Neuraxial anesthesia

The Patient on Low-Dose Aspirin For Neuraxial Anesthesia Part 1. McMahonMed.com, http //www.mcmahonmed.com/cme/an/cme176/05lesson.htm... 

When neuraxial anesthesia (epidural/spinal anesthesia) or spinal puncture is employed, patients who are anticoagulated or scheduled to be anticoagulated with low molecular weight heparins (LMWHs) or heparinoids for prevention of thromboembolic complications are at risk of developing an epidural or spinal hematoma, which can result in long-term or permanent paralysis. 

Neuraxial anesthesia and postoperative indwelling epidural catheter use Spinal or epidural hematomas, which may result in long-term or permanent paralysis, can occur with the use of anticoagulants and neuraxial (spinal/epidural) anesthesia or spinal puncture. The risk of these events may be higher with postoperative use of indwelling epidural catheters or concomitant use of other drugs affecting hemostasis, such as NSAIDs. 

Increased risk of spinal/epidural hematomas with neuraxial anesthesia or spinal puncture. Risk is further increased by use of indwelling spinal catheters, repeated/ traumatic epidural/spinal puncture, or use of drugs affecting hemostasis (NSAIDs, anticoagulants, platelet inhibitors). 

Pharmacological Profile. The profile of the ideal local anesthetic agent depends largely on the type and length of the surgical procedure for which it is applied. Procedures could include neuraxial (spinal and epidural) anesthesia, nerve and plexus blocks, or field blocks (local infiltration). In general, tine ideal agent should have a short onset of anesthesia and be useful for multiple indications such as infiltration, nerve blocks. 

The most serious complication of neuraxial block (epidural or spinal anesthesia) is spinal hematoma with resulting paraplegia, Based on the pharmacokinetic and pharmacodynamic profile of... 

Transient and permanent nerve damage can occur after regional anesthesia, particularly neuraxial anesthesia. The mechanism of this nerve damage is unclear. Some studies have shown an indirect effect. However, in crayfish giant axon, lidocaine had a dose- and time-dependent effect on isolated nerve function in vitro (31). At high concentrations lidocaine caused irreversible conduction block and total loss of resting membrane potential. These results in an isolated nerve suggest a direct neurotoxic effect of lidocaine. 

The primary adverse effect associated with fondaparinux therapy is bleeding." " The rate of major bleeding in the VTE prophylaxis trials was approximately 2% to 3%. The risk of major bleeding appears to be related to weight therefore, in patients who weigh less than 50 kg, fondaparinux is contraindicated for VTE prophylaxis, and the treatment dose is only 5 mg every 24 hours. Similar to UFH and the LMWHs, fondaparinux should be used with extreme caution in patients with neuraxial anesthesia or following a spinal puncture owing to the risk for spinal or epidural hematoma formation. Unlike UFH and the LMWHs, fondaparinux does not cause heparin-induced thrombocytopenia and does not produce cross-sensitivity in vitro." A specific antidote to reverse the antithrombotic activity of fondaparinux is not currently available, but several potential products have been evaluated. 

Central sensitization often expressed as hyperalgesia and allodynia has always been considered a factor in the development of this chronic pain state. Experimental data from animals and humans support the thought that the continuous afferent barrage from the periphery generates and maintains sensitization of central neimons. Furthermore, studies examining the dilference between neuraxial block over general anesthesia confirms this observation. 

The following guidelines are adapted from The 2010 Third ASRA Consensus Conference on Neuraxial Anesthesia and Anticoagulation, with additional information provided when available from current literature. 

Management of post-operative thromboprophylaxis and neuraxial anesthesia may be done safely and is based on total daily dosing, timing of dosing, and dosing schedule. Twice-daily dosing of LMWH may be associated with an increased risk of spinal hematoma and the first dose should be administered no earlier than 24 hours post-operatively. If a catheter is left in place for a continuous technique, it should be removed at least 2 hours prior to the first dose of LMWH. 

Eptifibatide (Integrilin) andTirofiban (Aggrastat), avoid neuraxial anesthesia... 

Neuraxial dose is determined by vertebral level of initial block placement and desired dermatome level of anesthesia/analgesia. Sympathetic block 0.25%, spinal 0.25-0.75% (6-15 mg), lumbar and thoracic epidural (25-150 mg) 0.25%, 0.5%, and 0.75% (non-obstetrical), caudal 0.25% and 0.5% (35-150 mg), epidural test dose (3 mL 0.25%). Use only the single-dose ampoule and single-dose vials for spinal, caudal, or epidural anesthesia as the multiple-dose vials contain a preservative and, therefore, should not be used for these procedures. 

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