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

Postoperative Pain Clinical Trial

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01337115
• Other study ID #: TA 007/11(004-DEFI/007-CES)
• Status: Completed
• Phase: N/A
• First received: April 15, 2011
• Last updated: May 17, 2012
• Start date: April 2011
• Est. completion date: March 2012

Study information

• Verified date: May 2012
• Source: Centro Hospitalar do Porto
• Contact: n/a
• Is FDA regulated: No
• Health authority: Portugal: Ethics Committee for Clinical Research
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 50
• Est. completion date: March 2012
• Est. primary completion date: February 2012
• Accepts healthy volunteers: No
• Gender: Both
• Age group: N/A and older

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Pain, Postoperative
• Postoperative Pain

Intervention

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
• 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

Locations

Country	Name	City	State
Portugal	Centro Hospitalar do Porto, Serviço de Anestesia	Porto

Sponsors (2)

Lead Sponsor	Collaborator
Centro Hospitalar do Porto	Universidade do Porto

Country where clinical trial is conducted

Portugal, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Visual Analogue Scores (VAS) - Pain Scores Measured in mm (0-100)	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	15-30 min after arrival on post anesthesia care unit (PACU)	No
Primary	VAS Results - Pain Measured in mm (0-100)	VAS pain scores are measured by blinded investigators 12h after surgery .; VAS scale: 0 - no pain 100 - worst possible pain	12h after surgery	No
Primary	VAS Results - Pain Scores Measured in mm (0-100)	VAS pain scores are measured by blinded investigators 24h after surgery .; VAS scale: 0 - no pain 100 - worst possible pain	24h after surgery	No
Secondary	Satisfaction With Anesthesia Technique in Each Arm of the Study	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	1 month after surgery	No