Articaine has emerged as a local anesthetic (LA) that produces sensory and motor blockade shorter than bupivacaine and lower in neurotoxicity than lidocaine.

Studies have shown that adding dexmedetomidine to LA produces prolongation of sensory and motor bock duration.

Early regain of motor power with adequate analgesia is needed in ambulatory surgery, for early start of physiotherapy. This study was designed to test efficacy of adding dexmedetomidine to articaine on the duration of sensory and motor block.

Articaine is an amide LA produced in the 1960s and first used in clinical trials in 1974. Although it is an amide that is similar to prilocaine in chemical structure, it contains a thiophene ring rather than a benzene ring. Articaine is a rapid and short acting LA, which has low neurotoxicity and appears to diffuse through tissues more readily than other commonly used LA agents. It is metabolized by nonspecific plasma esterases both in blood and tissues, leading to its rapid clearance.

α2-adrenergic receptor agonists have been the focus of interest for their sedative, analgesic, perioperative sympatholytic, and cardiovascular stabilizing effects along with providing reduction in anesthetic requirements. Dexmedetomidine may act on supraspinal (locus coeruleus) or spinal level or peripheral α2-adrenoreceptor to reduce nociceptive transmission, leading to analgesia.

Previous trials focused on adding dexmedetomidine to either levobupivacaine and bupivacaine, found augmentation of both sensory and motor block along with prolonged duration of effective analgesia. However, there remains limited knowledge of the analgesic efficacy and clinical utility of adding dexmedetomidine to articaine during peripheral nerve block in humans.

Inclusion Criteria:

• aged 18-60 years planned for upper limb surgery below the midhumerus with an expected time of less than 90 min usually under tourniquet.

Exclusion Criteria:

• allergies to local anesthetic,
• those with ASA III and IV,
• patients who refuse to participate,
• uncooperative patients,
• patients who have infection at the site of injection,
• patients who have bleeding disorder, and patients on anticoagulant drugs.