if fibrinogen concentration can be evaluated by dielectric permittivity changes in dielectric blood coagulation testing (DBCM) during cardiovascular surgery with cardiopulmonary bypass (CPB).

METHODS

We performed a single-center prospective observational study at a university hospital. One hundred patients undergoing cardiovascular surgery with CPB were enrolled. Whole-blood samples were obtained after weaning from CPB, and dielectric clot strength (DCS) was measured by intrinsic pathway testing with or without heparinase in DBCM. The FIBTEM test was performed during rotational thromboelastometry using the same samples, and maximum clot firmness (MCF) was evaluated. Spearman's correlation analysis was performed, and receiver operating characteristics (ROC) curve analyses were used to evaluate the performance of hypofibrinogenemia detection.

RESULTS

DCS showed a strong positive correlation with plasma fibrinogen concentration (Rs = 0.76, P < 0.0001). The area under the ROC curve for evaluating plasma fibrinogen concentration < 200 mg/dL was 0.91 (95% confidence interval (CI) 0.85-0.97) for DCS, compared with 0.88 (95% CI 0.81-0.94) for FIBTEM MCF. The optimal cutoff value of DCS was 17.0 (sensitivity 94%, specificity 80%).

CONCLUSIONS

DCS variables showed a significantly strong correlation with plasma fibrinogen concentration, and the diagnostic performance for hypofibrinogenemia was comparable to that for FIBTEM MCF. This novel methodology has the potential to provide a point-of-care test with sufficient accuracy for the detection of perioperative hypofibrinogenemia during cardiovascular surgery with CPB.

Does Intraoperative Fibrinogen Affect Blood Loss or Transfusion Practice After Aortic Arch Surgery: A Prematurely Ended Randomized Trial

Cardiovascular surgery is often complicated by significant bleeding due to perioperative coagulopathy. The effectiveness of treatment with fibrinogen concentrate to reduce the perioperative blood transfusion rate after thoracic aortic replacement surgery in prior studies has shown conflicting results. Therefore, we conducted a double-blind randomized controlled trial to investigate if a single dose of intraoperative fibrinogen administration reduced blood loss and allogeneic transfusion rate after elective surgery for thoracic arch aneurysm with deep hypothermic circulatory arrest. Twenty patients were randomized to fibrinogen concentrate (N = 10) or placebo (N = 10). The recruitment of study patients was prematurely ended due to a low inclusion rate. Perioperative transfusion, 5-minute bleeding mass after study medication and postoperative blood loss were not different between the groups with fibrinogen concentrate or placebo. Due to small volumes of postoperative blood loss and premature study termination, a beneficial effect of fibrinogen concentrate on the number of blood transfusions could not be established. However, treatment with fibrinogen efficiently restored fibrinogen levels and clot strength to preoperative values with a more effective preserved postoperative thrombin generation capacity. This result might serve as a pilot for further multicenter studies to assess the prospective significance of automated and standardized thrombin generation as a routine assay for monitoring perioperative coagulopathy and its impact on short- and long-term operative results.

Weight-adjusted dosing of fibrinogen concentrate and cryoprecipitate in the treatment of hypofibrinogenaemic bleeding adult cardiac surgical patients: a post hoc analysis of the Fibrinogen Replenishment in cardiac surgery randomised controlled trial

Background

Hypofibrinogenaemia is associated with excessive bleeding after cardiac surgery. Our aim was to compare the efficacy and safety of weight-adjusted vs empiric dosing of fibrinogen replacement in cardiac surgery.

Methods

In the Fibrinogen Replenishment in Cardiac Surgery (FIBRES) RCT, patients (n=735) received fibrinogen concentrate (4 g) or cryoprecipitate (10 units). In this post-hoc analysis, patients were grouped into quartiles based on increasing weight-adjusted dosing. Generalised estimating equations were used to account for hospital site, age, sex, surgical complexity, urgency, and critical preoperative status. The primary outcome was the number of units of red blood cells transfused within 24 h of cardiopulmonary bypass. Secondary outcomes included allogeneic blood components within 24 h, tamponade or major bleeding, and thromboembolic complications, ischaemic complications, or both within 28 days of cardiopulmonary bypass.

Results

The median weight-adjusted doses were 52 mg kg-1 of fibrinogen concentrate (inter-quartile range [IQR], 45-61; n=372) and 1.30 units per 10 kg of cryoprecipitate (IQR, 1.11-1.54; n=363). When patients were divided into quartiles of lowest to highest weight-adjusted dosing, no differences were seen in the primary outcome of red blood cell units transfused within 24 h of cardiopulmonary bypass between the lowest and highest quartiles in either the fibrinogen group (adjusted relative risk [RR]=0.90; 95% confidence interval [CI], 0.71-1.13; P=0.36) or the cryoprecipitate group (adjusted RR=1.04; 95% CI, 0.76-1.43; P=0.80). Results were similar for all secondary outcomes.

Conclusion

Outcomes for the lowest and highest weight-adjusted doses of fibrinogen replacement were comparable. Weight-adjusted dosing does not appear to offer advantages over empiric dosing in this context.

Clinical trial registration

NCT03037424.

Evaluation of plasma fibrinogen levels before and after coronary artery bypass graft surgery and its association with the need for blood products

Background:

The present study investigated the plasma level of fibrinogen before and after removing the pump in coronary artery bypass graft (CABG) surgery and its relationship with the need for blood products.

Materials and Methods:

The present study was performed on 60 patients who were candidates for CABG surgery. The fibrinogen level of these patients was assessed and recorded before surgery and immediately after removing the pump. In addition, their hemoglobin level was recorded before the operation and 2 h after. In addition, the number and type of blood products transfusion were recorded intraoperatively and postoperatively and also at the intensive care unit.

Results:

Patients’ fibrinogen level after removing the pump with the mean of 130.53 ± 122.01 mg/dl decreased significantly compared to before surgery with the mean of mg/dl 224.95 ± 132.88 mg/dl (P < 0.001). In addition, the prognostic value of fibrinogen after removing the pump in determining the postoperative need of blood transfusion showed that the cut-off value of fibrinogen was < 196 mg/dl with a sensitivity of 16.82% and specificity of 80%, but it was not statistically significant (area under the curve [95% confidence interval]: 0.519 [0.350–0.689]; P = 0.825).

Conclusion:

According to the results of the present study, due to significant changes in fibrinogen levels after removing the pump compared to preoperation, it seems that this factor can play an important role in prognosis of the need to postoperative blood transfusion, although the prognostic value and the critical point mentioned in our study was not significant and it is required to do further studies.

Fibrinogen and Bleeding in Adult Cardiac Surgery: A Review of the Literature

Background: Fibrinogen is a substrate for blood clots formation. In cardiac surgery, a number of different mechanisms lead to a decrease in fibrinogen levels and consequent impaired haemostasis. Patients undergoing cardiac surgery are therefore frequently exposed to blood loss and allogeneic blood transfusion, which are risk factors associated with morbidity and mortality. Thus, particular efforts in fibrinogen management should be made to decrease bleeding and the need for blood transfusion. Therefore, fibrinogen remains an active focus of investigations from basic science to clinical practice. This review aims to summarise the latest evidence regarding the role of fibrinogen and current practices in fibrinogen management in adult cardiac surgery. Methods: The PubMed database was systematically searched for literature investigating the role and disorders of fibrinogen in cardiac surgery and diagnostic and therapeutic procedures related to fibrinogen deficiency aimed at reducing blood loss and transfusion requirements. Clinical trials and reviews from the last 10 years were included. Results: In total, 146 articles were analysed. Conclusion: The early diagnosis and treatment of fibrinogen deficiency is crucial in maintaining haemostasis in bleeding patients. Further studies are needed to better understand the association between fibrinogen levels, bleeding, and fibrinogen supplementation and their impacts on patient outcomes in different clinical settings.

A comparison of the in vitro effects of three fibrinogen concentrates on clot strength in blood samples from cardiac surgery patients

BACKGROUND

Fibrinogen concentrate is used clinically to improve hemostasis in bleeding patients. We investigated and compared the efficacy of three commercially available fibrinogen concentrates to improve clot strength in blood samples from cardiac surgery patients.

OBJECTIVES

Postoperative blood samples were collected from 23 cardiac surgery patients. Samples were each divided into four vials, each supplemented with 1.125 mg of fibrinogen of one of three fibrinogen concentrates (RiaSTAP^® , Fibryga^® , FibCLOT^® ), or placebo. The fibrinogen dose corresponded to 2.5 g per 70 kg of body weight. Clot strength after supplementation was assessed in duplicate with rotational thromboelastometry (ROTEM^® ) using FIBTEM maximum clot firmness, EXTEM clot formation time, and maximum clot firmness assays.

RESULTS

In vitro fibrinogen concentrate supplementation of the samples resulted in higher plasma fibrinogen concentrations and improved clot strength with all three concentrates. Supplementation with FibCLOT increased FIBTEM maximum clot firmness (+46% [25th-75th percentile 35-55] compared to placebo) significantly more than did supplementation with Fibryga (+26% [21-35]) and RiaSTAP (+29% [22-47], p < .001). FibCLOT supplementation also shortened EXTEM clot formation time and increased EXTEM maximum clot firmness to a greater extent than did the other concentrates (both p < .001).

CONCLUSIONS

At the selected dose, FibCLOT was more effective than Fibryga and RiaSTAP in restoring clot strength in postoperative blood samples from cardiac surgery patients. These results may have implications for the choice of fibrinogen concentrate and dosing.

TEG6s Platelet Mapping assay for the estimation of plasma fibrinogen concentration during cardiovascular surgery: a single-center prospective observational study

PURPOSE

The Activator F (ActF) test on the TEG6s Platelet Mapping assay system is a means of quantifying blood viscoelasticity caused by fibrin network formation, triggered by reptilase and factor XIII, while platelets are inhibited. This unique methodology enables the measurement of blood viscoelasticity, even in highly heparinized blood. Here, we investigated whether fibrinogen concentration could be estimated using the ActF test in blood samples obtained during cardiopulmonary bypass (CPB) and after CPB in patients undergoing cardiovascular surgery.

METHODS

We performed a single-center prospective observational study at a university hospital. Forty patients aged ≥ 18 years who underwent elective cardiovascular surgery with CPB were enrolled. Blood samples were drawn after the induction of anesthesia, after declamping of the aorta during CPB, and after the reversal of heparinization using protamine (after CPB). Coagulation profiles were evaluated using the Platelet Mapping assay and standard laboratory tests.

RESULTS

There were strong correlations between the maximal amplitude of clot strength (MA) in the ActF test and fibrinogen concentration in samples drawn during CPB (R = 0.84, 95% confidence interval [CI] 0.72-0.91; P < 0.001) and after CPB (R = 0.83, 95% CI 0.70-0.91; P < 0.001). The areas under the receiver-operating characteristic curve for the ActF MA for fibrinogen concentrations < 150 mg/dL were 0.86 (95% CI 0.73-1.0) during CPB and 0.98 (95% CI 0.94-1.0) after CPB.

CONCLUSION

TEG6s Platelet Mapping ActF MA values strongly correlated with plasma fibrinogen concentration in highly heparinized blood during CPB and yielded highly accurate measurements of low fibrinogen concentrations.

Pro-Con Debate: Fibrinogen Concentrate or Cryoprecipitate for Treatment of Acquired Hypofibrinogenemia in Cardiac Surgical Patients

Cryoprecipitate has been the gold standard for treating acquired hypofibrinogenemia in cardiac surgery for nearly 50 years. More recently, fibrinogen concentrate has been used off-label in the United States and is the standard in European countries and Canada to treat the acquired hypofibrinogenemia during cardiac surgery. Fibrinogen concentrate has multiple potential advantages including rapid reconstitution, greater dose predictability, viral inactivation during processing, and reduced transfusion-related adverse events. However, because fibrinogen concentrate lacks the other components contained in the cryoprecipitate, it may not be the "ideal" product for replacing fibrinogen in all cardiac surgical patients, particularly those with longer cardiopulmonary bypass duration. In this Pro-Con commentary article, we discuss the advantages and disadvantages of using fibrinogen concentrate and cryoprecipitate to treat acquired hypofibrinogenemia in cardiac surgical patients.

Managing the coagulopathy associated with cardiopulmonary bypass

Cardiopulmonary bypass (CPB) has allowed for significant surgical advancements, but accompanying risks can be significant and must be expertly managed. One of the foremost risks is coagulopathic bleeding. Increasing levels of bleeding in cardiac surgical patients at the time of separation from CPB are associated with poor outcomes and mortality. CPB-associated coagulopathy is typically multifactorial and rarely due to inadequate reversal of systemic heparin alone. The components of the bypass circuit induce systemic inflammation and multiple disturbances of the coagulation and fibrinolytic systems. Anticipating coagulopathy is the first step in managing it, and specific patient and procedural risk factors have been identified as predictors of excessive bleeding. Medication management pre-procedure is critical, as patients undergoing cardiac surgery are commonly on anticoagulants or antiplatelet agents. Important adjuncts to avoid transfusion include antifibrinolytics, and perfusion practices such as red cell salvage, sequestration, and retrograde autologous priming of the bypass circuit have varying degrees of evidence supporting their use. Understanding the patient's coagulation status helps target product replacement and avoid larger volume transfusion. There is increasing recognition of the role of point-of-care viscoelastic and functional platelet testing. Common pitfalls in the management of post-CPB coagulopathy include overdosing protamine for heparin reversal, imperfect laboratory measures of thrombin generation that result in normal or near-normal laboratory results in the presence of continued bleeding, and delayed recognition of surgical bleeding. While challenging, the effective management of CPB-associated coagulopathy can significantly improve patient outcomes.

Transfusion in Pediatric Patients: Review of Evidence-Based Guidelines

Children require transfusion of blood components for a vast array of medical conditions, including acute hemorrhage, hematologic and nonhematologic malignancies, hemoglobinopathy, and allogeneic and autologous stem cell transplant. Evidence-based literature on pediatric transfusion practices is limited, particularly for non-red blood cell products, and many recommendations are extrapolated from studies in adult populations. Recognition of these knowledge gaps has led to increasing numbers of clinical trials focusing on children and establishment of pediatric transfusion working groups in recent years. This article reviews existing literature on pediatric transfusion therapy within the larger context of analogous data in adult populations.

Detection of hypofibrinogenemia during cardiac surgery: a comparison of resonance-based thrombelastography with the traditional Clauss method

: Bleeding after cardiac surgery is associated with significant morbidity and mortality. Hypofibrinogenemia is a crucial factor for bleeding in this setting and may be rapidly detected using point-of-care viscoelastic tests (POC-VET). However, the correlation of POC-VET with conventional coagulation assays is still unclear. The current study aimed to correlate resonance-based POC-VET assays (Haemonetics TEG 6s) with the traditional nonrapid Clauss method. Another aim was to identify a cut-off value for the detection of hypofibrinogenemia (fibrinogen plasma level below 150 mg/dl) focusing on the maximum amplitude of the TEG 6s citrated functional fibrinogen (CFF) assay. Adult patients undergoing cardiac surgery were screened for inclusion in this single-centre retrospective cohort study. Inclusion criteria were the availability of a TEG assay and timely corresponding laboratory results. Calculation of a CFF-maximum amplitude (CFF-MA) cut-off value was performed using receiver operating curve analysis in the baseline cohort and validated in the control cohort. The best correlation with the Clauss method was observed for the CFF-MA (r = 0.77; P < 0.0001) compared with the citrate kaolin maximum amplitude assay (r = 0.57; P < 0.0001) and the citrate kaolin heparinase maximum amplitude assay (r = 0.67; P < 0.0001). A cut-off value of 19.9 mm for the CFF-MA was calculated [area under the curve 0.87 (95% confidence interval: 0.82-0.92; P < 0.0001)]. This cut-off value had a sensitivity of 81.8% and a specificity of 71.1% for identification of hypofibrinogenemia in the control cohort. The resonance-based thrombelastography analyser can identify hypofibrinogenemia. Future clinical studies should investigate whether cut-off value guided coagulation therapy with POC-VET may improve patient outcomes in patients who suffer from bleeding complications.

Noteworthy Literature in Cardiac Anesthesia for 2019

This article represents a selective review of literature published in 2019. Initial results from PubMed searching for a combination of terms, including cardiac anesthesiology and anesthesiology outcomes, yielded more than 1400 publications. From there, we manually screened the results and identified 5 major themes for the year of 2019, including transcatheter techniques, delirium and anesthesiology, coagulation management following cardiopulmonary bypass, perfusion management with del Nido cardioplegia, and applied clinical research. The following research accomplishments have expanded what is possible and set ambitious goals for the future.

Effect of Fibrinogen Concentrate vs Cryoprecipitate on Blood Component Transfusion After Cardiac Surgery: The FIBRES Randomized Clinical Trial

IMPORTANCE

Excessive bleeding is a common complication of cardiac surgery. An important cause of bleeding is acquired hypofibrinogenemia (fibrinogen level <1.5-2.0 g/L), for which guidelines recommend fibrinogen replacement with cryoprecipitate or fibrinogen concentrate. The 2 products have important differences, but comparative clinical data are lacking.

OBJECTIVE

To determine if fibrinogen concentrate is noninferior to cryoprecipitate for treatment of bleeding related to hypofibrinogenemia after cardiac surgery.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial at 11 Canadian hospitals enrolling adult patients experiencing clinically significant bleeding and hypofibrinogenemia after cardiac surgery (from February 10, 2017, to November 1, 2018). Final 28-day follow-up visit was completed on November 28, 2018.

INTERVENTIONS

Fibrinogen concentrate (4 g; n = 415) or cryoprecipitate (10 units; n = 412) for each ordered dose within 24 hours after cardiopulmonary bypass.

MAIN OUTCOMES AND MEASURES

Primary outcome was blood components (red blood cells, platelets, plasma) administered during 24 hours post bypass. A 2-sample, 1-sided test for the ratio of the mean number of units was conducted to evaluate noninferiority (threshold for noninferiority ratio, <1.2).

RESULTS

Of 827 randomized patients, 735 (372 fibrinogen concentrate, 363 cryoprecipitate) were treated and included in the primary analysis (median age, 64 [interquartile range, 53-72] years; 30% women; 72% underwent complex operations; 95% moderate to severe bleeding; and pretreatment fibrinogen level, 1.6 [interquartile range, 1.3-1.9] g/L). The trial met the a priori stopping criterion for noninferiority at the interim analysis after 827 of planned 1200 patients were randomized. Mean 24-hour postbypass allogeneic transfusions were 16.3 (95% CI, 14.9 to 17.8) units in the fibrinogen concentrate group and 17.0 (95% CI, 15.6 to 18.6) units in the cryoprecipitate group (ratio, 0.96 [1-sided 97.5% CI, -∞ to 1.09; P < .001 for noninferiority] [2-sided 95% CI, 0.84 to 1.09; P = .50 for superiority]). Thromboembolic events occurred in 26 patients (7.0%) in the fibrinogen concentrate group and 35 patients (9.6%) in the cryoprecipitate group.

CONCLUSIONS AND RELEVANCE

In patients undergoing cardiac surgery who develop clinically significant bleeding and hypofibrinogenemia after cardiopulmonary bypass, fibrinogen concentrate is noninferior to cryoprecipitate with regard to number of blood components transfused in a 24-hour period post bypass. Use of fibrinogen concentrate may be considered for management of bleeding in patients with acquired hypofibrinogenemia in cardiac surgery.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03037424.

Society of Cardiovascular Anesthesiologists Clinical Practice Improvement Advisory for Management of Perioperative Bleeding and Hemostasis in Cardiac Surgery Patients

Bleeding after cardiac surgery is a common and serious complication leading to transfusion of multiple blood products and resulting in increased morbidity and mortality. Despite the publication of numerous guidelines and consensus statements for patient blood management in cardiac surgery, research has revealed that adherence to these guidelines is poor, and as a result, a significant variability in patient transfusion practices among practitioners still remains. In addition, although utilization of point-of-care (POC) coagulation monitors and the use of novel therapeutic strategies for perioperative hemostasis, such as the use of coagulation factor concentrates, have increased significantly over the last decade, they are still not widely available in every institution. Therefore, despite continuous efforts, blood transfusion in cardiac surgery has only modestly declined over the last decade, remaining at ≥50% in high-risk patients. Given these limitations, and in response to new regulatory and legislature requirements, the Society of Cardiovascular Anesthesiologists (SCA) has formed the Blood Conservation in Cardiac Surgery Working Group to organize, summarize, and disseminate the available best-practice knowledge in patient blood management in cardiac surgery. The current publication includes the summary statements and algorithms designed by the working group, after collection and review of the existing guidelines, consensus statements, and recommendations for patient blood management practices in cardiac surgery patients. The overall goal is creating a dynamic resource of easily accessible educational material that will help to increase and improve compliance with the existing evidence-based best practices of patient blood management by cardiac surgery care teams.

Consensus Report on Patient Blood Management in Cardiac Surgery by Turkish Society of Cardiovascular Surgery (TSCVS), Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care (SCTAIC)

Anemia, transfusion and bleeding independently increase the risk of complications and mortality in cardiac surgery. The main goals of patient blood management are to treat anemia, prevent bleeding, and optimize the use of blood products during the perioperative period. The benefit of this program has been confirmed in many studies and its utilization is strongly recommended by professional organizations. This consensus report has been prepared by the authors who are the task members appointed by the Turkish Society of Cardiovascular Surgery, Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care to raise the awareness of patient blood management. This report aims to summarize recommendations for all perioperative blood- conserving strategies in cardiac surgery.

Fibrinogen levels measured by the dry hematology method are lower than those measured by the Clauss method under a high concentration of heparin

The activity of fibrinogen has been reported to decrease soon after the onset of major bleeding and to be an important determinant of the final extent of bleeding and postoperative outcome. A device that measures the perioperative fibrinogen level using the dry hematology (DH) method has recently become available. The aim of this study was to compare perioperative fibrinogen levels measured by the DH method with those measured by the conventional Clauss method and to assess the effects of heparin on these measurements. The study included 206 samples from 36 patients undergoing major surgery who received high-dose heparin (HH group, 23 samples), low-dose heparin (LH group, 57 samples), or no heparin (C group, 126 control samples). Each sample was measured using the DH and Clauss methods. After excluding samples outside the effective measurement range, the three study groups (HH group, n=23; LH group, n=49; C group, n=115) were compared. The mean fibrinogen level measured by the DH method in the HH group (87.9 ± 3.1%) was significantly lower than that measured by the Clauss method. There were no significant differences between the fibrinogen measurements obtained by the two methods between the LH and C groups. In patients on high-dose heparin, the mean fibrinogen level measured by the DH method was significantly lower than that measured by the Clauss method. When hemorrhage requires emergency treatment, a method that can measure the fibrinogen level rapidly is important. The DH method may be useful for decision-making with regard to perioperative coagulation factor replacement.

The role of evidence-based algorithms for rotational thromboelastometry-guided bleeding management

Rotational thromboelastometry (ROTEM) is a point-of-care viscoelastic method and enables to assess viscoelastic profiles of whole blood in various clinical settings. ROTEM-guided bleeding management has become an essential part of patient blood management (PBM) which is an important concept in improving patient safety. Here, ROTEM testing and hemostatic interventions should be linked by evidence-based, setting-specific algorithms adapted to the specific patient population of the hospitals and the local availability of hemostatic interventions. Accordingly, ROTEM-guided algorithms implement the concept of personalized or precision medicine in perioperative bleeding management (‘theranostic’ approach). ROTEM-guided PBM has been shown to be effective in reducing bleeding, transfusion requirements, complication rates, and health care costs. Accordingly, several randomized-controlled trials, meta-analyses, and health technology assessments provided evidence that using ROTEM-guided algorithms in bleeding patients resulted in improved patient’s safety and outcomes including perioperative morbidity and mortality. However, the implementation of ROTEM in the PBM concept requires adequate technical and interpretation training, education and logistics, as well as interdisciplinary communication and collaboration.

A Low-dose human fibrinogen is not effective in decreasing postoperative bleeding and transfusion requirements during cardiac surgery in case of concomitant clinical bleeding and low FIBTEM values: A retrospective matched study

Background

Studies evaluating the hemostatic effects of fibrinogen administration in cardiac surgery are not conclusive.

Aims

We investigated whether the use of a low-dose human fibrinogen in case of clinical bleeding after protamine administration and concomitant low FIBTEM values is effective in reducing postoperative bleeding. Secondary end-point was to investigate the consumption of allogeneic blood products.

Setting and Design

This was a retrospective matched study conducted at university hospital.

Materials and Methods

Among 2257 patients undergoing surgery with cardiopulmonary (CPB) bypass, 73 patients received a median dose of 1 g human fibrinogen (ROTEM-Fibri group). This group was matched with 73 patients who had not received human fibrinogen (control group) among 390 patients having undergone surgery at the moment FIBTEM analysis was unavailable.

Statistical Analysis

Matching was performed for the type and the presence of redo surgery. McNemar and Wilcoxon paired tests were used to respectively compare the categorical and quantitative variables.

Results

The CPB bypass time was significantly higher in the ROTEM-Fibri group (P = 0.006). This group showed significantly higher bleeding in the first 12 and 24 h postoperatively (P < 0.001) and required significantly more transfusion of blood products (P < 0.001) and surgical revision (P = 0.007) when compared with the control group. There was no significant difference in the number of thromboembolic complications.

Conclusions

These results show that the administration of 1 g of fibrinogen based on low-FIBTEM values and clinical bleeding after protamine administration does not stop bleeding and the need for transfusion of allogeneic blood products.

Effects of fibrinogen and platelet transfusion on coagulation and platelet function in bleeding cardiac surgery patients

BACKGROUND

Excessive bleeding is a significant problem in cardiac surgery. Fibrinogen and platelet concentrate transfusion are used clinically to improve haemostasis and reduce bleeding but little is known about their functional effects on coagulation and platelet function in patients with ongoing bleeding.

METHODS

Forty-two patients with ongoing bleeding after cardiac surgery were included in an observational study. Patients received either fibrinogen concentrate (n = 16), platelet concentrate (n = 12), or both fibrinogen and platelets (n = 14), median doses 2 g fibrinogen and 2 units platelets given at one occasion. Blood samples were collected before and after transfusion. Coagulation (clotting time and clot stability) was analysed with rotational thromboelastometry, and platelet function with impedance aggregometry. In addition, platelet count and fibrinogen concentration was measured. Chest drain output was measured before and after the transfusion.

RESULTS

Fibrinogen infusion resulted in an increase in fibrinogen concentration and clot stability (P = 0.001), but had no effect on platelet aggregation. Platelet transfusion did not significantly affect coagulation, but improved arachidonic acid- and TRAP-induced platelet aggregation (P = 0.017 and 0.034 respectively) and increased platelet count. Combined fibrinogen and platelet transfusion shortened clotting time (P = 0.005) and increased clot stability (P = 0.001), and improved arachidonic acid- and TRAP-induced platelet aggregation (P = 0.004 and 0.016 respectively), and increased fibrinogen concentration and platelet count. The median bleeding volume was 150 (25th-75th percentile 70-240) mL/h before, and 60 (40-110) mL/h after transfusion of fibrinogen and/or platelet concentrate (P < 0.001).

CONCLUSION

The results demonstrate improved coagulation and platelet function following fibrinogen and platelet transfusion in patients bleeding after cardiac surgery.

Preventing and managing catastrophic bleeding during extracorporeal circulation

The use of extracorporeal circulation for cardiac surgery and extracorporeal life support poses tremendous challenges to the hemostatic equilibrium given its diametric tendency to trigger hyper- and hypocoagulopathy. The necessity of anticoagulant therapy to counteract the hemostatic activation by the extracorporeal circuitry compounded by unfavorable patient and surgical factors significantly increase the risk of catastrophic bleeding in patients who require extracorporeal circulation. Preoperative measures, such as stratification of high-risk bleeding patients, and optimization of the modifiable variables, including anemia and thrombocytopenia, provide a crude estimation of the likelihood and may modify the risk of catastrophic bleeding. The anticipation for catastrophic bleeding subsequently prompts the appropriate preparation for potential resuscitation and massive transfusion. Equally important is intraoperative prevention with the prophylactic application of tranexamic acid, an antifibrinolytic agent that has promising benefits in reduction of blood loss and transfusion. In the event of uncontrolled catastrophic bleeding despite preemptive strategies, all effort must be centered on regaining hemostasis through surgical control and damage control resuscitation to protect against worsening coagulopathy and end organ failure. When control of bleeding is reinstated, management should shift focus from systemic therapy to targeted hemostatic therapy aimed at the potential culprits of coagulopathy as identified by point of care hemostatic testing. This review article outlines the strategies to appropriately intervene using prediction, prevention, preparation, protection, and promotion of hemostasis in managing catastrophic bleeding in extracorporeal circulation.

Protocol for a phase III, non-inferiority, randomised comparison of a new fibrinogen concentrate versus cryoprecipitate for treating acquired hypofibrinogenaemia in bleeding cardiac surgical patients: the FIBRES trial

INTRODUCTION

Coagulopathic bleeding is a serious complication of cardiac surgery to which an important contributor is acquired hypofibrinogenaemia (plasma fibrinogen <1.5-2.0 g/L). The standard intervention for acquired hypofibrinogenaemia is cryoprecipitate, but purified fibrinogen concentrates are also available. There is little comparative data between the two therapies and randomised trials are needed.

METHODS AND ANALYSIS

FIBrinogen REplenishment in Surgery (FIBRES) is a multicentre, randomised (1:1), active-control, single-blinded, phase III trial in adult cardiac surgical patients experiencing clinically significant bleeding related to acquired hypofibrinogenaemia. The primary objective is to demonstrate that fibrinogen concentrate (Octafibrin/Fibryga; Octapharma) is non-inferior to cryoprecipitate. All patients for whom fibrinogen supplementation is ordered by the clinical team within 24 hours of cardiopulmonary bypass will receive 4 g of fibrinogen concentrate or 10 units of cryoprecipitate (dose-equivalent to 4 g), based on random allocation and deferred consent. The primary outcome is total red cell, platelet and plasma transfusions administered within 24 hours of bypass. Secondary outcomes include major bleeding, fibrinogen levels and adverse events within 28 days. Enrolment of 1200 patients will provide >90% power to demonstrate non-inferiority. One preplanned interim analysis will include 600 patients. The pragmatic design and treatment algorithm align with standard practice, aiding adherence and generalisability.

ETHICS AND DISSEMINATION

The study is approved by the local research ethics board and will be conducted in accordance with the Declaration of Helsinki, Good Clinical Practice guidelines and regulatory requirements. Patient consent prior to treatment is waived, as per criteria in the Tri-Council Policy Statement. Results will be published in the scientific/medical literature, and at international congresses. Non-inferiority of purified fibrinogen concentrate would support its use in acquired hypofibrinogenaemia. The results are likely to improve care for cardiac surgical patients experiencing significant bleeding, an understudied yet high-risk population.

TRIAL REGISTRATION NUMBER

NCT03037424; Pre-results.

Diagnostic and therapeutic medical devices for safer blood management in cardiac surgery: systematic reviews, observational studies and randomised controlled trials

Background

Anaemia, coagulopathic bleeding and transfusion are strongly associated with organ failure, sepsis and death following cardiac surgery.

Objective

To evaluate the clinical effectiveness and cost-effectiveness of medical devices used as diagnostic and therapeutic tools for the management of anaemia and bleeding in cardiac surgery.

Methods and results

Workstream 1 – in the COagulation and Platelet laboratory Testing in Cardiac surgery (COPTIC) study we demonstrated that risk assessment using baseline clinical factors predicted bleeding with a high degree of accuracy. The results from point-of-care (POC) platelet aggregometry or viscoelastometry tests or an expanded range of laboratory reference tests for coagulopathy did not improve predictive accuracy beyond that achieved with the clinical risk score alone. The routine use of POC tests was not cost-effective. A systematic review concluded that POC-based algorithms are not clinically effective. We developed two new clinical risk prediction scores for transfusion and bleeding that are available as e-calculators. Workstream 2 – in the PAtient-SPecific Oxygen monitoring to Reduce blood Transfusion during heart surgery (PASPORT) trial and a systematic review we demonstrated that personalised near-infrared spectroscopy-based algorithms for the optimisation of tissue oxygenation, or as indicators for red cell transfusion, were neither clinically effective nor cost-effective. Workstream 3 – in the REDWASH trial we failed to demonstrate a reduction in inflammation or organ injury in recipients of mechanically washed red cells compared with standard (unwashed) red cells.

Limitations

Existing studies evaluating the predictive accuracy or effectiveness of POC tests of coagulopathy or near-infrared spectroscopy were at high risk of bias. Interventions that alter red cell transfusion exposure, a common surrogate outcome in most trials, were not found to be clinically effective.

Conclusions

A systematic assessment of devices in clinical use as blood management adjuncts in cardiac surgery did not demonstrate clinical effectiveness or cost-effectiveness. The contribution of anaemia and coagulopathy to adverse clinical outcomes following cardiac surgery remains poorly understood. Further research to define the pathogenesis of these conditions may lead to more accurate diagnoses, more effective treatments and potentially improved clinical outcomes.

Study registration

Current Controlled Trials ISRCTN20778544 (COPTIC study) and PROSPERO CRD42016033831 (systematic review) (workstream 1); Current Controlled Trials ISRCTN23557269 (PASPORT trial) and PROSPERO CRD4201502769 (systematic review) (workstream 2); and Current Controlled Trials ISRCTN27076315 (REDWASH trial) (workstream 3).

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 5, No. 17. See the NIHR Journals Library website for further project information.

Comparison of Thrombelastography-Derived Fibrinogen Values at Rewarming and Following Cardiopulmonary Bypass in Cardiac Surgery Patients

BACKGROUND

The inflated costs and documented deleterious effects of excess perioperative transfusion have led to the investigation of targeted coagulation factor replacement strategies. One particular coagulation factor of interest is factor I (fibrinogen). Hypofibrinogenemia is typically tested for using time-consuming standard laboratory assays. The thrombelastography (TEG)-based functional fibrinogen level (FLEV) provides an assessment of whole blood clot under platelet inhibition to report calculated fibrinogen levels in significantly less time. If FLEV values obtained on cardiopulmonary bypass (CPB) during rewarming are similar to values obtained immediately after the discontinuation of CPB, then rewarming values could be used for preemptive ordering of appropriate blood product therapy.

METHODS

Fifty-one cardiac surgery patients were enrolled into this prospective nonrandomized study to compare rewarming fibrinogen values with postbypass values using TEG FLEV assays. Baseline, rewarming, and postbypass fibrinogen values were recorded for all patients using both standard laboratory assay (Clauss method) and FLEV. Mixed-effects regression models were used to examine the change in TEG FLEV values over time. Bland-Altman analysis was used to examine bias and the limits of agreement (LOA) between the standard laboratory assay and FLEVs.

RESULTS

Forty-nine patients were included in the analysis. The mean FLEV value during rewarming was 333.9 mg/dL compared with 332.8 mg/dL after protamine, corresponding to an estimated difference of -1.1 mg/dL (95% confidence interval [CI], -25.8 to 23.6; P = 0.917). Rewarming values were available on average 47 minutes before postprotamine values. Bland-Altman analysis showed poor agreement between FLEV and standard assays: mean difference at baseline was 92.5 mg/dL (95% CI, 71.1 to 114.9), with a lower LOA of -56.5 mg/dL (95% CI, -94.4 to -18.6) and upper LOA of 242.4 mg/dL (95% CI, 204.5 to 280.3). The difference between assays increased after CPB and persisted after protamine administration.

CONCLUSIONS

Our results revealed negligible change in FLEV values from the rewarming to postbypass periods, with a CI that does not include clinically meaningful differences. These findings suggest that rewarming samples could be utilized for ordering fibrinogen-specific therapies before discontinuation of CPB. Mean FLEV values were consistently higher than the reference standard at each time point. Moreover, bias was highly heterogeneous among samples, implying a large range of potential differences between assays for any 1 patient.

Effect of Desmopressin on the Amount of Bleeding and Transfusion Requirements in Patients Undergoing Heart Transplant Surgery

One of the most common risks after a heart transplant is bleeding. In this study, the effect of desmopressin administration on the amount of bleeding and transfusion requirements after heart transplant surgery was investigated. In a double-blind clinical trial, 48 patients who were candidates for heart transplant surgery were randomly assigned to two groups. In the intervention group, patients received desmopressin of 0.3 μg/kg, 30 min. before surgery. Patients in the control group received normal saline at the same amount and time. Homeostasis was evaluated using activated clotting time (ACT), PT, PTT and PLT before, 12 and 24 hr after surgery, and also, chest tube drainage, blood products transfusion requirements during the first day in both groups. No significant differences were found between the groups in terms of ACT, PT, PTT and PLT at all times. Transfusion of packed red blood cells and the mean drainages of chest tube during the first 24 hr after surgery were significantly lower in the desmopressin group compared to the saline group. Desmopressin may reduce post-operative bleeding in patients undergoing heart transplant surgery. Further studies are required to confirm the potential effect of desmopressin on establishing haemostasis after heart transplantation.