From the Guidelines
Spinal anesthesia can be safely administered in patients with normal coagulation parameters, which include a platelet count above 100,000/mm³, INR less than 1.5, and normal activated partial thromboplastin time (aPTT). For patients on anticoagulant medications, specific timing guidelines should be followed.
- Low molecular weight heparin (LMWH) should be discontinued 12 hours before spinal anesthesia for prophylactic doses and 24 hours for therapeutic doses, as suggested by 1.
- Unfractionated heparin should be stopped 4-6 hours prior, with an aPTT check before the procedure.
- Direct oral anticoagulants (DOACs) like rivaroxaban, apixaban, and dabigatran require 48-72 hours of discontinuation depending on renal function, as indicated by 1.
- Warfarin should be stopped 5 days before the procedure with INR normalization.
- Antiplatelet agents have varying recommendations: aspirin can generally be continued, clopidogrel should be discontinued 5-7 days prior, and ticagrelor 5 days prior, as recommended by 1. These guidelines aim to minimize the risk of spinal hematoma, a rare but potentially catastrophic complication that can cause permanent neurological damage. The timing for resuming anticoagulation after spinal anesthesia is equally important, typically waiting at least 6 hours after needle placement for prophylactic doses and longer for therapeutic anticoagulation, as suggested by 1.
From the Research
Bleeding Parameters Based on Spinal Anesthesia
The bleeding parameters based on spinal anesthesia are as follows:
- Platelet count threshold:
- Risk factors for bleeding:
- Female gender, increased age, a history of excessive bruising/bleeding, surgery to the hip, continuous catheter anesthetic technique, large needle gauge, multiple needle passes, and moderate or difficult needle placement are significant risk factors for bleeding 4
- Blood transfusion requirements:
- The amount of blood transfused and total intraoperative blood loss were not significantly reduced with the administration of a prophylactic low dose of tranexamic acid in spinal fixation surgery 5
- Hemostatic agents:
- Tranexamic acid (TXA) has been investigated as a hemostatic agent to reduce blood loss and transfusion requirements during spinal fixation surgery, but its efficacy is still being studied 5
- Platelet transfusion thresholds:
- The platelet count threshold recommended prior to lumbar punctures and epidural anaesthesia varies significantly, and there is significant uncertainty among clinicians regarding the correct management of patients with thrombocytopenia 6