Saphenous Nerve Block: Single Shot Versus Continuous Infusion to Supplement a Continuous Sciatic Nerve Block After Major Ankle Surgery

A Randomized Comparison of Single Injection vs. Continuous Saphenous Nerve Block to Supplement a Continuous Sciatic Nerve Block in Postoperative Pain Treatment After Major Ankle Surgery: Clinical Outcome and Cost Analysis

The most useful method to manage pain after major ankle surgery is infusion of local analgesics with a catheter close to the sciatic nerve.

Sensation from the ankle are carried by three nerves: The tibial and peroneal nerve (unified in the sciatic nerve) and the saphenous nerve.

Study purpose is to test whether continuous infusion of local analgesics by saphenous nerve catheter provide a better treatment of pain in comparison with a single injection nerve block. In addition cost-effectiveness of the two methods are compared.

The 50 patients of the trial are randomized in clusters of ten. We intend to do a preliminary analysis of the data from the first 40 patients. However, it is not an interim analysis. Fifty patients will be included independent of the result of the preliminary analysis. The random allocation of the last 10 patients will also be double-blinded.

Study Overview

• Status: Completed
• Conditions: Major Ankle Surgery
• Intervention / Treatment: Procedure: Continuous saphenous nerve block; Procedure: Placebo

Detailed Description

Major ankle surgery are known to be very painful the first 48 hours after the operation due to surgical oedema. This pain is difficult to control with systemic analgesics. Pain relief with systemic analgesics requires high doses of intravenous opioids and is associated with breakthrough pain and adverse effects of opioids (sedation, nausea, vomiting, obstipation, urinary retention, respiratory depression).

Continuous, peripheral nerve block with catheter technique for two days minimizes the need for systemic analgesics. Today such a continuous sciatic nerve block is part of the standard pain treatment after major ankle surgery on Aarhus University Hospital. Despite accurate placement of the catheter many patients are in great pain because the saphenous nerve remain unaffected. A single injection block relieve the pain but a block with Ropivacaine only last 8-15 hours.

Severe postoperative pain leads to high opioid dosages, cognitive blurring, nausea, vomiting, reduced ambulation, increased surgical stress response and increased morbidity. Pain problems and adverse effects prolongs postoperative observation time and maybe also time to discharge.

The aim of the study establish whether continuous saphenous nerve block is efficient (pain relief or reduced opioid consumption) and justified (cost-effectiveness analysis) compared with single injection block.

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Aarhus, Denmark, 8000
    • Aarhus University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria: Elective major ankle surgery

• total ankle arthroplasty
• subtalar fusion
• ankle fusion (non arthroscopic)

Exclusion Criteria:

• coagulation abnormalities
• infection in the region of needle insertion
• systemic infection
• preoperative consumption of high dose opioid
• preoperative sciatic or femoral nerve neuropathy
• preoperative sensory deficit in either of the lower extremities
• Charcot-Marie-Tooth disorder
• diabetic neuropathy
• severe peripheral vascular disease
• allergy to local anesthetics
• lack of understanding of Numeric Rank Scale (NRS)
• communication problems
• dementia
• body mass index above 35
• bilateral continuous sciatic nerve block
• lack of consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: 0,2% Ropivacaine; Patients randomized to the experimental group receive a continuous infusion of 0,2 % Ropivacaine by elastomeric infusion pump at 5 ml/h in the saphenous catheter after major ankle surgery. Infusion for 48 postoperative hours. All patients receive a preoperative single shot of Ropivacaine around saphenous and sciatic nerve and a postoperative continuous sciatic nerve block.	Procedure: Continuous saphenous nerve block; 0,2% Ropivacaine by elastomeric infusion pump at 5 ml/h for 48 postoperative hours; Other Names: Naropin
Placebo Comparator: Control; Patients randomized to the control group receive a continuous infusion of isoton saline by elastomeric infusion pump at 5 ml/h in their catheter after major ankle surgery. Infusion for 48 postoperative hours. All patients receive a preoperative single shot of Ropivacaine around saphenous and sciatic nerve and a postoperative continuous sciatic nerve block.	Procedure: Placebo; Isoton saline by elastomeric infusion pump at 5 ml/h for 48 postoperative hours

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Accumulated opioid consumption	First 48 hours postoperative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Success rate for saphenous nerve analgesia	Pain rated by NRS and opioid consumption	Postoperative, first 48 hours
Success rate for clinical analgesia of foot and ankle	Pain rated by NRS and opioid consumption	Postoperative, first 48 hours
Success rate for tibial and peroneal nerve block	Pain rated by NRS and test of sensation on the toes	Postoperative, first 48 hours
Localisation of worst pain		Postoperative, first 48 hours
Cost-effectiveness		2 first postoperative days

Collaborators and Investigators

• Sponsor: University of Aarhus
• Collaborators: Aarhus University Hospital
• Investigators: Principal Investigator: Thomas F Bendtsen, ph.d., MD, Aarhus University Hospital

Publications and helpful links

General Publications

• Fisker AK, Iversen BN, Christensen S, Linde F, Nielsen KK, Borglum J, Bendtsen TF. Combined saphenous and sciatic catheters for analgesia after major ankle surgery: a double-blinded randomized controlled trial. Can J Anaesth. 2015 Aug;62(8):875-82. doi: 10.1007/s12630-015-0379-y. Epub 2015 Apr 8.

Study record dates

Study Major Dates

• Study Start: September 1, 2011
• Primary Completion (Actual): October 1, 2012
• Study Completion (Actual): October 1, 2012

Study Registration Dates

• First Submitted: September 29, 2011
• First Submitted That Met QC Criteria: September 30, 2011
• First Posted (Estimate): October 3, 2011

Study Record Updates

• Last Update Posted (Estimate): October 19, 2012
• Last Update Submitted That Met QC Criteria: October 18, 2012
• Last Verified: October 1, 2012

More Information

Terms related to this study

• Keywords: Postoperative pain; Ropivacaine; Saphenous nerve; Continuous nerve block; Major ankle surgery
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Anesthetics, Local; Ropivacaine
• Other Study ID Numbers: 2011-0184