Evidence-based Medicine: Time for a change? - Journal of Medical ...

ORIGINAL ARTICLE
as compared to bupivacaine alone, which is
comparatively longer than that of the present
study finding. However more sedation,
change in the heart rate and mean arterial
pressure were observed in their study than
ours.
When the analgesic effects of 150µg of
intrathecal clonidine were compared with
placebo (saline) in cesarean section under
general anesthesia, Filos KS and co-workers 3
observed that clonidine provided pain relief for
7 +/- 2.2 hr vs. 3+/- 2.8 hr of saline. They also
investigated response to 150µg, 300µg, and
450µg doses of intrathecal clonidine in a
similar design and patient population and
observed that clonidine produced dosedependent
and long-lasting analgesia (7 +/-
1.3, 10 +/- 1.3, and 14 +/-1.3 hr respectively).
In both the studies, they found sedation was
dose dependent and more pronounced after
450 µg of intrathecal clonidine. The maximum
dose used in our study was 65 ìg and this low
dose of clonidine (1 µg/kg) might be cause
for single incidence of sedation in this series.
Our study also shows that moderate
prolongation of duration of analgesia is
possible with low dose clonidine without
sedation.
Many previous studies had used intrathecal
clonidine combined with opioids and local
anaesthetics for labour analgesia and
orthopaedic surgery. However, the
combination with opioids would seem less
attractive for obvious reasons. Using
intrathecal clonidine in place of opioids avoids
problems of respiratory depression, pruritus,
urinary retention and abuse liability.
The works of Dobrydnjov I et al 1 , Filos KS et
al 5 , Kock DM et al 9 , where clonidine was used
more than 75 ìg, found prolongation of
analgesia but at the expense of sedation. Even
though sedation is a well known side effect of
clonidine we had encountered only one case
in our study of intrathecal clonidine (1 µg/kg).
This might be because of low dose as
suggested by Eisenach et al 10 which stated
that clonidine produces dose dependent
sedation of rapid onset at the range 50-900
ìg, regardless of route of administration. Our
findings were in agreement with Kaabachi O
et al 7 which again underlines the safety of low
dose intrathecal clonidine.
Conclusion: It might be concluded that
intrathecal clonidine at the dose of 1µg/kg
significantly prolongs the post-operative pain
free period without significant cardiovascular
changes and side effects.
Reference
1. Dobrydnjov I, Axelsson K, Samartel J,
Holmstrom B. Postoperative pain relief
following intrathecal bupivacaine
combined with intrathecal or oral clonidine.
Acta Anaesthesiol Scand 2002; 46:806-
14.
2. Chiari A, Lober C, Eisenach JC, Wildling
E, Krenn C, Zavrsky A et al. Analgesic and
hemodynamic effects of intrathecal
clonidine as the sole analgesic agent
during first stage of labor:A doseresponse
study. Anesthesiology1999;
9:388-96.
3. Filos KS, Goudas LC, Patroni O, Polyzou
V. Intrathecal clonidine as a sole analgesic
for pain relief after cesarean section.
Anesthesiology 1992; 77:267-74.
4. Benhamou D, Thorin D, Brichant JF,
Dailland P, Milon D, Schneider M.
Intrathecal clonidine and fentanyl with
hyperbaric bupivacaine improve analgesia
during cesarean section . Anesth Analg
1998; 87: 609–13.
5. Filos KS, Goudas LC, Patroni O, Polyzou
V. Hemodynamic and analgesic profile
after intrathecal clonidine in humans. A
dose-response study. Anesthesiology
1994; 81:591-601.
6. Owens WD, Felts JA, Spitznagel EL Jr.
ASA physical Status classification: a study
of consistency of ratings. Anesthesiology
1978; 49:239-43.
7. Kaabachi O, Zarghouni A, Ouezini R,
Abdelaziz AB, Chattaoui O,Kokki H.
Clonidine 1 µg/kg is a safe and effective
32 JMS * JMS Vol 25 * Vol * No. 25 3 * No. * September, 1 * June, 2010 2011