A preliminary study using rotational thromboelastometry to investigate perioperative coagulation changes and to identify hypercoagulability in obese patients undergoing total hip or knee replacement

Rotational Thromboelastometry Predicts Transfusion Requirements in Total Joint Arthroplasties

The frequency of red blood cell (RBC) transfusions is high in total joint arthroplasties, and the hemorrhagic risk is associated with both surgery- and patient-related factors. This study aims to assess the ability of rotational thromboelastometry (ROTEM) to identify patients at high risk for transfusion and excessive bleeding. A prospective observational study was conducted including 206 patients who underwent total knee or hip arthroplasties. Assessment of the coagulation status was performed preoperatively and immediately postoperatively using ROTEM analysis and conventional coagulation tests. The number of RBC transfusions and the postoperative hemoglobin drop were recorded. ROTEM findings were compared between transfused and nontransfused patients, and also between patients with and without excessive bleeding. Higher values of postoperative FIBTEM maximum clot firmness (MCF) were associated with lower risks of transfusion (odds ration [OR]: 0.66, 95% confidence interval [CI]: 0.57-0.78, p<0.001) and excessive bleeding (OR: 0.58, 95% CI: 0.36-0.94, p=0.028). A postoperative FIBTEM MCF value ≤10mm had 80.1% (95% CI: 73.1-85.9%) sensitivity with 75.5% (95% CI: 60.4-87.1%) specificity to predict transfusion requirements, and 70.5% (95% CI: 63.6-76.8%) sensitivity with 88.8% (95% CI: 51.7-99.7%) specificity to predict excessive bleeding. The estimated average probability of transfusion in patients with FIBTEM MCF values of 0 to 4mm is 86.3%. ROTEM assay demonstrated high predictive ability for transfusion and excessive bleeding. Identification of patients at risk for transfusion could allow blood banks to ensure adequate blood supply, while also more intense blood-salvaging strategies could be implemented in these patients.

Association Between Thromboelastometry Identified Hypercoagulability and Thromboembolic Complications After Arthroplasty: A Prospective Observational Study in Patients With Obesity

The prothrombotic state of obesity can increase the risk of thromboembolism. We aimed to investigate if there was an association between baseline hypercoagulable rotational thromboelastometry (ROTEM) profile and thromboembolic complications in arthroplasty patients with obesity. Patients with a body mass index ≥ 25 kg/m2 and/or waist circumference ≥94 cm (M) and 80 cm (F) undergoing hip and knee arthroplasty had pre- and postoperative ROTEM. ROTEM values were compared by outcome status using an independent sample equal-variance t-test. Of the 303 total participants, hypercoagulability defined as extrinsically activated thromboelastometry maximum clot firmness G score ≥ 11 K dyne/cm2, was observed in 90 (30%) of the 300 participants with preoperative ROTEM assays. Clinically significant thromboembolic complications occurred in 5 (1.7%) study participants before discharge and in 10 (3.3%) by 90 days. These included 6 with pulmonary emboli, 3 with deep venous thrombus, and 1 with myocardial infarction. We found no evidence for an association between baseline hypercoagulability and incident thromboembolic events, analysis limited by the number of events. Postoperative decrease in platelets and an increase in fibrinogen were observed. ROTEM parameter changes differed across obesity categories.

Hypercoagulability in critically ill patients with COVID 19, an observational prospective study

OBJECTIVE

COVID 19 is often associated with hypercoagulability and thromboembolic (TE) events. The aim of this study was to assess the characteristics of hypercoagulability and its relationship with new-onset TE events and the composite outcome of need for intubation and/or death in intensive care unit (ICU) patients admitted for COVID.

DESIGN

Prospective observational study.

SETTING

Monocentric, intensive care, University Hospital of Clermont Ferrand, France.

PATIENTS

Patients admitted to intensive care from January 2020 to May 2021 for COVID-19 pneumonia.

INTERVENTIONS

Standard hemostatic tests and rotational thromboelastometry (ROTEM) were performed on admission and on day 4. Hypercoagulability was defined by at least one of the following criteria: D-dimers > 3000 μg/dL, fibrinogen > 8 g/L, EXTEM CFT below the normal range, EXTEM A5, MCF, Li 60 above the normal range, and EXTEM G-score ((5000 x MCF) / (100-MCF)) ≥ 11 dyne/cm2.

MEASUREMENTS AND MAIN RESULTS

Of the 133 patients included, 17 (12.7%) developed new-onset TE events, and 59 (44.3%) required intubation and/or died in the ICU. ROTEM was performed in 133 patients on day 1 and in 67 on day 4. Hypercoagulability was present on day 1 in 115 (86.4%) patients. None of the hypercoagulability indices were associated with subsequent new-onset TE events on days 1 and 4 nor with the need for intubation and/or ICU death. Hyperfibrinogenemia > 8g/dL, higher D-dimers and higher EXTEM Li 60 on day 4 were predictive of need for intubation and/or of ICU death.

CONCLUSIONS

Our study confirmed that most COVID-19 ICU patients have hypercoagulability on admission and almost all on day 4. Hyperfibrinogenemia or fibrinolysis shutdown on day 4 were associated with unfavorable outcome.

The Prognostic Performance of Rotational Thromboelastometry for Excessive Bleeding and Increased Transfusion Requirements in Hip Fracture Surgeries

BACKGROUND

 Hip fracture surgeries are associated with considerable blood loss, while the perioperative coagulopathy is associated with the bleeding risk of these patients. We aimed to evaluate the ability of rotational thromboelastometry (ROTEM) to detect patients at high risk for excessive bleeding and increased transfusion requirements.

METHODS

 We conducted a prospective observational study of 221 patients who underwent hip fracture surgeries. ROTEM analysis was performed preoperatively and immediately postoperatively. Blood loss parameters including blood loss volume, number of transfused red blood cell (RBC) units, and drop in hemoglobin levels were recorded. ROTEM parameters were compared between patients with and without excessive bleeding, and between patients with and without increased transfusion requirements (i.e., ≥2 RBC units).

RESULTS

 The postoperative FIBTEM MCF value ≤15 mm had 66.6% (95% confidence interval [CI]: 59.7-74.1%) sensitivity and 92.0% (95% CI: 80.7-97.7%) specificity to prognose excessive bleeding, and preoperative FIBTEM MCF value ≤15 mm had 80.4% (95% CI: 73.5-86.2%) sensitivity and 91.2% (95% CI: 80.7-97.0%) specificity to prognose increased transfusion requirements. Preoperative FIBTEM MCF ≤11 mm and postoperative FIBTEM MCF ≤15 mm were associated with considerably increased risks of excessive bleeding (odds ratio [OR]: 44.8, 95% CI: 16.5-121.3, p < 0.001; and OR: 23.0, 95% CI: 7.8-67.0, p < 0.001, respectively).

CONCLUSION

 ROTEM parameters demonstrated high prognostic accuracy for excessive bleeding and increased transfusion requirements. This can enable implementation of blood sparing strategies in high-risk patients, while blood banks could be better prepared to ensure adequate blood supply.