Information
- Complications of LAs include intravascular injection, local anesthetic systemic toxicity (LAST) (see Chapter 19), and allergic reactions. Use of ultrasound, addition of epinephrine to LA solutions, and intermittent aspiration during injection may help identify intravascular injection.
- Nerve damage is rare, with long-term neurologic injury occurring in 0.02% to 0.04% of peripheral nerve blocks. It may result from needle trauma, nerve compression, stretch, or ischemia, or be direct LA-induced neurotoxicity. Paresthesia with needle advancement or injection is not entirely predictive of nerve injury. However, if pain or paresthesia is encountered, one must consider this complication and redirect the needle. A combination of monitoring techniques, such as peripheral nerve stimulation, injection pressure monitoring, and ultrasound can be used for prevention.
- Hematomas may result from vascular puncture but usually resolve without residual problems. When considering RA for an anticoagulated or coagulopathic patient, one should consider following neuraxial guidelines (see Chapter 20), particularly for deeper blocks (eg, infraclavicular, paravertebral) where vessel compression for bleeding control is challenging.
- Infection risk is reduced with the use of aseptic technique (see Section I.I).
- Failure or incomplete block can be identified with a careful neurologic examination prior to the beginning of the surgical procedure.