Epidural caudal block: evaluation of length of analgesia with the association of lidocaine, fentanyl and clonidine

Abstracts

JUSTIFICATIVA E OBJETIVOS: A associação de diferentes substâncias aos anestésicos locais é feita com o objetivo de melhorar a qualidade do bloqueio e prolongar a duração da analgesia. O objetivo deste trabalho foi comparar a eficácia da associação de clonidina, clonidina e fentanil e do fentanil à lidocaína, no tempo de analgesia pós-operatória. MÉTODO: O estudo envolveu 64 pacientes com idade igual ou superior a 23 anos, estado físico I ou II (ASA), escalados para cirurgia proctológica orificial, submetidos à anestesia peridural sacral. Os pacientes foram distribuídos em 4 grupos de 16: grupo I (lidocaína isolada), grupo II (lidocaína e fentanil), grupo III (lidocaína, fentanil e clonidina) e grupo IV (lidocaína e clonidina). Foram comparadas as características dos bloqueios sensitivo e motor. RESULTADOS: Não houve diferença entre a latência, bem como no nível máximo de bloqueio entre os grupos. A ausência de bloqueio motor foi o resultado mais freqüente, encontrado em cerca de 64% dos pacientes. O intervalo de analgesia foi diferente entre os grupos, sendo mais significativo no grupo III. CONCLUSÕES: O uso da clonidina, associada ou não ao fentanil, prolongou o tempo de analgesia pós-operatória na anestesia peridural sacral com lidocaína.

ANALGÉSICOS; ANALGÉSICOS; ANALGESIA PÓS-OPERATÓRIA; ANALGESIA PÓS-OPERATÓRIA; ANALGESIA PÓS-OPERATÓRIA; TÉCNICAS ANESTÉSICAS; TÉCNICAS ANESTÉSICAS

SCIENTIFIC ARTICLE

Epidural caudal block: evaluation of length of analgesia with the association of lidocaine, fentanyl and clonidine^*

Bloqueo peridural sacral: evaluación de la duración de la analgesia con el uso asociado de lidocaína, fentanil y clonidina

Carlos Alberto de Souza Martins, TSA, M.D.^I; Pedro Wanderley de Aragão, M.D.^II; João de Oliveira Prazeres, M.D.^III; Mahiba Mattar Rahbani de Souza Martins, M.D.^IV

^IResponsável pelo Serviço de Anestesiologia da Clínica São Marcos, São Luís MA; Professor Adjunto da Disciplina de Farmacologia da UFMA; Mestre em Ciências da Saúde pela UFMA

^IIProfessor Adjunto da Disciplina de Farmacologia da UFMA; Coordenador do Centro de Estudos da Clínica São Marcos; Mestre em Ciências da Saúde pela UFMA; Membro Ativo da Associação Médica Brasileira; Membro da Sociedade Brasileira de Farmacologia e de Terapêutica Experimental; Membro da Sociedade Brasileira para o Progresso da Ciência; Membro da Sociedade Brasileira para o Estudo da Dor

^IIProfessor Adjunto da Disciplina de Anatomia da UFMA; Mestre em Ciências da Saúde pela UFMA

^IVProfessor Adjunto da Disciplina de Farmacologia da UFMA; Mestre em Ciências da Saúde pela UFMA

^{Correspondence}

SUMMARY

BACKGROUND AND OBJECTIVES: The association of different substances to local anesthetics aims to improve the blockade quality and prolonging analgesia. The aims of this study were to compare the effectiveness of the association of clonidine, clonidine and fentanyl, and fentanyl, to lidocaine for postoperative analgesia.

METHODS: Participated in this study 64 patients aged 23 years or above, physical status ASA I or II, undergoing to orificial proctologic surgery under epidural caudal anesthesia. Patients were distributed in 4 groups of 16: group I (lidocaine alone); group II (lidocaine and fentanyl); group III (lidocaine, fentanyl and clonidine); and group IV (lidocaine and clonidine). The quality of sensory and motor blockade were compared.

RESULTS: There has been no difference in onset and maximum block level among groups. Absence of motor block was the most frequent result, found in about 64% of patients. Analgesia length was different among groups, being more significant in group III.

CONCLUSIONS: Clonidine, associated or not to fentanyl, has prolonged postoperative analgesia after epidural caudal blockade with lidocaine.

Key Words: ANALGESICS, Opioids: fentanyl; ANESTHETIC TECHNIQUES, Regional: epidural caudal block; POSTOPERATIVE ANALGESIA: clonidine, lidocaine, regional block

RESUMEN

JUSTIFICATIVA Y OBJETIVOS: La asociación de diferentes substancias a los anestésicos locales es hecha con el objetivo de mejorar la cualidad del bloqueo y prolongar la duración de la analgesia. El objetivo de este trabajo fue comparar la eficacia de la asociación de clonidina, clonidina y fentanil y de fentanil a la lidocaína, en el tiempo de analgesia pós-operatoria.

MÉTODO: El estudio envolvió 64 pacientes con edad igual o superior a 23 años, estado físico I ó II (ASA), escalados para cirugía proctológica orificial, sometidos a anestesia peridural sacral. Los pacientes fueron distribuidos en 4 grupos de 16: grupo I (lidocaína aislada), grupo II (lidocaína y fentanil), grupo III (lidocaína, fentanil y clonidina) y grupo IV (lidocaína y clonidina). Se compararon las características de los bloqueos sensitivo y motor.

RESULTADOS: No hubo diferencia entre la latencia, bien como en el nivel máximo de bloqueo entre los grupos. La ausencia de bloqueo motor fue el resultado más frecuente, encontrado en cerca de 64% de los pacientes. El intervalo de analgesia fue diferente entre los grupos, siendo más significativo en el grupo III.

CONCLUSIONES: El uso de la clonidina, asociada o no al fentanil, prolongó el tiempo de analgesia pós-operatoria en la anestesia peridural sacral con lidocaína.

INTRODUCTION

Regional anesthesia for short procedures should be limited to surgery length, thus preventing its effects to go beyond the time needed for the procedure itself. On the other hand, it is desirable for analgesia to be maintained in the postoperative period. The search for higher quality when the aim is to reversibly intervene with nervous action potential conduction, has led to the use of associations of substances such as opioids and a₂ agonists to local anesthetics for different blockades, be them peripheral^1,2, spinal or epidural^3-7, to increase postoperative analgesia length and shorten onset after anesthetic administration. Caudal epidural space has been used as anesthetic route since Sicard and Cathelin, working independently, have used the sacrococcigeal hiatus for this aim in 1901⁸. The technique has become popular in 1940 when it was used for labor analgesia. It is an easy route, which can be used for orificial proctologic surgeries. Morphine has been associated to local anesthetics in epidural and spinal anesthesia, but its major inconvenient is to induce respiratory depression. One alternative has been more liposoluble opioids, such as fentanyl and sufentanil.

This study aimed at determining whether there are differences in analgesia length after the association of clonidine and fentanyl to lidocaine.

METHODS

After the Ethics Committee approval, participated in this randomized double-blind study 64 patients aged 23 years or above, physical status ASA I or II, scheduled for orificial proctologic surgeries. In addition to patients' refusal, exclusion criteria were neurological, cardiopulmonary, liver-kidney and psychiatric diseases. Patients were randomly distributed in four groups of 16, namely group I (lidocaine alone), group II (lidocaine and fentanyl), group III (lidocaine, fentanyl and clonidine), and group IV (lidocaine and clonidine).

Patients were monitored in the operating room with mercury column sphygmomanometer (Omron, model 12-605), periodically tested and duly gaged (noninvasive method) for systolic (SBP) and diastolic (DBP) blood pressure measurement, pulse oximetry for SpO₂ measurement and continuous ECG at CM₅ lead. Then, they were placed in the prone position with a pad under the pubic region. After venoclysis with 20G catheter, lactated Ringer's infusion was started and caudal epidural block was induced after sacral hiatus identification, with 25 x 7 needle without previous skin and subcutaneous infiltration. Administered volume after aspiration was always 20 mL, being 16 mL of 2% lidocaine with vasoconstrictor to all groups and the remaining solution being completed as follows: group I - 4 mL distilled water; group II - 2 mL distilled water and 2 mL = 100 µg fentanyl; group III - 2 mL = 100 µg fentanyl and 2 mL = 150 µg clonidine; group IV - 2 mL distilled water and 2 mL = 150 µg clonidine.

Solutions were prepared by one anesthesiologist and administered by a different anesthesiologist blind to the association. A third anesthesiologist blind to the group patients belonged to evaluated data.

Surgical analgesia length was defined as time elapsed between epidural injection and first spontaneous pain complaint leading to non steroid analgesic prescription.

Onset was defined as time elapsed between end of epidural injection and lack of pain evaluated by pinprick in the sensory area corresponding to S₄, S₅.

Blockade level was defined as the highest level with no response to pinprick after three successive stimulations at 2-minute intervals.

Motor block intensity was evaluated on lower limbs at surgery completion by modified Bromage's scale:

0 - no blockade;

1 - partial blockade - active leg bending;

2 - partial blockade - active feet bending only;

3 - total blockade - no limb movement.

Analysis of Variance followed by Newman-Kels test was used for statistical comparison of means of all groups. Non-parametric measurements were compared by Mode for maximum sensory block level.

RESULTS

Demographics data are shown in table I.

Brazilian Journal of Anesthesiology, 2004; 54: 4: 501 - 505

Epidural caudal block: evaluation of length of analgesia with the association

of lidocaine, fentanyl and clonidine

Carlos Alberto de Souza Martins; Pedro Wanderley de Aragão;

João de Oliveira Prazeres; Mahiba Mattar Rahbani de Souza Martins

Analgesia onset evaluated by pinprick and highest sensory block level are shown in table II. There have been no differences in onset and maximum sensory block among groups.

Brazilian Journal of Anesthesiology, 2004; 54: 4: 501 - 505

Epidural caudal block: evaluation of length of analgesia with the association

of lidocaine, fentanyl and clonidine

Carlos Alberto de Souza Martins; Pedro Wanderley de Aragão;

João de Oliveira Prazeres; Mahiba Mattar Rahbani de Souza Martins

Figure 1 shows that 0 blockade level has been the most frequent, found in approximately 64% of patients.

Brazilian Journal of Anesthesiology, 2004; 54: 4: 501 - 505

Epidural caudal block: evaluation of length of analgesia with the association

of lidocaine, fentanyl and clonidine

Carlos Alberto de Souza Martins; Pedro Wanderley de Aragão;

João de Oliveira Prazeres; Mahiba Mattar Rahbani de Souza Martins

Table III shows that there were differences among groups in analgesic length. Group III has shown prolonged analgesia as compared to other groups. Groups II and IV were not significantly different as compared to group I.

Brazilian Journal of Anesthesiology, 2004; 54: 4: 501 - 505

Epidural caudal block: evaluation of length of analgesia with the association

of lidocaine, fentanyl and clonidine

Carlos Alberto de Souza Martins; Pedro Wanderley de Aragão;

João de Oliveira Prazeres; Mahiba Mattar Rahbani de Souza Martins

DISCUSSION

There were no statistically significant differences among groups in onset, different from other studies where epidural fentanyl associated to lidocaine has shortened blockade onset⁹. Lack of motor block was the most frequent result, found in approximately 64% of patients. Analgesia duration was longer when clonidine and fentanyl were associated to lidocaine, but this increase was not significant for the group receiving lidocaine and fentanyl, in disagreement with some results found in the literature where there has been prolonged analgesia^5,10. Our results have shown that clonidine, associated or not to fentanyl, prolongs epidural lidocaine effects, being however statistically significant only for group III. Clonidine associated to local anesthetics has been increasingly used to improve blockade quality and manage pain. Clonidine induces spinal and supraspinal analgesia¹¹ via a₂-adrenergic receptors, in addition to a direct inhibitory effect on pain peripheral conduction pathways (A delta and C). There have been no side effects, such as hypotension, bradycardia and sedation in all groups.

With the methodology used in this study the authors concluded that clonidine associated or not to fentanyl, has prolonged postoperative analgesia after caudal epidural blockade with lidocaine.

REFERENCES

Submitted for publication May 30, 2003

Accepted for publication November 6, 2003

• 01. Culebras X, Van Gessel E, Hoffmeyer P et al - Clonidine combined with a long acting local anesthetic does not prolong postoperative analgesia after brachial plexus block but does induce hemodynamic changes. Anesth Analg, 2001;92:199-204.
• 02. Tschernco EM, Klepetko H, Gruber E et al - Clonidine added to the anesthetic solution enhances analgesia and improves oxygenation after intercostals nerve block for thoracotomy. Anesth Analg, 1988;87:107-111.
• 03. Lee JJ, Rubin AP - Comparison of a bupivacaine-clonidine mixture with plain bupivacaine for caudal analgesia in children. Br J Anaesth, 1994;72:258-262.
• 04. Rucci FS, Cardamone M, Migliori P - Fentanyl and bupivacaine mixtures for extradural blockade. Br J Anaesth, 1985;57: 275-284.
• 05. Constant I, Gall O, Gouyet L et al - Addition of clonidine or fentanyl to local anesthetics prolongs the duration of surgical analgesia after single shot caudal block in children. Br J Anaesth, 1998;80:294-298.
• 06. Mogensen T, Eliasen K, Ejlersen E et al - Epidural clonidine enhances postoperative analgesia from a combined low-dose epidural bupivacaine and morphine regimen. Anesth Analg, 1992;75:607-610.
• 07. Ben-David B, Solomon E, Levin H et al - Intrathecal fentanil with small-dose dilute bupivacaine: better anesthesia without prolonging recovery. Anaesth Analg, 1997;85:560-565.
• 08. Dripps RD, Eckenhoff JE, Vandam LD - Introduction to Anesthesia The Principles of Safe Practice, 7^th Ed, Philadelphia, W.B.Saunders Company, 1988;236.
• 09. Cherng CH, Wong CS, Ho ST - Epidural fentanyl speeds the onset of sensory block during epidural lidocaine anesthesia. Reg Anesth Pain Med, 2001;26:523-526.
• 10. Rucci FS, Cardamone M, Migliori P - Fentanyl and bupivacaine mixtures for extradural blockade. Br J Anaesth, 1985;57: 275-284.
• 11. Eisenach JC, De Kock M, Klimscha W - Alpha₂-adrenergic agonists for regional anesthesia. A clinical review of clonidine (1984-1995). Anesthesiology, 1996;85:655-674.

*

Received from Clínica de Proctologia da Universidade Federal do Maranhão (UFMA), São Luís, MA

Publication Dates

• Publication in this collection
  22 Sept 2004
• Date of issue
  Aug 2004

History

• Accepted
  06 Nov 2003
• Received
  30 May 2003