Neuraxial and peripheral nerve blocks in patients taking anticoagulant or thromboprophylactic drugs: challenges and solutions.

Incidence of hemorrhagic complications from neuraxial blockade is unknown, but classically cited as 1 in 150,000 epidurals and 1 in 220,000 spinals. However, recent literature and epidemiologic data suggest that for certain patient populations the frequency is higher (1 in 3,000). Due to safety concerns of bleeding risk, guidelines and recommendations have been designed to reduce patient morbidity/mortality during regional anesthesia. Data from evidence-based reviews, clinical series and case reports, collaborative experience of experts, and pharmacology used in developing consensus statements are unable to address all patient comorbidities and are not able to guarantee specific outcomes. No laboratory model identifies patients at risk, and rarity of neuraxial hematoma defies prospective randomized study so "patient-specific" factors and "surgery-related" issues should be considered to improve patient-oriented outcomes. Details of advanced age, older females, trauma patients, spinal cord and vertebral column abnormalities, organ function compromise, presence of underlying coagulopathy, traumatic or difficult needle placement, as well as indwelling catheter(s) during anticoagulation pose risks for significant bleeding. Therefore, balancing between thromboembolism, bleeding risk, and introduction of more potent antithrombotic medications in combination with regional anesthesia has resulted in a need for more than "consensus statements" to safely manage regional interventions during anticoagulant/thromboprophylactic therapy.