Comparative study of intrathecal 0.5% bupivacaine(12mg) versus 0.5% bupivacaine(8mg) with fentanyl(25µg) for ephedrine requirement in caesarean section

Spinal anaesthesia is the most common method of regional block in caesarean section. It produces sympathetic block, sensory analgesia and motor block depending on the dosage, concentration or volume of local anesthetics used. The dose of local anesthetics used in spinal anaesthesia varies with height of the patient, desired segmental level, the specific gravity of the drug and use of adjuvants. The most unavoidable response of spinal anaesthesia is hypotension which directly correlates with the dose of local anaesthetics used.

The addition of opiods to local anesthetic for spinal anaesthesia was first introduced in 1979 with morphinre. Opioids are synergistic with local anesthetics and intensify the sensory block without increasing the sympathetic block. They are commonly used as adjuvants with local anesthetics for potentiating their effects , thus offering hemodynamic stability by reducing the dose and side effects of local anesthetics. In the literature very few studies have been done to assess the actual vasopressor requirement by addition of opioids. The aim of our work is to study the efficacy of intrathecal fentanyl as an adjuvant to low dose bupivacaine to conventional dose bupivacaine on vasopressor requirement in caeserean section.