Clinical trial NCT04506879: Popliteal SNB:Evaluation of Block Dynamics After Subparaneural Injection Below CPN & TN
Official title: Ultrasound Guided Popliteal Sciatic Nerve Block: Evaluation of Block Dynamics After a Twin Subparaneural Injection Below the Divergence of Common Peroneal and Tibial Nerve.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Musculoskeletal Diseases or Conditions
Keywords: Popliteal Sciatic nerve block
Lead sponsor: Chinese University of Hong Kong
Sponsor class: OTHER
First posted: 2020-08-10
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: This study aims to assess the effect of twin subparaneural injection into individual paraneural sheaths of Common Peroneal Nerve (CPN) and Tibial Nerve (TN) below their point of divergence from the sciatic nerve on the sensory motor blockade after Popliteal Sciatic Nerve Block (PSNB) at the popliteal fossa (back of the thigh) for patients requiring lower limb surgeries.

Detailed description: Ultrasound (US) guided Popliteal Sciatic Nerve Block (PSNB) has been routinely used to provide surgical anaesthesia for ankle and foot surgeries, and the introduction of ultrasound (US) guidance has improved the ease and accuracy of performing PSNB. However, the challenge of achieving the optimal 'readiness for surgery' time after the US guided PSNB continues to confront anaesthesiologists. Cumulative evidence indicates that a subparaneural PSNB improves sensory motor block outcome when compared to subepimyseal PSNB where the local anaesthetic is deposited outside the paraneural sheath.

While these are encouraging results, producing sensory motor blockade, i.e. surgical anaesthesia in the area innervated by the sciatic nerve within 30 minutes of local anaesthetic (LA) injection, after a subparaneural PSNB, remains a challenge with the success rate varying from 62-92%. Reasons for this shortcoming, despite LA being deposited in subparaneural space, close to the epineurium of the sciatic nerve, is probably multifactorial as the nerve size, surface area exposed to local anaesthetic, and internal architecture (the connective tissue component) of the sciatic nerve and its branches are all seems to influence block onset time and completeness. It was observed from our clinical practice that distal subparaneural injection (twin halo) into individual paraneural sheaths of common peroneal nerve (CPN) and tibial nerve (TN) below the point of divergence at the popliteal fossa demonstrated a faster sensory motor blockade after PSNB. Therefore, this study aims to assess the effect of twin subparaneural injection into individual paraneural sheaths of CPN and TN below their point of divergence from the sciatic nerve on the sensory motor blockade after PSNB at the popliteal fossa.

Eligibility criteria: Inclusion Criteria:

* American Society of Anesthesiologists (ASA) physical status I-III scheduled to undergo elective foot and/or ankle surgery under regional anesthesia.

Exclusion Criteria:

* Patient refusal, ASA physical status \> Ⅲ, pregnancy, neuromuscular disorder, prior surgery in the popliteal fossa, coagulopathy, allergy to local anaesthetic drugs, and skin infection at the site of needle insertion.

Primary outcomes:
measure: the percentage of patients with complete sensory and motor block at 30 min
timeFrame: within 45 minutes after the block (at 5min, 10min, 15min, 20 min, 25min, 30min, 45 min)
Secondary outcomes:
measure: The time taken to complete sensory and motor blockade at 30 min, time to 'readiness for surgery'
timeFrame: within 45 minutes after the block (at 5min, 10min, 15min, 20 min, 25min, 30min, 45min)
measure: Success rate of the block
timeFrame: within 45 minutes after the block (at 5min, 10min, 15min, 20min, 25min, 30min, 45min)
measure: Complication
timeFrame: from immediately after the block till 24 hours afterwards
measure: Paraesthesia and degree of discomfort
timeFrame: during the block
Other outcomes:
Locations:
city: Shatin
country: Hong Kong
facility: Prince of Wales Hospital
state: New Territories
Study officials:
affiliation: Chinese University of Hong Kong
name: Manoj K Karmakar, MD
role: PRINCIPAL_INVESTIGATOR
References: