Vol 2 | Issue 2 | July-December 2021 | Page 143-144 | Ritesh Roy, Himjyoti Das, Neha Singh, Surajit Giri, Hetal Vadera, Vrushali Ponde
Authors: Ritesh Roy , Himjyoti Das , Neha Singh , Surajit Giri , Hetal Vadera , Vrushali Ponde 
 Department of Anaesthesia and Pain management Care Hospitals, Bhubaneswar, Odisha, India.
 Anesthesia and Critical care, Nazareth Hospital, Shillong, Assam, India.
 Department of Anesthesiology and Critical care, AIIMS, Bhubaneswar, Odisha, India.
 Department of Anesthesia, Pragati Hospital, Sivasagar, Assam, India.
 Department of Anaesthesia, Sterling Hospital, Rajkot, Gujarat, India.
 Department Anesthesiology, Surya Children Hospital, Mumbai, Maharashtra, India.
Address of Correspondence
Dr. Vrushali Ponde,
Consultant Paediatric Anaesthesiologist, Surya Children Anaesthesia Services, Mumbai, Maharashtra, India.
Clinical Pearl for a Successful and Safe PNS Guided Peripheral Nerve Block
PRE OP PREPARATION
Pre-procedural evaluation with history of antiplatelet or antithrombotic drug use
Assess neurological status in patient with trauma and neuropathy
Explain the procedure and complications
Possibilities of failure of the procedure, multiple injections and conversion to GA must be explained
Obtain informed written consent
PRE PROCEDURE PREPARATION ( AORA Check list)
Perform the block in a dedicated block room or in OT
Confirm the site before starting the procedure
Block room must be equipped with monitoring devices and equipment
Ensure all resuscitative emergency drugs, equipment and Intralipid present in the cart
Secure venous access before performing the procedure
Connect monitor for ECG, Non-invasive blood pressure (NIBP), and peripheral oxygen saturation
BEFORE GIVING BLOCK
STOP BEFORE YOU BLOCK: Confirm again about patient and site of block
Calculate and keep drugs needed for block in labelled syringes ready before the procedure
Maintain asepsis throughout the procedure
A small dose of sedative / anxiolytic may be necessary for anxious patients. Infiltrate the injection site with lignocaine.
Positive electrode is Red, and negative is Black (Positive is attached to patient, negative end is attached to the Needle). Machines may have different colour coding for the electrodes
PNS stimulation is not possible in patient receiving neuromuscular blocking agent
Presence of neuraxial anaesthesia doesn’t affect the stimulation of intact motor unit by PNS
Always use insulated needle
For superficial blocks: Use 50 mm needle, current at 1.0 mA.
For deeper blocks: Use 100 mm needle, current at 1.5 mA
Set PNS in 0.2ms current duration & frequency at 2 Hz.
End motor response (EMR) between 0.3mA to 0.5mA is considered safe and ideal (except lumbar plexus block where below 0.5mA is unsafe).
For children 25mm needle is preferred.
Repeated aspiration before injection of drug at 3-5ml aliquot is a safe practice.
Never try to inject against high resistance, use of injection pressure monitoring device is advisable.
Keep talking to the patient while injecting the drug for early detection of the signs of the toxicity.
Injection of Dextrose solution is preferred over sodium chloride for hydro dissection as saline will abolish muscle twitches.
DESIRABLE END MOTOR RESPONSE
|Interscalene Brachial plexus block||Any two contractions of pectoralis major, deltoid, triceps or biceps.|
|Supraclavicular Brachial plexus block||Finger or wrist twitches (flexion or extension)|
|Infraclavicular Brachial Plexus Block||Posterior cord response is desirable (Extension of wrist and fingers)|
|Axillary Brachial Plexus Block||Median nerve- Flexion of first three fingers
Musculocutaneous nerve- Elbow flexion Radial nerve- Fingers extension
Ulnar nerve- Flexion of fourth &little finger along with apposition of thumb towards little finger
|Femoral Nerve Block||Dancing of patella (Twitches of quadriceps muscle)|
|Sciatic Nerve Block||Planter flexion or dorsi flexion|
|Lumbar Plexus Block||Quadriceps contraction|
|Ilioinguinal & Iliohypogastric Nerve Block||Lower Abdominal muscle & Inguinal region Twitches (T10-L1 territory)|
|Thoracic Paravertebral Block||Corresponding intercostal muscles twitches|
|Serratus Anterior Plane (SAP) Block||Serratus anterior muscle twitches/ Dancing of Scapula.|
|PEC1 Block||Pectoralis Major muscle twitches|
Document the procedure. Date, Time, Needle type, size, disappearance of EMR at what current, setting of the PNS before injection of the drug, injection resistance or ease of injection, tingling or numbness during or immediately after injection, vitals etc.
Assessment of Dermatome, Myotome and osteotome at 30minute. If all are blocked, then only we can proceed for incision and surgery
|How to Cite this Article: Roy R, Das H, Singh N, Giri S, Vadera H, Ponde V | Clinical Pearl For A Successful And Safe PNS Guided Peripheral Nerve Block | July-December 2021; 2(2): 143-144.