Peripheral Nerve Block (Upper Limb)

Introduction

A peripheral nerve block is a type of regional anesthesia that involves injecting a local anesthetic around a specific nerve or group of nerves to numb the area. In the case of an upper limb peripheral nerve block, the goal is to provide analgesia and anesthesia to the arm, forearm, and hand.

Indications

Upper limb peripheral nerve blocks are commonly used for:

• Surgical procedures such as carpal tunnel release, wrist and hand surgeries, and elbow surgeries
• Pain management for conditions like complex regional pain syndrome (CRPS) and neuropathic pain
• Diagnostic procedures like nerve conduction studies and electromyography (EMG)

Types of Upper Limb Peripheral Nerve Blocks

There are several types of upper limb peripheral nerve blocks, including:

• Interscalene block: targets the brachial plexus at the level of the interscalene groove, providing anesthesia to the shoulder and upper arm
• Supraclavicular block: targets the brachial plexus above the clavicle, providing anesthesia to the upper arm, forearm, and hand
• Infraclavicular block: targets the brachial plexus below the clavicle, providing anesthesia to the upper arm, forearm, and hand
• Axillary block: targets the axillary nerve, providing anesthesia to the forearm and hand
• Wrist block: targets the median, ulnar, and radial nerves at the wrist, providing anesthesia to the hand

Technique

The technique for performing an upper limb peripheral nerve block typically involves:

• Preparation of the patient, including positioning and skin preparation
• Use of a nerve stimulator or ultrasound guidance to locate the target nerve
• Injection of a local anesthetic around the nerve, using a sterile technique
• Monitoring of the patient's vital signs and sensation during and after the procedure

Local Anesthetics Used

Commonly used local anesthetics for upper limb peripheral nerve blocks include:

• Lidocaine
• Bupivacaine
• Ropivacaine
• Mepivacaine

Advantages and Benefits

The advantages and benefits of upper limb peripheral nerve blocks include:

• Effective pain relief during and after surgery
• Reduced need for systemic opioids and their associated side effects
• Improved patient satisfaction and reduced anxiety
• Faster recovery times and reduced hospital stays

Risks and Complications

Possible risks and complications of upper limb peripheral nerve blocks include:

• Nerve damage or injury
• Local anesthetic toxicity
• Infection or abscess formation
• Bleeding or hematoma formation
• Pneumothorax (in the case of supraclavicular blocks)

Contraindications

Contraindications to upper limb peripheral nerve blocks include:

• Coagulopathy or bleeding disorders
• Infection at the injection site
• Allergy to local anesthetics
• Patient refusal or inability to cooperate

Post-Procedure Care

After an upper limb peripheral nerve block, patients should be monitored for:

• Sensation and motor function in the affected limb
• Pain levels and need for additional analgesia
• Bleeding or hematoma formation at the injection site
• Signs of local anesthetic toxicity, such as numbness or tingling around the mouth or metallic taste

Frequently Asked Questions (FAQs)

What is a peripheral nerve block?
Injection of local anesthetic around a specific nerve.

Why is it used for upper limb surgery?
To provide pain relief and numbness.

How long does the procedure take?
Typically 10-30 minutes.

Is it performed under sedation or general anesthesia?
Either, depending on patient and procedure.

What are the benefits of peripheral nerve block?
Reduced pain, less need for systemic pain meds.

Are there risks or complications associated?
Yes, including nerve damage and infection.

How long does the numbness last?
Several hours to a day.

Can I go home after the procedure?
Usually, but depends on type of surgery.

Will I have full use of my arm after the block wears off?
Yes, once numbness resolves.

Do I need to follow special instructions after the procedure?
Yes, to avoid injury and promote healing.