Comparison of Three Different Doses of Nalbuphine as Adjuvant to Intrathecal Hyperbaric Bupivacaine in Knee Joint Surgeries

Author(s): Amit Pradhan1, Ranjitha Kusumanchi2, Pulak Priyadarshi Padhi 3, Saswati Das4 1,

Postoperative pain is the most challenging task in patients undergoing knee joint
surgeries under spinal anaesthesia. Spinal anaesthesia with bupivacaine provides
adequate intraoperative conditions but falls short in providing prolonged
postoperative pain relief. Intrathecal opioids are synergistic with local anaesthetics
and intensify the sensory block without affecting the sympathetic block. This study
intends to compare three different doses of intrathecal nalbuphine as an adjuvant
to 0.5 % hyperbaric bupivacaine and determine the optimal dose in knee joint
A double-blind comparative study was conducted in one hundred and twenty
American Society of Anaesthesiologists (ASA) I and II patients undergoing knee
joint surgeries in a randomised prospective way. The patients were randomly
allocated to A, B, and C groups who received 0.4, 0.8 and 1.2 mg nalbuphine
respectively added to 12.5 mg of 0.5 % hyperbaric bupivacaine. The onset,
duration of block, duration of effective analgesia, Visual Analogue Scale (VAS)
score, and the incidence of adverse effects were studied and compared between
the groups.
The mean onset time of sensory and motor block of group B and C was significantly
faster as compared to the onset in group A. The duration of sensory, motor
blockade and duration of analgesia were highest with 1.2 mg of nalbuphine
followed by 0.8 and 0.4 mg (P < 0.05). VAS readings were comparable in all the
groups. Hemodynamic variability among the three groups was comparable.
Incidence of adverse effects was highest in group C when compared with others,
although it was statistically insignificant (P > 0.05).
Nalbuphine in a dose of 0.8 mg when added to 0.5 % hyperbaric bupivacaine for
subarachnoid block in patients undergoing knee joint surgeries provides excellent
analgesia, prolonged duration of sensory block and motor block, with minimal
adverse effects.