The Analgesic Efficacy of Magnesium and Ketorolac in Ultrasound Supraclavicular Block
Status:
Recruiting
Trial end date:
2020-11-30
Target enrollment:
Participant gender:
Summary
Despite many regional anesthetic techniques have been described for anesthesia of the
brachial plexus which is responsible for the sensory and motor innervation of entire upper
limb, still, supraclavicular block (SCB) is the regional anesthetic technique of choice.
SCB has been described as the spinal anesthesia of the upper limb as it offers dense
anesthesia of the brachial plexus for the surgical procedures below the arm from elbow to
hand. Although the SCB has a high incidence of complications like pneumothorax, the use of
ultrasound-guided block improved the safety for the patient. There are several adjuvants have
been added to SCB aiming for prolongation of the duration of peripheral nerve block as
fentanyl, alpha 2 adrenergic agonist (Dexmedetomidine, Clonidine), tramadol, ketorolac and
Magnesium sulfate.
Magnesium has anti-nociceptive effects in animal and human models, principally related to
blocking the N-methyl-D-aspartate (NMDA) receptors and regulation of calcium influx into
cells. Calcium influx leads to a sequence of central sensitization such as windup phenomenon
and long term potentiation which are crucial mechanisms that determine the duration and
intensity of post-operative pain. Magnesium prevents central sensitization triggered by
peripheral nociceptive stimulation in response to painful stimuli.
Non-Steroidal Anti-Inflammatory drugs (NSAID) inhibit synthesis of prostaglandins from
arachnoid acid in phospholipid membranes resulting in decreased afferent nociceptive signals
from the site of surgery. There are a lot of studies supported the analgesic effect when
NSAIDs are concentrated at a peripheral site compared to the systemic administration therapy.
Ketorolac is a parenteral NSAIDs. Studies have shown that ketorolac as an adjuvant to local
anesthetics during peripheral nerve block enhanced duration and quality of analgesia.