Role of Using a Thromboelastometry-Based Protocol for Transfusion Management in Combined Coronary Artery Bypass Grafting and Valve Surgery: A Randomized Clinical Trail
Indian journal of hematology & blood transfusion : an official journal of Indian Society of Hematology and Blood Transfusion. 2021;37(3):422-429
The aim of this study was to evaluate the impact of using a thromboelastometry-based protocol on transfusion requirements in patients undergoing combined coronary artery bypass grafting (CABG) and valve surgery. 80 adult patients scheduled for elective combined CABG and valve surgery were included in this clinical trial study. Patients were randomly allocated to the thromboelastometry (ROTEM) (n = 40) or control groups (n = 40). In the ROTEM group, transfusion was directed according to a thromboelastometry-based protocol. In the control group, transfusion was conducted according to the routine practices including conventional coagulation testing and clinical judgments. Finally, transfusion requirements were compared between groups. Use of thromboelastometry- based protocol resulted in 67% reduction in blood products units' consumption as well as 23% in the percentage of patients transfused. This reduction was especially evident in relation to fresh frozen plasma (FFP) and platelet consumption. No significant differences were found both in the percentage of patients receiving RBC and number of transfused RBC units. Using thromboelastometry tests incorporated a protocol results in reduction of transfusion requirements in patients undergoing elective combined CABG and valve surgery.
Comparison between intraoperative bleeding score and ROTEM® measurements to assess coagulopathy during major pediatric surgery
Transfusion and apheresis science : official journal of the World Apheresis Association : official journal of the European Society for Haemapheresis. 2021;:103191
PURPOSE Intraoperative bleeding should be regularly assessed visually to guide coagulation management. Whereas viscoelastic testing with ROTEM® measurement has been proven to be useful in detecting coagulopathies, the visual assessment is not standardized. This study therefore aims to compare a standardized visual assessment with ROTEM® results. METHODS A 5-point bleeding score was created and applied in a recently published randomized controlled trial in major pediatric non-cardiac surgery. This score assesses overall bleeding tendency and the occurrence of diffuse bleeding, aqueous bleeding, bleeding outside the operative field, and the ability to control bleeding. Validity of this score was tested by post hoc comparison to the results of simultaneously performed ROTEM® measurements. RESULTS Signs of coagulopathic bleeding were assessed at 183 time points. Mild to moderate bleeding intensity was judged at 103 time points, in 42 % abnormal ROTEM® traces were obtained simultaneously. When severe bleeding was scored, abnormal ROTEM values occurred in 58 %, and FIBTEM-values were significantly lower than in the "no bleeding group". Altogether, the correlation between bleeding score and ROTEM® measurements was not significant. CONCLUSIONS The standardized visual assessment did not correlate well with ROTEM® measurements, suggesting that it is not useful to detect coagulopathy. Trial registry number: ClinicalTrials.gov identifier No. NCT01487837.
Rotational thromboelastometry reduces blood loss and blood product usage after lung transplantation
The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation. 2021
BACKGROUND The shortage of blood products has become a worldwide problem, especially during the COVID-19 Pandemic. Here, we investigated whether a point of care (POC) approach to perioperative bleeding and coagulopathy based on rotational thromboelastometry (ROTEM) results could decrease perioperative blood loss and the perioperative consumption of blood products during lung transplantation. METHODS Patients undergoing bilateral lung transplantation were randomized into two groups: In the first group, designated the "non POC" group, the management of perioperative bleeding and coagulopathy was based on the clinical experience of the anesthesiologist; in the second group, designated the "POC" group, the management of perioperative bleeding, and coagulopathy was based on the ROTEM results. RESULTS After performing an interim statistical analysis, the project was prematurely terminated as the results were significantly in favor of the POC approach. Data were analyzed for the period January 2018 until June 2020 when 67 patients were recruited into the study. There was significantly decreased perioperative blood loss in the POC group (n = 31 patients) with p = 0.013, decreased perioperative consumption of RBC with p = 0.009, and decreased perioperative consumption of fresh frozen plasma with p < 0.0001 (practically no fresh frozen plasma was used in the POC group) without deteriorating clot formation in secondary and primary hemostasis as compared to the non POC group (n = 36). CONCLUSION POC management of perioperative bleeding and coagulopathy based on ROTEM results is a promising strategy to decrease perioperative blood loss and the consumption of blood products in lung transplantation.
Utility of Viscoelastic Tests to Predict Flap Thrombosis: A Systematic Review
Plastic and reconstructive surgery. Global open. 2021;9(8):e3769
BACKGROUND Flap thrombosis is a rare but devastating complication in microsurgery. Preoperative identification of patients at increased risk for microvascular thrombosis remains challenging. Viscoelastic testing (VET) provides a comprehensive evaluation of the clotting process and can effectively identify hypercoagulability. However, the utility of VET in microvascular reconstruction remains unclear. METHODS A systematic review of the association between VET and pedicle thrombosis and free flap loss was performed in accordance with Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. Identified studies were reviewed independently by two authors for pertinent data. RESULTS Six studies met inclusion criteria. Heterogenous study design and outcome reporting complicated direct comparisons and precluded a formal meta-analysis. Four studies found a statistically significant relationship between VET results and flap thrombosis or flap loss. The maximum clot strength and the fibrinogen-to-platelet ratio (FPR) were key viscoelastic parameters in these studies, both representing a measure of maximal clot strength. Specifically, an elevated FPR (>42%) generated a sensitivity and specificity for flap loss ranging from 57% to 75% and 60% to 82%, respectively. Notably, the negative predictive value for flap failure with a normal preoperative FPR was greater than 90% in all studies reporting a correlation. The remaining two studies reported no predictive value for VET with respect to flap failure or pedicle thrombosis. CONCLUSION The results of this review suggest that VET, particularly parameters relating to clot strength, may help clinicians identify patients at risk for flap thrombosis. However, uncontrolled and heterogenous reporting limit definitive conclusions, and high-quality diagnostic studies are needed to better determine the clinical utility of viscoelastic testing for free flap patients.
Viscoelastic testing to assess the effects of rapid fibrinogen concentrate administration after cardiopulmonary bypass: insights from the REPLACE study
Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis. 2021
Haemorrhage during and following surgery results in increased morbidity and mortality. Low plasma fibrinogen levels have been associated with increased blood loss and transfusion requirements. Fibrinogen supplementation has been shown to reduce bleeding in coagulopathic patients. This post hoc study evaluated fibrinogen repletion and pharmacokinetic data from the REPLACE study. One hundred and fifty-two adult patients undergoing elective aortic surgery requiring cardiopulmonary bypass (CPB) with defined bleeding of 60-250 g at first 5 min bleeding mass were included in the phase III trial. Patients were randomized to receive either fibrinogen concentrate (FCH) or placebo following CPB removal. Plasma fibrinogen levels and viscoelastic testing parameters (ROTEM-based FIBTEM and EXTEM assays) were measured before, during, and after study treatment administration. A mean dose of 6.3 g FCH was administered in the FCH group, with a median infusion duration of 2 min. Immediately following completion of FCH administration, a rapid increase in plasma fibrinogen levels to near baseline (median change from baseline -0.10 g/l) was seen in the FCH group but not in the placebo group (median change from baseline -1.29 g/l). FCH administration also caused an immediate increase in FIBTEM maximum clot firmness (MCF) to 23 mm and improvements in EXTEM coagulation time and clot formation time by the end of infusion. There was a strong correlation between the plasma fibrinogen level and FIBTEM MCF. Treatment with high doses of FCH with a rapid infusion time resulted in immediate recovery to baseline levels of plasma fibrinogen and viscoelastic testing parameters.
Cardiopulmonary bypass and dual antiplatelet therapy: a strategy to minimise transfusions and blood loss
BACKGROUND Patients with preoperative dual antiplatelet therapy prior to coronary artery bypass surgery are at risk of bleeding and blood component transfusion. We hypothesise that an optimised cardiopulmonary bypass strategy reduces postoperative blood loss and transfusions. METHODS In total, 60 patients admitted for coronary artery bypass grafting with ticagrelor and aspirin medication withdrawn <96 hours before surgery were prospectively randomised into two equal sized groups. Cardiopulmonary bypass combined a closed Cortiva((R)) heparin-coated circuit with low systemic heparinisation (activated clotting time < 250 seconds) and intraoperative cell salvage in the study group, whereas the control group used a Balance((R)) coated open circuit, full systemic heparinisation (activated clotting time > 480 seconds) and conventional cardiotomy suction. This perfusion strategy was evaluated by the chest drain volume after 24 hours, perioperative haemoglobin and platelet loss accompanied by global coagulation assessments. RESULTS Patients in the study group demonstrated significantly better outcomes signified by lower blood loss 554 +/- 224 versus 1,100 +/- 989 mL (p < 0.001), reduced packed red cell transfusion 7% versus 53% (p < 0.001), reduced haemoglobin -28 +/- 15 versus -40 +/- 14 g/L (p = 0.004) and platelet loss -35 +/- 36 versus -82 +/- 67 x 10(9)/L (p = 0.001). Indices of rotational thromboelastometry indicated shorter clotting times within the internal and external pathways. Adenosine diphosphate activated platelet function was within normal range based on Multiplate((R)) aggregometry, while ROTEM((R)) platelet analyses indicated inhibited function both preoperatively and post-bypass. Platelet inhibition by aspirin was verified throughout the perioperative period. Platelet function showed no intergroup differences. CONCLUSION A stringent perfusion strategy reduced blood loss and transfusions in dual antiplatelet therapy patients requiring urgent surgery.
The Ability of Thromboelastography to Detect Hypercoagulability: A Systematic Review & Meta-Analysis
Journal of orthopaedic trauma. 2019
OBJECTIVE We aimed to review the current literature on the use of viscoelastic hemolytic assays (VHA), like thromboelastography (TEG) and rotational thromboelastometry (ROTEM), during the perioperative period of patients and determine the ability of TEG and ROTEM to detect hypercoagulability and identify increased risk for the development of venous thromboembolism (VTE). DATA SOURCES PubMed, EMBASE, and Cochrane online databases were queried through February 11, 2018 by pairing the terms "thromboelastography," "viscoelastic hemostatic assays," and "rotational thromboelastometry" with "venous thromboembolism," "deep vein thrombosis," "pulmonary embolism," and "hypercoagulability." STUDY SELECTION Inclusion and exclusion criteria were established to determine relevance and quality of data, of which 2.54% of initially identified studies met. DATA EXTRACTION AND SYNTHESIS Articles and citations were reviewed for relevance by two independent individuals following PRISMA guidelines as well as a quality assessment of data as established by Zaza et. al. In studies that separated patients postoperatively by VTE development or no VTE development, data were pooled utilizing a modified DerSimmion and Laird random effects model. RESULTS 1,893 articles, were assessed for eligibility, yielding 370 abstracts. Of the 370 abstracts, 35 studies were included, and of these, only five were included in the meta-analysis. Studies included post-surgical patients in a variety of surgical fields, encompassing a total of 8,939 patients, with 717 thrombotic events reported. Elevated MA was a statistically significant indicator of hypercoagulability across at least one perioperative time point in 17 (50%) of the articles reviewed, consisting of 6,348 (72%) patients. The pooled mean MA value for defining hypercoagulability was greater than 66.70 mm. Using a pre-published value for hypercoagulability of 65mm, the combined effect of MA on the development of VTE in postsurgical patients was determined to be 1.31 (95% CI, .74-2.34, p=.175) and was 46% sensitive and 62% specific in predicting a postoperative VTE. CONCLUSION Only one parameter, MA, was consistently used to both define hypercoagulability and be predictive of VTE following traumatic injury and surgical intervention; however, there remains a broad variability in the definition of hypercoagulability as determined by MA and thus limits its predictive ability. Additionally, when hypercoagulability was measured throughout the perioperative period, TEG consistently demonstrated hypercoagulability starting on post-op day one (POD1).
Hidden Blood Loss following 2- to 3- level Posterior Lumbar Fusion
The spine journal : official journal of the North American Spine Society. 2019
BACKGROUND CONTEXT Patients undergoing single-level posterior lumbar decompression and fusion (PLDF) usually do not need transfusions. However, patients undergoing two or three-level PLDF occasionally require transfusion postoperatively even when estimated blood loss (EBL) or blood loss from drains appears acceptable. Estimating the volume of HBL is critical in perioperative fluid management. PURPOSE To determine the volume of hidden blood loss (HBL) in 2- or 3- level PLDF. STUDY DESIGN Single center, multi-surgeon, secondary analysis from a prospective randomized clinical trial of cell-saver use. PATIENT SAMPLE Patients enrolled in a prospective randomized trial of cell-saver undergoing two- or three-level PLDF were included in this analysis. METHODS Total blood loss was calculated using four estimation formulas including Bourke's, Gross', Camarasa's, and Lopez-Picado's formulas. HBL was determined by subtracting the visible loss (EBL and blood loss from drains) from the calculated total blood loss. RESULTS A total of 89 patients (36 males, mean age 62 years) were included. Seventy-five patients underwent open two-level fusion while 14 had three-level fusions. Intervertebral fusion was performed in 20 patients. Mean surgical time was 261 minutes, and EBL was 685 ml. Mean blood loss from drains was 824 ml. Seventy patients received allogenic blood while 47 Cell Saver blood reinfused intraoperatively. Hidden blood loss was calculated to be 678 ml, 963 ml, 1267 ml, and 819 ml using each formula. CONCLUSIONS HBL following two or three-level PLDF was substantial and more than EBL. Postoperative management of blood loss should take HBL into account.
Point-of-care viscoelastic hemostatic testing in cardiac surgery patients: a systematic review and meta-analysis
Canadian Journal of Anaesthesia = Journal Canadien D'anesthesie. 2018;65((12):):1333-1347.
PURPOSE Thromboelastography and rotational thromboelastometry are point-of-care (POC) viscoelastic tests used to help guide blood product administration. It is unclear whether these tests improve clinical or transfusion-related outcomes. The objective of this study was to appraise data from randomized trials evaluating the benefit of POC testing in cardiac surgery patients. Primary outcomes were the proportion of patients transfused with blood products and all-cause mortality. SOURCE Medline (Ovid), EMBASE (Ovid), CENTRAL (the Cochrane Library-Wiley), Web of Science, Biosis, Scopus, and CINAHL databases, as well as clinical trial registries and conference proceedings were queried from inception to February 2018. PRINCIPAL FINDINGS We identified 1,917 records, 11 of which were included in our analysis (8,294 patients). Point-of-care testing was not associated with a difference in the proportion of patients transfused with any blood product (risk ratio [RR], 0.90; 95% confidence interval [CI], 0.79 to 1.02; I(2) = 51%; four trials, 7,623 patients), or all-cause mortality (RR, 0.73; 95% CI, 0.47 to 1.13; I(2) = 5%; six trials, 7,931 patients). Nevertheless, POC testing was weakly associated with a decrease in the proportion of patients receiving red blood cells (RBC) (RR, 0.91; 95% CI, 0.85 to 0.96; I(2) = 0%; seven trials, 8,029 patients), and heterogeneous reductions in frozen plasma (FP) (RR, 0.58; 95% CI, 0.34 to 0.99; I(2) = 87%; six trials, 7,989 patients) and platelets (RR, 0.66; 95% CI, 0.49 to 0.90; I(2) = 65%; seven trials, 8,029 patients). Meta-analysis of the number of units of RBCs and FP was not possible due to heterogeneity in reporting, however POC testing significantly reduced the units of platelets transfused (standard mean difference, -0.09; 95% CI, -0.18 to 0.00; four trials, 7,643 patients). CONCLUSION Our review indicates that in cardiac surgery patients, POC viscoelastic hemostatic testing is not associated with a reduction in the proportion of patients receiving any blood product or all-cause mortality. However, viscoelastic testing is weakly associated with a reduction in proportion of patients transfused with specific blood products. Presently, the benefits associated with viscoelastic testing in cardiac surgery patients are insufficiently robust to recommend routine implementation of this technology. TRIAL REGISTRATION PROSPERO (CRD4201706577). Registered 11 May 2017.
Effect of thrombelastography on timing of coronary artery bypass grafting
Experimental and Therapeutic Medicine. 2018;16((2)):579-584.
The guiding value of thrombelastography (TEG) on the selection of surgical timing for patients scheduled for coronary artery bypass grafting (CABG) was investigated. A total of 90 subjects with acute coronary syndrome (ACS) treated between February 2014 and December 2016 in Henan Provincial People's Hospital were recruited. The patients received dual antiplatelet therapy (DAPT) and were scheduled for CABG. Subjects were randomly allocated into two groups, TEG group (n=45) and non-TEG group (n=45). Patients in the TEG group withheld medications at 24 h prior to surgery and received TEG examination. Based on maximum amplitude of adenosine diphosphate (MAADP), subjects were further grouped into three sub-groups with MAADP <35 mm, 35-50 mm, and >50 mm, and accordingly received CABG within 1 day, 3-5 days and 5 days later, respectively. Subjects in the control group (non-TEG group) received CABG 5-7 days after medication withdrawal. Chest drainage volume within 24 h after surgery and red blood cell transfusion during perioperative period were compared. Other recorded parameters were incubation period, intensive care unit length of stay, hospital stay, incidence of 30-day adverse events and readmission rate. The average waiting time before CABG for patients of TEG group was shorter compared with the commonly recommended time. The red blood cell transfusions during perioperative period of subjects in TEG group and non-TEG group were significantly different (P=0.23). The median hospital stay of subjects in TEG group was shorter than that of non-TEG group (P=0.037). The bleeding amount of patients in TEG group was 220.16+/-80.56 ml, which was significantly lower than that of non-TEG group (435.29+/-90.16). The difference was statistically significant (P=0.032). The results suggested that TEG assay-based evaluation of platelet function for patients scheduled for CABG reasonably guides surgeons with appropriate surgical timing and reduces the amount of time patients wait to be treated.