The effect of dexamethasone on single-shot adductor canal blockade in total knee arthroplasty: a pilot study

• Register: ANZCTR
• Last refreshed on: 13 January 2020
• Main ID: ACTRN12614000982617
• Date of registration: 12/09/2014
• Prospective Registration: Yes
• Primary sponsor: Fremantle Hospital and Health Services
• 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
• Date of first enrolment: 15/09/2014
• Target sample size: 30
• Recruitment status: Not yet recruiting
• URL: https://anzctr.org.au/ACTRN12614000982617.aspx
• Study type: Interventional
• Study design: Purpose: Treatment; Allocation: Randomised controlled trial; Masking: Blinded (masking used);Assignment: Parallel;Type of endpoint: Pharmacodynamics;
• Phase: Phase 2

Countries of recruitment

Australia

Contacts

• Name: Dr Gareth Prosser

• Name: Dr Alex Wycherley

Key inclusion & exclusion criteria

Inclusion criteria: Elective primary total knee replacement
Age >18
Spinal anaesthesia as part of technique
Intra-articular local anaesthetic infiltration

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
Pregnancy
Patient <55kg weight
Uncontrolled diabetics
Contraindication to nerve blockade


Age minimum: 18 Years
Age maximum: No limit
Gender: Both males and females

Health Condition(s) or Problem(s) studied

Anaesthesiology - Anaesthetics

Musculoskeletal - Osteoarthritis

Post operative pain management ;Total knee arthroplaty;
Post operative pain management

Total knee arthroplaty

Intervention(s)

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 adr

Primary Outcome(s)

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”. [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(s)

Pain score – Numerical rating scale 0-10
[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.
]

Physiotherapy goals achieved - Yes or No
Form to be filled in by the physiotherapist [Recorded in the evening of Day 0, 1, 2 post-op. Recorded in the evening by physiotherapist. ]

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.[Recorded in the evening of Day 0, 1, 2 post-op]

Time from block to first use of patient-controlled analgesia. This time is recorded by the nursing staff on patient-controlled analgesia documentation.[Recorded in the evening of Day 0, 1, 2 post-op.]

Secondary ID(s)

Nil

Source(s) of Monetary Support

Fremantle and Kaleeya Hospitals Fremantle Hospital Medical Research Foundation

Ethics review

Status: Approved
Approval date:
Contact:

Fremantle Human Research Ethics Committee