Popliteal SNB:Evaluation of Block Dynamics After Subparaneural Injection Below CPN & TN
Condition: Musculoskeletal Diseases or Conditions
MeSH terms: Musculoskeletal Diseases
Study type: Interventional

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.
    

Intervention name(s): Popliteal Sciatic nerve block
Intervention type(s): Procedure
Intervention description(s): Patients schedule for lower limb surgery under regional anesthesia will receive ultrasound guided subparaneural popliteal sciatic nerve block. After identification of the common peroneal nerve and tibial nerve, local anesthetic agents will be injected close to each nerve below the point of divergence at the popliteal fossa. The spread of the drug and the sensory and motor function of that limb will be assessed regularly till it is ready for surgery.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Popliteal Sciatic nerve block