Spinal anesthesia is an established technique used in obstetric surgeries, It provides
adequate analgesia both intra and post-operative and also avoids complications associated
with general anesthesia for mother and fetus. The quality of spinal anesthesia has been
reported to be improved by using additives Dexmedetomidine is a highly selective
α2-adrenoreceptor agonist that has been introduced to anesthesia. It produces dose-dependent
sedation, anxiolysis, and analgesia without respiratory depression. Neostigmine is an
anticholinesterase agent, which inhibits the hydrolysis of acetylcholine by competing with
acetylcholine for attachment to acetyl cholinesterase; administration of Neostigmine through
intrathecal route apparently activates the descending pain inhibitory system that relies on
spinal cholinergic interneuron. Study conducted to evaluate whether neostigmine given by
intrathecal route with 0.5% hyperbaric bupivacaine for spinal anesthesia can provide
prolongation of sensory blockade duration as effective as dexmedetomidine given by the same
route and in compination with same drug with lower cost, more stable hemodynamics and
comparable side effects. After obtaining Institutional Ethics Committee approval and written
informed consent,54 patients American Society of Anesthesiologist (ASA) physical status I and
II were enrolled into the study and were randomlyassigned into 3 groups. Group 1were received
10 mg (2ml) hyperbaric bupivacaine and 0.1 ml (10 μg) DXM and 0.1 ml normal saline, Group 2
were received 10 mg (2ml) hyperbaric bupivacaine and 0.1 ml (50 μg) neostigmine and 0.1 ml
normal saline and Group 3were received 10 mg (2ml) hyperbaric bupivacaine and 0.2 ml normal
saline as control.
The investigators measured the time to reach T4 dermatome sensory block, peak sensory level,
Time to reach Bromage 3 motor block, the regression time for sensory and motor block, also
the investigators measured hemodynamic, sedation score, visual analogue score, any
complications occurred and Apgar score for fetus during blockade and the investigators
assessed the duration of pain relief .