Efficacy of dexmedetomidine as an adjuvant in femoral nerve block for post-op pain relief in hip surgery: A prospective randomized double-blind controlled study

Dexmedetomidine as an Adjuvant in Peripheral Nerve Block

Peripheral nerve block technology is important to balanced anesthesia technology. It can effectively reduce opioid usage. It is the key to enhance clinical rehabilitation as an important part of the multimodal analgesia scheme. The emergence of ultrasound technology has accelerated peripheral nerve block technology development. It can directly observe the nerve shape, surrounding tissue, and diffusion path of drugs. It can also reduce the dosage of local anesthetics by improving positioning accuracy while enhancing the block's efficacy. Dexmedetomidine is a highly selective drug α₂-adrenergic receptor agonist. Dexmedetomidine has the characteristics of sedation, analgesia, anti-anxiety, inhibition of sympathetic activity, mild respiratory inhibition, and stable hemodynamics. Numerous studies have revealed that dexmedetomidine in peripheral nerve blocks can shorten the onset time of anesthesia and prolong the time of sensory and motor nerve blocks. Although dexmedetomidine was approved by the European Drug Administration for sedation and analgesia in 2017, it has not yet been approved by the US Food and Drug Administration (FDA). It is used as a non-label drug as an adjuvant. Therefore, the risk-benefit ratio must be evaluated when using these drugs as adjuvants. This review explains the pharmacology and mechanism of dexmedetomidine, the effect of dexmedetomidine on various peripheral nerve block as an adjuvant, and compare it with other types of adjuvants. We summarized and reviewed the application progress of dexmedetomidine as an adjuvant in nerve block and look forward to its future research direction.

The difficulty of choosing the method of analgesia after total replacement of the lower limb large joints (case report, literature review)

A case of successful treatment of a patient with a periprosthetic fracture of the femur is described. The fracture occurred one day after total hip replacement as a result of a fall, possibly associated with postoperative conduction analgesia. Lower limb large joints total replacement may become the most frequently performed type of elective surgery already in the current decade. The increasing prevalence of osteoporosis, osteoarthritis, rheumatic diseases and hip fractures is an objective prerequisite for it. Despite of all efforts, the problem of postoperative pain control during these surgical interventions currently remains unresolved. There is currently no “gold standard” for pain relief after total hip and knee replacement surgeries. An excellent ratio of effectiveness and safety is demonstrated by multimodal pain relief programs based on peripheral nerve blocks. However, while having undeniable advantages, conduction anesthesia/analgesia has a critically important drawback. The cornerstone of postoperative rehabilitation for patients undergoing total hip or knee replacement is their early activation. All methods of conduction anesthesia are associated with motor blockade. In particular, femoral nerve block causes weakness of quadriceps muscle of thigh, inducing patients’ inadvertent falling when attempting to stand or walk. The situation with the choice of the method of anesthesia after total replacement of the lower limb large joints can be described as “a long way to go”.