Continuous peripheral nerve blocks: state of the art

Purpose of review: This review was performed through a Medline research to evaluate articles published between January 2004 and April 2005. Technical procedures, indications, drugs, infusion regimens, and complications of continuous peripheral nerve blocks were considered. Recent findings: A total of 27 articles were reviewed. With respect to technical procedures, the authors focused on advantages of stimulating catheters or ultrasound guidance. With the help of these techniques, a correct catheter placement as close to the targeted nerve as possible was obtained. The total amount of local anesthetic administered was thereby reduced. Using ultrasound needle guidance, the spread of local anesthetic around the nerve could be visualized. Articles dealing with the choice of local anesthetic showed equianalgesia and equipotency of continuous perineural infusion of levobupivacaine 0.125% and ropivacaine 0.2%. The best infusion regimen for postoperative analgesia appears to be a combination of a preset basal rate administered together with small bolus doses in almost all continuous peripheral nerve blocks. Overall, complications such as infections, local anesthetic toxic plasma levels, hematoma formation, or nerve injury seem to be rare in continuous peripheral nerve blockade. Summary: Continuous peripheral nerve blockade is an effective and safe technique for postoperative analgesia, even when administered at home. To optimize this technique, further studies are needed to help minimize the risk of side effects, improve techniques to locate the targeted nerve (stimulating catheters or ultrasound imaging) and choose less toxic drugs (levobupivacaine and ropivacaine) with more effective infusion regimens.