Effect of a Sciatic Block (SNB) Combined With a Continuous Femoral Block (CFNB) on Pain Scores After Knee Arthroplasty

• ClinicalTrials.gov Identifier: NCT01337115
• Recruitment Status: Completed
• First Posted: April 18, 2011
• Results First Posted: June 19, 2012
• Last Update Posted: June 19, 2012
• Sponsor: Centro Hospitalar do Porto
• Collaborator: Universidade do Porto
• Information provided by (Responsible Party): Raul Carvalho, Centro Hospitalar do Porto

Study Description

Brief Summary:

The purpose of this study is to determine if the addition of a sciatic nerve block (SNB) to a continuous femoral nerve block (CFNB) improves post-operative analgesia after knee arthroplasty.

Condition or disease	Intervention/treatment	Phase
Postoperative Pain	Procedure: SNB plus CFNB; Procedure: CFNB	Not Applicable

Detailed Description:

Background: Postoperative pain after total knee replacement /arthroplasty (TKA) is a major concern. It is severe pain in 60% of patients and moderate in 30%. Continuous femoral nerve blocks (CFNB) are considered an excellent choice for regional anesthesia for major knee repair but there are some controversies about the need of supplemental obturator or sciatic nerve blocks for achieving better postoperative analgesia. A recent meta-analysis states there is no sufficient evidence to recommend or discharge these associations.

Objectives: We aim to assess the efficacy of the association of a sciatic nerve block (SNB) and a continuous femoral nerve block (CFNB) for reducing postoperative pain in patients submitted to TKA. Methods: A randomized controlled study on 50 patients submitted to TKA. Control group receives a femoral nerve block with a catheter before general anesthesia is induced and the intervention group gets a similar block plus a single shot SNB before general anesthesia. Both groups start a continuous local anesthetic infusion through femoral catheter after the end of surgery and supplemental oral diclofenac and paracetamol. Pain scores are measured until 24h postoperatively, side effects and patient satisfaction are monitored.

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 50 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Double (Investigator, Outcomes Assessor)
• Primary Purpose: Treatment
• Official Title: Effect of a Single Shot Sciatic Nerve Block (SNB) Combined With a Continuous Femoral Block (CFNB) on Pain Scores After Knee Arthroplasty. A Randomized Controlled Trial
• Study Start Date: April 2011
• Actual Primary Completion Date: February 2012
• Actual Study Completion Date: March 2012

Arms and Interventions

Arm	Intervention/treatment
Active Comparator: Continuous femoral nerve block (CFNB); A continuous femoral nerve block is performed for peri-operative analgesia and a bolus of 30 ml of ropivacaine 0.375% is injected before induction of general anesthesia and surgery starts. An infusion of 8ml/h of ropivacaine 0.2% is started in post anesthesia care unit (PACU) and maintained for 48h	Procedure: CFNB; A continuous femoral nerve block is performed for peri-operative analgesia and a bolus of 30 ml of ropivacaine 0.375% is injected before induction of general anesthesia and surgery starts. An infusion of 8ml/h of ropivacaine 0.2% is started in post anesthesia care unit (PACU) and maintained for 48h; Other Names: Peripheral nerve blocks; Local anesthetics; Ropivacaine; Femoral nerve block
Experimental: Single shot SNB plus CFNB; A single shot sciatic nerve block (SNB) is performed before surgery with 25ml of 0.2% ropivacaine in addition to the continuous femoral nerve block (CFNB) performed in the control group before induction of general anesthesia and surgery starts. An infusion of 8ml/h of ropivacaine 0.2% is started in Post anesthesia care unit (PACU) and maintained for 48h	Procedure: SNB plus CFNB; A single shot sciatic nerve block (SNB) is performed with 25 ml of 0.2% ropivacaine before surgery in addition to an isolated continuous femoral nerve block (CFNB) in the control group; Other Names: Peripheral nerve blocks; Local anesthetics; Ropivacaine; Femoral nerve block; Sciatic nerve block

Outcome Measures

Primary Outcome Measures :

1. Visual Analogue Scores (VAS) - Pain Scores Measured in mm (0-100) [ Time Frame: 15-30 min after arrival on post anesthesia care unit (PACU) ]
   Pain scores measured by Visual Analogue Score (VAS) scale at 15-30min after Post anesthesia care unit (PACU) arrival VAS is a 100mm scale to measure pain. 0mm - no pain 100mm - worst possible pain
2. VAS Results - Pain Measured in mm (0-100) [ Time Frame: 12h after surgery ]

   VAS pain scores are measured by blinded investigators 12h after surgery .

   VAS scale:

   0 - no pain 100 - worst possible pain

3. VAS Results - Pain Scores Measured in mm (0-100) [ Time Frame: 24h after surgery ]

   VAS pain scores are measured by blinded investigators 24h after surgery .

   VAS scale:

   0 - no pain 100 - worst possible pain

Secondary Outcome Measures :

1. Satisfaction With Anesthesia Technique in Each Arm of the Study [ Time Frame: 1 month after surgery ]

   Satisfaction with the anesthesia technique using a categorical scale with three levels:

   Bad Reasonable Good/Very Good A Fisher's Exact test is made to asses any differences in the distribution of patients in each arm to each level of the categorical scale

Eligibility Criteria

• Ages Eligible for Study: Child, Adult, Older Adult
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Criteria

Inclusion Criteria:

• Unilateral total knee replacement

Exclusion Criteria:

• Contra-indication for general anesthesia
• Infection on puncture site
• Coagulation disorders
• Pre-existent neuropathies
• Allergies to local anesthetics, paracetamol, diclofenac and tramadol
• Severe dyspepsia
• Less than 50kg weigh
• Body Mass Index (BMI) greater than 40
• American Society of Anesthesiologists (ASA) Physical Status 4 or 5
• Absence of capacity to use the Visual Analog Score (VAS) scale
• Refusal to give informed consent

Contacts and Locations

Locations

Portugal

Centro Hospitalar do Porto, Serviço de Anestesia

Porto, Portugal, 4099-001

Sponsors and Collaborators

Centro Hospitalar do Porto

Universidade do Porto

Investigators

• Principal Investigator: Raul MS Carvalho, MD; Centro Hospitalar do Porto

More Information

• Responsible Party: Raul Carvalho, Anesthesiology Consultant, Centro Hospitalar do Porto
• ClinicalTrials.gov Identifier: NCT01337115
• Other Study ID Numbers: TA 007/11(004-DEFI/007-CES)
• First Posted: April 18, 2011
• Results First Posted: June 19, 2012
• Last Update Posted: June 19, 2012
• Last Verified: May 2012

Keywords provided by Raul Carvalho, Centro Hospitalar do Porto:

Postoperative pain; Knee arthroplasty; Peripheral nerve blocks; Sciatic nerve block; Femoral nerve block

Additional relevant MeSH terms:

Pain, Postoperative; Postoperative Complications; Pathologic Processes; Pain; Neurologic Manifestations; Ropivacaine; Anesthetics, Local; Anesthetics; Central Nervous System Depressants; Physiological Effects of Drugs; Sensory System Agents; Peripheral Nervous System Agents