Part of the book: Acupuncture in Modern Medicine
Regional anesthesia is not always performed independently, but rather is frequently employed as part of a general anesthesia technique. Thus, its procedures and usefulness should be considered in settings where general anesthesia is used. In this chapter, new perspectives regarding the interaction of regional and general anesthesia are presented, as well as novel tips for improving nerve block techniques during the course of general anesthesia, Regional anesthetics inhibit superoxide generation of neutrophils by inhibition of protein kinase C activity and also have potent antioxidant activities, while inhalation general anesthetics have contrasting effects. Therefore, it is considered that regional anesthetics are able to compensate for shortcomings of inhalation general anesthetics by reducing surgical oxidative stress. In clinical settings, combined use of regional with general anesthesia provides better intraoperative hemodynamics than general anesthesia alone, particularly in high‐risk patients affected by severe cardiovascular disease. To further improve the analgesic potency and duration of regional anesthesia, especially in cases in which a peripheral nerve block is performed, addition of low molecular weight dextran as an adjuvant to the local anesthetic solution is quite effective. Furthermore, recent advancements in ultrasound technology have made previously difficult regional anesthesia techniques easier and safer to achieve. A typical example is use of a caudal block in adults, which is quite difficult with a conventional method. Expanding its indication to adults is beneficial, especially for high‐risk patients undergoing surgery in the lower abdomen. Furthermore, proper in‐line positioning of ultrasound images is key for successful and easy completion of ultrasound‐guided procedures, such as needle insertion to the target. We have been able to establish such a positioning method by use of an iPad and the VT‐100 image transfer system (Scalar Co., Tokyo, Japan). Following consideration of the present findings and related experience, it is evident that performance of regional anesthesia under general anesthesia provides great advantages, including better and safe anesthesia management.
Part of the book: Current Topics in Anesthesiology
Advances in ultrasound technology and the increased risk of opioid overdose following surgery have expanded applications of nerve block for surgical cases, resulting in reevaluation of adjuvants used to potentiate local anesthetics. We have found that a mixture of local anesthetic with low-molecular weight dextran, one such local anesthetic adjuvant, greatly enhances analgesic duration and potency in patients receiving an interfascial compartment nerve block under ultrasound-guidance as well as those receiving a single peripheral nerve block. Notably, a compartment nerve block in the abdominal trunk with an extra-large amount of low-molecular weight dextran mixture, which results in a longer duration of the injected drugs at the injection site, provides good analgesia that is comparable to epidural anesthesia. Such a dextran mixture also suppresses systemic absorption of local anesthetics, thus reducing their systemic toxicity, which enhances regional anesthesia safety. Furthermore, it controls unintended spread of injected local anesthetics, thus increasing nerve block accuracy. In this chapter, recent findings regarding use of low-molecular weight dextran as a local anesthetic adjuvant obtained in our laboratory are presented.
Part of the book: Topics in Regional Anesthesia