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Background
and Objectives:
To evaluate the efficacy and safety of Clonidine as an
adjuvant to Ropivacaine in supraclavicular brachial plexus blockade in respect
to,
1. Onset, peak and duration
of sensory blockade.
2. Onset, peak and duration
of motor blockade.
3. Duration of effective
post-operative analgesia.
4. Total dose and frequency
of rescue analgesics required in 24 hours.
5. Sedation score.
6. Effects on hemodynamic
variables- Heart Rate (HR), Mean Arterial Blood pressure (MAP) and peripheral
oxygen saturation (SpO2).
7. Complications if any.
Methods:
After Approval from Institutional
review board and informed written consent from the patients, this prospective,
randomized, double blind controlled clinical study was carried out in 120
patients of ASA physical status I and II, aged 20 – 60 years of either sex
scheduled for upper limb orthopedic surgeries.
Patients were randomized to one of the
two groups by sealed envelope method.
Group R
(n = 60) – Ropivacaine 0.5% 30 cc + 0.6 cc normal saline
Group RC (n =60) –Ropivacaine 0.5%30 cc
+ 0.6 cc (90 μg) clonidine
Monitoring consisting of heart rate,
mean arterial blood pressure and peripheral oxygen saturation was established
and baseline vital parameters were recorded.
After securing intravenous line,
supraclavicular brachial plexus block was performed with the aid of nerve
locator. Patients were observed for onset, peak and duration of sensory and
motor brachial plexus blockade. Changes in visual analogue score (VAS) were
noted and the first rescue analgesic was injected when VAS exceeded 5. The time
for first rescue analgesic required and the total number of rescue analgesic
doses injected in 24 hours was also noted in both the groups.
Changes in HR, BP, Sedation Score and
SpO2 were also recorded as per the specified time.
Results:
Mean time of onset of sensory
blockade was 11.36±2.42 min and 9.84±1.58 min respectively in groups R and RC.
Henceforth, the onset of sensory blockade was significantly earlier in group RC
as compared to group R. (p=0.0001)
Mean time to achieve peak of sensory
blockade was 18.18±3.47 and 13.78±1.94
minutes respectively in group R and RC. Henceforth, the time to achieve peak of
sensory blockade was significantly earlier in group RC as compared to group R. (P<0.0001)
Mean duration of sensory blockade was 477.00±29.77 and 678.42±104.07 minutes respectively in groups R and RC. Henceforth, the duration
of sensory blockade was significantly
prolonged in group RC as compared to group R. (P<0.0001)
The duration of analgesia was
prolonged with addition of clonidine to ropivacaine. Mean duration of analgesia
was 584.6±34.41 and 801±80.46 minutes respectively in groups R and RC.
Henceforth, the duration of analgesia was significantly prolonged in group RC
as compared to group R. (P<0.0001)
In group R, majority of patients
needed minimum of two analgesic doses during 24 hour study period while in
group RC, majority of patients needed only one analgesic dose.
Hence, clonidine as an adjuvant to ropivacaine
provided significantly earlier onset and peak and prolonged duration of sensory
blockade and analgesia as compared to control group.
Similar findings were noted for
motor characteristics of supraclavicular brachial blockade in the present study.
Mean time of onset was16.26±3.80
and 14.5±2.36 min respectively in group R and group RC (p=0.0094), peak was 37.56±3.03
and 22.85±3.94 min respectively in group R and group RC (p<0.0001) and duration of motor blockade was 417.20±35.343 and 547.80±34.184 min
respectively in group R and group RC which was statistically significant.
(P<0.0001) Henceforth, the
onset and peak of motor blockade was significantly earlier and duration was
significantly prolonged in groups RC as compared to group R.
Hence, clonidine as an adjuvant
to ropivacaine provided significantly earlier onset and peak and prolonged
duration of motor blockade as compared to control group.
In this study, sedation score was higher in group RC (score
2) as compared to group R (score 0) without any adverse consequences. (P<0.05)
On comparison of hemodynamics amongst
the two groups, there was statistically significant decrease in HR and BP in
group RC as compared to group R. Two patients developed bradycardia in group RC,
which responded to Inj.atropine and was not clinically significant.
SpO2
remained stable and comparable in both groups throughout the study
period. (P>0.05)
Except bradycardia (3% in group RC), no
other complication was observed in two groups.
Conclusion:
From
this study, it is concluded that addition of 90 μg of clonidine to ropivacaine
in supraclavicular brachial plexus blockade is safe and effective in improving
the quality of blockade, prolongs the duration and provides effective analgesia
with adequate sedation well extending into the postoperative period without any
adverse events. |