European Journal of Cardiovascular Medicine

Introduction: Hyperbaric bupivacaine (0.5 %) has been the gold standard drug for the safe conduct of spinal anaesthesia in recent times. Various additives have been used along with hyperbaric bupivacaine to prolong the duration of analgesia. Out of these, fentanyl and midazolam have been two of the most commonly used. Here a clinical study was undertaken to compare the effects of intrathecal midazolam and fentanyl as additives to intrathecal bupivacaine for spinal anaesthesia. Aims: To compare the effects of intrathecal midazolam 1mg and fentanyl 25 μg as additives to 3ml of 0.5% hyperbaric bupivacaine (15mg) for spinal anaesthesia with respect to the onset and duration of sensory and motor blockade, duration of effective analgesia, perioperative hemodynamic changes and any side effects of these drugs. Methodology: This is a prospective randomized study studied in 100 patients posted for various elective lower limb, lower abdominal, gynaecological and urological surgeries under spinal anaesthesia. They were randomly divided into two groups, Group A (Midazolam) and Group B (Fentanyl) each consisting of 50 patients in the age group of 18 years to 60 years posted for elective surgeries under spinal anesthesia. Subarachnoid block was administered in L3-L4 intervertebral space. The data collected were statistically analyzed. Results: Addition of 25 μg intrathecal fentanyl to hyperbaric bupivacaine resulted in a statistically significant duration of sensory blockade (Group A ; 206.56 min; Group B ; 230.06 min) and motor blockade (Group A ; 225.56 min; Group B ; 251.88 min).  The duration of effective analgesia was also significantly longer in group B (Group A ; 246.2 min; Group B ; 264.32 min). Incidence of hypotension and bradycardia is found to be similar in both groups. There was no significant difference between the two groups with respect to the occurrence of nausea. 4% of people in fentanyl group developed pruritus where as none in midazolam group developed it. None of them had urinary retention, respiratory depression, lower limb weakness or any other neurological deficits. There were no statistical differences in the sedation scores between the two groups. Conclusion: The results suggest that the use of 25 μg intrathecal fentanyl provides longer surgical analgesia, prolongs the duration of sensory and motor blockade, and offers relative hemodynamic stability with minimal side effects. Hence fentanyl is an excellent additive to Bupivacaine for prolangation of spinal anaesthesia