This scoping review summarizes current evidence on adjuvants used in regional anaesthesia and peripheral nerve blocks, such as dexamethasone, alpha-2 agonists, buprenorphine, ketamine, and magnesium. Adding adjuvants can modify block characteristics and improve pain control while reducing the need for local anaesthetics or other analgesics. Progress has been made in understanding their mechanisms of action. In the last two years, publications on dexmedetomidine have increased, though interest in dexamethasone may decline due to only moderate evidence. Opioid adjuvants are also being studied more. All adjuvants show varying efficacy, but evidence for dexmedetomidine remains lower than for dexamethasone.
Several anesthetic drugs show promise as novel antidepressants for treatment-resistant depression. Ketamine has acute, transient antidepressant and antisuicidal effects. Nitrous oxide has also shown antidepressant efficacy. Converging preclinical and clinical data indicate that isoflurane (and perhaps propofol), dosed to burst suppression, produces relatively rapid, robust, and durable antidepressant effects without the adverse cognitive effects associated with electroconvulsive therapy (ECT). Ketamine is the most well-studied among them. Anesthetic-induced burst suppression may offer an alternative to ECT. Further study is needed to understand how these drugs work and how they might be used effectively.