Suprascapular Nerve Block - An Overview

Introduction

The suprascapular nerve is a mixed motor and sensory peripheral nerve emerging from the upper trunk of the brachial plexus. The nerve delivers sensory branches to several locations in the shoulder area in addition to providing motor innervation to the shoulder muscles. In addition to controlling some shoulder muscles, this nerve senses movement in the shoulder joint. By focusing on particular regions, blocking the suprascapular nerve effectively numbs and reduces shoulder discomfort. Blocking it can aid with shoulder discomfort without damaging the phrenic nerve. This technique is a substitute for another block that may result in problems with the diaphragm. This nerve block can be performed in two methods. One uses landmarks, and the other uses ultrasound for better accuracy. The first, for severe shoulder discomfort, has been in use since 1941 and is known as the landmark-based posterior approach. However, owing to the tiny size and location of the nerve in the shoulder, the usual approach is still difficult. Recently, techniques like ultrasonography and nerve stimulation have made it simpler to identify and block the nerve. In 2012, Andreas Siegenthaler presented a novel approach to guide the suprascapular nerve block using ultrasound from the front to guide the suprascapular nerve block. Suprascapular nerve block (SSNB) is one safe and efficient way to manage pain in chronic shoulder illnesses. The procedure involves seating the patient down and placing their upper limbs next to their torso while an anesthetic is injected into the supraspinatus fossa of the injured shoulder.

What Are the Indications of Suprascapular Nerve Block?

• Many types of shoulder pain can be effectively treated with a suprascapular nerve block.

• In 1941, it was first performed to treat excruciating shoulder discomfort.

• This block may help those with long-term ailments, including tendinitis, arthritis, or discomfort following surgery.

• It is particularly beneficial for severe shoulder pain following surgery or trauma.

• It is advised for patients with lung conditions during procedures since alternative techniques may impair breathing.

What Are the Contraindications of Suprascapular Nerve Block?

• Refusal on the part of the patient is a strict contraindication to the suprascapular nerve block technique, which is an elective pain treatment method.

• The majority of peripheral nerve blocks are performed on conscious patients so that the patient may provide input that could change the needle's placement. Hence the incapacity to participate during the treatment is a relative contraindication.

• Under general anesthesia, however, it is thought to be safe to execute peripheral nerve blocks when otherwise indicated, especially when employing ultrasound guidance.

• Peripheral nerve blocks will not be performed on patients who have established allergies to any local anesthetics, but this is extremely uncommon.

What Are the Equipment Required for Suprascapular Nerve Block?

• Ultrasonography-guided peripheral nerve blocks are carried out with the use of diagnostic ultrasonography equipment.

• The ideal device would feature a low-frequency (two to five Megahertz) curved array probe for deeper structures and a high-frequency (five to 13 Megahertz) linear probe for surface structures.

• For single-injection nerve blocks, the echogenic short bevel block needle is often used.

• If a longer block duration is required, a 17-gauge Touhy needle may be utilized to make the insertion of a peripheral nerve catheter easier.

• The doctor performing the procedure will decide which local anesthetic to use, but different Bupivacaine or Ropivacaine concentrations are commonly used.

• To improve the quality or increase the nerve block's duration, additional drugs may be added to the block solution.

• Povidone-iodine skin disinfecting solution or two percent chlorhexidine.

• A suitable syringe that is equipped with extension tubing.

• The American Society of Anesthesiologists Standard monitors (non-invasive blood pressure monitoring, electrocardiogram, pulse oximetry) with sterile ultrasonic probe cover and gel.

How to Prepare for Suprascapular Nerve Block?

• Suprascapular nerve blocks can be performed by a licensed healthcare provider.

• To correctly posture patients, provide sedation, or aid administer local anesthetic injections, more assistance might be needed.

• The first step in the procedure is to get the patient's informed consent.

• Standard vital sign monitors are installed, and the patient can be positioned once the pertinent risks, benefits, and alternatives have been discussed.

• The posterior technique to reach the scapula and suprascapular notch is best performed in an upright seated position.

• The anterior approach lateral to the supraclavicular brachial plexus is best performed in a reclining position.

• The anatomy around the clavicle may be easier to see when the patient is covered with a blanket behind their shoulders.

What Is the Technique of Suprascapular Nerve Block?

There are two techniques for suprascapular nerve blocks: anterior and posterior.

Anterior Approach:

• Locate the supraclavicular brachial plexus by using ultrasonography above the clavicle.

• To locate the suprascapular nerve, trace the brachial plexus in the direction of the cricoid cartilage.

• After following the nerve downward and confirming placement with a tiny injection of block solution, keep injecting until the nerve is surrounded.

Posterior Approach:

• Position the ultrasound above the scapula to see the trapezius and supraspinatus muscles.

• Identify the suprascapular canal and artery, then locate the nerve running alongside.

• Insert the needle from medial to lateral, avoiding the acromion process.

• Inject a small amount of solution to confirm placement, then continue until the nerve is well surrounded. If the nerve is not seen, inject below the supraspinatus fascia.

What Are the Complications of Suprascapular Nerve Block?

A suprascapular nerve block can be performed with less difficulty if ultrasonography is used judiciously and the needle tip is constantly monitored. A possible danger is pneumothorax, which happens in approximately one percent of instances and is frequently brought on by needless needle advancement. Prevent vertical entry into the suprascapular notch to lower the risk of pneumothorax. To increase safety, elevate the scapula by placing the ipsilateral hand on the contralateral shoulder. Precautionary aspiration and regular examinations are crucial because an additional risk is accidental injection into adjacent blood arteries. An injection is safe when the local anesthetic distribution is visible on ultrasonography. Peripheral nerve blocks have general hazards such as bleeding, infection, toxicity from local anesthetics, and nerve damage.

Conclusion

Suprascapular nerve block is an effective method for the treatment of acute, chronic, and postoperative shoulder discomfort. By using ultrasound guidance, problems are reduced, and accuracy and safety are improved. Even with risks like vascular damage and pneumothorax, cautious needle insertion and continuous visualization greatly minimize these concerns. When performed carefully and after a full evaluation of the patient, suprascapular nerve block becomes an efficient and well-tolerated intervention that offers specific relief to patients with a variety of shoulder conditions.