Prediction of bleeding by thromboelastography in ICU patients with haematological malignancy and severe sepsis

Thrombocytopenia in the intensive care unit: diagnosis and management

BACKGROUND

This narrative review aims to describe the epidemiology and aetiologies of thrombocytopenia in critically ill patients, the bleeding risk assessment in thrombocytopenic patients, and provide an update on platelet transfusion indications.

RESULTS

Thrombocytopenia is a common disorder in critically ill patients. The classic definition relies on an absolute platelet count below 150 × 109/L. Alternatively, the definition has extended to a relative decrease in platelet count (typically within a range of >30->50% decrease) from baseline, yet remaining above 150 × 109/L. Thrombocytopenia may result from multiple mechanisms depending upon the underlying conditions and the current clinical setting. Regardless of the causes, thrombocytopenia accounts as an independent determinant of poor outcomes in critically ill patients, albeit often of unclear interpretation. Nevertheless, it is well established that thrombocytopenia is associated with an increased incidence of bleeding complications. However, alternative factors also contribute to the risk of bleeding, making it difficult to establish definite links between nadir platelet counts at the expense of potential adverse events. Platelet transfusion represents the primary supportive treatment of thrombocytopenia to prevent or treat bleeding. As randomised controlled trials comparing different platelet count thresholds for prophylactic platelet transfusion in the ICU are lacking, the prophylactic transfusion strategy is largely derived from studies performed in stable haematology patients. Similarly, the platelet count transfusion threshold to secure invasive procedures remains based on a low level of evidence. Indications of platelet transfusions for the treatment of severe bleeding in thrombocytopenic patients remain largely empirical, with platelet count thresholds ranging from 50 to 100 × 109/L. In addition, early and aggressive platelet transfusion is part of massive transfusion protocols in the setting of severe trauma-related haemorrhage.

CONCLUSION

Thrombocytopenia in critically ill patients is very frequent with various etiologies, and is associated with worsened prognosis, with or without bleeding complications. Interventional trials focused on critically ill patients are eagerly needed to better delineate the benefits and harms of platelet transfusions.

Should viscoelastic testing be a standard point-of-care test on all intensive care units?

Viscoelastic tests (VETs) have transformed assessment of haemostasis and transfusion practices in trauma, cardiac and liver transplantation centres. Impaired haemostasis is a common problem on the general intensive care unit (ICU), but routine use of VETs is rare. We have accordingly reviewed the evidence to determine whether there is evidence to support the use of VETs as a standard point of care test on all ICUs in assessing and managing patients. The benefits of using VETs in the management of major haemorrhage, namely faster identification of a coagulopathy, in particular early detection of fibrinolysis, and reduced transfusion requirements for blood products have been seen in the general ICU. Validation of treatments algorithms is now required to standardise practice. There is also emerging evidence to support the use of VETs to guide urgent treatment decisions in patients with a coagulopathy or in patients taking anti-coagulants or anti-platelet therapies. We recommend that departments independently review the feasibility of setting up a viscoelastic point of care service which considers the applicability to their patient cohort, the financial cost and the personnel required.

Application of Rotational Thromboelastometry in Patients with Acute Promyelocytic Leukemia

Introduction

Hemorrhagic early death (HED) remains a major cause of treatment failure among patients with acute promyelocytic leukemia (APL). We aimed to investigate the prognostic potential of rotational thromboelastometry (ROTEM) for bleeding in patients with APL.

Materials and Methods

31 newly-diagnosed APL patients (median age of 40 years; 14 female/17 male) that underwent treatment at the Clinic of Hematology UCCS from 2016-2020 with all-trans retinoic acid and anthracyclines were recruited. CBCs (complete blood count), conventional coagulation tests (CCTs), and ROTEM parameters obtained before treatment initiation were evaluated.

Results

All patients demonstrated at least one ROTEM parameter out of the reference range. ROTEM parameters associated with significant hemorrhage were EXTEM clotting time (CT) (P = 0.041) and INTEM amplitude 10 (A10) (P = 0.039), however, only EXTEM CT (P = 0.036) was associated with HED. Among CBCs and CCTs, only platelets were associated with significant bleeding (P = 0.015), while D-dimer was associated with both bleeding and HED (P = 0.001 and P = 0.002, respectively).

Conclusion

Our results indicate that ROTEM parameters may reveal hypocoagulability in APL patients and have the potential to improve current hemorrhage prognostic methods. Additionally, these results suggest the combination of ROTEM and CCTs might be useful in identifying patients at risk for HED.

Transfusion strategies in bleeding critically ill adults: a clinical practice guideline from the European Society of Intensive Care Medicine

PURPOSE

To develop evidence-based clinical practice recommendations regarding transfusion practices and transfusion in bleeding critically ill adults.

METHODS

A taskforce involving 15 international experts and 2 methodologists used the GRADE approach to guideline development. The taskforce addressed three main topics: transfusion support in massively and non-massively bleeding critically ill patients (transfusion ratios, blood products, and point of care testing) and the use of tranexamic acid. The panel developed and answered structured guideline questions using population, intervention, comparison, and outcomes (PICO) format.

RESULTS

The taskforce generated 26 clinical practice recommendations (2 strong recommendations, 13 conditional recommendations, 11 no recommendation), and identified 10 PICOs with insufficient evidence to make a recommendation.

CONCLUSIONS

This clinical practice guideline provides evidence-based recommendations for the management of massively and non-massively bleeding critically ill adult patients and identifies areas where further research is needed.

Thromboelastography parameters in diagnosing periprosthetic joint infection and predicting reimplantation timing

BACKGROUND

Coagulation-related biomarkers are drawing new attention in the diagnosis of periprosthetic joint infection (PJI). The thromboelastography (TEG) assay provides a comprehensive assessment of blood coagulation; therefore, it could be a promising test for PJI. This study aims to assess the value of TEG in diagnosing PJI and to determine the clinical significance of TEG in analysing reimplantation timing for second-stage revision.

METHODS

From October 2017 to September 2020, 62 patients who underwent revision arthroplasty were prospectively included. PJI was defined by the 2011 Musculoskeletal Infection Society criteria, in which 23 patients were diagnosed with PJI (Group A), and the remaining 39 patients were included as having aseptic loosening (Group B). In group A, 17 patients completed a two-stage revision in our centre. C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), D-dimer, and TEG parameters (clotting time, α-angle, MA [maximum amplitude], amplitude at 30 min, and thrombodynamic potential index) were measured preoperatively in all included patients. In addition, receiver operating characteristic curves were used to evaluate the diagnostic value of these biomarkers.

RESULTS

ESR (area under curve [AUC], 0.953; sensitivity, 81.82; specificity, 94.87) performed best for PJI diagnosis, followed by MA (AUC, 0.895; sensitivity, 82.61; specificity, 97.44) and CRP (AUC, 0.893; sensitivity, 82.61; specificity, 94.74). When these biomarkers were combined in pairs, the diagnostic value improved compared with any individual biomarker. The overall success rate of the two-stage revision was 100%. Furthermore, ESR and MA were valuable in determining the time of reimplantation, and their values all decreased below the cut-off values before reimplantation.

CONCLUSION

TEG could be a promising test in assisting PJI diagnosis, and a useful tool in judging the proper timing of reimplantation.

Thromboelastography versus standard coagulation testing in the assessment and reversal of coagulopathy among cirrhotics: a systematic review and meta-analysis

The utility of thromboelastography/thromboelastometry currently has unvalidated clinical benefit in the assessment and reversal of coagulopathy among cirrhotic patients as compared to standard coagulation testing. A novel systematic review and meta-analysis was conducted in order to assess pooled outcome data among patients receiving thromboelastography/thromboelastometry as compared to standard coagulation testing. As compared to standard coagulation testing, there was a significant reduction in the number of patients requiring pRBC, platelet, and fresh frozen plasma transfusions among thromboelastography/thromboelastometry group with pooled OR 0.53 (95% CI 0.32-0.85; P = 0.009), 0.29 (95% CI 0.12-0.74; P = 0.009), and 0.19 (95% CI 0.12-0.31; P < 0.00001), respectively. Similarly, there was a significant reduction in number of pRBC, platelet, and fresh frozen plasma units transfused in the thromboelastography/thromboelastometry group with pooled MD -1.53 (95% CI -2.86 to -0.21; P = 0.02), -0.57 (95% CI -1.06 to -0.09; P = 0.02), and -2.71 (95% CI -4.34 to -1.07; P = 0.001), respectively. There were significantly decreased total bleeding events with pooled OR 0.54 (95% CI 0.31-0.94; P = 0.03) and amount of intraoperative bleeding during liver transplantation with pooled MD -1.46 (95% CI -2.49 to -0.44; P = 0.005) in the thromboelastography/thromboelastometry group. Overall, there was no significant difference in mortality between groups with pooled OR 0.91 (95% CI 0.63-1.30; P = 0.60). As compared to standard coagulation testing, a thromboelastography/thromboelastometry-guided approach to the assessment and reversal of cirrhotic coagulopathy improves overall number of patients exposed to blood product transfusions, quantity of transfusions, and bleeding events.

Relationship of thromboelastography and conventional clotting test values with severe bleeding in critically ill patients with coagulopathy: A prospective study

INTRODUCTION

This study aimed to ascertain the associations of thromboelastography (TEG^® ) and standard laboratory test (SLTs) values with the presence of bleeding in critically ill patients with known coagulopathy.

METHODS

Three groups of coagulopathic patients with (a) hepatic failure, (b) postoperative period after prolonged cardiac surgery, and (c) complex abdominal surgery with sepsis were prospectively included in this study. On intensive care unit (ICU) admission, patients were stratified into two groups according to whether they had major bleeding (MB) (evident overt bleeding, important bleeding apparent on imaging studies, and/or need for moderate-massive blood transfusion and hemodynamic instability). Blood samples were drawn for the SLTs (international normalized ratio [INR], activated partial thromboplastin time [aPTT], platelet count, and fibrinogen level [Clauss]) and TEG whole blood coagulation assays. Receiver operating characteristic (ROC) curves were generated to determine the efficiency of TEG and SLTs for detecting bleeding. The correlations between SLTs and TEG parameters with similar coagulation profiles were evaluated by Spearman rank-order analysis.

RESULTS

Eighty-three patients were included, and bleeding was confirmed in 45 (54%). The fibrinogen level demonstrated the best accuracy for detecting bleeding with an area under the curve and 95% confidence intervals [AUC (95% CI)] of 0.74 (0.63-0.85) with the best cutoff value of ≤ 2 g/L. Regarding TEG-MA, the AUC (CI) obtained with the optimal cutoff value of ≤ 51 mm was 0.68 (0.56-0.80).

CONCLUSIONS

Both conventional clotting tests and TEG values were poorly associated with bleeding in this critically ill cohort of patients with coagulopathy.