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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of dexamethasone on single-shot adductor canal blockade in total knee arthroplasty: a pilot study
Scientific title
The effect of dexamethasone on single-shot adductor canal blockade in total knee arthroplasty: a pilot study
Secondary ID [1] 285234 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Post operative pain management
292863 0
Total knee arthroplaty 292905 0
Condition category
Condition code
Anaesthesiology 293162 293162 0 0
Musculoskeletal 293194 293194 0 0

Study type
Description of intervention(s) / exposure
All elective total knee arthroplasty patients will recieve an adductor canal block as part of a multi-modal regional anaesthetic technique consisting of an adductor canal block, spinal anaesthetic and local infiltration analgesia. The duration of sensory block of the adductor canal block will be compared between patients recieving no dexamethasone, perineural dexamethasone added to the block and dexamethasone given intravenously.

Adductor canal nerve blocks are to be performed before spinal anaesthesia using ultrasound, and the corresponding “numb patch” on medial malleolus marked out using a skin marker.

After assessment for eligibility and informed consent at pre-assessment, patients will be randomised into one of three groups.

Group P (Placebo) - Adductor canal block with 75mg ropivicaine (10mls) and 2mls 0.9% normal saline in block mixture. 2mls 0.9% Normal saline intravenously.

Group N (Peri-neural) - Adductor canal block with 75mg ropivicaine (10mls) and 8mg (2mls) 0.9% dexamethasone in block mixture. 2mls 0.9% Normal saline intravenously.

Group IV (Intravenous) - Adductor canal block with 75mg ropivicaine (10mls) and 2mls 0.9% normal saline in block mixture. 8mg (2mls) dexamethasone intravenously.

Adductor canal block administered at time = 0hrs.
Expected duration of adductor canal block = 6-12hours
Expected duration of adductor canal block with dexamethasone = 6-24hours.

All groups will receive the following.
*Spinal anaesthesia with 2.4-2.6ml 0.5% hyperbaric bupivacaine with 100mcg intrathecal morphine.
(Administered at time = 30 mins, spinal duration = up to 4 hours, intrathecal morphine duration = up to 24 hours).
*Intra-articular local anaesthetic infiltration (225mg ropivicaine, 0.5mg adrenaline +/- 30mg ketorolac made up to 100ml 0.9% saline).
(Administered at time = 1 hour, duration = up to 12 hours).
*2mg tropisteron, 0.25mg droperidol, cyclizine 50mg intravenously for anti-emesis.
(Antiemetics administered at time = 30mins, duration of antiemetics = 4-6hours).
*Sedation with propofol and/or midazolam and fluid management at the discretion of the anaesthetist.
(Administered at time = 30mins, duration = duration of surgery).
*Postoperative patient controlled analgesia with morphine.
(Administered at time = end of surgery, duration = 3 days).

Overall duration of surgery = 1-3 hours.
Intervention code [1] 290108 0
Treatment: Drugs
Comparator / control treatment
Control/placebo (Group P): standard treatment, no dexamethasone

2mL NaCl 0.9% for perineural injection
2mL NaCl 0.9% for intravenous injection
Control group

Primary outcome [1] 293023 0
Duration of sensory block.

Adductor canal block, as well as providing analgesia for the knee joint, also causes a numb patch on the medial malleolus that can be tested for sharp pain sensation. This will be done using a drawing up needle (does not pierce skin), on the centre of the “numb patch”.
Duration is defined as the time of adductor canal block to time for patient to feel sharp sensation (rather than dull or no sensation) on the “numb patch”.
Timepoint [1] 293023 0
4 hourly measurements by nurses once back on the ward, its time coinciding with the usual post op vital signs measurement.

72 hours post-operative, or until return of normal sensation if longer than this
Secondary outcome [1] 310192 0
Pain score – Numerical rating scale 0-10
Timepoint [1] 310192 0
Checked every 4 hours post-op to coincide with standard post-op vitals measurement. Patient is asked by ward nursing staff to verbally rate their pain score from 0 (=no pain) to 10 (=worst ever pain).

Also checked each morning on day 1 and day 2 during rest and movement to coincide with pain-nurse assessments.
Secondary outcome [2] 310193 0
Time from block to first use of patient-controlled analgesia. This time is recorded by the nursing staff on patient-controlled analgesia documentation.
Timepoint [2] 310193 0
Recorded in the evening of Day 0, 1, 2 post-op.
Secondary outcome [3] 310194 0
Amount of morphine used in patient-controlled analgesia. The total amount used is displayed by the patient-controlled analgesia syringe pump and is recorded by the nursing staff on the patient-controlled analgesia documentation.
Timepoint [3] 310194 0
Recorded in the evening of Day 0, 1, 2 post-op
Secondary outcome [4] 310195 0
Physiotherapy goals achieved - Yes or No
Form to be filled in by the physiotherapist
Timepoint [4] 310195 0
Recorded in the evening of Day 0, 1, 2 post-op. Recorded in the evening by physiotherapist.

Key inclusion criteria
Elective primary total knee replacement
Age >18
Spinal anaesthesia as part of technique
Intra-articular local anaesthetic infiltration
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Allergy to local anaesthetic or dexamethasone
Allergy to morphine
Currently on oral or IV steroids
Complex chronic pain issues
Severe renal or hepatic impairment
Patient <55kg weight
Uncontrolled diabetics
Contraindication to nerve blockade

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Participants will be drawn from the Fremantle & Kaleeya Hospitals elective orthopaedic lists. Patients will be recruited preoperatively after discussion with the research nurses and doctors at Fremantle. They will be given written information at the same time.

Allocation concealment will be performed by using sealed opaque envelopes, drawn up by a research doctor who is not otherwise involved in the clinical trial.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Phase 2
Type of endpoint(s)
Statistical methods / analysis
Primary End Point
Block duration will be analysed as non-parametric data, presented as median with interquartile ranges, groups compared using Kruskal-Wallis

Secondary End Points
Pain scores will be determined using the numerical rating scale. Pain score data will be analysed as non-parametric data, presented as median with an inter-quartile range with groups compared using the Kruskal-Wallis test.

The time from block to first PCA use will be analysed as non-parametric data, presented as median with inter-quartile range, with groups compared using Kruskal-Wallis tests. Total morphine consumption data will also be presented as median with inter-quartile range with groups compared using Kruskal-Wallis.

The ability to do physiotherapy will be presented as yes or no answer. Physiotherapy data will be analysed using the Chi Square test.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 8642 0
6160 - Fremantle

Funding & Sponsors
Funding source category [1] 289857 0
Name [1] 289857 0
Fremantle and Kaleeya Hospitals
Fremantle Hospital Medical Research Foundation
Address [1] 289857 0
Alma Street
WA 6160
Country [1] 289857 0
Primary sponsor type
Fremantle Hospital and Health Services
Alma Street
WA 6160
Secondary sponsor category [1] 288539 0
Name [1] 288539 0
Address [1] 288539 0
Country [1] 288539 0

Ethics approval
Ethics application status
Ethics committee name [1] 291580 0
Fremantle Human Research Ethics Committee
Ethics committee address [1] 291580 0
Fremantle Hospital
Alma Street
WA 6160
Ethics committee country [1] 291580 0
Date submitted for ethics approval [1] 291580 0
Approval date [1] 291580 0
Ethics approval number [1] 291580 0

Brief summary
Patients who have knee joint replacement operations can be in a lot of pain afterwards. The doctor will often use a special local anaesthetic injection called a nerve block to try to reduce this pain. These injections use an ultrasound machine to find the nerves. By injecting local anaesthetic right next to these nerves, patients can have less pain after the operation compared to patients who only have local anaesthetic injected into the surgical wound. The main side effect of some of the nerve blocks is leg weakness. It is important that a patient can get up and walk as soon as possible after a knee operation. Too much leg weakness can stop this from happening or lead to a patient falling over and injuring themselves.
A nerve block called an “adductor canal block” is currently being used in patients having knee operations. This nerve block can result in a similar amount of pain relief as other nerve blocks but causes much less leg weakness. It can be given either as a one-off injection or by placing a very fine tube, a catheter, next to the nerve and giving a continuous drip of local anaesthetic. Although one-off injections are easier and quicker to perform, the pain relief effects do not last as long as the catheter method.
When performing a nerve block, a steroid medication called dexamethasone can be mixed with the local anaesthetic solution to make the pain relief effects last longer. Studies have shown that dexamethasone makes the nerve blocks used in shoulder and arm surgery last longer. Whether dexamethasone would have the same effect on an adductor canal block is not known as it has not been studied before. If dexamethasone was shown to make an adductor canal block last longer, it could be used in knee surgery patients to keep them comfortable for a longer time after their operation. Intravenous dexamethasone (given via a drip in a vein) is widely used for the management of nausea and vomiting associated with general anaesthesia, although it is officially off-license for use via a drip.
We intend to do a small pilot study to find out whether dexamethasone has an effect on how long an adductor canal block lasts. This will involve doing an adductor canal block, with or without dexamethasone, on patients already having knee joint replacement surgery. If we can show that using dexamethasone in adductor canal blocks can make the block last longer, we will then plan to do a larger study comparing the one-off adductor canal block with dexamethasone against the adductor canal block catheter.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 50970 0
Dr Alistair Davies
Address 50970 0
Anaesthetic Department
Fremantle Hospital
Alma Street
WA 6160
Country 50970 0
Phone 50970 0
+61 8 94313333
Fax 50970 0
+61 8 94312171
Email 50970 0
Contact person for public queries
Name 50971 0
Dr Alex Wycherley
Address 50971 0
Anaesthetic Department
Fremantle Hospital
Alma Street
WA 6160
Country 50971 0
Phone 50971 0
+61 8 94313333
Fax 50971 0
+61 8 94312171
Email 50971 0
Contact person for scientific queries
Name 50972 0
Dr Gareth Prosser
Address 50972 0
Orthopaedic Surgery
Fremantle Hospital
Alma Street
WA 6160
Country 50972 0
Phone 50972 0
+61 8 94313333
Fax 50972 0
Email 50972 0

No data has been provided for results reporting
Summary results
Not applicable