Nerve Block Anaesthesia

Nerve block procedures offer significant benefits tailored to the scope and complexity of the medical procedure: 

• Comfort and awareness: Patients can remain awake and breathe naturally, which can be safer for patients with high anaesthesia-related risks (e.g., heart or lung conditions) and efficient for localised surgeries. This also allows faster recovery time.
• Better pain control: Provide targeted pain relief, often reducing the need for strong pain-relief medications.
• Reduced risk of breathing complications: Reduces chances of post-surgery breathing complications like aspiration (inhaling stomach contents), breathing difficulties, or lung infections.
• No breathing tube needed: Unlike general anaesthesia, nerve blocks usually do not require intubation or an airway device.
• Reduced opioid use: Lowers the need for opioids, reducing the risk of side effects or dependency.
• Fewer general anaesthesia side effects: Minimises the risk of complications associated with general anaesthesia, such as nausea, vomiting, or drowsiness.
• Cancer pain relief: Can ease pain caused as a result of tumours pressing on nerves or other structures, improving comfort and quality of life.

The nerve block procedure involves the following steps:

• Finding the target nerve: Ultrasound or body landmarks are used to guide the needle toward the target nerve.
• Needle insertion: A fine needle is inserted at the appropriate depth and angle to reach the target nerve.
• Test dose: A small amount of local anaesthetic is injected to confirm proper needle placement (e.g., through ultrasound visualisation).
• Confirmation of block success: This can be done through multiple ways, such as checking loss of sensation, loss of limb movement or muscle control, and visualising the anaesthetic spread around the nerve on ultrasound (ultrasound-guided anaesthesia).
• Full injection: After confirming block success, the full dose is injected around the target nerve(s) to block sensation and movement in the surgical area.

Risks/Potential side effects

While nerve block anaesthesia is generally safe, it is associated with some risks depending on the type of block, the location, the technique used, and the patient's overall health.

• Local complications (near the injection site):
  • Infection: Rare, but possible at the needle insertion site.
  • Hematoma: Bleeding at the injection site or around the nerve can cause pooling of blood (hematoma), resulting in swelling, bruising, and pressure on surrounding structures.
  • Temporary nerve irritation or injury: May cause numbness, tingling, weakness, or loss of sensation (rarely permanent).
  • Local anaesthetic toxicity: Toxicity can occur due to anaesthetic overdose or accidental injection into a blood vessel. Symptoms include ringing in the ears, metallic taste in the mouth, dizziness, irregular heartbeat, and (rarely) seizures.
  • Direct nerve trauma: In rare cases, the needle may accidentally puncture the nerve, resulting in pain, weakness, or loss of sensation.
• Whole-body (systemic) complications:
  • Allergic reactions: Though uncommon, some patients may have an allergic reaction to the local anaesthetic, resulting in symptoms like rash, swelling, or more severe reactions (e.g., anaphylaxis).
  • Accidental injection into a blood vessel: The anaesthetic might be inadvertently injected into the bloodstream, causing symptoms like dizziness, seizures, or irregular heartbeat.
  • Breathing problems: Certain blocks around the neck or spinal cord might affect respiratory function or cause paralysis if the anaesthetic spreads to unintended areas.
• Complications specific to certain blocks:
  • Lung puncture (pneumothorax): Possible during blocks near the collarbone or upper chest; may cause a collapsed lung needing urgent care.
  • Diaphragm paralysis: If the anaesthetic affects the phrenic nerve, it can cause diaphragm paralysis, resulting in breathing difficulty.
  • Temporary limb weakness: Nerve blocks like femoral or sciatic nerve blocks can cause temporary weakness or loss of movement in the affected limb, which typically resolves once the anaesthetic wears off.
  • Bleeding or clot formation: A blood vessel could be accidentally punctured during the procedure, leading to bleeding or clot formation.
  • Low blood pressure (hypotension): Some blocks to nerve networks around abdominal organs can potentially lead to a drop in blood pressure.
  • Nearby organ injury: Accidental damage to nearby organs, such as the kidneys or liver, is also possible during the procedure.
• Other potential risks:
  • Block failure: In some cases, the nerve block may not provide complete pain relief and may require additional pain control.
  • Post-operative pain: Delayed pain or residual discomfort after the block wears off can be present, especially if the block was only partially successful.
  • Psychological effects: In rare cases, anxiety or psychological distress can occur, particularly if the patients have a fear of needles or medical procedures.
• Long-term complications (rare):
  • Chronic nerve pain: Persistent pain due to nerve damage or irritation from the anaesthetic injection can happen.
  • Fibrosis or scarring: Over time, scarring or fibrosis at the injection site may occur, potentially leading to difficulties with future procedures.

• Monitoring: You will be observed for any side effects or complications like bruising, nerve injury, or allergic reactions to the anaesthetic.
• Pain control: Additional pain-relief medications may be given after the nerve block wears off to manage any residual discomfort.
• Follow-up: The team ensures that the block wears off safely and checks for any delayed complications. Most patients can return to normal activities once sensation and movement are back.