Evidence-based use of FFP: the influence of a priming strategy without FFP during CPB on postoperative coagulation and recovery in pediatric patients

The Year in Review: Anesthesia for Congenital Heart Disease 2023

This review highlights published literature in 2023 that is related to the anesthetic management of patients with congenital heart disease (CHD). Though not inclusive of all topics, 31 articles are discussed and four primary themes emerged: transfusion and hemostasis, outcomes and risk assessment, monitoring, and pharmacology.

Plasma: indications, controversies, and opportunities

Plasma is overused as a blood product worldwide; however, data supporting appropriate use of plasma is scant. Its most common utilization is for treatment of coagulopathy in actively bleeding patients; it is also used for coagulation optimization prior to procedures with specific coagulation profile targets. A baseline literature review in PUBMED and Google Scholar was done (1 January 2000 to 1 June 2023), utilizing the following search terms: plasma, fresh frozen plasma, lyophilized plasma, indications, massive transfusion protocol, liver disease, warfarin reversal, cardiothoracic surgery, INR < 2. An initial review of the titles and abstracts excluded all articles that were not focused on transfusional medicine. Additional references were obtained from citations within the retrieved articles. This narrative review discusses the main indications for appropriate plasma use, mainly coagulation factor replacement, major hemorrhage protocol, coagulopathy in liver disease, bleeding in the setting of vitamin K antagonists, among others. The correlation between concentration of coagulation factors and INR, as well as the proper plasma dosing with its volume being weight-based, is also discussed. A high value approach to plasma utilization is supported with a review of the clinical situations where plasma is overutilized or unnecessary. Finally, a discussion of novel plasma products is presented for enhanced awareness.

Plasma-Free Strategy for Cardiac Surgery with Cardiopulmonary Bypass in Infants < 10 kg: A Retrospective, Propensity-Matched Study

BACKGROUND

Infants < 10 kg undergoing cardiac surgery with cardiopulmonary bypass (CPB) may receive either fresh frozen plasma (FFP) or other solutions in the CPB priming volume. The existing comparative studies are controversial. No study addressed the possibility of total avoidance of FFP throughout the whole perioperative course in this patient population. This retrospective, non-inferiority, propensity-matched study investigates an FFP-free strategy compared to an FFP-based strategy.

METHODS

Among patients <10 kg with available viscoelastic measurements, 18 patients who received a total FFP-free strategy were compared to 27 patients (1:1.5 propensity matching) receiving an FFP-based strategy. The primary endpoint was chest drain blood loss in the first 24 postoperative hours. The level of non-inferiority was settled at a difference of 5 mL/kg.

RESULTS

The 24-h chest drain blood loss difference between groups was -7.7 mL (95% confidence interval -20.8 to 5.3) in favor of the FFP-based group, and the non-inferiority hypothesis was rejected. The main difference in coagulation profile was a lower level of fibrinogen concentration and FIBTEM maximum clot firmness in the FFP-free group immediately after protamine, at the admission in the ICU and for 48 postoperative hours. No differences in transfusion of red blood cells or platelet concentrate were observed; patients in the FFP-free group did not receive FFP but required a larger dose of fibrinogen concentrate and prothrombin complex concentrate.

CONCLUSIONS

An FFP-free strategy in infants < 10 kg operated with CPB is technically feasible but results in an early post-CPB coagulopathy that was not completely compensated with our bleeding management protocol.

A ROTEM-guided algorithm aimed to reduce blood product utilization during neonatal and infant cardiac surgery

BACKGROUND

Neonates and infants undergoing cardiac surgery tend to receive high volumes of blood products. The use of rotational thromboelastometry (ROTEM^®) has been shown to reduce the administration of blood products in adults after cardiac surgery. We sought to develop a targeted administration of blood products based on ROTEM^® to reduce blood product utilization during and after neonatal and infant cardiac surgery.

METHODS

We conducted a retrospective review of data from a single center for neonates and infants undergoing congenital cardiac surgery using cardiopulmonary bypass (CPB) from September 2018-April 2019 (control group). Then, using a ROTEM^® algorithm, we collected data prospectively between April-November 2021 (ROTEM group). Data collected included age, weight, gender, procedure, STAT score, CPB time, aortic cross-clamp time, volume, and type of blood products administered in the operating room and cardiothoracic intensive care unit (CTICU). In addition, ROTEM^® data, coagulation profile in CTICU, chest tube output at 6 and 24 hours, use of factors concentrate, and thromboembolic complications were recorded.

RESULTS

The final cohort of patients included 28 patients in the control group and 40 patients in the ROTEM group. The cohort included neonates and infants undergoing the following procedures: arterial switch, aortic arch augmentation, Norwood procedure, and comprehensive stage II procedure. There were no differences in the demographics or procedure complexity between the two groups. Patients in the ROTEM^® group received fewer platelets (36 ± 12 vs. 49 ± 27 mL/kg, p 0.028) and cryoprecipitate (8 ± 3 vs. 15 ± 10 mL/kg, p 0.001) intraoperatively when compared to the control group.

CONCLUSION

The utilization of ROTEM^® may have contributed to a significant reduction in some blood product administration during cardiac surgery for infants and neonates. ROTEM^® data may play a role in reducing blood product administration in neonatal and infant cardiac surgery.

Thromboelastography in the Perioperative Period: A Literature Review

Assessing coagulation status is essential for prompt intervention to reduce morbidity and mortality related to bleeding and thrombotic complications during the perioperative period. Traditional coagulation tests such as platelet count, activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), and activated clotting time (ACT) provide only static evaluation. These tests are not designed for assessment of dynamically changing coagulation conditions during the perioperative time. However, viscoelastic coagulation testing such as thromboelastography (TEG) produces a rapid numerical and graphical representation that helps to detect and direct targeted hemostatic therapy. Searching the literature through PubMed, Medline, Ovid, CINAHL, and ClinicalTrials.gov we retrieved 210 studies, which represent the use of TEG in the perioperative period. The included studies were categorized under various settings such as trauma, obstetrics, orthopedics, intensive care unit (ICU), cardiovascular, transplant, and miscellaneous scenarios. TEG showed promising results in trauma surgeries in predicting mortality, hypercoagulability, and bleeding even when it was compared to conventional methods. TEG was also useful in monitoring anticoagulant therapy in orthopedic and obstetric surgeries; however, its role in predicting thrombotic events, hypercoagulability, or complications was questionable. In ICU patients, it showed promising results, especially in the prediction or improvement of sepsis, coagulopathy, thrombotic events, ICU duration, hospital stay, and ventilator duration. TEG parameters effectively predicted hypercoagulation in transplant surgeries. Regarding cardiovascular surgeries, they were effective in the prediction of the need for blood products, coagulopathy, thrombotic events, and monitoring anticoagulation therapy. More randomized clinical trials comparing TEG parameters with standardized tools are needed to produce robust results to standardize its use in different perioperative settings.

The impact of using fresh frozen plasma in cardiopulmonary bypass preparation on thromboelastometric parameters and receiving blood products among pediatric patients undergoing cardiac surgery

Introduction: The aim of this study was to determine the effect of fresh frozen plasma (FFP) for priming of cardiopulmonary bypass (CPB) circuit on rotational thromboelastometry (ROTEM) and transfusion in pediatric cardiac surgery. Methods: Eighty patients younger than seven years old, were divided into case (FFP) (n=40) and control (n=40) groups. In the case group,10-20 mL/kg fresh frozen plasm was used for priming the CPB. The control group received 10-20 mL/kg of hydroxyethyl starch. ROTEM was done before surgical incision and after separation from CPB. The amount of transfusion (platelet and FFP) in the operating room and 24 hours after surgery were recorded. Results: Statistically significant difference was found between the case and control group in terms of changes in the Rotem parameters. The amount of transfusion of platelets in the operating room was significantly higher in the control group than in the case group. Conclusion: It seems that adding FFP to the prime solution is more effective in young patients and infants due to the higher susceptibility of the infant coagulation system to coagulation and hemorrhagic disorders in comparison with other patients.

Transfusion therapy of neonatal and paediatric patients: They are not just little adults

Patient blood management (PBM) strategies are needed in the neonate and paediatric population, given that haemoglobin thresholds used are often higher than recommended by evidence, with exposure of children to potential complications without meaningful benefit. A literature review was performed on the following topics: evidence-based transfusions of blood components and pharmaceutical agents. Other topics reviewed included perioperative coagulation assessment and perioperative PBM. The Transfusion and Anaemia Expertise Initiative (TAXI) consortium published a consensus statement addressing haemoglobin (Hb) transfusion threshold in multiple subsets of patients. A multicentre trial (PlaNeT-2) reported a higher risk of bleeding and death or serious new bleeding among infants who received platelet transfusion at a higher (50 000/μl) compared to a lower (25 000/μl) threshold. Recent data support the use of a restrictive transfusion threshold of 25 000/μl for prophylactic platelet transfusions in preterm neonates. The TAXI-CAB consortium mentioned that in critically ill paediatric patients undergoing invasive procedures outside of the operating room, platelet transfusion might be considered when the platelet count is less than or equal to 20 000/μl and there is no benefit of platelet transfusion when the platelet count is more than 50 000/μl. There are limited controlled studies in paediatric and neonatal population regarding plasma transfusion. Blood conservation strategies to minimise allogenic blood exposure are essential to positive patient outcomes neonatal and paediatric transfusion practices have changed significantly in recent years since randomised controlled trials were published to guide practice. Additional studies are needed in order to provide practice change recommendations.

Evaluating the Impact of Cardiopulmonary Bypass Priming Fluids on Bleeding After Pediatric Cardiac Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES

Cardiopulmonary bypass (CPB) predisposes young children to coagulopathy. The authors evaluated possible effects of CPB priming fluids on perioperative bleeding in pediatric cardiac surgery.

DESIGN

Meta-analysis and systematic review of previously published studies.

SETTING

Each study was conducted in a surgical center or intensive care unit.

PARTICIPANTS

Studies investigating patients <18 years without underlying hematologic disorders were included.

INTERVENTIONS

The authors evaluated randomized controlled trials (RCTs) published between 1980 and 2020 on MEDLINE, EMBASE, PubMed, and CENTRAL databases. The primary outcome was postoperative bleeding; secondary endpoints included blood product transfusion, mortality, and safety.

MEASUREMENTS AND MAIN RESULTS

Twenty eligible RCTs were analyzed, with a total of 1,550 patients and a median of 66 patients per study (range 20-200). The most frequently assessed intervention was adding fresh frozen plasma (FFP) to the prime (8/20), followed by albumin (5/20), artificial colloids (5/20), and blood-based priming solutions (3/20). Ten studies with 771 patients evaluated blood loss at 24 hours in mL/kg and were included in a meta-analysis. Most of them investigated the addition of FFP to the priming fluid (7/10). No significant difference was found between intervention and control groups, with a mean difference of -0.13 (-2.61 to 2.34), p = 0.92, I² = 69%. Further study endpoints were described but their reporting was too heterogeneous to be quantitatively analyzed.

CONCLUSIONS

This systematic review of current evidence did not show an effect of different CPB priming solutions on 24-hour blood loss. The analysis was limited by heterogeneity within the dataset regarding population, type of intervention, dosing, and the chosen comparator, compromising any conclusions.

Plasma and Platelet Transfusions Strategies in Neonates and Children Undergoing Cardiac Surgery With Cardiopulmonary Bypass or Neonates and Children Supported by Extracorporeal Membrane Oxygenation: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present the recommendations and consensus statements with supporting literature for plasma and platelet transfusions in critically ill neonates and children undergoing cardiac surgery with cardiopulmonary bypass or supported by extracorporeal membrane oxygenation from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of nine experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed one good practice statement, two recommendations, and three expert consensus statements.

CONCLUSIONS

Whereas viscoelastic testing and transfusion algorithms may be considered, in general, evidence informing indications for plasma and platelet transfusions in neonatal and pediatric patients undergoing cardiac surgery with cardiopulmonary bypass or those requiring extracorporeal membrane oxygenation support is lacking.

Transfusion in Neonatal Patients: Review of Evidence-Based Guidelines

Transfusion of red blood cells, platelets, and fresh frozen plasma in neonatal patients has not been well characterized in the literature, with guidelines varying greatly between institutions. However, anemia and thrombocytopenia are highly prevalent, especially in preterm neonates. When transfusing a neonatal patient, clinicians must take into consideration physiologic differences, gestational and postnatal age, congenital disorders, and maternal factors while weighing the risks and benefits of transfusion. This review of existing literature summarizes current evidence-based neonatal transfusion guidelines and highlights areas of current ongoing research and those in need of future studies.

Fresh Frozen Plasma versus Crystalloid Priming of Cardiopulmonary Bypass Circuit in Pediatric Surgery

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

In congenital cardiac surgery, priming cardiopulmonary bypass (CPB) with fresh frozen plasma (FFP) is performed to prevent coagulation abnormalities. The hypothesis was that CPB priming with crystalloids would be different compared with FFP in terms of bleeding and/or need for blood product transfusion.

Methods

In this parallel-arm double-blinded study, patients weighing between 7 and 15 kg were randomly assigned to a CPB priming with 15 ml · kg−1 PlasmaLyte or 15 ml · kg−1 FFP in addition to a predefined amount of packed red blood cells used in all patients. The decision to transfuse was clinical and guided by point-of-care tests. The primary endpoints included postoperative bleeding tracked by chest tubes, number of patients transfused with any additional blood products, and the total number of additional blood products administered intra- and postoperatively. The postoperative period included the first 6 h after intensive care unit arrival.

Results

Respectively, 30 and 29 patients in the FFP and in the crystalloid group were analyzed in an intention-to-treat basis. Median postoperative blood loss was 7.1 ml · kg−1 (5.1, 9.4) in the FFP group and 5.7 ml · kg−1 (3.8, 8.5) in the crystalloid group (P = 0.219); difference (95% CI): 1.2 (−0.7 to 3.2). The proportion of patients additionally transfused was 26.7% (8 of 30) and 37.9% (11 of 29) in the FFP and the crystalloid groups, respectively (P = 0.355; odds ratio [95% CI], 1.7 [0.6 to 5.1]). The median number of any blood products transfused in addition to priming was 0 (0, 1) and 0 (0, 2) in the FFP and crystalloid groups, respectively (P = 0.254; difference [95% CI], 0 [0 to 0]). There were no study-related adverse events.

Conclusions

The results demonstrate that in infants and children, priming CPB with crystalloids does not result in a different risk of postoperative bleeding and need for transfusion of allogeneic blood products.

Effect of two different colloid priming strategies in infants weighing less than 5 kg undergoing on-pump cardiac surgeries

Our aim was to explore the effect of two different priming strategies (artificial colloid only vs. artificial colloid combined with human serum albumin) on the prognosis of children weighing less than 5 kg undergoing on-pump congenital heart disease (CHD) surgery. A total of 65 children weighing less than 5 kg who underwent on-pump CHD surgery in our hospital from September 2016 to December 2017 were enrolled in this study. The children were randomly divided into two groups: artificial colloid priming group (AC group, n = 33) and artificial colloid combined albumin priming group (ACA group, n = 32). The primary clinical endpoint was the peri-CPB colloid osmotic pressure (COP). Secondary clinical endpoints included perioperative blood product and hemostatic drug consumption, postoperative renal function, coagulation function, postoperative renal function, and postoperative recovery parameters. COP values were not significant in the priming system as well as peri-CPB time points between the two groups (P > .05). Platelet consumption in the AC group was significantly lower than that in the ACA group (P < .05). There were no significant differences in the use of other blood products and hemostatic drugs as well as perioperative coagulation parameters between the two groups (P > .05). Postoperative length of stay in the AC group was significantly lower than that in the ACA group (P < .05). There were no significant differences in mortality, postoperative mechanical ventilation time, ICU time, and perioperative adverse events (including postoperative AKI) occurrences between the two groups (P > .05). In the on-pump cardiac surgeries of patients weighing less than 5 kg, total colloidal priming would not affect peri-CPB COP values, postoperative coagulation function, and blood products consumption. Total artificial colloidal priming strategy is feasible in low-weight patients.

Fibrinogen levels and postoperative chest drain blood loss in low-weight (<10 kg) children undergoing cardiac surgery

Introduction:

Low-weight (<10 kg) children undergoing cardiac surgery with cardiopulmonary bypass are prone to dilution and consumption of soluble coagulation factors and fibrinogen. Low levels of fibrinogen may represent a possible cause of severe postoperative chest drain blood loss. The present study investigates the association between post–cardiopulmonary bypass fibrinogen levels and postoperative chest drain blood loss and severe bleeding, aiming to identify possible cut-off values to trigger specific interventions.

Methods:

Prospective cohort study on 77 patients weighing <10 kg undergoing cardiac surgery with cardiopulmonary bypass. Haemostasis and coagulation data were collected before surgery (standard tests and thromboelastometry), after protamine (thromboelastometry) and at the arrival in the intensive care unit (standard tests). The primary outcome variable was severe bleeding (chest drain blood loss >30 ml kg-1/24h).

Results:

Factors being independently associated with severe bleeding were the international normalized ratio and the fibrinogen levels at the arrival in the intensive care unit. Once corrected for other confounders, fibrinogen levels had an odds ratio of 0.2 (95% confidence interval = 0.011-0.54) per 1 gL-1for severe bleeding. The discrimination power was fair (area under the curve = 0.770). The best cut-off value was identified at a fibrinogen level of 150 mg dL-1, with a sensitivity of 52%, a specificity of 85% and a positive predictive value of 60% for severe bleeding.

Conclusion:

Both a prolonged international normalized ratio and low fibrinogen levels were predictive for severe bleeding, underscoring the role of coagulation factors dilution and consumption in this specific patient population.

Substitution of artificial colloids for fresh frozen plasma in pediatric cardiopulmonary bypass surgery

BACKGROUND

In many centers, fresh frozen plasma is generally used as the main component of pump prime in pediatric cardiopulmonary bypass. However, many factors have resulted in stringent control of plasma transfusion and prompted the study of safe and efficient substitutes.

AIMS

The aim of this study was to investigate the feasibility of a priming strategy with gelatin during cardiopulmonary bypass in pediatric patients undergoing cardiac surgery and identify the factors associated with postoperative chest-tube drainage.

METHODS

We reviewed 1164 pediatric patients who underwent cardiac surgery with cardiopulmonary bypass between January 2012 and April 2013 in Fuwai hospital. Infants and children were primed with different types of solution: plasma or gelatin. Clinical data included postoperative coagulation function (pharmacological agents, chest-tube drainage, and transfusion requirements), recovery indicators (mechanical ventilator time, ICU stay and hospital stay), incidence of in-hospital mortality, and morbidity. Multivariate linear regression analysis was used to identify factors correlated with postoperative chest-tube drainage.

RESULTS

No difference in mortality or morbidity was found between the plasma and gelatin groups. In infants, increased chest-tube drainage (postoperation 12 hours, median difference -0.046 ml/kg/hr, 95%CI: -0.105 to -0.007, P = 0.001; postoperation 24 hours, median difference -0.047 ml/kg/hr, 95%CI: -0.081 to -0.025, P < 0.001), and decreased transfusion (red blood cell, median difference 0.00 ml/kg/hr, 95%CI: 0.000-100, P < 0.001; fresh frozen plasma, median difference 5.556 ml/kg/hr, 95%CI: 2.30-8.333, P = 0.001), and recovery time (mechanical ventilator time, median difference 3.00 hours, 95%CI: 1.00-5.500, P < 0.001; ICU stay, median difference 17.00 hours, 95%CI: 1.00-22.000, P = 0.001; hospital stay, median difference 1.00 day, 95%CI: 0.00-2.000, P = 0.038) were demonstrated in the gelatin group. In children, the transfusion requirements (red blood cell, median difference 100 ml, P < 0.001;fresh frozen plasma, median difference 1.11 ml/kg, 95%CI: 0.000-2.42, P = 0.001) were decreased in the gelatin group. Multivariate linear regression analysis revealed that the type of priming solution (β = 1.940,95%CI: 1.057-2.823,P < 0.001), bypass time (β = 0.024, 95%CI: 0.013-0.036, P < 0.001), and age (β = -0.257, 95%CI: -0.422 to -0.09, P = 0.002) were independent variables correlating with chest-tube drainage in infants.

CONCLUSION

In the general pediatric patients undergoing elective cardiac surgery, substitution of gelatin for fresh frozen plasma in cardiopulmonary bypass is feasible.

Oncotic pressure and paediatric cardiopulmonary bypass: establishing baseline data for complex congenital cardiac surgery and its relation to risk stratification

Objectives:

Colloid osmotic pressure (COP) is a major determinant of fluid shift in paediatric patients undergoing corrective surgery for congenital heart disease (CHD) using cardiopulmonary bypass (CPB). However, very few baseline data are available for those patients requiring surgery within the first few weeks and months of life. Our aim was to determine if our CHD population exhibited COP similar to that of other extremely ill subsets of patients and, if so, whether this related to risk stratification model scores.

Methods:

Thirty consecutive patients under 10 kg underwent cardiac surgery with CPB. Data were collected on COP, albumin concentration, prime composition, post-operative length of ventilation and intensive care unit (ICU) stay as well as risk stratification utilising Risk Adjustment for Congenital Heart Surgery (RACHS-1) and Partial Risk Adjustment in Surgery (PRAiS) scoring systems.

Results:

The patients had a mean pre-bypass COP of 13.9±2.5 mmHg. A significant negative correlation was observed between pre-operative baseline COP and length of ventilation (r=0.7; p<0.001) and a significant negative correlation between PRAiS (r=0.64; p<0.001) and RACHS-1 (r=0.5; p=0.004) scores and baseline COP was seen.

Conclusions:

Neonatal and paediatric patients requiring surgical correction of complex congenital cardiac malformations exhibit extremely low baseline COP, comparable to other sick neonatal populations, and are lower than those previously reported. Baseline COP correlates significantly with predicted survival rates and time spent on a ventilator.

Mechanical blood trauma in assisted circulation: sublethal RBC damage preceding hemolysis

After many decades of improvements in mechanical circulatory assist devices (CADs), blood damage remains a serious problem during support contributing to variety of adverse events, and consequently affecting patient survival and quality of life. The mechanisms of cumulative cell damage in continuous-flow blood pumps are still not fully understood despite numerous in vitro, in vivo, and in silico studies of blood trauma. Previous investigations have almost exclusively focused on lethal blood damage, namely hemolysis, which is typically negligible during normal operation of current generation CADs. The measurement of plasma free hemoglobin (plfHb) concentration to characterize hemolysis is straightforward, however sublethal trauma is more difficult to detect and quantify since no simple direct test exists. Similarly, while multiple studies have focused on thrombosis within blood pumps and accessories, sublethal blood trauma and its sequelae have yet to be adequately documented or characterized. This review summarizes the current understanding of sublethal trauma to red blood cells (RBCs) produced by exposure of blood to flow parameters and conditions similar to those within CADs. It also suggests potential strategies to reduce and/or prevent RBC sublethal damage in a clinically-relevant context, and encourages new research into this relatively uncharted territory.

Fresh frozen plasma for cardiovascular surgery

BACKGROUND

Fresh frozen plasma (FFP) is a blood component containing procoagulant factors, which is sometimes used in cardiovascular surgery with the aim of reducing the risk of bleeding. The purpose of this review is to assess the risk of mortality for patients undergoing cardiovascular surgery who receive FFP.

OBJECTIVES

To evaluate the risk to benefit ratio of FFP transfusion in cardiovascular surgery for the treatment of bleeding patients or for prophylaxis against bleeding.

SEARCH METHODS

We searched 11 bibliographic databases and four ongoing trials databases including the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 3, 2015), MEDLINE (OvidSP, 1946 to 21 April 2015), EMBASE (OvidSP, 1974 to 21 April 2015), PubMed (e-publications only: searched 21 April 2015), ClinicalTrials.gov, World Health Organization (WHO) ICTRP and the ISRCTN Register (searched 21 April 2015). We also searched the references of all identified trials and relevant review articles. We did not limit the searches by language or publication status.

SELECTION CRITERIA

We included randomised controlled trials in patients undergoing major cardiac or vascular surgery who were allocated to a FFP group or a comparator (no plasma or an active comparator, either clinical plasma (any type) or a plasma-derived blood product). We included participants of any age (neonates, children and adults). We excluded studies of plasmapheresis and plasma exchange.

DATA COLLECTION AND ANALYSIS

Two authors screened all electronically derived citations and abstracts of papers identified by the review search strategy. Two authors assessed risk of bias in the included studies and extracted data independently. We took care to note whether FFP was used therapeutically or prophylactically within each trial.

MAIN RESULTS

We included 15 trials, with a total of 755 participants for analysis in the review. Fourteen trials compared prophylactic use of FFP against no FFP. One study compared therapeutic use of two types of plasma. The timing of intervention varied, including FFP transfusion at the time of heparin neutralisation and stopping cardiopulmonary bypass (CPB) (seven trials), with CPB priming (four trials), after anaesthesia induction (one trial) and postoperatively (two trials). Twelve trials excluded patients having emergency surgery and nine excluded patients with coagulopathies.Overall the trials were small, with only four reporting an a priori sample size calculation. No trial was powered to determine changes in mortality as a primary outcome. There was either high risk of bias, or unclear risk, in the majority of trials included in this review.There was no difference in the number of deaths between the intervention arms in the six trials (with 287 patients) reporting mortality (very low quality evidence). There was also no difference in blood loss in the first 24 hours for neonatal/paediatric patients (four trials with 138 patients; low quality evidence): mean difference (MD) -1.46 ml/kg (95% confidence interval (CI) -4.7 to 1.78 ml/kg); or adult patients (one trial with 120 patients): MD -12.00 ml (95% CI -101.16 to 77.16 ml).Transfusion with FFP was inferior to control for preventing patients receiving any red cell transfusion: Peto odds ratio (OR) 2.57 (95% CI 1.30 to 5.08; moderate quality evidence). There was a difference in prothrombin time within two hours of FFP transfusion in eight trials (with 210 patients; moderate quality evidence) favouring the FFP arm: MD -0.71 seconds (95% CI -1.28 to -0.13 seconds). There was no difference in the risk of returning to theatre for reoperation (eight trials with 398 patients; moderate quality evidence): Peto OR 0.81 (95% CI 0.26 to 2.57). Only one included study reported adverse events as an outcome and reported no significant adverse events following FFP transfusion.

AUTHORS' CONCLUSIONS

This review has found no evidence to support the prophylactic administration of FFP to patients without coagulopathy undergoing elective cardiac surgery. There was insufficient evidence about treatment of patients with coagulopathies or those who are undergoing emergency surgery. There were no reported adverse events attributable to FFP transfusion, although there was a significant increase in the number of patients requiring red cell transfusion who were randomised to FFP. Variability in outcome reporting between trials precluded meta-analysis for many outcomes across all trials, and there was evidence of a high risk of bias in most of the studies. Further adequately powered studies of FFP, or comparable pro-haemostatic agents, are required to assess whether larger reductions in prothrombin time translate into clinical benefits. Overall the evidence from randomised controlled trials for the safety and efficacy of prophylactic transfusion of FFP for cardiac surgery is insufficient.