The aim of this work was to reduce the bleeding risk during thrombolysis using the viscoelastic blood coagulation tests.
Patient data The patients' age, body measurements, general and coagulation-related medical history, SARS-COV2 status, APACHE-II, frailty score will be recorded. Sampling times and examinations The following considerations will be taken into account in the course of examining and providing care to the patients: Imaging procedures: CT angiography of the chest To confirm embolism and the results of lysis 12 to 24 hours after it is completed mandatory Echocardiography Right ventricle diameter mandatory views to be recorded: TAPSE mandatory parasternal longitudinal section IVC minimum and maximum diameter mandatory parasternal basal cross-section extent of tricuspid regurgitation mandatory apical 4 chamber estimated APsys mandatory subcostal 4 chamber D sign? mandatory IVC McConnel sign? optional 60/60 sign optional right heart thrombus optional Tricuspid annulus with reduced S' (\<9.5 cm/s) tissue doppler optional Lower limb Doppler ultrasound Search for the origin of thromboembolism, preferably prior to lysis optional Table 2: Summary of the imaging procedures required for the study The condition for enrolment into the study is PE confirmed by CT angiography of the chest, with haemodynamic impact confirmed by echocardiography; the recording of the test in the IMPAX system is also a requirement. To assess the effectiveness of thrombolysis, echocardiography must be repeated after the lysis is completed, and then 12 to 24 hours later; the same is true for long-term follow-up. Blood analyses: Laboratory tests blood type + antibody screening mandatory blood count mandatory INR mandatory aPTI mandatory D-dimer mandatory fibrinogen mandatory Troponin T mandatory NT-proBNP mandatory creatinine mandatory urea mandatory electrolytes (Na+; K+; Ca2+ (t/ion); Mg2+; Cl-, phosphate) mandatory liver function (AST, ALT, LDH) mandatory Blood gases pH; pO2; pCO2 mandatory HCO3-; BE mandatory hgb mandatory Na+; K+; Ca2+; Cl- mandatory blood glucose mandatory lactate mandatory Table 3: Summary of the laboratory and point-of-care blood tests required for the study The above lab parameters are planned to be obtained upon enrolment of a patient. Also, in addition to regular blood gas testing during the treatment, targeted testing for coagulation parameters and factors might be necessary. Invasive interventions: Arterial cannulation invasive pressure monitoring; pressurised infusion without heparin! mandatory PVC at least one, but preferably two, minimum G18 mandatory CVC only if vasopressor must be delivered; giving dobutamine to increase inotropy is not in itself an indication for a CVC! optional bladder catheter indication should be considered; if in doubt, should be inserted before the start of lysis optional endotracheal tube only for an indication not associated with pulmonary embolism optional Table 4: Considerations for the invasive interventions required for the study Study phase and follow-up The study period is expected to last from 1 October 2021 to 31 December 2024. Follow-up (subject to a separate consent from the patients) will take place 1, 3 and 12 months after the thrombolysis and is planned to include quality of life questionnaires (EuroQOL -5D-5L), assessment of physical capacity (6MW, or, if unfeasible, Timed Up\&Go test), echocardiography, ClotPro and blood gas testing. Methodology and organisation of the study Potential recruits are the patients of Semmelweis University with relevant impact on circulation (high-risk or intermediate to high-risk categories), whose PE is confirmed by CT angiography of the chest. Patients may come from the Emergency Care Unit or may be hospitalised patients from another department. The patient will then be admitted to the Anaesthesiology and Intensive Therapy Clinic and receive care there until stabilised. Instable patients who are enrolled will all be administered a fixed dose (100 mg/h) (see the section 'Inclusion criteria'). High risk or intermediate-high risk patients who can be stabilised will be randomised and then receive either a fixed dose (100 mg/2h) or a ClotPro-controlled variable dose of thrombolytic treatment. Coagulation tests ClotPro tests are planned before and regularly after the start of treatment: EX, IN, FIB, TPA, AP, RVV and ECA tests will be required. Statistical methods Statistical analyses will be performed by Social Sciences software (SPSS; SPSS Inc, Chicago, Illinois, USA). Continuous and discrete variables will be analysed by independent samples t tests (two categories) and one-way analyses of variance (one-way ANOVA; more categories), respectively. Two continuous variables will be compared by Spearman's rank correlation test. Discrete variables will be tested by Pearson's Chi squared test. Ordinary variables will be compared by Mann-Whitney U test or Kruskal-Wallis test. For multivariate analyses, logistic regression models will be generated. Significance level will be set to 5% (p ≤ 0.05).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
33
The 2019 ESC guideline for the diagnosis and management of acute pulmonary embolism (PE) recommended thrombolytic therapy only in high-risk PE cases because of the bleeding risk. The most often used drug for thrombolysis is the rtPA and the recommended dose is 100 mg over two hours. According to the literature, the risk of major haemorrhage is 10-13% and fatal or intracranial bleeding is 1.7-3.6% among patients receiving thrombolysis.
Semmelweis University Department of Anesthesiology and Intensive Therapy
Budapest, Hungary
Major, life threatening bleeding due to profuse bleeding
Hemorrhagic shock due to profuse bleeding: * hemoglobin reduction \> 30 g/l AND * Systolic blood pressure \< 90 mmHg OR * Reduction in systolic blood pressure \> 40 mmHg OR * Preserved systolic blood pressure achieved through increased dose of inotropic/vasopressor therapy
Time frame: during the treatment with tPA (on the control arm 2 hours, on the intervention arm variable > 2 hours)
Major, life threatening bleeding due to intracranial haemorrhage
Intracranial hemorrhage - new onset of neurological symptoms
Time frame: during the treatment with tPA (on the control arm 2 hours, on the intervention arm variable > 2 hours)
Minor bleeding: Haemoglobin reduction > 10g/l during the treatment
Haemoglobin reduction \> 10g/l, but less, than 30 g/l
Time frame: during the treatment with tPA (on the control arm 2 hours, on the intervention arm variable > 2 hours)
Efficiency - Short therm: hemodynamic stabilization
absence of circulatory shock/circulatory support ceased
Time frame: 36 hours after treatment
Efficiency - Short therm: significant regression or absence of embolus mass on post treatment pulmonary angio CT scan
Time frame: 24 hours after treatment
Efficiency - Long therm: further improvement on pulmonary CT scan
Long term: further improvement on pulmonary CT scan
Time frame: One month after the treatment
Efficiency - Long therm: absence of right hearth failure on echocardiography
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Absence of right heart failure on echocardiography: * no D-sign AND * basal right ventricle/left ventricle ratio \< 1 AND * tricuspidal annular plain systolic excursion \> 16 mm AND * Tissue Doppler Imaging: peak systolic velocity of tricuspid annulus \> 9.5 cm/s
Time frame: One year after the treatment
Efficiency - Long therm: improvement on 6 minutes walking test
Long term: improvement on 6 minutes walking test. The measured parameters: * 6 minutes walking test distance ( 6MWD - in meter) * 6MWD/predicted 6MWD (%) * distance desaturation product (DSP - m%)
Time frame: One year after the treatment