Intravenous regional anesthesia is one of the well-known techniques of regional anesthesia
for short surgical operations on the upper and lower limbs. It was first introduced back in
1908. Later on it was popularized even more for the same purpose by using two tourniquets to
isolate an exsanguinated extremity then injection of local anesthesia. It was proved over
time to be safe and effective with minimal side effects and complications.
Magnesium sulfate (MgSO4) has been used over the 20th century for prevention and treatment of
pre-eclamptic and eclampsia seizures during pregnancy because of its superior safety profile
over other drugs used for the same purpose. The specific mechanisms of action of magnesium
sulfate still unclear but are probably multi-factorial. It may act as a vasodilator on
peripheral as well as cerebral vasculature, to decrease peripheral vascular resistance and/or
relieve vasoconstriction. Additionally, it may also protect the blood-brain barrier and limit
cerebral edema formation, or it may also act as a central anticonvulsant.
Fentanyl; was first introduced back in 1990 for palliative use as fentanyl patch. Few years
later, it became available in different forms of administration being highly lipophilic. Few
years later it became the most widely used synthetic opioid in medicine. It is an opioid
analgesic with a rapid onset and short duration of action. It is a potent μ-opioid receptor
pure agonist. Fentanyl is 50 to 100 times more potent than morphine. Fentanyl has a
relatively wide therapeutic index, which makes it a very safe surgical anesthetic drug when
monitored carefully.