Antithrombotic therapy in children

Comparative Risk of Bleeding of Anticoagulant Therapy with Vitamin K Antagonists (VKAs) and with Non-Vitamin K Antagonists in Patients Undergoing Dental Surgery

OBJECTIVES

A wide variety of approaches have been proposed to manage anticoagulant drugs in patients undergoing dental surgery; vitamin K antagonists and novel direct oral anticoagulants have been used. The present study aims to explore the existing evidence concerning the management of patients in anticoagulant therapy undergoing oral surgery procedures and to give suggestions related to peri- and post-operative measures.

MATERIALS AND METHODS

A comprehensive search of databases was conducted to identify studies that evaluated the relationship between direct oral anticoagulants and dental procedures. The present scoping review was realized in adherence with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The publications varied from randomized controlled trials (RCT) to cohort trials. Only articles written in English language and published between 2000 to 2020 were screened. The studies were included if discussing the management of a patient in anticoagulant therapy (warfarin or direct oral anticoagulants) scheduled for tooth extraction.

RESULTS

33 studies were selected and included in the qualitative review. Nineteen considered anticoagulant therapy with warfarin, six considered anticoagulant therapy with new oral anticoagulants and eight compared patients taking warfarin with patients taking direct oral anticoagulants.

CONCLUSIONS

No case of extractive surgery should alter the posology of the drug: thromboembolic risks derived from discontinuation are heavier than hemorrhagic risks.

CLINICAL RELEVANCE

direct oral anticoagulants are safer in terms of bleeding and manageability and bleeding episodes are manageable with local hemostatic measures.

Improvement in long-term ECMO by detailed monitoring of anticoagulation: a case report

INTRODUCTION

The use of unfractionated heparin (UFH) as an anticoagulant during long-term extracorporeal support presents a unique challenge for the clinician in balancing the amount of anticoagulant to maintain adequate anticoagulation without causing excessive bleeding. Activated clotting times (ACT) and activated partial thromboplastin times (aPTT) are the most common modality to monitor UFH on extracorporeal membrane oxygenation (ECMO). Limitations to these tests include consumptive coagulopathies, clotting factor deficiencies, platelet dysfunction, and fibrinolysis. The following case report describes the use of alternative monitoring strategies to assess more accurately anticoagulation during ECMO.

CASE REPORT

A 20-month-old female presented to the emergency department with a 5-6 day history of cough, fever, tachypnea, and respiratory distress. She was diagnosed with influenza A and B with pneumonia. The patient was placed on veno-venous ECMO (V-V ECMO) after mechanical ventilation failed. On ECMO day eight, the patient developed a thrombus in her inferior vena cava and pleural effusions, obstructing cannula flow. Laboratory tests revealed the ACT was within range, yet the aPTT was dropping, despite increased heparin. Heparin levels were low and antithrombin-III (AT) concentrations were 40%. Recombinant AT was given and subsequent aPTTs were within the therapeutic range. Later, the aPTT decreased to <50 sec, heparin levels were within the therapeutic range, while fibrinogen was >475 mg/ dL, and Factor VIII >150 IU/dL, suggesting an acute phase reaction or ongoing systemic inflammation, increasing the risk for thrombosis. We maintained heparin assays between 0.5-0.7 IU/mL and AT >60% to assure heparin's effect. The patient showed no signs of excess bleeding, blood product administration, or clots in the circuit, suggesting proper anticoagulation. The patient was successfully weaned on day 33 and is currently alive and at home.

CONCLUSION

Monitoring of anti-Xa UFH and AT proved effective for measuring anticoagulation and detecting inconsistencies in other anticoagulation parameters, leading to steady levels of heparin without further complications.

Perioperative thromboprophylaxis in children: development of a guideline for management

BACKGROUND

Venous thromboembolic (VTE) events can occur in children at the time of surgery where a patient has associated prothrombotic risk factors. There is currently little advice available to anesthetists on how to assess the risks and provide prophylaxis.

AIM/OBJECTIVE

To increase awareness of thrombosis in the perioperative pediatric patient, and to give some guidance when considering prophylaxis in this group.

METHOD/RESULTS

A guideline outlining risk factors for venous thromboembolism in patients presenting for surgery was written as a flowchart. Recommendations for low risk patients was early mobilization and good hydration; for moderate risk patients having major general surgery to include physical prophylaxis where size permits, i.e. elastic stockings and compression devices; for high-risk patients undergoing major orthopaedic or general surgery to also receive prophylactic low molecular weight heparin enoxaparin 0.5 mg x kg(-1) b.d.

CONCLUSION

Children with multiple risk factors for VTE should be considered for prophylactic measures when presenting for prolonged major surgery.