Intrathecal Diamorphine Versus Femoral Nerve Block in Primary Total Knee Arthroplasty

Randomised, Observer Blinded, Controlled Trial of Intrathecal Diamorphine Versus Femoral Nerve Block for Post-operative Analgesia Following Primary Total Knee Arthroplasty

Primary total knee arthroplasty (TKA) is commonly associated with moderate to severe early post-operative pain. The primary aim of this study was to investigate the impact of either a single-shot femoral nerve block (FNB) or intrathecal diamorphine (ID) on post-operative pain after TKA

The Null Hypothesis is that there is no difference in the post operative pain relief provided for TKA by a single-shot femoral nerve block (FNB) as compared to intrathecal diamorphine (ID).

Study Overview

• Status: Completed
• Conditions: Osteoarthritis
• Intervention / Treatment: Procedure: Femoral Nerve Block with levobupivicaine; Procedure: Intrathecal injection of diamorphine

Detailed Description

In 2008, the Prospect Working Group, a multidisciplinary expert panel, published their consensus guidelines on the relative merits of different anaesthetic and analgesic techniques for TKA based on a review of the available published literature up to 2005. These guidelines supported the use of general anaesthesia combined with a femoral nerve block for surgery and postoperative analgesia, or alternatively spinal anaesthesia with local anaesthetic combined with spinal morphine. The preference for femoral nerve block in favour of intrathecal opiates was as a consequence of the greater potential for side effects with the latter technique. The authors conceded that there were a lack of well-conducted studies on this subject, graded their recommendations as level D (expert opinion), and concluded further research was needed. Consequently there has been debate around the conclusions drawn and clinicians have not universally accepted the recommendations.

Most researchers to date have focused on short-term outcomes such as static pain scores and/or opiate consumption. It is also important however to investigate dynamic pain scores, patient reported outcomes, the attainment of rehabilitation goals, length of stay and longer term functional outcomes. In addition, the use of the total pain relief score (TOTPAR) as described by Cooper and Beaver, assesses the cumulative response to treatment. This is a well validated area under the time-analgesic effect curve (AUC) derivation for pain relief which is commonly used by meta-analyses of analgesic interventions. The aim of this study is to investigate all these endpoints in patients receiving a single-shot femoral nerve block (FNB) for TKA as compared to intrathecal diamorphine (ID), a more commonly used spinal opiate in United Kingdom anaesthetic practice.

• Study Type: Interventional
• Enrollment (Actual): 120
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Devon
    • Exeter, Devon, United Kingdom, EX1 2ED
      • Royal Devon and Exeter Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years and older (ADULT, OLDER_ADULT, CHILD)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Adult patients scheduled for primary unilateral Total Knee Arthroplasty

Exclusion Criteria:

• Uni-compartmental surgery, bilateral surgery, contra-indication to spinal anaesthesia or peripheral nerve block (anticoagulation, hydrocephalus, raised intracranial pressure), allergy to local anaesthetics or diamorphine, malignant hyperthermia or other concerns over general anaesthesia, chronic opiate use and chronic pain medication use (e.g. gabapentin, pregabalin, amitriptyline).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: SINGLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Femoral Nerve Block with levobupivicaine; A single injection femoral nerve block (FNB) was performed in the supine position with a 50mm insulated needle (NanoLine, Pajunk, Geisingen, Germany) and peripheral nerve stimulator set at 1Hertz (Hz) with pulse width 0.1ms. Once a quadriceps muscle twitch was identified at a stimulated current between 0.2 and 0.5milliamperes (mA), 20mls of 0.375% levobupivacaine (75mg) was injected in fractionated amounts after negative aspiration	Procedure: Femoral Nerve Block with levobupivicaine; A single injection femoral nerve block (FNB) performed in the supine position with a 50mm insulated needle (NanoLine, Pajunk, Geisingen, Germany) and peripheral nerve stimulator set at 1Hz with pulse width 0.1ms. Once a quadriceps muscle twitch is identified at a stimulated current between 0.2 and 0.5mA, 20mls of 0.375% levobupivacaine (75mg) is injected in fractionated amounts after negative aspiration
Active Comparator: Intrathecal injection of diamorphine; 500mcg of intrathecal diamorphine (ID) (dissolved in 0.5mls normal saline)	Procedure: Intrathecal injection of diamorphine; 500mcg of intrathecal diamorphine (ID) (dissolved in 0.5mls normal saline)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Median pain score (NRS: see below) at rest	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain) assessed at times 3, 6, 12, 24, 48 and 72 hrs postoperatively.	Over 72 hours post operatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain on movement	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 3 hrs postoperatively
Pain on movement	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 6 hrs postoperatively
Pain on movement	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 12 hrs postoperatively
Pain on movement	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 24 hrs postoperatively
Pain on movement	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 48 hrs postoperatively
Pain on movement	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 72 hrs postoperatively
Pain at rest	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 3 hrs postoperatively
Pain at rest	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 6 hrs postoperatively
Pain at rest	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 12 hrs postoperatively
Pain at rest	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 24 hrs postoperatively
Pain at rest	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 48 hrs postoperatively
Pain at rest	Numerical rating scale (NRS) score (where 0 = no pain and 10 = worst possible pain)	At 72 hrs postoperatively
Morphine consumption	Cumulative consumption in milligrams	Over 72 hrs postoperatively

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quality of recovery score 40	Quality of recovery score is a 40 point patient reported outcome measure devised by Paul Myles and reported in the British Journal of Anaesthesia 84 (1): 11-15 (2000). This psychometric tool assess emotional state, physical comfort, psychological support, physical independence and pain grading each out of 5 (0= lowest score and 5 = highest score). We ranked total score as extremely poor (0-40), poor (41-80), satisfactory (81-120), good (121-160) or excellent (161-200).	Day 2 post operatively
Total Pain Relief Score (TOTPAR)	Percentage of the maximum total pain relief was calculated by dividing the total pain relief (TOTPAR) over the three days by the maximum potential pain relief and expressed as a percentage (%maxTOTPAR)	Day 1,2 and 3 post-operatively
Functional health outcome measure	The Oxford Knee Score (OKS) is a 12-item patient-reported questionnaire specifically designed and developed to assess function and pain after total knee arthroplasty. It is short, reproducible, valid and sensitive to clinically important changes. The OKS was designed to be completed by the patient thus minimising potential bias unwittingly introduced by surgeons when assessing the results themselves. The PRO was designed and developed by researchers within Public Health and Primary Health Care at the University of Oxford in association with surgical colleagues at the Nuffield Orthopaedic Centre. The OKS at 6 weeks was compared to the preoperative OKS to describe the change in functional outcome.	At 6 weeks post-operatively
Physical health outcome	EuroQol 5 Dimensions Score/Visual Analogue Score (EQ-5D™/VAS). This is a standardised instrument for use as a measure of health outcome. It uses a patient self reporting 5 point (3 level) questionnaire and visual analogue scale to measure health. Health improvement at 6 weeks was assessed by comparing with pre-operative scores.	A 6 weeks post-operatively

Collaborators and Investigators

• Sponsor: Royal Devon and Exeter NHS Foundation Trust
• Investigators: Principal Investigator: Matthew Grayling, MBBS, Royal Devon and Exeter Hospital

Study record dates

Study Major Dates

• Study Start: February 1, 2010
• Primary Completion (Actual): May 1, 2012
• Study Completion (Actual): July 1, 2012

Study Registration Dates

• First Submitted: August 20, 2013
• First Submitted That Met QC Criteria: August 26, 2013
• First Posted (Estimate): August 29, 2013

Study Record Updates

• Last Update Posted (Estimate): August 29, 2013
• Last Update Submitted That Met QC Criteria: August 26, 2013
• Last Verified: August 1, 2013

More Information

Terms related to this study

• Keywords: Arthroplasty; Analgesia
• Additional Relevant MeSH Terms: Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis; Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Analgesics, Opioid; Narcotics; Heroin
• Other Study ID Numbers: 10/H0202/1