Content uploaded by Albino Leoni
Author content
All content in this area was uploaded by Albino Leoni on Aug 13, 2014
Content may be subject to copyright.
185
CAN J ANESTH 2000 / 47: 2 / pp 185–187
Purpose: To evaluate the effectiveness of cervical plexus block performed with ropivacaine 0.75% or 1%, or
mepivacaine 2%.
Methods: In a prospective, randomized, double-blind study, 60 patients received deep cervical plexus block with
0.2 ml·kg–1 divided among C
2-C4 injections using ropivacaine 0.75% and 1% or mepivacaine 2%. A blinded
observer recorded loss of pin-prick sensation every minute in the C2-C4 dermatomes until readiness for surgery.
Then, a superficial cervical block was performed with 0.15 ml·kg–1 lidocaine 1%. The need for intraoperative sup-
plemental analgesia and degree of pain and time of first postoperative pain medication were also recorded.
Results: General anesthesia was not required to complete surgery in any case. No differences in the need for
intraoperative supplemental analgesia was observed (7, 6, and 9 patients with ropivacaine 0.75% and 1% or
mepivacaine 2%, respectively). Readiness to surgery required 15 (10 - 25) min with ropivacaine 0.75%, 18 (8 -
20) min with ropivacaine 1%, and 15 (5 - 20) min with mepivacaine 2% (P= NS); while patients asked for first
postoperative pain medication after 10 (4 - 13) hr and 9 (6.5 - 11) hr with ropivacaine 0.75% and 1% compared
with 5 (0 - 8) hr with mepivacaine 2% (P< 0.05).
Conclusion: Ropivacaine 0.75% or 1% are appropriate choices when performing cervical plexus anesthesia for
carotid endarterectomy, providing nerve block characteristics similar to those of mepivacaine 2%, but with the
advantage of longer postoperative pain relief.
Objectif : Évaluer l’efficacité du blocage du plexus cervical réalisé avec de la ropivacaïne 0,75 % ou 1 %, ou de
la mépivacaïne 2 %.
Méthode : Lors d’une étude prospective, randomisée et à double insu, 60 patients ont reçu un blocage profond
du plexus cervical avec 0,2 ml·kg–1 divisé en injections C2-C4 de ropivacaïne 0,75 % et 1 % ou de mépivacaïne
2 %. Un observateur impartial a enregistré la perte de sensation à la piqûre à chaque minute dans les dermatomes
de C2-C4 jusqu’à l’insensibilité nécessaire à l’opération. Un blocage cervical superficiel a ensuite été réalisé avec
0,15 ml·kg–1 de lidocaïne 1 %. Les besoins d’analgésie d’appoint peropératoire et le degré de la douleur ainsi que
le moment de la première demande postopératoire d’analgésique ont aussi été notés.
Résultats : Aucun patient n’a eu besoin d’anesthésie générale pendant l’intervention chirurgicale. Aucune dif-
férence d’analgésie supplémentaire peropératoire n’a été observée (7, 6, et 9 patients avec la ropivacaïne 0,75
% et 1 % ou la mépivacaïne 2 %, respectivement). Pour être prêt à l’opération, il a fallu 15 (10 - 25) min avec
la ropivacaïne 0,75 %, 18 (8 - 20) min avec la ropivacaïne 1 %, et 15 (5 - 20) min avec la mépivacaïne 2 % (P
= NS); les patients ont demandé une première dose d’analgésie postopératoire après 10 (4 - 13) h et 9 (6,5 -
11) h avec la ropivacaïne 0,75 % et 1 % en comparaison de 5 (0 - 8) h avec la mépivacaïne 2 % (P< 0,05).
Conclusion : La ropivacaïne 0,75 % ou 1 % constitue un bon choix pour réaliser une anesthésie du plexus cer-
vical lors d’une endartériectomie carotidienne, les caractéristiques du blocage nerveux étant similaires à celles de
la mépivacaïne 2 %, mais comportant l’avantage d’un soulagement prolongé de la douleur postopératoire.
Brief Report
Cervical plexus anesthe-
sia for carotid
endarterectomy: com-
parison of ropivacaine
and mepivacaine
Albino Leoni MD,
Silvio Magrin
MD,
Giuseppe Mascotto
MD,
Andrea Rigamonti
MD,
Giorgio Gallioli
MD,
Fausto Muzzolon
MD,
Guido Fanelli
MD,
Andrea Casati
MD
From the Department of Anaesthesiology, University of Milan, Milan, Italy.
Address correspondence to: Dr. A. Casati, Department of Anaesthesia and Intensive Care, IRCCS H San Raffaele, Via Olgettina 60,
20132 Milan, Italy. Phone: +39-2-26432656; Fax: +39-2-26412823; E-mail: casati.andrea@hsr.it
Accepted for publication November 14, 1999
HEN performing cervical plexus anes-
thesia for carotid endarterectomy a 1:1
lidocaine-bupivacaine mixture or mepi-
vacaine is often used to produce fast
onset and intermediate duration nerve blockade.
1,2
Ropivacaine is a new, long-acting local anesthetic,
3but
little is known about its use in deep cervical plexus anes-
thesia. This prospective, randomized, double-blind
study was designed to compare ropivacaine 0.75% and
1% with mepivacaine 2% when performing deep cervi-
cal plexus anesthesia for carotid endarterectomy.
Materials and methods
With Ethical Committee Approval and informed,
written, patient consent, 60 patients receiving cervical
plexus anesthesia for elective carotid endarterectomy
were studied. A pilot study with eight patients per
group had been performed previously to calculate the
estimated sample size (we wished to detect a five
minute difference in the time required to achieve ade-
quate surgical anesthesia between mepivacaine 2% and
ropivacaine 0.75% or 1%, accepting a two-tailed error
of 5%, and a ß error of 10%,
4
)
All patients received 0.05 mg·kg
–1 midazolam iv
premedication 15 min before block placement fol-
lowed by 0.5 mg atropine im. Then, standard moni-
toring was applied (including continuous arterial
blood pressure through a radial artery catheter), and
patients were randomly divided (sealed envelopes
technique) into three groups of 20 patients to receive
deep cervical plexus anesthesia with 0.2 ml·kg
–1of
ropivacaine 0.75% and 1% or mepivacaine 2%. After
sterile syringes had been prepared in a double-blinded
fashion by one of the authors not taking further part
in patient management, deep cervical plexus block was
performed using a three injection technique at the C
2
,
C
3
, and C
4levels
5by one of four attending anesthesi-
ologists with extensive expertise in deep cervical
plexus block (SM, GM, GG, or A.L). The total
amount of local anesthetic solution to be injected was
equally divided among the three injection sites.
A blinded, trained observer (AR or FM) evaluated
the patient every minute until loss of pinprick sensa-
tion in the C
2
-C
4
dermatomes (readiness to surgery).
Then, a superficial cervical block was performed with
0.15 ml·kg
–1lidocaine 1%.
5If the patient complained
of pain during surgery, supplemental lidocaine 1% was
administered superficially (into the skin and subcuta-
neous tissues) or deep (into and around the carotid
sheath) by the surgeon, who was blinded to patient
grouping. If this proved to be ineffective, 1 µg·kg
–1
fentanyl ivwas given, hopefully avoiding interference
with patient communication to assess his/her neuro-
logical status. Needs for anesthetic and analgesic sup-
plementation were also recorded. Nitrate or etile-
phrine were given intraoperatively as required by the
surgical procedure, and their total consumption was
recorded.
Postoperative analgesia consisted of 100 mg keto-
profen iv prn. Postoperative pain relief was defined as
the time lasting from block placement to the first
request for postoperative pain medication. The degree
of pain at first pain medication request was also mea-
sured on a 100 mm visual analogue scale (VAS).
Statistical analysis was performed using the pro-
gram Systat 7.0 (SPSS Inc, Chicago, IL). The
Kruskall-Wallis test and the Mann-Whitney U- test
with Bonferroni’s correction were used to analyze
continuous variables. Categorical data were analyzed
using the contingency table analysis with the Fisher
exact test. A value of P< 0.05 was considered signifi-
cant. Results are presented as median (range), or as
number (%).
Results
No differences in patient age, weight, height, and
male/female ratio were observed between studied
groups (Table I). No signs of central nervous system
(CNS) or cardiovascular toxicity, or other untoward
events were reported in any patient. The injected
doses of local anesthetic solution were 100 ± 18 mg
with ropivacaine 0.75% , 137 ± 25 mg with ropiva-
caine 1% , and 275 ± 41 mg with mepivacaine 2%.
Table II shows onset times of deep cervical plexus
anesthesia as well as total intraoperative consumption
of lidocaine 1%, intravenous fentanyl, nitrate and
fenilephrine. General anesthesia was not required to
complete surgery in any case, and no differences in the
need for block supplementation were observed among
the three groups.
No differences in the degree of pain as measured
with the visual analogue scale were observed at time of
first analgesic administration (31 ± 30 mm, 24 ± 26
mm, and 26 ± 30 mm after ropivacaine 0.75%, and 1%
or mepivacaine 2%, respectively). However, postoper-
ative pain relief was longer in patients receiving ropi-
186CANADIANJOURNALOFANESTHESIA
W
TABLE IDemographic data.
Ropivacaine
0.75% Ropivacaine
1% Mepivacaine
(n = 20)(n = 20)(n = 20)
Age (yr)70 (53 - 83)70 (54 - 82)72 (53 - 84)
Weight (kg)64 (50 - 93)66 (50 - 92)70 (50 - 95)
Height (cm)163 (155 - 175)167 (150 - 178)165 (155 - 182)
Sex (Male/Female)10 / 1015 / 514 / 6
Data are presented as median (range), except for sex (number).
vacaine 0.75% (10 hr; range 4 - 13 hr) and 1% (9 hr;
range 6.5 - 11 hr) than in patients receiving mepiva-
caine 2% (5 hr; range 0 - 8 hr) (P< 0.05).
Discussion
This prospective, randomized, double-blind study
suggested that, when used at the same volume to per-
form deep cervical plexus anesthesia, ropivacaine
0.75% or 1% are as effective as mepivacaine 2%, with
the advantage of prolonged postoperative analgesia.
Based on previous experience of ropivacaine use in dif-
ferent peripheral nerve blocks,
6,7these findings could
have been predicted. However, we were unaware of
previous investigations comparing different ropiva-
caine concentrations with mepivacaine 2% for deep
cervical plexus anesthesia. Bupivacaine might appear
more appropriate than mepivacaine as a control drug,
due to its pharmacokinetic properties, but mepiva-
caine is routinely used in our Department for deep
cervical plexus anesthesia, because of its short latency
and is the reason for our choice.
To minimize the risk of overdosing local anesthetics
due to the combination of deep and superficial blocks,
8
a mixture of two different local anesthetics was used for
the two different blocks, with a delay between deep and
superficial blocks placement. However, plasma concen-
trations of local anesthetics may reach near the toxic
threshold during cervical plexus anesthesia,
9and usual
recommendations like multiple aspiration and slow
injection must be emphasized.
The consumption of intraoperative anesthetic/anal-
gesic supplementation observed using the three injec-
tion technique at C
2
-C
4is similar to that reported by
Stoneham et al.
10when performing deep cervical plexus
anesthesia using a single injection technique at C
4
.
In conclusion, this randomized double-blind study
demonstrated that ropivacaine 0.75% and 1% are suit-
able choices when performing cervical plexus anesthe-
sia for carotid endarterectomy, providing nerve block
characteristics similar to those of mepivacaine 2%, with
the advantage of a longer postoperative pain relief.
References
1Davies MJ, Murrell GC, Cronin KD, Meads AC,
Dawson A. Carotid endarterectomy under cervical
plexus block - a prospective clinical audit. Anaesth
Intensive Care 1990; 18: 219–23.
2Covino BG, Vassallo G. Local Anesthetics: Mechanism
of Action and Clinical Use. Grune Stratton: 1976.
3McClure JH. Ropivacaine. Br J Anaesth 1996; 76:
300–7.
4Browner WS, Black D, Newman B, Hulley SB.
Estimating sample size and power. In: Hulley SB,
Cummings SR (Eds.). Designing Clinical Research - an
Epidemiologic Approach. Baltimore: Williams &
Wilkins, 1988; 139–50.
5Murphy TM. Somatic blockade of head and neck. In:
Cousins MJ, Bridenbaugh PO (Eds.). Neural Blockade
in Clinical Anesthesia and Management of Pain, 2nd
ed. Philadelphia: Lippincott Company, 1988: 533–58.
6Fanelli G, Casati A, Beccaria P, et al.A double-blind
comparison of ropivacaine, bupivacaine and mepiva-
caine during sciatic and femoral nerve blockade.
Anesth Analg 1998; 87: 597–600.
7Casati A, Leoni A, Aldegheri G, Berti M, Torri G,
Fanelli G. A double-blind study of axillary brachial
plexus block by 0.75% ropivacaine or 2% mepivacaine.
Eur J Anaesth 1998; 15: 549–52.
8Goldberg MJ. Complication of cervical plexus block or
fugue state? Anesth Analg 1995; 81: 1108–9.
9Tissot S, Frering B, Gagnieu MC, Vallon JJ, Motin J.
Plasma concentrations of lidocaine and bupivacaine
after cervical plexus block for carotid surgery. Anesth
Analg 1997; 84: 1377–9.
10Stoneham MD, Doyle AR, Knighton JD, Dorje P,
Stanley JC. Prospective, randomized comparison of
deep or superficial cervical plexus block for carotid
endoarterctomy surgery. Anesthesiology 1998; 89:
907–12.
Leoni et al.: ROPIVACAINEFORCERVICALPLEXUSBLOCK187
TABLE IITime required for onset of deep cervical plexus anesthesia, and total intraoperative consumption of supplemental lidocaine
and fentanyl, nitrate, and fenilephrine after cervical plexus anesthesia performed with either 0.75%, 1% ropivacaine, or 2% mepivacaine.
Ropivacaine
0.75% Ropivacaine
1% Mepivacaine
(n = 20)(n = 20)(n = 20)
Onset of Deep Cervical Block (min)15 (10 - 25)18 (9 - 20)15 (5 - 20)
Intraoperative Lidocaine 1% consumption (ml)7 (0 - 30)5 (0 - 25)9 (0 - 30)
Intraoperative Fentanyl consumption (mg)0 (0 - 0.15)0 (0 - 0.05)0 (0 - 0.1)
Intraoperative Nitrate consumption (mg)2 (0 - 6)2 (0 - 8)2 (0 - 15)
Intraoperative Fenilephrine consumption (mg)1 (0 - 8)0 (0 - 2)1 (0 - 5)
Data are presented as median (range).
