Al-Meeri, Nasreldeen Mohamed Mosleh
(2006)
A comparison of plain ropivacaine 0.5% with plain bupivacaine 0.5% in spinal anaesthesia for orthopaedic surgery.
Masters thesis, Universiti Sains Malaysia.
Abstract
INTRODUCTION
Bupivacaine is a popular local anaesthetic drug used for spinal anesthesia, it is relatively
cardiotoxic and has a longer duration of motor blockade leading to longer discharge time,
research for newer local anaesthetic with less cardiotoxicity and minimal motor blockade is
aimed. Ropivacaine is a relatively new long-acting local anesthetic used in spinal
anaesthesia, which is structurally and pharmacologically closely related to bupivacaine.
However, unlike bupivacaine, which is synthesized as a racemic mixture, ropivacaine is
synthesized as a pure S (-) enantiomer. This characteristic feature of the drug may
contribute to its faster return of motor function than bupivacaine, and with lower risk of
cardiotoxicity.
METHODOLOGY
A double blind randomized clinical trial on 72 ASA grade 1- II patients who were
scheduled to undergo orthopedic surgery of the lower limb with duration of operation less
than 3 hours were included in the study. These patients received an intrathecal injection of
either: 15 mg of 0.5% plain ropivacaine (3 ml), or 15 mg of 0.5% plain bupivacaine (3 ml)
for the above procedure.
RESULTS
The mean onset of sensory block at T12 dermatome was 4 minutes (SD ±3.4) 1n
bupivacaine group and in ropivacaine group it was 5.1 minutes (SD ±3.3) (P<0.207).
Where as to reach Tl 0 in bupivacaine group was 6.4 minutes (SD ±3.3) and in ropivacaine
group reached in 9.3 minutes (SD ±5.2) (P<O.Ol5). Regarding sensory block at T4, 20
patients (55.5%) in bupivacaine group reached this level with mean onset of sensory block
in 6.9 minutes (SD ±3.7). Where as only 4 patients (11 %) in ropivacaine group were able to
reach the level of T4 in 15 minutes (SD ±4.08) (P<O.OOl). The duration of sensory block
was assessed by the patient's first request for analgesia. In bupivacaine group the mean
duration of time of sensory block was 5.4 hours (SD ±1.2) and in ropivacaine group it was
6.5 hours (SD ±2.44) (P<0.02). The mean onset of motor block to reach Modified Bromage
Score (MBS 1) in bupivacaine group was 1.4 minutes (SD ±0.8) and in ropivacaine group it
was 2.1 minutes (SD ±1.5) (P<0.01). And to reach MBS2, in bupivacaine group and in
ropivacaine group was 1.6 minutes (SD ±0.9) and 3.0 minutes (SD ±2.0) respectively
(P<O.OOl). While to reach MBS3 bupivacaine group was 2.1 minutes (SD ±1.1) and in
ropivacaine group it was 3.6 minutes (SD ±1.8) (P<O.OOI). In the bupivacaine group the
mean duration of motor block was 4.7 hours (SD ±1.1) and in ropivacaine group was 3.5
hours (SD ±1.4) (P<O.OOl).
CONCLUSION
Ropivacaine in a dose of 15 mg as 0.5% solution can be used with an acceptable onset of
sensory and motor blockade with a longer duration of analgesia and early mobilization for
lower limb orthopedic surgery of duration less than three hours and a level of lower than
T12 dermatome.
Where as to reach Tl 0 in bupivacaine group was 6.4 minutes (SD ±3.3) and in ropivacaine
group reached in 9.3 minutes (SD ±5.2) (P<O.Ol5). Regarding sensory block at T4, 20
patients (55.5%) in bupivacaine group reached this level with mean onset of sensory block
in 6.9 minutes (SD ±3.7). Where as only 4 patients (11 %) in ropivacaine group were able to
reach the level of T4 in 15 minutes (SD ±4.08) (P<O.OOl). The duration of sensory block
was assessed by the patient's first request for analgesia. In bupivacaine group the mean
duration of time of sensory block was 5.4 hours (SD ±1.2) and in ropivacaine group it was
6.5 hours (SD ±2.44) (P<0.02). The mean onset of motor block to reach Modified Bromage
Score (MBS 1) in bupivacaine group was 1.4 minutes (SD ±0.8) and in ropivacaine group it
was 2.1 minutes (SD ±1.5) (P<0.01). And to reach MBS2, in bupivacaine group and in
ropivacaine group was 1.6 minutes (SD ±0.9) and 3.0 minutes (SD ±2.0) respectively
(P<O.OOl). While to reach MBS3 bupivacaine group was 2.1 minutes (SD ±1.1) and in
ropivacaine group it was 3.6 minutes (SD ±1.8) (P<O.OOI). In the bupivacaine group the
mean duration of motor block was 4.7 hours (SD ±1.1) and in ropivacaine group was 3.5
hours (SD ±1.4) (P<O.OOl).
CONCLUSION
Ropivacaine in a dose of 15 mg as 0.5% solution can be used with an acceptable onset of
sensory and motor blockade with a longer duration of analgesia and early mobilization for
lower limb orthopedic surgery of duration less than three hours and a level of lower than
T12 dermatome.
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