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395
O iginal Resea ch A icle
E ec o Clonidine and Bupi acaine in In a hecal Ve sus Pe iphe al
Ne e Block Rou es in A h oscopic Knee Su ge y: P ospec i e
Obse a ional S udy
Ami Kuma Mukhe jee1, Debabanhi Ba ua2, Saba ni Sanyal3, P o esso A pi a Laha4
1Ex. Senio Residen , MD Anaes hesiology, Depa men o Anaes hesiology, Medical College Hospi al,
Kolka a, Wes Bengal – 700073
2Assis an P o esso , MD Anaes hesiology, Depa men o Anaes hesiology, Medical College Hospi al,
Kolka a, Wes Bengal – 700073
3Ex. Senio Residen , MD Anaes hesiology, Depa men o Anaes hesiology, Medical College Kolka a,
Wes Bengal 700073
4Head o he Depa men , MD Anaes hesiology, Depa men o Anaes hesiology, IPGMER and SSKM
Hospi al, Kolka a, Wes Bengal 700023
Recei ed: 01-07-2025 / Re ised: 16-08-2025 / Accep ed: 08-09-2025
Co esponding Au ho : D . Saba ni Sanyal
Con lic o in e es : Nil
Abs ac
Backg ound and Aims: A la ge numbe o pa ien s unde going a h oscopic knee su ge ies complain o
inadequa e pain elie . Clonidine and bupi acaine we e adminis e ed h ough in a hecal ou e and emo oscia ic
ne e block ou e and e alua ed o mo e a ou able pe iope a i e ou come be ween hem.
Me hods: An open label andomized con olled ial was planned in a e ia y ca e hospi al in Eas e n India in
which 50 Ame ican Socie y o Anaes hesiologis s I and II pa ien s unde going a h oscopic knee su ge y we e
en olled. They we e di ided in o wo g oups-G oup IT and G oup NB, by using compu e -gene a ed block
andomiza ion echnique. G oup IT ecei ed 1 μg/kg o clonidine along wi h 0.5% hype ba ic bupi acaine,
whe eas G oup NB ecei ed 0.25% bupi acaine and 1 μg/kg clonidine in emo oscia ic ne e block (FSNB).
Pos ope a i e pain- ee in e al and block cha ac e is ics we e he p ima y ou comes s udied.
Resul s: Pain- ee du a ion was 522.08(±21.18) min in G oup NB (P < 0.001) in compa ison o 325.33(±17.85)
min in G oup IT. Senso y block and mo o blockade in NB we e 469.58(± 15.17) and 264.88(±14.87) min,
espec i ely, and was signi ican ly p olonged in compa ison o G oup IT (P < 0.001). The mean escue
analgesic equi emen was less in G oup NB as compa ed o G oup IT.
Conclusion: Clonidine in a dose o 1 μg/kg wi h bupi acaine has be e pe iope a i e ou come h ough FSNB
ou e in compa ison o i s use ia in a hecal ou e in a h oscopic knee su ge y. I p o ided s able haemodynamic
and espi a o y pa ame e s in a and pos ope a i ely, inc eased du a ion o senso y block and pain- ee pe iod,
lesse 24 h escue analgesic equi emen making i ideal o pos knee su ge y pain.
Keywo ds: A h oscopic Su ge y, Clonidine, Pos ope a i e Pain.
This is an Open Access a icle ha uses a unding model which does no cha ge eade s o hei ins i u ions o access and dis ibu ed unde
he e ms o he C ea i e Commons A ibu ion License (h p://c ea i ecommons.o g/licenses/by/4.0) and he Budapes Open Access
Ini ia i e (h p://www.budapes openaccessini ia i e.o g/ ead), which pe mi un es ic ed use, dis ibu ion, and ep oduc ion in any medium,
p o ided o iginal wo k is p ope ly c edi ed.
In oduc ion
Inc eased pe o mance o a h oscopic knee
su ge ies necessi a es adequa e pos ope a i e
analgesia.[1] Regional anaes he ic echniques wi h
adju an s a e commonly u ilized o ex end he
analgesic e ec in o he pos ope a i e pe iod.[2]
Clonidine, an α2-ad ene gic ecep o agonis , has
been e alua ed as an al e na i e o in a hecal
opioid o con ol o pain and has p o en o be a
po en analgesic, ee o a leas some o he opioid-
ela ed side e ec s.[3] On he o he hand, clonidine
has also been shown o p olong senso y analgesia
when gi en as an adjunc o pe iphe al ne e
blocks, wi h lesse episodes o hypo ension and
b adyca dia.[4] Al hough he s udies employing
clonidine show a p olonga ion in he analgesic
du a ion, di e en imes and dosages ha e been
used wi h limi ed s udies showing compa ison
be ween he e icacies when used h ough di e en
ou es in simila doses in a single ype o
su ge y.[2] The p esen s udy has been planned o
explo e he e ec o clonidine wi h bupi acaine
h ough wo di e en ou es- in a hecal and
pe iphe al ne e blocks ( emo al-scia ic ne e
block in his case) and e alua e mo e a ou able
ou come be ween he wo. P ima y ou come o
in e es will be analgesic du a ion and block
cha ac e is ics while he seconda y ou comes will
be hemodynamic and seda ion sco es.[2]
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396
Me hods
A e app o al om Ins i u ional E hics Commi ee
and w i en in o med consen , 50 Ame ican Socie y
o Anaes hesiologis s I and II pa ien s o ei he sex
unde going a h oscopic knee su ge y we e
included in his open label andomized con olled
ial. Pa ien s be ween 20 and 40 yea s o age and
weighing be ween 60 and 75 kg we e en olled. Any
pa ien s wi h con aindica ions o spinal anaes hesia
like spinal de o mi ies, neu ological disease,
coagula ion abno mali ies, any local in ec ions a
he si e o injec ion, and e usal o gi e consen
we e excluded om he s udy. Pa ien s wi h a
his o y o d ug alle gy o con aindica ions o
nons e oidal an i-in lamma o y d ugs we e also
excluded om he s udy.[2] Randomiza ion was
done by compu e gene a ed block andomiza ion
p ocedu e. The pa ien s we e andomly alloca ed o
ei he o he wo ou es o anaes hesia; hose gi en
bupi acaine and clonidine in a hecally designa ed
as G oup IT, and hose gi en bupi acaine and
clonidine h ough FSNB as G oup NB. No blinding
was possible in his s udy. No na co ics we e used
in p emedica ion.[2]
Pa ien s in G oup IT ecei ed spinal anaes hesia
wi h hype ba ic bupi acaine (0.5%)-2 ml and
clonidine (1 μg/kg) ollowed by il ing o he able
owa ds he side o ope a ing leg (unila e al spinal
anaes hesia). The le el o spinal anaes hesia was
ensu ed o be abo e he T11 de ma ome. On he
o he hand, G oup NB pa ien s ecei ed 20 ml and
30 ml o isoba ic bupi acaine (0.25%) along wi h
0.5 μg/kg clonidine in each o he emo al and
scia ic ne e block espec i ely. The ne e block
was pe o med wi h he help o ne e s imula o
(Plexygon, Vygon, Ecouen, F ance). Wi h an ini ial
cu en o 1 mA and equency o 1 Hz, he ne e
s imula o needle was in oduced ill he mo o
esponse was p esen a a cu en o app oxima ely
0.5mA, ollowing which local anaes he ic mix u e
was adminis e ed.[5] The onse o block in each
pa ien was eco ded. Senso y block was es ed by
loss o cold empe a u e and pin p ick sensa ion
a ound knee. Mo o blockade was measu ed by
modi ied B omage scale[6], conside ing S age 2 as
sa is ac o y o he su ge y o p oceed.
Modi ied B omage Scale[6]:
0: No mo o block
1: Inabili y o aise ex ended leg; able o mo e
knees and ee
2: Inabili y o aise ex ended leg and mo e knee;
able o mo e ee 3: Comple e block o mo o limb
Hemodynamic and espi a o y pa ame e s (Pulse
a e, NIBP, espi a o y a e, SpO2) was moni o ed
e e y 5 min up o 30 min a e gi ing anaes hesia
and he ea e e e y 15 min in aope a i ely and 30
min pos ope a i ely o 4 h. The ea e , pa ien s
we e moni o ed pos ope a i ely o du a ion o
senso y and mo o block.
While s udying block cha ac e is ics, e u n o
sensa ion a ound he knee join and e u n o mo o
powe a he knee join was es ed a 15 min
in e al in he pos ope a i e pe iod. The du a ion o
senso y block was de ined om injec ion o he
d ug ill e u n o sensa ion a ound he knee join
(L4 de ma ome).[2] Modi ied B omage scale was
used o measu e mo o block.[6] The du a ion o
mo o block was de ined om injec ion o he es
d ug up o he abili y o lex knee join (modi ied
B omage scale - S age 1).
Pa ien s we e educa ed abou he 11 poin e bal
a ing sco e (VRS) whe e 0 as no pain and 10 as
wo s imaginable pain.[2] When he VRS was mo e
han 3 a any poin o ime wi hin 24 h
pos ope a i ely, i s escue analgesia in he o m
o diclo enac 75 mg IM was gi en. I he VRS a e
30 min o adminis a ion o IM diclo enac was
g ea e han 3, ano he dose o IM diclo enac was
adminis e ed ill a o al o 3 doses in 24 h. I he
pain sco e a any ime in he 24h was mo e han 3
e en a e 3 doses o i s escue analgesia, a
second escue analgesic o IV en anyl o 1 μg/kg
was adminis e ed. The o al escue analgesic
consump ion in 24 h in each g oup we e no ed.
Seda ion was assessed wi h Ramsay seda ion sco es
bo h in a- and pos -ope a i ely a 15- and 30-min
in e als espec i ely ill seda ion sco es achie ed
baseline alues. All pa ien s we e shi ed o he
wa ds o 24 h obse a ion. Sample size es ima ion
was based on a p e ious s udy whe e he esponse
wi hin each subjec g oup was no mally dis ibu ed
wi h s anda d de ia ion 2.[7] I he ue di e ence
be ween each g oup is 2, we needed o s udy 22
subjec s o he G oup IT and 22 subjec s o he
G oup NB o be able o ejec he null hypo hesis
ha he popula ion means o bo h he g oups a e
equal wi h p obabili y (powe ) 0.9. The Type I
e o p obabili y associa ed wi h his es o his
null hypo hesis is 0.05. The e o e, we ensu ed a
leas 25 pa ien s in each g oup o adjus o any
po en ial d opou s. Le ene’s es was used o assess
he equali y o a iances o each and e e y
a iable calcula ed o he wo g oups. Da a we e
analysed by S a is ical Package o Social Sciences
e sion 18.0 s a is ical analysis so wa e and g aphs
we e made using G aphPad P ism 7 so wa e. A
alue o P < 0.05 is conside ed signi ican .
Resul s
A o al o 50 cases we e en olled, o which 48
pa ien s comple ed he s udy. Two cases we e
excluded which included one pa ien in G oup IT
due o inadequa e le el o spinal blockade, and one
pa ien in G oup NB due o ailu e o FSNB,
necessi a ing adminis a ion o gene al anaes hesia.
Bo h g oups we e compa able ega ding age, sex,
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Mukhe jee e al. In e na ional Jou nal o Cu en Pha maceu ical Re iew and Resea ch
397
weigh , ASA s a us o du a ion o su ge y al hough,
mo e numbe o males we e s udied in each g oup
[Table 1].
Table 1: Demog aphic da a
Pa ien cha ac e is ic
G oup IT
G oup NB
P
Age (yea s)
29.38(±6.22)
26.50(± 5.66)
0.10
Sex (male/ emale)
22/2
23/1
0.56
Weigh (kg)
67.33(± 4.58)
66.42(±4.82)
0.50
ASA s a us (1/2)
20/4
22/2
0.39
Du a ion o su ge y (min)
105.17(±13.00)
107.63(±12.64)
0.51
ASA = Ame ican Socie y o Anaes hesiologis s
Onse o senso y and mo o block was signi ican ly ea lie in G oup IT in compa ison o G oup NB (P<0.001)
[Table 2]. Haemodynamic pa ame e s showed s a is ically signi ican di e ences (P<0.05) be ween 45-90 min
in aope a i ely, wi h G oup IT showing dec eased pulse a e and mean a e ial p essu e om baseline alues in
compa ison o G oup NB [Figu e 1]. No s a is ically signi ican di e ences in haemodynamic and espi a o y
pa ame e s we e ound be ween he g oups in pos ope a i e pe iod.
Figu e 1: Haemodynamic pa ame e s showing lesse pulse a e and mean a e ial p essu e in G oup IT
in compa ison o G oup NB, especially du ing he la e hal o in aope a i e pe iod
Table 2: Block cha ac e is ics
Cha ac e is ic o block
G oup IT
G oup NB
P
Onse o block
Tempe a u e (min)
5.63(±0.77)
6.58(±0.83)
< 0.001
Pin p ick (min)
9.08(±1.18)
12.75(±2.15)
< 0.001
Mo o (min)
12.50(±1.35)
19.04(±2.25)
< 0.001
Du a ion o block
Mo o blockade (min)
180.33(±13.20)
264.88(±14.87)
< 0.001
Senso y blockade (min)
288.29(±15.86)
469.58(±15.17)
< 0.001
Du a ion o senso y and mo o blockade in G oup NB was signi ican ly highe (P<0.001) han G oup
P
u
ls
e
a
e
(
p
e
m
in )
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398
IT [Table 2]. The mean pos ope a i e pain- ee
pe iod was much highe in G oup NB (P<0.001)
han in G oup IT [Table 3]. The escue analgesic
equi emen was signi ican ly less (P<0.05) in
G oup NB as shown by o al 24h escue analgesic
[Table 3] and mean 24h escue analgesic equency
[Figu e 2].
None o he pa ien s in ei he g oup equi ed a
second escue analgesic. An inc ease in mean
seda ion sco es we e no ed in bo h he g oups a e
15 min o d ug adminis a ion, in he i s 6h
pos ope a i ely, bu was no associa ed wi h ai way
comp omise o desa u a ion. Mean seda ion sco es
in he i s 6 h pos ope a i ely was ound o be
highe in G oup IT in compa ison o G oup NB
(P<0.05) [Table 3].
Table 3: Pos ope a i e analgesia and seda ion
G oup IT
G oup NB
P
Pain- ee pe iod (min)
325.33(±17.85)
522.08(±21.18)
< 0.001
24 h escue analgesic (mg)
100.0(±36.12)
71.88(±26.89)
0.004
Seda ion sco e (6 h)
2.58(±0.50)
2.29(±0.46)
0.043
Figu e 2: Mean escue analgesic equency in he pos ope a i e pe iod (24 h) showing less analgesic
equi emen s in G oup NB in compa ison o G oup IT
Discussion
Clonidine, when added o bupi acaine in FSNB,
showed longe pain- ee pe iod and lesse o al
escue analgesic consump ion han when i is added
o bupi acaine in a hecally. Clonidine was used in
a dose o 1 μg/kg as his dose has been sa ely
used.[8,9]
Cu en ad ances o pain he apy ha e ocused on
ei he imp o ing d ug o mula ions o ca he e
sys ems o local in il a ions o imp o e
pe o mance o egional anaes he ic echniques.
These ad ances ha e he po en ial o side e ec s
om ca he e mig a ion a e home discha ge.[10]
An ideal adju an , pe mi ing single adminis a ion,
and no causing sys emic side e ec s, p olonging
senso y blockade wi hou inc easing mo o
blockade du a ion is needed o adequa e pain
elie . E ec o clonidine along wi h bupi acaine
was compa ed h ough wo di e en ou es-
in a hecal and FSNB, and he ou e wi h be e
pe iope a i e ou come was sough . Pa ien s o
G oup IT had a much ea lie onse o senso y and
mo o block han in pa ien s o G oup NB.
Haemodynamic pa ame e s we e main ained close
o baseline alues in case o G oup NB; whe eas
G oup IT showed lesse pulse a e and mean
a e ial p essu e, especially du ing he la e hal o
in aope a i e pe iod. Addi ion o clonidine o
bupi acaine in ne e block esul ed in sa is ac o y
p olonga ion o analgesic du a ion o
522.08(±21.18) min gi ing a pain- ee du a ion o
abou 9 h. In a hecal clonidine wi h bupi acaine
imp o es he du a ion o mo o block and analgesic
quali y wi hou delay in abili y o oid o eadiness
o home discha ge ollowing knee a h oscopy[11]
bu cen al neu axial echniques hemsel es
p olong home discha ge when compa ed o wound
in il a ions o gene al anaes hesia alone.[10]
S ebel e al.[8] compa ed 37.5, 75 and 150 μg o
in a hecal clonidine and ound ha in a hecal
clonidine p oduced dose dependen inc ease in
spinal anaes hesia and pain elie wi hou any
un owa d side e ec . Cucchia o and Ganesh[4]
epo ed mean mo o block o 9.6 h a e addi ion
o clonidine 1 μg/kg o local anaes he ic in
pe iphe al ne e block bu he assessmen o block
cha ac e is ics migh di e om ou s udy due o
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Mukhe jee e al. In e na ional Jou nal o Cu en Pha maceu ical Re iew and Resea ch
399
he e ospec i e na u e o he s udy and
in e e ence om a ie y o pe iphe al ne e blocks
included. P olonged mo o block may ad e sely
a ec hospi al discha ge as i delays neu ological
examina ion. We epo an inc ease in mo o
blockade du a ion lesse han hose epo ed by
Cucchia o and Ganesh[4] and hence no signi ican
inc eases in hospi al s ay we e obse ed p obably
due o low concen a ion o clonidine used (0.5
μg/kg in each block). FR Mon es e al.[7]
concluded ha combined scia ic- emo al ne e
block o ou pa ien a h oscopic knee su ge y
o e ed sa is ac o y anaes hesia, wi h a clinical
p o ile simila o ha o low-dose spinal
anaes hesia. Scia ic- emo al ne e blocks we e
associa ed wi h signi ican ly lowe pain sco es
du ing he i s 6 pos ope a i e hou s. We epo a
be e clinical p o ile in G oup NB pa ien s in e ms
o s abili y o haemodynamic and espi a o y
pa ame e s, inc eased du a ion o senso y block
and pain- ee in e al, lesse 24 h escue analgesic
equi emen s and low seda ion sco es. Nee u Sahni
e al.[2] concluded ha clonidine in a dose o 1
μg/kg was sa e and e ec i e adju an wi h
bupi acaine in p olonging analgesia h ough
a ious ou es (in a hecal, emo al-scia ic ne e
block, in a-a icula ) employed o pos knee
su ge y pain. The maximum p olonga ion o
analgesia was ound o be achie ed h ough FSNB
ou e.
Clonidine po en ia es he senso y and mo o block
o in a hecal local anaes he ics by 30-50% and is
mo e e ec i e o dynamic pain con ol while
opioids a e e ec i e o pain a es .[12,13] Hence,
clonidine migh be e ec i e o pe mi ing ea ly
mo emen especially in he ambula o y se ing.
Clonidine inhibi s he elease o subs ance P in he
spinal co d, ac i a es inhibi o y G-p o eins a spinal
and sup aspinal si es wi hin he cen al ne ous
sys em and supp esses neu o ansmission in
pe iphe al senso y Aδ and C ne e ib es. In ne e
blocks, clonidine may also p oduce local
asocons ic ion, esul ing in a delayed abso p ion
o local anaes he ic and block p olonga ion apa
om di ec ly binding o α2-ad ene gic ecep o s
loca ed on p ima y a e en e minals, on neu ons
in he supe icial laminae o he spinal co d and
se e al b ains em nuclei implica ed in
analgesia.[4,14]
Haemodynamic and seda ion e ec s o clonidine
a e mo e common in highe doses.[14] Though
mean seda ion sco es in he i s 6 pos ope a i e h
was ound o be highe in G oup IT in compa ison
o G oup NB, i was no clinically signi ican ,
simila o he s udy on in a hecal clonidine in
doses o 37.5, 75, and 150 μg/kg.[8] Bupi acaine
alone in ne e block shows lowe pain sco es in he
ini ial 6 h o pos ope a i ely, bu a compa able
pos ope a i e analgesia wi h he in a hecal ou e
la e .[7] Hence, addi ion o clonidine in ne e
block signi ican ly imp o ed pos ope a i e
analgesia and dec eased escue analgesic
equi emen in compa ison o in a hecal ou e.
A signi ican inding o ou s udy is ha we a e
using 0.25% bupi acaine wi h 1μg/kg clonidine in
FSNB ou e and able o p oduce mo o blockade
(S age 2 o Modi ied B omage Scale) equi ed o
he su ge y o p oceed. Thus we a e using hal he
concen a ion o local anaes he ic equi ed
o he wise o p oduce mo o blockade, he eby
minimising he po en ial chances o any local
anaes he ic oxici y, besides being economical.
The limi a ion o using 0.25% bupi acaine is delay
in onse o mo o block ( 19.04 ±2.25 min) which
in u n delays s a ing o he ope a ion. Ano he
limi a ion o ou s udy is ha i is no blinded, so
nei he he pa icipan ’s no he obse e ’s bias
could be elimina ed om he s udy.
Conclusion
Clonidine in a dose o 1 μg/kg wi h bupi acaine has
mo e a ou able pe iope a i e ou come in emo al-
scia ic ne e block ou e in compa ison o i s use
ia in a hecal ou e in a h oscopic knee su ge y. I
p o ided s able haemodynamic and espi a o y
pa ame e s in a and pos ope a i ely, inc eased
du a ion o senso y block and pain- ee pe iod,
lesse 24 h escue analgesic equi emen making i
ideal o pos knee su ge y pain.
Re e ences
1. Buckenmaie CC 3 d. Anaes hesia o
ou pa ien knee su ge y. Bes P ac Res Clin
Anaes hesiol 2002; 16:255-70.
2. Sahni N, Panda NB, Jain K, Ba a YK, Dhillon
MS, Jaganna h P. Compa ison o di e en
ou es o adminis a ion o clonidine o
analgesia ollowing an e io c ucia e ligamen
epai . J Anaes hesiol Clin Pha macol 2015;
31:491-5.
3. Se hi BS, Samuel M, S ee as a a D. E icacy
o analgesic e ec s o low dose in a hecal
clonidine as adju an o bupi acaine. Indian J
Anes h. 2007;51:415.
4. Cucchia o G, Ganesh A. The e ec s o
clonidine on pos ope a i e analgesia a e
pe iphe al ne e blockade in child en.
Anes hAnalg2007; 104:532-7.
5. Mille Ronald D, E iksson La s I, Fleishe Lee
A, Wiene -K onish Jeanine P, Cohen Neal H,
Young William L. Mille ’s anes hesia 8 h
Edi ion 2015 Volume 1;47:1722.
6. B omage PR: Ac a Anaes hesiol Scand Suppl
16:55, 1965.
7. Mon es FR, Za a e E, G ueso R, Gi aldo JC,
Venegas MP, Gomez A, e al. Compa ison o
spinal anes hesia wi h combined scia ic
emo al ne e block o ou pa ien knee
In e na ional Jou nal o Cu en Pha maceu ical Re iew and Resea ch e-ISSN: 0976-822X, p-ISSN: 2961-6042
Mukhe jee e al. In e na ional Jou nal o Cu en Pha maceu ical Re iew and Resea ch
400
a h oscopy. J Clin Anes h. 2008; 20:415-20.
8. S ebel S, Gu zele JA, Schneide MC,
Aeschbach A, Kindle CH. Small dose
in a hecal clonidine and isoba ic bupi acaine
o o hopaedic su ge y: A dose- esponse
s udy. Anes h Analg 2004; 99:1231-8.
9. Elia N, Culeb as X, Mazza C, Schi e E,
T amè MR. Clonidine as an adju an o
in a hecal local anes he ics o su ge y:
Sys ema ic e iew o andomized ials. Reg
Anes h Pain Med 2008; 33:159-67.
10. Rawal N. Pos ope a i e pain ea men o
ambula o y su ge y. Bes P ac Res Clin
Anaes hesiol 2007; 21:129-48.
11. T an KM, Ganley TJ, Wells L, Ganesh A,
Minge KI, Cucchia o G. In aa icula
bupi acaine-clonidine-mo phine e sus
emo al-scia ic ne e block in pedia ic
pa ien s unde going an e io c ucia e ligamen
econs uc ion. Anes h Analg 2005; 101:1304-
10.
12. Me i i a R, Kuusniemi K, Jaakkola P,
Pihlajamäki K, Pi känen M. Unila e al spinal
anaes hesia o ou pa ien su ge y: A
compa ison be ween hype ba ic bupi acaine
and bupi acaine-clonidine combina ion. Ac a
Anaes hesiol Scand 2009; 53:788-93.
13. Si es BD, Beach M, Biggs R, Rohan C, Wiley
C, Rassias A, e al. In a hecal clonidine added
o a bupi acaine-mo phine spinal anes he ic
imp o es pos ope a i e analgesia o o al knee
a h oplas y. Anes h Analg 2003; 96:1083-8.
14. Kamibayashi T, Maze M. Clinical uses o
alpha2 –ad ene gic agonis s. Anes hesiology
2000; 93:1345-9.
