Abstract:
To increase the duration of analgesia produced by local anaesthetics a number
of adjuvants have been added to centrineuraxial block. Administration of intrathecal
Clonidine or Dexmedetomidine has shown to improve the quality of spinal
anaesthesia. It abolishes pain of somatic origin without any neurotoxicity. In view of
the above considerations, this clinical study was undertaken to assess the behaviour
and feasibility of administration of intrathecal Clonidine or Dexmedetomidine as an
adjuvant for bupivacaine intrathecally in patients posted for elective lower abdominal
or lower limb surgeries.
Method
This clinical study was conducted on 156 adult patients of ASA physical
status I, II and III in the age group of 18-60years of either sex posted for elective
lower abdominal or lower limb surgeries under spinal anaesthesia after taking
informed consent.
Patients were randomly divided on an alternative basis into 3 groups of 52 each
Group-B: 0.5% Bupivacaine 15mg + 0.5 ml Normal saline
Group-C: 0.5% Bupivacaine 15mg + 50 µg Clonidine (Test solution was
diluted with Normal saline to a total volume of 3.5ml)
Group-D : 0.5% Bupivacaine 15mg + 5 µg Dexmedetomidine(Test solution
was diluted with Normal saline to a total volume of 3.5ml)
Parameters
Onset and duration of sensory block and motor block, highest level of sensory
blockade, duration of analgesia, vitals and side effects were assessed.
XIII
Results
The onset of motor block was faster in group C and group D as compared to
group B, fastest in group C followed by group D. The duration of sensory and motor
blockade and duration of analgesia was longer in group C and D as compared to
group B, longest in group D followed by C and B. There was no significant
haemodynamic changes in all the three groups.
Conclusion
Supplementation of bupivacaine spinal block with a low dose of intrathecal
Dexmedetomidine (5 µg) or Clonidine (50 µg) produces a significantly shorter onset
of motor and sensory block and a significantly longer sensory, motor block and longer
analgesia than bupivacaine alone. These doses have an effect on sedation level, heart
rate and mean arterial pressure which does not however require any therapeutic
intervention.
