Perioperative Monitoring of Thromboelastograph on Blood Protection and Recovery for Severely Cyanotic Patients Undergoing Complex Cardiac Surgery

Epidemiology of severe bleeding in children following cardiac surgery involving cardiopulmonary bypass: use of Bleeding Assessment Scale for critically Ill Children (BASIC)

OBJECTIVES

To describe the epidemiology of severe bleeding in the immediate post-operative period in children who undergo cardiopulmonary bypass surgery using the Bleeding Assessment Scale for critically Ill Children (BASIC).

STUDY DESIGN

Retrospective cohort study in a paediatric ICU from 2015 to 2020.

RESULTS

356 children were enrolled; 59% were male with median (IQR) age 2.1 (0.5-8) years. Fifty-seven patients (16%) had severe bleeding in the first 24 hours post-operatively. Severe bleeding was observed more frequently in younger and smaller children with longer bypass and cross-clamp times (p-values <0.001), in addition to higher surgical complexity (p = 0.048). Those with severe bleeding received significantly more red blood cells, platelets, plasma, and cryoprecipitate in the paediatric ICU following surgery (all p-values <0.001). No laboratory values obtained on paediatric ICU admission were able to predict severe post-operative bleeding. Those with severe bleeding had significantly less paediatric ICU-free days (p = 0.010) and mechanical ventilation-free days (p = 0.013) as compared to those without severe bleeding.

CONCLUSIONS

Applying the BASIC definition to our cohort, severe bleeding occurred in 16% of children in the first day following cardiopulmonary bypass. Severe bleeding was associated with worse clinical outcomes. Standard laboratory assays do not predict bleeding warranting further study of available laboratory tests.

Plasma and Platelet Transfusion Strategies in Critically Ill Children Following Severe Trauma, Traumatic Brain Injury, and/or Intracranial Hemorrhage: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present consensus statements and supporting literature for plasma and platelet transfusions in critically ill children with severe trauma, traumatic brain injury, and/or intracranial hemorrhage 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 with severe trauma, traumatic brain injury, and/or intracranial hemorrhage.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of eight experts developed expert-based statements for plasma and platelet transfusions in critically ill neonates and children with severe trauma, traumatic brain injury, and/or intracranial hemorrhage. 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 and six expert consensus statements.

CONCLUSIONS

The lack of evidence precludes proposing recommendations on monitoring of the coagulation system and on plasma and platelets transfusion in critically ill pediatric patients with severe trauma, severe traumatic brain injury, or nontraumatic intracranial hemorrhage.

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.

Epidemiology of Bleeding in Critically Ill Children With an Underlying Oncologic Diagnosis

Supplemental Digital Content is available in the text.

Critically ill children with malignancy have significant risk of bleeding but the exact epidemiology is unknown. We sought to describe severe bleeding events and associated risk factors in critically ill pediatric patients with an underlying oncologic diagnosis using the newly developed Bleeding Assessment Scale in Critically Ill Children definition.

Viscoelastic testing in pediatric patients

A tailored transfusion algorithm based on viscoelastic testing in the perioperative period or in trauma patients is recommended by guidelines for bleeding management. Bleeding management strategies in neonates and children are mostly extrapolated from the adult experience, as published evidence in the youngest age group is scarce. This manuscript is intended to give a structured overview of what has been published on the use of viscoelastic testing to guide bleeding management in neonates and children. Several devices that use either the traditional viscoelastic method or resonance viscoelastography technology are on the market. Reference ranges for children have been evaluated in only some of them. As most of the hemostasis maturation processes can be observed during the first year of life, adult reference ranges for viscoelastic testing could be applied over the age of 1 year. The majority of the published trials in children are based on retrospective analyses describing the correlation between viscoelastic testing and standard laboratory testing or focusing on the prediction of bleeding. Clinically more relevant studies in pediatric patients undergoing cardiac surgery have demonstrated that the implementation of a transfusion algorithm based on viscoelastic testing has significantly reduced transfusion requirements and that this approach has enabled a rapid detection of coagulation disorders in the presence of excessive bleeding. Although further studies are urgently needed, experts have reviewed the use of a transfusion algorithm based on viscoelastic testing in children as a feasible approach, as it has been shown to improve bleeding management and rationalize blood product transfusion.

Pediatric Fibrinogen PART II-Overview of Indications for Fibrinogen Use in Critically Ill Children

Bleeding is frequently seen in critically ill children and is associated with increased morbidity and mortality. Fibrinogen is an essential coagulation factor for hemostasis and hypofibrinogenemia is an important risk factor for bleeding in pediatric and adult settings. Cryoprecipitate and fibrinogen concentrate are often given to critically ill children to prevent bleeding and improve fibrinogen levels, especially in the setting of surgery, trauma, leukemia, disseminated intravascular coagulopathy, and liver failure. The theoretical benefit of fibrinogen supplementation to treat hypofibrinogenemia appears obvious, yet the evidence to support fibrinogen supplementation in children is sparce and clinical indications are poorly defined. In addition, it is unknown what the optimal fibrinogen replacement product is in children and neonates or what the targets of treatment should be. As a result, there is considerable variability in practice. In this article we will review the current pediatric and applicable adult literature with regard to the use of fibrinogen replacement in different pediatric critical care contexts. We will discuss the clinical indications for fibrinogen supplementation in critically ill children and the evidence to support their use. We summarize by highlighting current knowledge gaps and areas for future research.

Prevention of postoperative bleeding after complex pediatric cardiac surgery by early administration of fibrinogen, prothrombin complex and platelets: a prospective observational study

Background

Postoperative bleeding is a major problem in children undergoing complex pediatric cardiac surgery. The primary aim of this prospective observational study was to evaluate the effect of an institutional approach consisting of early preventive fibrinogen, prothrombin complex and platelets administration on coagulation parameters and postoperative bleeding in children. The secondary aim was to study the rate of re-intervention and postoperative transfusion, the occurrence of thrombosis, length of mechanical ventilation, ICU stay and mortality.

Methods

In fifty children (age 0–6 years) with one or more predefined risk factors for bleeding after cardiopulmonary bypass (CPB), thrombelastography (TEG) and standard coagulation parameters were measured at baseline (T1), after CPB and reversal of heparin (T2), at sternal closure (T3) and after 12 h in the ICU (T4). Clinical bleeding was evaluated by the surgeon at T2 and T3 using a numeric rating scale (NRS, 0–10).

Results

After CPB and early administration of fibrinogen, prothrombin complex and platelets, the clinical bleeding evaluation score decreased from a mean value of 6.2 ± 1.9 (NRS) at T2 to a mean value of 2.1 ± 0.8 at T3 (NRS; P <  0.001). Reaction time (R), kinetic time (K), maximum amplitude (MA) and maximum amplitude of fibrinogen (MA-fib) improved significantly (P <  0.001 for all), and MA-fib correlated significantly with the clinical bleeding evaluation (r = 0.70, P <  0.001). The administered total amount of fibrinogen (mg kg^− 1) correlated significantly with weight (r = − 0.42, P = 0.002), priming volume as percentage of estimated blood volume (r = 0.30, P = 0.034), minimum CPB temperature (r = − 0.30, P = 0.033) and the change in clinical bleeding evaluation from T2 to T3 (r = 0.71, P <  0.001). The incidence of postoperative bleeding (> 10% of estimated blood volume) was 8%. No child required a surgical re-intervention, and no cases of thrombosis were observed. Hospital mortality was 0%.

Conclusion

In this observational study of children with an increased risk of bleeding after CPB, an early preventive therapy with fibrinogen, prothrombin complex and platelets guided by clinical bleeding evaluation and TEG reduced bleeding and improved TEG and standard coagulation parameters significantly, with no occurrence of thrombosis or need for re-operation.

Trial registration

German Clinical Trials Register DRKS00018109 (retrospectively registered 27th August 2019).

Individualized, Intraoperative Dosing of Fibrinogen Concentrate for the Prevention of Bleeding in Neonatal and Infant Cardiac Surgery Using Cardiopulmonary Bypass (FIBCON): A Phase 1b/2a Randomized Controlled Trial

BACKGROUND

Mediastinal bleeding is common following pediatric cardiopulmonary bypass surgery for congenital heart disease. Fibrinogen concentrate (FC) represents a potential therapy for preventing bleeding.

METHODS

We performed a single-center, phase 1b/2a, randomized controlled trial on infants 2.5 to 12 kg undergoing cardiopulmonary bypass surgery, aimed at (1) demonstrating the feasibility of an intraoperative point-of-care test, rotational thromboelastometry, to screen out patients at low risk of postoperative bleeding and then guide individualized FC dosing in high-risk patients and (2) determining the dose, safety, and efficacy of intraoperative FC supplementation. Screening occurred intraoperatively 1-hour before bypass separation using the rotational thromboelastometry variable fibrinogen thromboelastometry maximum clot firmness (FibTEM-MCF; fibrinogen contribution to clot firmness). If FibTEM-MCF ≥7 mm, patients entered the monitoring cohort. If FibTEM-MCF ≤6 mm, patients were randomized to receive FC/placebo (2:1 ratio). Individualized FC dose calculation included weight, bypass circuit volume, hematocrit, and intraoperative measured and desired FibTEM-MCF. The coprimary outcomes, measured 5 minutes post-FC administration were FibTEM-MCF (desired range, 8-13 mm) and fibrinogen levels (desired range, 1.5-2.5 g/L). Secondary outcomes were thrombosis and thrombosis-related major complications and postoperative 24-hour mediastinal blood loss.

RESULTS

We enrolled 111 patients (cohort, n=21; FC, n=60; placebo, n=30); mean (SD) age, 6.4 months (5.8); weight, 5.9 kg (2.0). Intraoperative rotational thromboelastometry screening effectively excluded low-risk patients, in that none in the cohort arm (FibTEM-MCF, ≥7 mm) demonstrated clinically significant early postoperative bleeding (>10 mL/kg per 4 hours). Among randomized patients, the median (range) FC administered dose was 114 mg/kg (51-218). Fibrinogen levels increased from a mean (SD) of 0.91 (0.22) to 1.7 g/L (0.41). The postdose fibrinogen range was 1.2 to 3.3 g/L (72% within the desired range). The corresponding FibTEM-MCF values were as follows: pre-dose, 5.3 mm (1.9); post-dose, 13 mm (3.2). Ten patients (8 FC and 2 placebo) exhibited 12 possible thromboses; none were clearly related to FC. There was an overall difference in mean (SD) 24-hour mediastinal drain loss: cohort, 12.6 mL/kg (6.4); FC, 11.6 mL/kg (5.2); placebo, 17.1 mL/kg (14.3; ANOVA P=0.02).

CONCLUSIONS

Intraoperative, individualized dosing of FC appears feasible. The need for individualized dosing is supported by the finding that a 4-fold variation in FC dose is required to achieve therapeutic fibrinogen levels. Registration: URL: https://eudract.ema.europa.eu/; Unique identifier: 2013-003532-68. URL: https://www.isrctn.com/; Unique identifier: 50553029.

Use of Coagulation Point-of-Care Tests in the Management of Anticoagulation and Bleeding in Pediatric Cardiac Surgery: A Systematic Review

Bleeding and coagulation management are essential aspects in the management of neonates and children undergoing cardiac surgery. The use of point-of-care tests (POCTs) in a pediatric setting is not as widely used as in the adult setting. This systematic review aims to summarize the evidence showed by the literature regarding the use of POCTs in children undergoing cardiac surgery. We included all studies examining the pediatric population (<18 years old) undergoing cardiac surgery in which the coagulation profile was assessed with POCTs. Three electronic databases (PubMed, Embase, and the Cochrane Controlled Clinical Trials register) were searched. Tests involved were heparin effect tests, viscoelastic tests, and platelet function tests. Due to the wide heterogeneity of the patients and tests studied, a formal meta-analysis was impossible, and the results are therefore presented through a systematic review. Eighty articles were found, of which 47 are presented in this review. At present, literature data are too weak to define POCTs as a "gold standard" for the treatment of perioperative bleeding in pediatric cardiac surgery. Nevertheless, introduction of POCTs into postoperative algorithms has shown to improve bleeding management, patient outcome, and cost efficiency.

Viscoelastic haemostatic assays in the perioperative period of surgical procedures: Systematic review and meta-analysis

OBJECTIVE

The aim of this study is to evaluate the safety and efficacy of Viscoelastic Haemostatic Assays (VHA) to guide transfusions in patients undergoing surgical procedures.

DESIGN

Systematic review with meta-analysis of randomized controlled trials up until June 5, 2019.

SETTING

Hospitalized patients.

INTERVENTIONS

VHAs compared to the Standard-Of-Care (SOC), which are represented by standard laboratory tests and/or clinical decisions.

MEASUREMENTS

Primary - Risk of death, acute kidney injury, thrombotic events and reoperation for bleeding; Secondary - Risk of use of red blood cells (RBC), platelets, fresh frozen plasma (FFP), fibrinogen, factor VIIa, prothrombin complex, volume of RBC, platelets and FFP, length of hospital stay, and length of ICU stay.

RESULTS

VHAs were associated to a statistically significant reduction in mortality (7.3% vs. 12.1%; RR = 0.64, p-value = 0.03), risk of acute kidney injury (10.5% vs. 17.6%; RR = 0.53, p-value = 0.005), volume of red blood cells (RBCs) transfused (MD = -1.63 U, p-value = 0.02), risk of platelet transfusion (23.9% vs. 27.3%; RR = 0.74, p-value = 0.006), risk of fresh frozen plasma (FFP) transfusion (RR = 0.57, p-value = 0.001), and volume of FFP transfused (MD = -0.90, p-value = 0.0003). No significant differences were observed in terms of thrombotic events, reexploration for bleeding, RBC transfusion, volume of platelets transfused, use of fibrinogen, prothrombin complex, or factor VIIa, length of hospitalization and length of ICU stay.

CONCLUSION

Viscoelastic haemostatic assays are safe and efficacious for coagulation control in patients undergoing surgical procedures, therefore it should be considered for use in practice.

Thromboelastography-guided therapy improves patient blood management and certain clinical outcomes in elective cardiac and liver surgery and emergency resuscitation: A systematic review and analysis

Essentials TEG-guided therapy has been shown to be valuable in a number of surgical settings. This systematic review and analysis specifically evaluated the effects of TEG-guided therapy. TEG-guided therapy can improve blood product utilization and enhance resource management. Use of TEG improved key patient outcomes, including bleed rate, length of stay and mortality.

BACKGROUND

Thromboelastography (TEG 5000 and 6s Thrombelastograph Hemostasis Analyzer; Haemonetics) is a point-of-care system designed to monitor and analyze the entire coagulation process in real time. TEG-guided therapy has been shown to be valuable in a variety of surgical settings.

OBJECTIVE

To conduct an analysis of published clinical trials to evaluate the effects of TEG-guided transfusion for the management of perioperative bleeding on patient outcomes.

PATIENTS/METHODS

We searched MEDLINE (PubMed) and EMBASE for original articles reporting studies using TEG vs controls in a perioperative setting for inclusion in this systematic review. We identified nine eligible randomized controlled trials (RCTs) in two elective surgery settings (cardiac surgery and liver surgery), but only one RCT in the emergency setting.

RESULTS

In the elective surgery study meta-analysis, platelet (P = 0.004), plasma (P < 0.001) and red blood cell transfusion (P = 0.14), operating room length of stay (LoS) (P = 0.005), intensive care unit LoS (P = 0.04) and bleeding rate (P = 0.002) were reduced with TEG-guided transfusion vs controls. Although blood product use was reduced, rates of mortality remained comparable between the TEG group and control group. In the emergency setting evaluation, the RCT reported lower mortality in the TEG group than in the control group (P = 0.049). In addition, there were significant reductions in platelet and plasma transfusion (P = 0.04 and P = 0.02, respectively), and the number of ventilator-free days increased, in the TEG group as compared with the control group (P = 0.10).

CONCLUSIONS

This systematic review and analysis indicate that TEG-guided hemostatic therapy can enhance blood product management and improve key patient outcomes, including LoS, bleeding rate, and mortality.

Thromboelastography or rotational thromboelastometry for bleeding management in adults undergoing cardiac surgery: a systematic review with meta-analysis and trial sequential analysis

Background

Severe bleeding and massive transfusion of blood products may be associated with increased morbidity and mortality of cardiac surgery. A transfusion algorithm incorporating thromboelastography (TEG) or rotational thromboelastometry (ROTEM) can help to determine the appropriate time and target for the use of hemostatic blood products, which may thus reduce the quantity of blood loss as well as blood products transfused.

Methods

We conducted meta-analysis and trial sequential analysis to evaluate the effects of TEG or ROTEM-guided transfusion algorithms vs. standard treatments for patients undergoing cardiac surgery with cardiac pulmonary bypass.

Results

Nineteen studies with a total of 15,320 participants, including 13 randomized controlled trials (RCTs), were included. All-cause mortality was not reduced either in overall studies or in RCTs. Blood loss volume was reduced by 132 mL in overall studies [mean difference (MD): -132.46, 95% CI: -207.49, -57.43; I² =53%, P<0.01], and by 103 mL in RCTs (MD: -103.50, 95% CI: -156.52, -50.48; I² =0%, P<0.01). The relative risks (RRs) in RCTs were 0.89 (95% CI: 0.80-0.98; I² =0%, P=0.02) for red blood cells transfusion, 0.59 (95% CI: 0.42-0.82; I² =55%, P<0.01) for fresh frozen plasma transfusion, and 0.81 (95% CI: 0.74-0.90; I² =0%, P<0.01) for platelet transfusion, respectively. Trial sequential analysis of continuous data on blood loss and dichotomous outcomes on transfusion of blood products suggested the benefits of a TEG/ROTEM-guided algorithm.

Conclusions

TEG or ROTEM-guided transfusion strategies may reduce blood loss volume and the transfusion rates in adult patients undergoing cardiac surgery.

Pro-coagulant haemostatic factors for the prevention and treatment of bleeding in people without haemophilia

BACKGROUND

Some hospital patients may be at risk of or may present with major bleeding. Abnormalities of clotting (coagulation) are often recorded in these people, and the traditional management has been with transfusions of blood components, either to prevent bleeding (prophylactic) or to treat bleeding (therapeutic). There is growing interest in the use of targeted therapies with specific pro-coagulant haemostatic (causing bleeding to stop and to keep blood within a damaged blood vessel) factor concentrates in place of plasma.

OBJECTIVES

To assess the effects and safety of pro-coagulant haemostatic factors and factor concentrates in the prevention and treatment of bleeding in people without haemophilia.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (2018, issue 3), MEDLINE (from 1948), Embase (from 1974), CINAHL (from 1938), PubMed (publications in process to 18 April 2018), PROSPERO, Transfusion Evidence Library (from 1950), LILACS (from 1980), IndMED (from 1985), KoreaMed (from 1934), Web of Science Conference Proceedings Citation Index (from 1990) and ongoing trial databases to 18 April 2018.

SELECTION CRITERIA

We included RCTs that compared intravenous administration of a pro-coagulant haemostatic factor concentrate, either with placebo, current best or standard treatment, or another pro-coagulant haemostatic factor concentrate for prevention or treatment of bleeding. There was no restriction on the types of participants. We excluded studies of desmopressin, tranexamic acid and aminocaproic acid and use of pro-coagulant haemostatic factors for vitamin K over-anticoagulation.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodological procedures.

MAIN RESULTS

We identified 31 RCTs with 2392 participants and 22 ongoing trials. There were 13 therapeutic RCTs that randomised 1057 participants (range from 20 to 249 participants) and 18 prophylactic trials that randomised 1335 participants (range 20 to 479 participants). The pro-coagulant haemostatic factor concentrate was fibrinogen in 23 trials, Factor XIII in seven trials and pro-thrombin complex concentrates (PCC) in one trial.Seventeen trials had industrial funding or support, eight studies either did not declare their funding or were unclear about their source of funding and six studies declared non-industrial funding sources.Certainty in the evidence and included study biasOur certainty in the evidence, using GRADE criteria, ranged from very low to high across all outcomes. We assessed most outcomes as being of low certainty. Risks of bias were a concern in many of the RCTs; randomisation methodology was unclear in 15 RCTs, with allocation concealment unclear in 14 RCTs and at high risk of bias in five RCTs. The blinding status of outcome assessors was unclear in 13 RCTs and at high risk of bias in five RCTs, although most outcomes in these trials were objective and not prone to observer bias. Study personnel were often unblinded or insufficient information was available to assess their level of blinding (five RCTs were at unclear risk and seven at high risk of bias).Primary outcomesAll-cause mortality was reported by 21 RCTs, arterial thromboembolic events by 22 RCTs, and venous thromboembolic events by 21 RCTs.Fibrinogen concentrate: prophylactic trials with inactive comparator (nine RCTs)The trials had heterogeneous clinical settings and outcome time points, so we did not pool the data. Compared to placebo, there was no evidence that prophylactic fibrinogen concentrate reduced all-cause mortality (4 RCTs; 248 participants). Compared to inactive comparators there was low- to moderate-quality evidence that prophylactic fibrinogen concentrate did not increase the risk of arterial or venous thromboembolic complications (7 RCTs; 398 participants).Fibrinogen concentrate: prophylactic trials with active comparator (two RCTs)There was no mortality or incidence of thromboembolic events in these two RCTs (with 57 participants).Fibrinogen concentrate: therapeutic trials with inactive comparator (eight RCTs)The trials had heterogeneous surgical settings and outcome time points, so we pooled data for subgroups only. Compared to an inactive comparator, there was no evidence (quality ranging from low to high) that fibrinogen concentrate reduced all-cause mortality in actively bleeding participants (7 RCTs; 724 participants). Compared to inactive comparators there was no evidence that the use of fibrinogen concentrate in active bleeding increased arterial (7 RCTs; 607 participants) or venous (6 RCTs; 562 participants) thromboembolic events.Fibrinogen concentrate: therapeutic trials with active comparator (four RCTs)We did not pool the outcome data, as they were not measured at comparable time points. Compared to other active pro-coagulant agents, there was no evidence (very low to moderate quality) that fibrinogen concentrate reduced all-cause mortality in actively bleeding participants (4 RCTs; 220 participants). There was no evidence that fibrinogen concentrate increased the risk of arterial (3 RCTs; 126 participants) or venous (4 RCTs; 220 participants) thromboembolic events.FactorXIII: Prophylactic trials with inactive comparator (six trials)The trials were heterogeneous in their surgical settings and time points for outcome analysis, so we pooled data for subgroups only. Compared to an inactive comparator, there was no evidence that prophylactic Factor XIII reduced all-cause mortality (5 RCTs; 414 participants). There was no evidence (very low to low quality) of a difference in the arterial or venous event rate between Factor XIII and inactive comparators (4 trials; 354 participants).FactorXIII: therapeutic trials with inactive comparator (one trial)There was no mortality or incidence of thromboembolic events in this trial.Prothrombin complex concentrate (PCC): prophylactic trials with inactive comparator (one trial)There was no evidence (moderate quality) that PCC reduced all-cause mortality (1 trial; 78 participants). No thromboembolic complications were reported in this trial.

AUTHORS' CONCLUSIONS

The paucity of good-quality comparable evidence precludes the drawing of conclusions for clinical practice. Further research is required to determine the risk-to-benefit ratio of these interventions. The sample sizes of future RCTs would need to be greatly increased to detect a reduction in mortality or thromboembolic events between treatment arms. To improve consistency in outcome reporting, the development of core outcome sets is essential and may help address a number of the limitations identified in this review.

Assessment of Thrombelastography and Platelet Life Span in Ovines

Ovines are a common animal model for the study of cardiovascular devices, where consideration of blood biocompatibility is an essential design criterion. In the ovine model, tools to assess blood biocompatibility are limited and continued investigation to identify and apply additional assays is merited. Toward this end, the thrombelastograph, clinically utilized to assess hemostasis, was used to characterize normal ovine parameters. In addition, platelet labeling with biotin was evaluated for its potential applicability to quantify ovine platelet life span. Mean ovine thrombelastograph values were reaction-time: 4.9 min, K-time: 2 min, angle: 64.1°, maximum amplitude: 68.6mm, actual clot strength: 11.9 kd/s, and coagulation index: 1.5. Reaction time was significantly shorter and maximum amplitude, actual clot strength, and coagulation index were all significantly higher when compared to normal human thrombelastograph values suggesting some hypercoagulability of sheep blood. Biotinylation and reinfusion of ovine platelets allowed temporal tracking of the labeled platelet cohort with flow cytometry. These data indicated a mean ovine platelet life span of 188h with a half-life of 84h. The collection of these parameters for normal ovines demonstrates the applicability of these techniques for subsequent studies where cardiovascular devices may be evaluated and provides an indication of normal ovine values for comparison purposes.

Strategies for Prevention and Management of Bleeding Following Pediatric Cardiac Surgery on Cardiopulmonary Bypass: A Scoping Review

OBJECTIVE

We aimed to systematically describe, via a scoping review, the literature reporting strategies for prevention and management of mediastinal bleeding post pediatric cardiopulmonary bypass surgery.

DATA SOURCES

MEDLINE, EMBASE, PubMed, and Cochrane CENTRAL Register.

STUDY SELECTION

Two authors independently screened publications from 1980 to 2016 reporting the effect of therapeutic interventions on bleeding-related postoperative outcomes, including mediastinal drain loss, transfusion, chest re-exploration rate, and coagulation variables. Inclusions: less than 18 years, cardiac surgery on cardiopulmonary bypass.

DATA EXTRACTION

Data from eligible studies were extracted using a standard data collection sheet.

DATA SYNTHESIS

Overall, 299 of 7,434 screened articles were included, with observational studies being almost twice as common (n = 187, 63%) than controlled trials (n = 112, 38%). The most frequently evaluated interventions were antifibrinolytic drugs (75 studies, 25%), blood products (59 studies, 20%), point-of-care testing (47 studies, 16%), and cardiopulmonary bypass circuit modifications (46 studies, 15%). The publication rate for controlled trials remained constant over time (4-6/yr); however, trials were small (median participants, 51; interquartile range, 57) and overwhelmingly single center (98%). Controlled trials originated from 22 countries, with the United States, India, and Germany accounting for 50%. The commonest outcomes were mediastinal blood loss and transfusion requirements; however, these were defined inconsistently (blood loss being reported over nine different time periods). The majority of trials were aimed at bleeding prevention (98%) rather than treatment (10%), nine studies assessed both.

CONCLUSIONS

Overall, this review demonstrates small trial sizes, low level of evidence, and marked heterogeneity of reported endpoints in the included studies. The need for more, higher quality studies reporting clinically relevant, comparable outcomes is highlighted. Emerging fields such as the use of coagulation factor concentrates, goal-directed guidelines, and anti-inflammatory therapies appear to be of particular interest. This scoping review can potentially guide future trial design and form the basis for therapy-specific systematic reviews.

Impact of thrombelastography in paediatric intensive care

We assessed the clinical impact of thrombelastography (TEG®) results (TEG® 5000, Haemonetics Corporation, Braintree, MA, USA) by measuring their ability to cause changes in a theoretical treatment plan and contribute to the understanding of haemostasis. We prospectively included paediatric intensive care unit (PICU) patients who had standard tests of haemostasis and TEG ordered and had an arterial catheter or extracorporeal access port in situ. Blood for standard tests and TEG was taken simultaneously. Independent of patient care, general patient information and results of standard laboratory tests were presented to five clinicians who were asked to document their theoretical treatment plan. Clinicians were then shown TEG results and asked if they caused a change in their plan, if they confirmed initial standard laboratory test results, if they enabled a better understanding of haemostasis and if they provided additional information. Inter-rater agreement between the clinicians was determined. Forty-two TEG results were obtained from 34 patients. Overall, the inclusion of TEG results led to a change in treatment plan in 97 of 207 occasions (47%), confirmed standard laboratory test results in 177 of 204 occasions (87%), enabled a better understanding of haemostasis in 140 of 204 occasions (69%) and provided additional information in 131 of 204 occasions (64%). Variation existed between clinicians, seemingly due to individual differences, with poor inter-rater agreement. We conclude that TEG results led to changes in treatment plans almost half the time, confirmed findings of standard tests and provided a better understanding of haemostasis, but randomised controlled trials are required to determine the role and influence of TEG results on patient outcome.

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.

Routine use of viscoelastic blood tests for diagnosis and treatment of coagulopathic bleeding in cardiac surgery: updated systematic review and meta-analysis

Viscoelastic point-of-care tests are commonly used to provide prompt diagnosis of coagulopathy and allow targeted treatments in bleeding patients. We updated existing meta-analyses that have evaluated the clinical effectiveness of viscoelastic point-of-care tests vs the current standard of care for the management of cardiac surgery patients at risk of coagulopathic bleeding. Randomized controlled trials comparing viscoelastic point-of-care diagnostic testing with standard care in cardiac surgery patients were sought. All-cause mortality, blood loss, reoperation, blood transfusion, major morbidity, and intensive care unit and hospital length of stay were analysed using random-effects modelling. Fifteen trials that randomized a total of 8737 participants were included for the analysis. None of the trials was classified as low risk of bias. The use of thromboelastography- (TEG®) or thromboelastometry (ROTEM®)-guided algorithms did not reduce mortality [risk ratio (RR) 0.55, 95% confidence interval (CI) 0.28-1.10] without heterogeneity (I2=1%), reoperation for bleeding, stroke, ventilation time, or hospital length of stay compared with standard care. Use of TEG® or ROTEM® resulted in reductions in the frequency of red blood cell (Risk Ratio 0.88, 95% Confidence Interval 0.79-0.97; I2=43%) and platelet transfusion (Risk Ratio 0.78, 95% Confidence Interval 0.66-0.93; I2=0%). Group Reading Assessment and Diagnostic Evaluation (GRADE) assessment demonstrated that the quality of the evidence was low or very low for all estimated outcomes. Routine use of viscoelastic point-of-care tests did not improve important clinical outcomes beyond transfusion in adults undergoing cardiac surgery.

Does whole blood coagulation analysis reflect developmental haemostasis?

: Developmental haemostasis has been well documented over the last 3 decades and age-dependent reference ranges have been reported for a number of plasmatic coagulation parameters. With the increasing use of whole blood point-of-care tests like rotational thromboelastometry (ROTEM) and platelet function tests, an evaluation of age-dependent changes is warranted for these tests as well. We obtained blood samples from 149 children, aged 1 day to 5.9 years, and analysed conventional plasmatic coagulation tests, including activated partial prothrombin time, prothrombin time, and fibrinogen (functional). Whole blood samples were analysed using ROTEM to assess overall coagulation capacity and Multiplate analyzer to evaluate platelet aggregation. Age-dependent changes were analysed for all variables. We found age-dependent differences in all conventional coagulation tests (all P values < 0.05), but there was no sign of developmental changes in whole blood coagulation assessment when applying ROTEM, apart from clotting time in the EXTEM assay (P < 0.03). Despite marked differences in mean platelet aggregation between age groups, data did not reach statistical significance. Citrate-anticoagulated blood showed significantly reduced platelet aggregation compared with blood anticoagulated with heparin or hirudin (all P values < 0.003). We confirmed previous developmental changes in conventional plasmatic coagulation test. However, these age-dependent changes were not displayed in whole blood monitoring using ROTEM or Multiplate analyzer. Type of anticoagulant had a significant influence on platelet aggregation across all age groups.

The effect of fibrinogen concentrate on perioperative bleeding in transurethral resection of the prostate: a double-blind placebo-controlled and randomized study

Essentials Perioperative bleeding during prostate surgery is still a common morbidity. Anticoagulant and antiplatelet medications contribute to the risk of hemorrhage and prolonged hospital stay. Multiple pharmacological agents have been proposed, but none of them have been widely accepted. It is crucial to find a safe and effective modality to reduce hemorrhage.

SUMMARY

Background Hemorrhage during transurethral resection of the prostate (TUR-P) has always been a concern. Several studies have shown preoperative administration of fibrinogen concentrate to have promising results in reducing hemorrhage in cardiac surgery. Objectives To investigate the hemostatic effect of fibrinogen concentrate administration on reducing the amount of bleeding during TUR-P in patients with benign prostatic hyperplasia. Methods Sixty men with benign prostatic hyperplasia, who were chosen to undergo TUR-P, entered this prospective randomized double-blind placebo-controlled study. The participants were randomly assigned to two groups: treatment (n = 31) and placebo (n = 29). They received an infusion of 2 g of fibrinogen concentrate (treatment group) or normal saline (placebo group) before surgery. Data regarding the amount of bleeding, the operation and complications were recorded and analyzed. Results No difference was observed in bleeding between the fibrinogen and placebo groups during (521 mL versus 557 mL, respectively) and after (291 mL versus 341 mL, respectively) surgery. This lack of difference was also seen in operation time (43 min versus 42 min), irrigating fluid volume used during (17 L versus 19 L) and after (29 L versus 28 L) surgery, and resected adenoma volume (19 g versus 19 g). The mean blood pressure was also similar in both groups as a confounding factor for the amount of bleeding. Conclusion Preoperative administration of fibrinogen concentrate had no significant influence on intraoperative and postoperative bleeding in TUR-P surgery.

Comparing efficacy and safety of fibrinogen concentrate to cryoprecipitate in bleeding patients: a systematic review

BACKGROUND

Bleeding is associated with the depletion of fibrinogen, thus increasing the risk of coagulopathy, further bleeding and transfusion requirements. Both fibrinogen concentrate and cryoprecipitate replenish low plasma fibrinogen levels. This systematic review aims to identify and evaluate evidence of efficacy and safety of fibrinogen concentrate and cryoprecipitate in bleeding patients.

METHOD

Cochrane Central Register of Controlled Trials (CENTRAL), Medline, EMBASE up to 2nd of March 2015 were among the electronic search strategies of randomized controlled trials and non-randomized studies with meta-analysis employed. Studies for inclusion required bleeding patients being treated with either fibrinogen concentrate or cryoprecipitate. Mortality was the primary endpoint. Secondary outcomes included bleeding, coagulopathy, transfusion requirements and clinical complications related to the intervention. PRISMA methodology, a data-extraction form and the Cochrane risk of bias tool were all employed.

RESULTS

Four studies were eligible for inclusion in this systematic review; one randomized controlled trial (RCT) consisting of 66 patients and three observational studies involving 218 patients in total. No mortality was reported in the published papers. There were no differences in fibrinogen-level increase, bleeding, RBC transfusions or thromboembolic complications. The RCT showed a possible increased functional improvement of haemostasis after cryoprecipitate therapy compared to fibrinogen concentrate.

CONCLUSION

The available evidence directly comparing fibrinogen concentrate to cryoprecipitate is sparse and with high risk of bias. Recommendation of one product over the other for fibrinogen substitution in the bleeding patient with acquired hypofibrinogenaemia is currently not possible. Future research should guide us towards evidence-based decisions of product superiority.

Thromboelastography (TEG) or thromboelastometry (ROTEM) to monitor haemostatic treatment versus usual care in adults or children with bleeding

BACKGROUND

Severe bleeding and coagulopathy are serious clinical conditions that are associated with high mortality. Thromboelastography (TEG) and thromboelastometry (ROTEM) are increasingly used to guide transfusion strategy but their roles remain disputed. This review was first published in 2011 and updated in January 2016.

OBJECTIVES

We assessed the benefits and harms of thromboelastography (TEG)-guided or thromboelastometry (ROTEM)-guided transfusion in adults and children with bleeding. We looked at various outcomes, such as overall mortality and bleeding events, conducted subgroup and sensitivity analyses, examined the role of bias, and applied trial sequential analyses (TSAs) to examine the amount of evidence gathered so far.

SEARCH METHODS

In this updated review we identified randomized controlled trials (RCTs) from the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 1); MEDLINE; Embase; Science Citation Index Expanded; International Web of Science; CINAHL; LILACS; and the Chinese Biomedical Literature Database (up to 5 January 2016). We contacted trial authors, authors of previous reviews, and manufacturers in the field. The original search was run in October 2010.

SELECTION CRITERIA

We included all RCTs, irrespective of blinding or language, that compared transfusion guided by TEG or ROTEM to transfusion guided by clinical judgement, guided by standard laboratory tests, or a combination. We also included interventional algorithms including both TEG or ROTEM in combination with standard laboratory tests or other devices. The primary analysis included trials on TEG or ROTEM versus any comparator.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data; we resolved any disagreements by discussion. We presented pooled estimates of the intervention effects on dichotomous outcomes as risk ratio (RR) with 95% confidence intervals (CIs). Due to skewed data, meta-analysis was not provided for continuous outcome data. Our primary outcome measure was all-cause mortality. We performed subgroup and sensitivity analyses to assess the effect based on the presence of coagulopathy of a TEG- or ROTEM-guided algorithm, and in adults and children on various clinical and physiological outcomes. We assessed the risk of bias through assessment of trial methodological components and the risk of random error through TSA.

MAIN RESULTS

We included eight new studies (617 participants) in this updated review. In total we included 17 studies (1493 participants). A total of 15 trials provided data for the meta-analyses. We judged only two trials as low risk of bias. The majority of studies included participants undergoing cardiac surgery.We found six ongoing trials but were unable to retrieve any data from them. Compared with transfusion guided by any method, TEG or ROTEM seemed to reduce overall mortality (7.4% versus 3.9%; risk ratio (RR) 0.52, 95% CI 0.28 to 0.95; I(2) = 0%, 8 studies, 717 participants, low quality of evidence) but only eight trials provided data on mortality, and two were zero event trials. Our analyses demonstrated a statistically significant effect of TEG or ROTEM compared to any comparison on the proportion of participants transfused with pooled red blood cells (PRBCs) (RR 0.86, 95% CI 0.79 to 0.94; I(2) = 0%, 10 studies, 832 participants, low quality of evidence), fresh frozen plasma (FFP) (RR 0.57, 95% CI 0.33 to 0.96; I(2) = 86%, 8 studies, 761 participants, low quality of evidence), platelets (RR 0.73, 95% CI 0.60 to 0.88; I(2) = 0%, 10 studies, 832 participants, low quality of evidence), and overall haemostatic transfusion with FFP or platelets (low quality of evidence). Meta-analyses also showed fewer participants with dialysis-dependent renal failure.We found no difference in the proportion needing surgical reinterventions (RR 0.75, 95% CI 0.50 to 1.10; I(2) = 0%, 9 studies, 887 participants, low quality of evidence) and excessive bleeding events or massive transfusion (RR 0.38, 95% CI 0.38 to 1.77; I(2) = 34%, 2 studies, 280 participants, low quality of evidence). The planned subgroup analyses failed to show any significant differences.We graded the quality of evidence as low based on the high risk of bias in the studies, large heterogeneity, low number of events, imprecision, and indirectness. TSA indicates that only 54% of required information size has been reached so far in regards to mortality, while there may be evidence of benefit for transfusion outcomes. Overall, evaluated outcomes were consistent with a benefit in favour of a TEG- or ROTEM-guided transfusion in bleeding patients.

AUTHORS' CONCLUSIONS

There is growing evidence that application of TEG- or ROTEM-guided transfusion strategies may reduce the need for blood products, and improve morbidity in patients with bleeding. However, these results are primarily based on trials of elective cardiac surgery involving cardiopulmonary bypass, and the level of evidence remains low. Further evaluation of TEG- or ROTEM-guided transfusion in acute settings and other patient categories in low risk of bias studies is needed.

Management of postpartum haemorrhage

Postpartum Haemorrhage (PPH) is a major cause of maternal morbidity and mortality. Treatment of acquired coagulopathy observed in severe PPH is an important part of PPH management, but is mainly based on literature in trauma patients, and data thus should be interpreted with caution. This review describes recent advances in transfusion strategy and in the use of tranexamic acid and fibrinogen concentrates in women with PPH.

Assessment of coagulation profile by thromboelastometry in adult patients with cyanotic congenital heart disease

BACKGROUND

Patients with cyanotic congenital heart disease (CCHD) have an increased risk of bleeding and thrombotic complications. Prolonged conventional coagulation screening parameters, such as activated partial thromboplastin time or prothrombin time, are reported in less than 20% of CCHD patients.

METHODS

The aim of this study was to determine the haemostatic abnormalities in 32 adult patients with CCHD by rotation thromboelastometry (ROTEM) with assessment of coagulation dynamic properties, as a guide for perioperative prophylaxis or haemostatic therapy. The control group consisted of 35 healthy subjects.

RESULTS

Our results suggest that CCHD patients, in comparison to healthy controls, had a tendency to hypocoagulate with delayed activation of haemostasis and clot formation, initiated by both intrinsic and extrinsic activators. The growth of the clot was slower and the clot firmness was decreased, which may additionally contribute to bleeding diathesis. Moreover, the clot lysis readings suggest higher clot stability in the CCHD group. All velocity parameters were markedly lower in the CCHD patients, indicating a decreased rate of clot formation. Although coagulation tests and platelet count were normal, the usefulness of rotation thromboelastometry in monitoring or guiding therapy in CCHD patients is demonstrated.

CONCLUSION

In conclusion, our results provide new insights into the data on hypocoagulation with impaired clot lysis in adult CCHD patients as determined by ROTEM. Our findings may assist in determining the optimal management of patients with CCHD undergoing surgery.

Assessing the Methodology for Calculating Platelet Contribution to Clot Strength (Platelet Component) in Thromboelastometry and Thrombelastography

The viscoelastic properties of blood clot have been studied most commonly using thrombelastography (TEG) and thromboelastometry (ROTEM). ROTEM-based bleeding treatment algorithms recommend administering platelets to patients with low EXTEM clot strength (e.g., clot amplitude at 10 minutes [A10] <40 mm) once clot strength of the ROTEM® fibrin-based test (FIBTEM) is corrected. Algorithms based on TEG typically use a low value of maximum amplitude (e.g., <50 mm) as a trigger for administering platelets. However, this parameter reflects the contributions of various blood components to the clot, including platelets and fibrin/fibrinogen. The platelet component of clot strength may provide a more sensitive indication of platelet deficiency than clot amplitude from a whole blood TEG or ROTEM® assay. The platelet component of the formed clot is derived from the results of TEG/ROTEM® tests performed with and without platelet inhibition. In this article, we review the basis for why this calculation should be based on clot elasticity (e.g., the E parameter with TEG and the CE parameter with ROTEM®) as opposed to clot amplitude (e.g., the A parameter with TEG or ROTEM®). This is because clot elasticity, unlike clot amplitude, reflects the force with which the blood clot resists rotation within the device, and the relationship between clot amplitude (variable X) and clot elasticity (variable Y) is nonlinear. A specific increment of X (ΔX) will be associated with different increments of Y (ΔY), depending on the initial value of X. When calculated correctly, using clot elasticity data, the platelet component of the clot can provide a valuable insight into platelet deficiency in emergency bleeding.

Cyanotic congenital heart disease (CCHD): focus on hypoxemia, secondary erythrocytosis, and coagulation alterations

Children with cyanotic congenital heart disease (CCHD) have complex alterations in their whole blood composition and coagulation profile due to long-standing hypoxemia. Secondary erythrocytosis is an associated physiological response intended to increase circulating red blood cells and oxygen carrying capacity. However, this response is frequently offset by an increase in whole blood viscosity that paradoxically reduces blood flow and tissue perfusion. In addition, the accompanying reduction in plasma volume leads to significant deficiencies in multiple coagulation proteins including platelets, fibrinogen and other clotting factors. On the one hand, these patients may suffer from severe hyperviscosity and subclinical 'sludging' in the peripheral vasculature with an increased risk of thrombosis. On the other hand, they are at an increased risk for postoperative hemorrhage due to a complex derangement in their hemostatic profile. Anesthesiologists caring for children with CCHD and secondary erythrocytosis need to understand the pathophysiology of these alterations and be aware of available strategies that lessen the risk of bleeding and/or thrombosis. The aim of this review is to provide an updated analysis of the systemic effects of long-standing hypoxemia in children with primary congenital heart disease with a specific focus on secondary erythrocytosis and hemostasis.

The influence of cardiopulmonary bypass priming without FFP on postoperative coagulation and recovery in pediatric patients with cyanotic congenital heart disease

Transfusion guidelines have been produced for the evidence-based use of fresh frozen plasma (FFP). However, the inappropriate use of FFP is still a worldwide problem, especially in the prophylactic settings. In the present study, 100 cyanotic pediatric patients (age 6 months to 3 years) undergoing cardiac surgery with cardiopulmonary bypass (CPB) were randomized to receive either 10-20 ml/kg FFP (FFP group, n = 50) or 10-20 ml/kg 4 % succinylated gelatin (Gelofusine, GEL group, n = 50) in the priming solution. Rapid thromboelastography (r-TEG) was measured before skin incision and 15 min after heparin neutralization. Postoperative renal and hepatic function, mediastinal chest tube drainage, transfusion requirements, and recovery time were observed. The relationships between hematologic and demographic data and postoperative bleeding volume were also analyzed. The results showed that there were significantly elevated levels of fibrinogen (r-TEG parameters: fibrinogen contribution to maximal amplitude (MAf) and fibrinogen level (FLEV)) in the FFP group compared to the GEL group. The postoperative blood loss, total transfusion requirements, and recovery time were not significantly different between the two groups, indicating that there were no obvious clinical benefits of using FFP in the priming. The maximal amplitude (MA) of r-TEG measured after heparin neutralization was correlated with the 6-h postoperative bleeding volume. In addition, preoperative fibrinogen level rather than FFP priming was an independent predictor of postoperative blood loss.

CONCLUSION

Prophylactic use of FFP in the priming solution does not have obvious clinical benefits in cyanotic congenital heart disease (CCHD) patients. Gelofusine, an artificial colloid, is a safe and effective substitute of FFP in the priming solution. Furthermore, r-TEG can be used as a "real-time" assessment tool to evaluate postoperative bleeding and guide transfusion after cardiac surgery in pediatric patients.

Fibrinogen concentrate for bleeding--a systematic review

Fibrinogen concentrate as part of treatment protocols increasingly draws attention. Fibrinogen substitution in cases of hypofibrinogenaemia has the potential to reduce bleeding, transfusion requirement and subsequently reduce morbidity and mortality. A systematic search for randomised controlled trials (RCTs) and non-randomised studies investigating fibrinogen concentrate in bleeding patients was conducted up to November 2013. We included 30 studies of 3480 identified (7 RCTs and 23 non-randomised). Seven RCTs included a total of 268 patients (165 adults and 103 paediatric), and all were determined to be of high risk of bias and none reported a significant effect on mortality. Two RCTs found a significant reduction in bleeding and five RCTs found a significant reduction in transfusion requirements. The 23 non-randomised studies included a total of 2825 patients, but only 11 of 23 studies included a control group. Three out of 11 found a reduction in transfusion requirements while mortality was reduced in two and bleeding in one. In the available RCTs, which all have substantial shortcomings, we found a significant reduction in bleeding and transfusions requirements. However, data on mortality were lacking. Weak evidence from RCTs supports the use of fibrinogen concentrate in bleeding patients, primarily in elective cardiac surgery, but a general use of fibrinogen across all settings is only supported by non-randomised studies with serious methodological shortcomings. It seems pre-mature to conclude whether fibrinogen concentrate has a routine role in the management of bleeding and coagulopathic patients. More RCTs are urgently warranted.

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

Objective:

Although fresh frozen plasma (FFP) is one of the most commonly used hemostatic agents in clinical specialties today, there is little evidence available supporting its administration. Our present study observed the effects of a priming strategy without FFP during cardiopulmonary bypass (CPB) on postoperative coagulation and clinical recovery in pediatric patients, aiming to supply new evidence for evidence-based use of FFP.

Method:

Eighty pediatric patients with congenital heart disease undergoing cardiac surgery with CPB were randomized to receive either 10-20 ml/kg 4% succinylated gelatin (Gelofusine, GEL group, n = 40) or 1-2 units FFP (FFP group, n = 40) in the pump prime. Rapid-thromboelastography (r-TEG) and functional fibrinogen level were measured before skin incision and 15 minutes after heparin reversal. We recorded the volume of chest tube drainage, transfusion requirements and the dosage of pharmacological agents. The ventilation time, ICU length of stay and hospitalization time after surgery were also collected.

Results:

After heparin neutralization, there were significantly elevated levels of fibrinogen in the FFP group, which were manifested by r-TEG parameters MAf and FLEV. No significant differences were observed between the two groups in postoperative bleeding, transfusion requirements and the usage of pharmacological agents. Recovery time was also comparable between the two groups.

Conclusion:

In conclusion, prophylactic use of FFP in the priming solution does not provide clinical benefits as presumed. Artificial colloids, such as Gelofusine, can be used safely and effectively as a substitute for FFP in the pump prime. TEG is an effective assessment tool to evaluate postoperative coagulation function in pediatric patients.

Restoring hemostasis: fibrinogen concentrate versus cryoprecipitate

Fibrinogen plays a key role in the coagulation process, and therefore maintaining adequate quantities of fibrinogen is an essential step in achieving satisfactory hemostasis in patients with acquired hypofibrinogenemia. Potential options for treating acquired hypofibrinogenemia in patients with uncontrolled bleeding include the use of cryoprecipitate or fibrinogen replacement therapy. This review provides a brief overview of the hemostatic process and the methods for assessing coagulopathy and discusses the efficacy and safety of cryoprecipitate and fibrinogen concentrate in restoring fibrinogen levels, achieving hemostasis and reducing transfusion requirements in different patient populations requiring rapid hemostasis. Other issues relevant to the clinical use of these agents in restoring hemostasis, including variations in product composition, preparation time and cost, are also examined.

Fibrinogen concentrate in bleeding patients

BACKGROUND

Hypofibrinogenaemia is associated with increased morbidity and mortality, but the optimal treatment level, the use of preemptive treatment and the preferred source of fibrinogen remain disputed. Fibrinogen concentrate is increasingly used and recommended for bleeding with acquired haemostatic deficiencies in several countries, but evidence is lacking regarding indications, dosing, efficacy and safety.

OBJECTIVES

We assessed the benefits and harms of fibrinogen concentrate compared with placebo or usual treatment for bleeding patients.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 8); MEDLINE (1950 to 9 August 2013); EMBASE (1980 to 9 August 2013); International Web of Science (1964 to 9 August 2013); CINAHL (1980 to 9 August 2013); LILACS (1982 to 9 August 2013); and the Chinese Biomedical Literature Database (up to 10 November 2011), together with databases of ongoing trials. We contacted trial authors, authors of previous reviews and manufacturers in the field.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs), irrespective of blinding or language, that compared fibrinogen concentrate with placebo/other treatment or no treatment in bleeding patients, excluding neonates and patients with hereditary bleeding disorders.

DATA COLLECTION AND ANALYSIS

Three review authors independently abstracted data; we resolved any disagreements by discussion. Our primary outcome measure was all-cause mortality. We performed subgroup and sensitivity analyses to assess the effects of fibrinogen concentrate in adults and children in terms of various clinical and physiological outcomes. We presented pooled estimates of the effects of intervention on dichotomous outcomes as risk ratios (RRs) and on continuous outcomes as mean differences, with 95% confidence intervals (CIs). We assessed the risk of bias through assessment of trial methodological components and the risk of random error through trial sequential analysis.

MAIN RESULTS

We included six RCTs with a total of 248 participants; none of the trials were determined to have overall low risk of bias. We found 12 ongoing trials, from which we were unable to retrieve any data. Only two trials provided data on mortality, and one was a zero event study; thus the meta-analysis showed no statistically significant effect on overall mortality (2.6% vs 9.5%, RR 0.28, 95% CI 0.03 to 2.33). Our analyses on blood transfusion data suggest a beneficial effect of fibrinogen concentrate in reducing the incidence of allogenic transfusions (RR 0.47, 95% CI 0.31 to 0.72) but show no effect on other predefined outcomes, including adverse events such as thrombotic episodes.

AUTHORS' CONCLUSIONS

In the six available RCTs of elective surgery, fibrinogen concentrate appears to reduce transfusion requirements, but the included trials are of low quality with high risk of bias and are underpowered to detect mortality, benefit or harm. Furthermore, data on mortality are lacking, heterogeneity is high and acute or severe bleeding in a non-elective surgical setting remains unexplored. Currently, weak evidence supports the use of fibrinogen concentrate in bleeding patients, as tested here in primarily elective cardiac surgery. More research is urgently needed.

Fibrinogen concentrate reduces intraoperative bleeding when used as first-line hemostatic therapy during major aortic replacement surgery: results from a randomized, placebo-controlled trial

OBJECTIVES

We assessed whether fibrinogen concentrate as targeted first-line hemostatic therapy was more effective than placebo or a standardized transfusion algorithm in controlling coagulopathic bleeding in patients undergoing major aortic surgery.

METHODS

In this single-center, prospective, double-blind study, adults undergoing elective thoracic or thoracoabdominal aortic replacement surgery involving cardiopulmonary bypass were randomized to intraoperative fibrinogen concentrate (n = 29) or placebo (n = 32). Study medication was given if patients had clinically relevant coagulopathic bleeding, measured by 5-minute bleeding mass, after cardiopulmonary bypass removal, protamine administration, and surgical hemostasis. Fibrinogen concentrate dosing was individualized using the thromboelastometric FIBTEM test. If bleeding continued, a standardized transfusion algorithm was followed. In the placebo group, all 32 patients received 1 transfusion cycle of fresh-frozen plasma/platelets, and 30 patients required a second transfusion cycle; none of these patients received any other procoagulant therapy. Change in bleeding rate after treatment was compared using t tests.

RESULTS

Mean change in bleeding rate after fibrinogen concentrate was -48.3 g/5 min, compared with 0.4 g/5 min after placebo (P < .001), -16.1 g/5 min after 1 transfusion cycle (fresh-frozen plasma or platelets; P = .003), and -28.0 g/5 min after 2 transfusion cycles (fresh-frozen plasma and platelets; P = .11). Reductions in bleeding rate were greater for patients with higher bleeding rates before treatment, especially with fibrinogen concentrate.

CONCLUSIONS

FIBTEM-guided intraoperative hemostatic therapy with fibrinogen concentrate is more effective than placebo in controlling coagulopathic bleeding during major aortic replacement surgery. Fibrinogen concentrate is also more effective than 1 cycle of fresh-frozen plasma/platelets and is more rapid than--and at least as effective as--2 cycles of fresh-frozen plasma/platelets.

Pharmacologic tools to reduce bleeding in surgery

Strategies to reduce blood loss and the need for transfusions in surgery include enhancement of coagulation, inhibition of fibrinolysis, and an improved decision algorithm for transfusion based on bedside monitoring of global hemostasis. The synthetic antifibrinolytic drug tranexamic acid has emerged as an effective alternative in this respect for orthopedic and cardiac surgery. Although it seems less effective than aprotinin, it has not been associated with the increased risk of mortality of the latter. Thromboelastography to monitor the global hemostatic capacity and to guide the appropriate use of blood components in cardiac surgery is also effective in reducing the need for transfusion. Patients on antithrombotic drug therapy may need reversal before surgery to avoid excessive blood loss, or intraoperatively in cases of unexpected bleeding. Available options are protamine for unfractionated or low-molecular-weight heparin, recombinant activated factor VII for fondaparinux, prothrombin complex concentrate for vitamin K antagonists and possibly for oral factor Xa inhibitors, dialysis and possibly activated prothrombin complex concentrate for oral thrombin inhibitors, desmopressin for aspirin and possibly for thienopyridines, and platelet transfusions for the latter.

Impact of a unique international conference on pediatric mechanical circulatory support and pediatric cardiopulmonary perfusion research

There is no question that the International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion is a unique event that has had a significant impact on the treatment of neonatal, infantile, and pediatric cardiopulmonary patients around the globe since 2005. This annual event will continue as long as there is a need to fill the gap for underserved patient population. It will also continue to recognize promising young investigators based on their full manuscripts for young investigator awards.

Use of point-of-care testing for plasma therapy

Use of point-of-care testing (POCT) has been driven by limitations of laboratory-based testing as a tool for decisions for transfusions of blood components. Clinical settings such as liver transplantation, cardiothoracic surgery, and trauma are particularly in need of such diagnostic tests because of the complex coagulopathies that can develop in these settings of substantial hemorrhage and need for blood component support. Successful implementation of POCT requires collaboration between surgery, anesthesia, critical care, and the laboratory to ensure proper quality control of equipment, operator training and competency, medical records test results, billing procedures, and consensus-derived transfusion algorithms for cost-effective, targeted blood component transfusion support. In this review we summarize clinical evidence for the effectiveness of POCT, along with some future directions for this strategy.

The FIB-PPH trial: fibrinogen concentrate as initial treatment for postpartum haemorrhage: study protocol for a randomised controlled trial

BACKGROUND

Postpartum haemorrhage (PPH) remains a leading cause of maternal mortality worldwide. In Denmark 2% of parturients receive blood transfusion. During the course of bleeding fibrinogen (coagulation factor I) may be depleted and fall to critically low levels, impairing haemostasis and thus worsening the ongoing bleeding. A plasma level of fibrinogen below 2 g/L in the early phase of postpartum haemorrhage is associated with subsequent development of severe haemorrhage. Use of fibrinogen concentrate allows high-dose substitution without the need for blood type crossmatch. So far no publications of randomised controlled trials involving acutely bleeding patients in the obstetrical setting have been published. This trial aims to investigate if early treatment with fibrinogen concentrate reduces the need for blood transfusion in women suffering severe PPH.

METHODS/DESIGN

In this randomised placebo-controlled double-blind multicentre trial, parturients with primary PPH are eligible following vaginal delivery in case of: manual removal of placenta (blood loss ≥ 500 ml) or manual exploration of the uterus after the birth of placenta (blood loss ≥ 1000 ml). Caesarean sections are also eligible in case of perioperative blood loss ≥ 1000 ml. The exclusion criteria are known inherited haemostatic deficiencies, prepartum treatment with antithrombotics, pre-pregnancy weight <45 kg or refusal to receive blood transfusion. Following informed consent, patients are randomly allocated to either early treatment with 2 g fibrinogen concentrate or 100 ml isotonic saline (placebo). Haemostatic monitoring with standard laboratory coagulation tests and thromboelastography (TEG, functional fibrinogen and Rapid TEG) is performed during the initial 24 hours.Primary outcome is the need for blood transfusion. To investigate a 33% reduction in the need for blood transfusion, a total of 245 patients will be included. Four university-affiliated public tertiary care hospitals will include patients during a two-year period. Adverse events including thrombosis are assessed in accordance with International Conference on Harmonisation (ICH) good clinical practice (GCP).

DISCUSSION

A widespread belief in the benefits of early fibrinogen substitution in cases of PPH has led to increased off-label use. The FIB-PPH trial is investigator-initiated and aims to provide an evidence-based platform for the recommendations of the early use of fibrinogen concentrate in PPH.

TRIAL REGISTRATION

ClincialTrials.gov NCT01359878.

Clinical effectiveness of fresh frozen plasma compared with fibrinogen concentrate: a systematic review

Introduction

Haemostatic therapy in surgical and/or massive trauma patients typically involves transfusion of fresh frozen plasma (FFP). Purified human fibrinogen concentrate may offer an alternative to FFP in some instances. In this systematic review, we investigated the current evidence for the use of FFP and fibrinogen concentrate in the perioperative or massive trauma setting.

Methods

Studies reporting the outcome (blood loss, transfusion requirement, length of stay, survival and plasma fibrinogen level) of FFP or fibrinogen concentrate administration to patients in a perioperative or massive trauma setting were identified in electronic databases (1995 to 2010). Studies were included regardless of type, patient age, sample size or duration of patient follow-up. Studies of patients with congenital clotting factor deficiencies or other haematological disorders were excluded. Studies were assessed for eligibility, and data were extracted and tabulated.

Results

Ninety-one eligible studies (70 FFP and 21 fibrinogen concentrate) reported outcomes of interest. Few were high-quality prospective studies. Evidence for the efficacy of FFP was inconsistent across all assessed outcomes. Overall, FFP showed a positive effect for 28% of outcomes and a negative effect for 22% of outcomes. There was limited evidence that FFP reduced mortality: 50% of outcomes associated FFP with reduced mortality (typically trauma and/or massive bleeding), and 20% were associated with increased mortality (typically surgical and/or nonmassive bleeding). Five studies reported the outcome of fibrinogen concentrate versus a comparator. The evidence was consistently positive (70% of all outcomes), with no negative effects reported (0% of all outcomes). Fibrinogen concentrate was compared directly with FFP in three high-quality studies and was found to be superior for > 50% of outcomes in terms of reducing blood loss, allogeneic transfusion requirements, length of intensive care unit and hospital stay and increasing plasma fibrinogen levels. We found no fibrinogen concentrate comparator studies in patients with haemorrhage due to massive trauma, although efficacy across all assessed outcomes was reported in a number of noncomparator trauma studies.

Conclusions

The weight of evidence does not appear to support the clinical effectiveness of FFP for surgical and/or massive trauma patients and suggests it can be detrimental. Perioperatively, fibrinogen concentrate was generally associated with improved outcome measures, although more high-quality, prospective studies are required before any definitive conclusions can be drawn.

Artificial organs 2010: a year in review

In this Editor's Review, articles published in 2010 are organized by category and briefly summarized. As the official journal of The International Federation for Artificial Organs, The International Faculty for Artificial Organs, and the International Society for Rotary Blood Pumps, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level."Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide such meaningful suggestions to the author's work whether eventually accepted or rejected and especially to those whose native tongue is not English. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, Wiley-Blackwell, for their expert attention and support in the production and marketing of Artificial Organs. In this Editor's Review, that historically has been widely received by our readership, we aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. We look forward to recording further advances in the coming years.