Publications

Background: Subarachnoid block is the most commonly used anesthetic technique for lower
limb surgeries. Fentanyl is very often combined with hyperbaric bupivacaine as an adjuvant.
This study was conducted to compare the block characteristics by administrating bupivacaine
and fentanyl in a sequential and premixed manner. Aims and Objectives: The primary
objective was to compare the effects of hyperbaric bupivacaine and fentanyl administered
either as a premixed solution or sequentially on block characteristics-onset of sensory and
motor blockade, regression of block and duration of analgesia. The secondary objective was
to study the hemodynamic changes and adverse effects. Materials and Methods: A total
of 72 patients scheduled to undergo lower limb surgery were allocated to three groups.
Patients in Group A received 15 mg of 0.5 % bupivacaine heavy (H), followed by 25 mcg of
fentanyl intrathecally using different syringes. Group B received 25 mcg of fentanyl, followed
by 15 mg of 0.5% bupivacaine H in a separate syringe. Group C received premixed 0.5 %
bupivacaine H 15 mg and fentanyl 25 mcg in single syringe. The block characteristics-onset
and regression of sensory and motor blockade, duration of analgesia, and adverse effects were
studied. Results: The mean time (minutes) taken for onset of sensory block was 2.40±0.51
in group A, 4.80±0.53 in Group B and 6.70±0.50 in Group C. Mean time (minutes) taken for
onset of motor block was 4.35±0.43 in Group A, while it was 5.64±0.65 and 7.32±0.64
in Groups B and C, respectively. Two segment regression and duration of motor blockade
were found to be longer in Group A. Conclusion: Sequential intrathecal administration of
bupivacaine followed by fentanyl has a faster onset and prolonged duration of block when
compared to the premixed group.
Key words: Intrathecal injection; Fentanyl; Bupivacaine