PENG vs placebo 'sham' block RCT

We propose a study to investigate the effect of the PENG block, compared to placebo in a
triple-blind randomised controlled trial format.
We aim to achieve this by randomising participants into a two-armed nested, prospective,
multi-centre cohort study, to receive placebo or our study intervention (the PENG block) along
with standard of care.
The participant, anaesthetist and surgeon will be blinded to the study medication administered.
The post-operative pain team, at FMC and Noarlunga known as the Acute Pain Service (APS),
will also be blinded. This team routinely follows up all participants who have undergone a hip
arthroplasty. They will know that the participant has received a regional technique, but not
whether it is with ropivacaine or placebo.
This study shall not influence the surgical technique, this is left entirely to the
treating surgeon. Standard Local infiltration analgesia is 100ml of 0.1% ropivicaine with adrenaline. Anaesthetic technique is standardised to the following: a spinal anaesthetic unless contraindicated or unable to be performed despite multiple attempts, dose 2.0-2.8mL bupivacaine plain 0.5%. Post operative analgesia is standardised. Intrathecal morphine is standardised as not to be given. IV dexamethasone dose is standardised at 8mg at time of block placement.
The study investigators shall not recruit their own patients, to prevent any possible coercion. If
necessary, the anaesthetists involved in the study shall exchange places with each other to
prevent this.
The placebo block and PENG block shall use the same equipment (ultrasound and
chlorhexidine skin disinfectant). Randomisation shall occur following consent and participant
inclusion.
To this date, no complications have been described resulting from PENG blocks. One editorial
report describes a case of temporary quadriceps weakness following the block, but this is
not a complication, and occurs invariably with the femoral nerve block, another commonly
performed regional technique. We have also been performing the PENG block for hip surgeries
within our department for some time, and have not noted any complications.
Post-operatively, each participant will be visited on the ward by the Acute Pain Service which is
a routine part of their care. In this consultation they will discuss their pain levels, pain
medication use, and ability to mobilise since their surgery, all part of the standard questions
asked by this service. As part of this study, a study investigator shall pre-
operatively conduct a series of questionnaires, Brief Pain Inventory, QoR-15, PROMIS anxiety, Pain Catastophising Scale and PROMIS depression. Post-operatively the QoR-15, and the Brief Pain Inventory will be repeated on Day 1 postoperatively between 0800 and 0930. We shall conduct a timed up and go test pre-operatively as well as postoperatively. This is the
time it takes for a patient stand up from a standard height armchair, walk 3 metres, walk back
to the chair, and sit back down.
There is no long term follow up in the primary analysis of this study. There is a planned secondary analysis of persistent and chronic pain/opiate use outcomes to follow at the 6 week and 3 month postoperative points.

The pericapsular nerve group (PENG) block is superior to placebo 'sham' blocks in hip arthroplasty surgery in reducing patients pain scores (Numeric Rating Scale of 0 to 10), on the day of surgery

Pre-operative, day of surgery, day after surgery, day of discharge

1.) Non invasive skin markings and blunt needle to simulate a 'sham' block (control group) or 2.) study intervention which is ropivicaine 0.5% 20mLs as a PENG block according to the technique described by Giron-Arango et al. in 2018