Extended three-in-one block versus intravenous analgesia for postoperative pain management after reconstruction of anterior cruciate ligament of the knee

Abstracts

JUSTIFICATIVA E OBJETIVOS: O bloqueio femoral contínuo (3-em-1) é usado para a analgesia pós-operatória de artroplastia de quadril e joelho com bons resultados, apresentando vantagens sobre outras técnicas de analgesia locorregional ou sistêmica e com baixa incidência de complicações. O objetivo deste estudo foi avaliar clinicamente a utilidade do bloqueio femoral contínuo em comparação com a analgesia por via venosa na reconstrução do ligamento cruzado anterior. MÉTODO: Foi realizado um estudo prospectivo, controlado, com 60 pacientes com estado físico ASA I. Os paciente foram divididos em dois grupos: Grupo 1 (n = 30): bloqueio femoral contínuo com infusão de bupivacaína e clonidina; Grupo 2 (n = 30): infusão por via venosa de cetoprofeno. A intervenção cirúrgica foi realizada sob raquianestesia e sedação. O tratamento da dor pós-operatória foi feito com analgesia controlada pelo paciente (PCA) usando morfina. A dor pós-operatória foi registrada 2, 4, 6, 24 e 36 horas após a intervenção cirúrgica usando a Escala Visual Analógica (VAS). O consumo de morfina, a satisfação dos pacientes e as complicações também foram registradas. RESULTADOS: No Grupo 1, o VAS pós-operatório entre 4 e 48 horas após a intervenção cirúrgica foi de 21 mm ± 2 e no Grupo 2 foi de 45 mm ± 4 (p < 0,001). O uso de morfina no período de 4 a 48 horas no Grupo 1 foi de 4,5 mg ± 1,5 e no Grupo 2 foi de 25,5 mg ± 3 (p < 0,001). No Grupo 1, 6,7% dos pacientes apresentaram náusea ou vômito no pós-operatório (NVPO) comparado com 20% no Grupo 2. CONCLUSÕES: O bloqueio 3-em-1 com bupivacaína e clonidina em infusão contínua forneceu analgesia mais eficaz, maior satisfação do paciente, reduziu o consumo de morfina por via venosa e apresentou menor incidência de NVPO do que a analgesia sistêmica.

ANALGESIA, Regional; CIRURGIA, Ortopédica

SCIENTIFIC ARTICLE

Extended three-in-one block versus intravenous analgesia for postoperative pain management after reconstruction of anterior cruciate ligament of the knee^*

Bloqueo 3 en 1 prolongado versus analgesia sistemica en el tratamiento del dolor postoperatorio después de la reconstrucción del ligamento cruzado anterior de la rodilla

Víctor A. Contreras-Domínguez^I; Paulina E. Carbonell-Bellolio^II; Álvaro C. Ojeda-Greciet^III; Edgardo S. Sanzana^IV

^IProfessor Assistente de Anestesiologia, Facultad de Medicina, Universidad de Concepción

^IIAnestesiologista, Departamento de Anestesiología, Hospital Traumatologico de Concepción

^IIICirurgião Ortopédico, Departmento de Cirugía Ortopédica, Hospital Traumatologico de Concepción

^IVInstrutor de Cirurgia Ortopédica, Facultad de Medicina, Universidad de Concepción

^{Correspondence to}

SUMMARY

BACKGROUND AND OBJECTIVES: Continuous femoral block (three-in-one) is used for postoperative analgesia in hip and knee replacements with good results, with advantages over other locoregional analgesic or intravenous techniques having low incidence of complications. The aim of this study was to clinically evaluate the utility of continuous femoral block compared with intravenous analgesia in reconstruction of anterior cruciate ligament.

METHODS: Controlled prospective study of 60 patients ASA I. Patients were divided into two groups: Group 1 (n = 30): continuous femoral block with an infusion of bupivacaine and clonidine; and Group 2 (n = 30): intravenous ketoprofen infusion. Surgery was performed under spinal anesthesia and sedation. Postoperative pain management with morphine patient controlled analgesia (PCA). Postoperative pain recorded at 2, 4, 6, 24 and 36 hours after surgery using Visual Analog Scale (VAS). Morphine consumption, satisfaction's score and complications are registered.

RESULTS: In Group 1 postoperative VAS between 4 and 48 hours was 21 mm ± 2 and in Group 2 was 45 mm ± 4 (p < 0.001). Morphine consumption between 4 and 48 hours in Group 1 was 4.5 mg ± 1.5 and in Group 2 was 25.5 mg ± 3 (p < 0.001). In Group 1, 6.7% of patients presented postoperative nausea or vomiting (PONV) compared to 20% in Group 2.

CONCLUSION: The three-in-one block with bupivacaine and clonidine in continuous infusion provides more efficient analgesia, patient satisfaction and less consumption of intravenous morphine and PONV than intravenous analgesia.

Key Words: ANALGESIA, Regional: three-in-one block, systemic; SURGERY, Orthopedic: anterior cruciate ligament reconstruction.

RESUMEN

JUSTIFICATIVA Y OBJETIVOS: El bloqueo femoral continuo (tres-en-uno) se usa para la analgesia postoperatoria de artroplastia de cadera y rodilla con buenos resultados, presentando ventajas sobre otras técnicas de analgesia loco regional o sistemica y con baja incidencia de complicaciones. El objetivo de este estudio fue el de evaluar clínicamente la utilidad del bloqueo femoral continuo en comparación con la analgesia intravenosa en la reconstrucción del ligamento cruzado anterior.

MÉTODOS: Se realizó un estudio prospectivo controlado con 60 pacientes de estado físico ASA I. Los pacientes fueron divididos en dos grupos: Grupo 1 (n = 30): bloqueo femoral continuo con infusión de bupivacaína y clonidina; y Grupo 2 (n =3 0): infusión intravenosa de cetoprofeno. La intervención quirúrgica se hizo bajo raquianestesia y sedación. El tratamiento del dolor postoperatorio se hizo con analgesia controlada por el paciente (PCA) usando morfina. El dolor postoperatorio fue registrada 2, 4, 6, 24 y 36 horas después de la intervención quirúrgica usando la Escala Visual Analógica (VAS). El consumo de morfina, la satisfacción de los pacientes y las complicaciones también fueron registrados.

RESULTADOS: En el Grupo 1, el VAS postoperatorio entre 4 y 48 horas trás de la intervención quirúrgica fue de 21 mm ± 2 y en el Grupo 2 fue de 45 mm ± 4 (p < 0.001). El uso de morfina en el período de 4 a 48 horas en el Grupo 1 fue de 4,5 mg ± 1,5 y en el Grupo 2 de 25,5 mg ± 3 (p < 0.001). En el Grupo 1, 6,7% de los pacientes presentaron náusea o vómito en el postoperatorio (NVPO) comparado con 20% del Grupo 2.

CONCLUSIONES: El bloqueo 3-en-1 con bupivacaína y clonidina en infusión continua suministró analgesia más eficaz, mayor satisfacción del paciente, redució el consumo de morfina intravenosa y presentó una menor incidencia de NVPO que la analgesia sistemica.

INTRODUCTION

Continuous femoral nerve block (CFB) has been used with good results as a postoperative analgesic technique in both hip and knee replacements ^1-3, in skin grafting in burned patients ⁴, considering all the advantages and low side effects compared with other locoregional analgesic techniques or intravenous (IV) infusions ^5,6.

CFB is an excellent alternative to epidural analgesia (EA) or patient controlled analgesia (PCA) intravenous opioids in acute pain relief in major orthopedic surgery ⁷. This technique also avoids complications such as epidural bleeding that can be produced in patients undergoing low molecular-weight heparin treatment ⁸.

The continuous infusion of local anesthetics (LA) can produce systemic side effects such as confusion, hypotension, hypoxia, arrhythmias, convulsions and coma. However, with the use of CFB these complications are rare, due to the low concentrations of LA used and the low plasmatic level reached ⁹.

During EA is frequent to have hypotension, cardiorespiratory depression or neurological symptoms, especially when used in older or high risk patients. The CFB seems to be very advantageous over EA ¹⁰.

Postoperative pain after anterior cruciate ligament (ACL) reconstruction is moderate to severe in 89% of the patients. The administration of preemptive analgesics (i.e. ketorolac 60 mg IV) or intrarticular LA (bupivacaine 1 mg.kg^-1) in association with postoperative oral analgesia ¹¹ doesn't change pain scores.

The aim of this study was to clinically evaluate the efficacy of the continuous femoral block compared with intravenous analgesia in reconstruction of anterior cruciate knee ligament under arthroscopic assistance.

METHODS

After informed written consent and with institutional approval of the ethics committee, 60 ASA physical status I patients scheduled for elective unilateral reconstruction of anterior cruciate knee ligament (ACL), assisted by arthroscopy under spinal anesthesia were included in this study.

We included patients aged between 18 and 51 years old, with a body mass index (BMI) < 30. Patients were excluded for the following reasons: if they had coagulation abnormality, LA allergy, local infection, preexisting neurological deficit, hypertension, diabetes, hepatic or kidney diseases, chronic treatment with alpha₂-agonists (clonidine), or if they were unable to understand pain scales or the use of a PCA device.

Patients were then randomly divided into two groups of 30 patients each, where Group 1 received a continuous infusion of bupivacaine 0.125 % plus clonidine 1 µg.mL^-1 at the rate of 10 mL.h^-1 by a femoral catheter during postoperative period, and Group 2 received a continuous intravenous (IV) infusion of ketoprofen at a dose of 300 mg in 24 hours.

In all patients of Group 1, 3-in-1 block was performed before spinal anesthesia by using the landmarks of Winnie et al. ¹². The femoral artery was located below the inguinal ligament, and an 18G short-beveled cannula (Polyplex^® C 50, Polymedic, Carneres sur Seine, France) was inserted just lateral to the artery. The femoral nerve was accurately located with a peripheral nerve stimulator (TOF Watch S^®, Organon, Ireland). With a starting output of 1.5 mA, the needle was advanced under intermittent aspiration at an angle of 30° to 45° to the skin until twitches of the quadriceps muscle (ascension of the patella) were elicited.

Its position was then optimized and judged adequate when output lower than 0.4 mA still elicited contraction of the quadriceps. A 20G catheter was then inserted using a Seldinger technique and threaded 12 cm into the femoral nerve sheath. After a negative aspiration test for blood, the catheter was fixed.

All patients of both groups received spinal anesthesia. Lumbar puncture was performed at L₃—L₄ or L_4—L₅ interspace with a 25G pencil point needle and 12.5 mg of 0.75% hyperbaric bupivacaine with 2.5 µg sufentanyl were administered. In all patients sedation during surgery was provided by a target-controlled-infusion (TCI) of propofol 1% (Base Primea Orchestra^®, Fressenius-Vial, France). As well, all patients received 30 mg of intravenous ketorolac before pneumatic ischemia was started, and then, three times daily during the first 48 hours postoperatively.

In the recovery room, the correct positioning of the femoral nerve sheath catheter was confirmed by an injection of 10 mL bupivacaine 0.125% plus 1 µg.mL^-1 of clonidine. Loss of temperature sensation (sensory block) was assessed by using an ether-soaked swab involving the distribution of the femoral nerve (anterior aspect of the thigh). After this test, the PMP pump (Abbott Laboratories, USA) was started with a solution of bupivacaine 0.125% plus clonidine 1 µg.mL^-1 at the rate of 10 mL.h^-1 (Group 1). Patients in Group 2 received IV continuous analgesia with 300 mg of ketoprofen in 24 hours. Supplemental analgesia was standardized by the administration of IV PCA morphine (bolus 1.5 mg, lockout time 10 minutes, security range 20 mg in 4 hours).

Immediately after recovery room discharge, all patients started identical pharmacological therapy (antibiotics, low molecular-weight heparin) and kinetic assistance with a passive motion machine that was applied 8 hours after discharge.

Pain was measured by visual analog scale (VAS, ranging from 0 = no pain to 100 = worst pain imaginable) and recorded at 2, 6, 12, 24, 36 and 48 hours after surgery.

Side effects, morphine consumption and satisfactory scores (by using a VAS rating from 0 = not satisfied to 100 = entirely satisfied) at the end of the study period were recorded.

All data were collected by other anesthesiologists not involved in the anesthetic procedure or in the patient care in the recovery room.

A power analysis suggested that 15 patients would need to be enrolled in the study groups to observe at least 50% reduction in the VAS scores between the IV continuous analgesia and the femoral block group to provide a 95% chance of detecting such a reduction at the 0.01 level of significance. To improve the clinical significance of our results, we decided to include 30 patients in each group. Statistical analysis was performed by using a one-way analysis of variance followed by a Bonferroni t-test, for the parametric data. The PCA morphine demands were analyzed with a Kruskal-Wallis test. Demographic data were compared by using Chi-square test. Values of p < 0.05 were considered significant. Results are expressed as mean ± SD.

RESULTS

Demographic data are presented in table I. No difference was noted among the groups. In the recovery room, complete loss of temperature sense in the distribution of the femoral nerve was observed in all patients of Group 1.

The VAS Scores at 2, 4, 6, 24, 36 and 48 postoperative hours, morphine consumption, incidence of nausea and vomiting (PONV) and satisfaction score at 48 h are presented in table II.

Pain score at 4, 6, 24, 36 and 48 hours were significantly lower in Group 1 compared with Group 2 (p < 0.001 and p < 0.01). When compared with Group 1, morphine consumption was significantly higher in Group 2 (p < 0.001).

The satisfaction Score was lower than 60 points in Group 2, and higher than 80 points in Group 1 (p < 0.05).

The incidence of PONV in Group 1 was significantly lower than Group 2 (p < 0.01).

In Group 1 femoral nerve block was well maintained during the entire study period. Except for PONV, no other side effects or technical problems were noted in the two groups.

DISCUSSION

This prospective, randomized trial showed that femoral nerve block with bupivacaine and clonidine in continuous infusion delivery system provides more efficient analgesia, highest patient satisfaction, lowest pain scores and consumption of intravenous morphine and lower incidence of PONV than intravenous analgesia.

The reconstruction of ACL based on "bone-tendon-bone" technique (autologous grafting of patellar tendon) is highly recommended in young sportsman patients because of its major biomechanical resistance and good functional results observed in long term series.

The management of postoperative pain after ACL reconstruction has been developed by the intravenous analgesia (continuous or PCA techniques), intra-articular analgesia (IA), epidural analgesia (EA) and femoral nerve block (three-in-one block), either with single shot or with continuous administration.

The IV analgesia in patients undergoing either general or regional anesthesia is commonly associated with high consumption of intravenous morphine, high incidence of nausea and postoperative vomiting (PONV) and low patient's satisfaction scores ¹³. This is corroborated in this series of 60 patients, where IV analgesia group has higher pain scores, morphine consumption, PONV incidence and less satisfaction scores compared to the "three-in-one" block group (p < 0.001). The role of other analgesic intravenous drugs may be interesting in the management of patients undergoing orthopedic surgery under general anesthesia. The administration of small doses of ketamine in the perioperative period reduces postoperative morphine requirements and improves mobilization 24 hours after arthroscopic anterior ligament repair ^13,14. This interesting strategy could be important to be used in association with intravenous analgesia. In this experience, the postoperative morphine consumption and the incidence of PONV were significantly higher in the intravenous Group than in the "three-in-one" block Group.

The epidural analgesia provides good postoperative analgesia, but increases the incidence of adverse effects such as hypotension, bilateral motor and sensory block and urinary retention. Problems associate with the management of the epidural catheter and the risk of epidural hematoma in patients undergoing anticoagulant therapy reduces its use ⁸.

Chew et al. ¹⁵ demonstrated the utility of infrapatelar compartment continuous infusion of bupivacaine 0.25 or 0.5%. Branson et al. ¹⁶ used diluted intrarticular (IA) morphine (2 or 5 mg) with good analgesic results in the first 24 hours. After this period, the pain increased and the kinetic therapy resulted difficult. The IA technique is limited to management of postoperative pain in major knee surgery because its utility is restricted to the first 24 hours after injection. In this study, especially in the three-in-one group, the pain scores were adequate for these patients.

The continuous infusion of 0.125% of bupivacaine at the rate of 0.14 mL.kg^-1.h^-1 is considered a very good choice to maintain the extended "three-in-one" block ¹⁷. In the management of postoperative pain after total knee arthroplasty, the continuous infusion or patient-controlled techniques for "three-in-one" block were efficient ¹⁸. However, the "three-in-one" technique leads to the administration of large volumes of local anesthetic with a potential risk of toxicity caused by accumulation of the drug after prolonged periods of infusion ¹⁹.

Edkin et al. ²⁰ showed the utility of a single-shot dose in femoral block to reduce the postoperative pain in patients with ACL reconstruction. In this study, 92% of the patients did not require supplemental IV morphine during the first 24 hours. In 1.200 consecutive cases of complex surgery of knee, William et al. ²¹ showed that the use of femoral-sciatic nerve blocks for complex outpatients' knee surgery was associated with less postoperative pain before same-day discharge and with few hospital admissions. The use of nerve blocks for acute pain management in patients undergoing anterior cruciate ligament reconstruction is associated with post anesthesia care unit (PACU) bypass and reliable same-day discharge. Although the cost savings via staffing reductions, extrapolating the results to a large volume of all type of invasive outpatients orthopedic procedures may have the potential to create significant hospital cost saving ²². In this study, the pain scores obtained in the "three-in-one" block Group were lower than those obtained by the intravenous continuous analgesia Group (p < 0.001).

In a series of 211 femoral nerve catheters that were placed using aseptic technique, Cuvillon et al. ²³ removed the catheters after 48 hours and semi-quantitative bacteriological culture was performed on each distal catheter tip. In this study, 57% of catheters had positive bacterial colonization. Accordingly to these results, in this series was maintained the femoral nerve sheath catheters in place only for the first 48 postoperative hours.

In accordance with the concept of balanced analgesia ²⁴, IV ketorolac was administrated to all patients before starting surgery, and clonidine was added in continuous infusion "three-in-one" block Group.

The addition of clonidine to local anesthetic solutions prolongs duration of anesthesia and analgesia after a single-shot brachial plexus block ²⁵, but does not affect postoperative pain when given as a sole analgesic ²⁶. The mechanism of action of clonidine on peripheral nerves is unknown. Actually, three mechanisms of action may be proposed: local vasoconstriction of peripheral nerves by activation of postsynaptic adrenergic receptors ²⁷ which lead to a decrease in the systemic absorption of the local anesthetic. In second place, clonidine may have a local anesthetic activity. Its topic application on the rabbit cornea results in 140 times more potent as a surface anesthetic compared to procaine ²⁸. In vivo, this hypothesis has not yet been proved ²⁷. Finally, clonidine may have a potentiating effect on local anesthetics ²⁹. Recently, Mannion et al. ³⁰ demonstrated that intravenous but not perineural clonidine prolongs postoperative analgesia after psoas compartment block with levobupivacaine in patients with hip fractures. Even though all this controversies, literature evidences a benefit in the addition of clonidine to low concentrations of local anesthetic solutions for postoperative pain management in continuous peripheral nerve blocks ^2,14. For this reason, was added clonidine in a concentration dose of 1 µg.mL^-1 to bupivacaine 0.125% in "three-in-one" block continuous infusion.

In this study, there were no complications attributed to the use of "three-in-one" block or intravenous analgesia techniques.

In conclusion, this prospective, randomized trial confirms that extended "three-in-one" block with bupivacaine and clonidine in continuous infusion delivery system provides more efficient analgesia after reconstruction of ACL of the knee, better patient satisfaction scores and less consumption of intravenous morphine, with low incidence of PONV compared with intravenous analgesia.

REFERENCES

Submitted em 19 de maio de 2006

Accepted para publicação em 2 de fevereiro de 2007

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*

Received from Departmento de Anestesiología e Cirugía Ortopédica, Facultad de Medicina, Universidad de Concepción, Concepción, Chile

Publication Dates

• Publication in this collection
  10 May 2007
• Date of issue
  June 2007

History

• Received
  19 May 2006
• Accepted
  02 Feb 2007