Clinical trial NCT01445210: Saphenous Nerve Block: Single Shot Versus Continuous Infusion to Supplement a Continuous Sciatic Nerve Block After Major Ankle Surgery
Official title: 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
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Major Ankle Surgery
Keywords: Postoperative pain
Major ankle surgery
Continuous nerve block
Saphenous nerve
Ropivacaine
Lead sponsor: University of Aarhus
Sponsor class: OTHER
Collaborators: name: Aarhus University Hospital
First posted: 2011-10-03
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: 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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Accumulated opioid consumption
timeFrame: First 48 hours postoperative
Secondary outcomes:
measure: Success rate for saphenous nerve analgesia
timeFrame: Postoperative, first 48 hours
measure: Success rate for clinical analgesia of foot and ankle
timeFrame: Postoperative, first 48 hours
measure: Success rate for tibial and peroneal nerve block
timeFrame: Postoperative, first 48 hours
measure: Localisation of worst pain
timeFrame: Postoperative, first 48 hours
measure: Cost-effectiveness
timeFrame: 2 first postoperative days
Other outcomes:
Locations:
city: Aarhus
country: Denmark
facility: Aarhus University Hospital
Study officials:
affiliation: Aarhus University Hospital
name: Thomas F Bendtsen, ph.d., MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.