Major/minor nerve block anaesthesia Home A-Z Health Information Health Library A-Z Major/minor Nerve Block Anaesthesia Overview Nerve block procedures are used to prevent pain signals from a specific nerve or group of nerves from reaching the brain, thereby preventing pain from being felt in the area supplied by the target nerve(s). Major and minor nerve blocks are valuable tools in local/regional anaesthesia, providing targeted pain relief for surgeries of varying durations and complexities. While major nerve blocks target larger or more important nerves or nerve plexuses (networks/structures formed by the intermingling of the nerve fibres that provide extensive control over the motor and sensory functions of the body), minor nerve blocks typically target smaller nerves that provide sensation to more specific regions of the body. Therefore, major nerve blocks are typically used for larger (involving large areas of the body) and more complex surgeries that require deep anaesthesia, while minor nerve blocks are used to provide effective anaesthesia for smaller and more localised procedures. The choice between using a major or minor nerve block depends on the type of surgery, the part of the body being treated, and the desired level of anaesthesia. Benefits Both major and minor nerve block procedures offer significant benefits tailored to the scope and complexity of the medical procedure. Major nerve blocks provide extensive and long-lasting pain relief for large body regions, while minor nerve blocks deliver localised and efficient pain control for smaller areas.Patients can remain awake and breathe normally: This feature makes nerve blocks a safer and more efficient option for a variety of surgical procedures, particularly for patients with high anaesthesia risks (e.g., patients with chronic respiratory disease or cardiovascular issues) or those undergoing surgeries in localised regions of the body. This also means faster recovery time.Better post-operative pain control: Both major and minor blocks provide targeted pain relief, which can lead to faster recovery times and better post-surgical comfort. Further, patients require fewer pain-relief medications.Reduced risk of respiratory complications: Individuals undergoing nerve block procedures are at a lower risk of developing complications like aspiration (inhaling stomach contents), breathing difficulties, or post-operative lung infections (lung infections after surgery).No need for tracheal intubation: In general anaesthesia, a breathing tube or other airway device (intubation) is often required as the patient is unconscious, and normal breathing may be suppressed. With nerve blocks, the patient breathes naturally without assistance.Reduced opioid use: Nerve blocks, particularly when combined with other analgesics (pain-relief drugs) help reduce the need for systemic opioids (a class of drugs that reduce pain perception throughout the body), thereby minimizing the risks of opioid-related side effects and addiction.Fewer general anaesthesia side effects: Nerve blocks allow for surgeries to be performed with reduced or no general anaesthesia, thereby lowering the risk of complications associated with general anaesthesia, such as nausea, vomiting, or prolonged sedation.Cancer pain relief: Nerve blocks can relieve pain that is caused as a result of tumours pressing on nerves or other structures. The celiac plexus block is used for abdominal cancers (e.g., pancreatic, gastric, and liver cancer), lumbar sympathetic block is used for relieving pelvic or lower limb pain, and stellate ganglion block is used to relieve cancer-related pain in the head, neck, or upper limbs. Technique As with other anaesthesia technique, the first step of nerve block procedures also involves apreoperative stage where medical history, medications, allergies, and contraindications to anaesthesia (i.e., specific situations or conditions where administering anaesthesia could pose a significant risk to the patient) are taken into account. The next steps are provided below.Identification of the target nerve: In this step, ultrasound or anatomical landmarks are used to guide the needle toward the target nerve (ultrasound-guided nerve block and palpation, respectively)Needle insertion: The needle is inserted at such a depth an angle that it reaches the target nerve at the appropriate angle.Test anaesthetic injection: Once the needle is in the correct position, a small test dose of the local anaesthetic injected. After confirming proper needle placement (e.g., through ultrasound visualization), The next step is confirmation of block success.Confirmation of block success: This can be done through multiple ways.Sensory testing: This involves testing for loss of sensation in the area served by the blocked nerve (e.g., using cold or touch stimuli).Motor testing: This involves checking for loss of motor function (e.g., limb movement or muscle control).Ultrasound: This involves using visualisation of the spread of the anaesthetic around the nerve as confirmation of block success (ultrasound-guided blocks/ultrasound-guided anaesthesia).Local anaesthetic injection: After confirming block success,the full dose of the anaesthetic is injectedaround the target nerve(s) ensuring loss of sensation and movement in the area to be operate.Post-procedure care: This involves monitoring for any side effects or complications (e.g., hematoma (blood leakage from blood vessels into the surrounding tissue), nerve injury, or allergic reactions to the anaesthetic). Additionally, pain control and follow-up might be needed on a case-by-case basis.Pain control: Additional analgesics (pain-relief medications) might be needed after the nerve block procedure to manage any residual discomfort.Follow-up: It is ensured that the block wears off safely, and the patient is assessed for any delayed complications. Risks While nerve block anaesthesia is generally safe, it is associated with some risks, which can range from mild, temporary issues like bruising or headache to more serious complications like nerve injury, infection, or cardiac problems. The risks depend on the type of block, the location, the technique used, and the patient's overall health.Local complications:Infection: Although rare, any invasive procedure, including a nerve block, carries the risk of infection at the needle insertion site.Hematoma: Bleeding can occur at the injection site or around the nerve, leading to a collection of blood (hematoma), which can cause swelling, bruising, and pressure on surrounding structures.Nerve injury: Accidental damage to the nerve being targeted—or surrounding nerves—may result in temporary, or very rarely, permanent loss of sensation or motor function.Local anaesthetic toxicity: If too much anaesthetic is injected—or if it is accidentally injected into a blood vessel—local anaesthetic toxicity can occur. Symptoms include ringing in the ears, metallic taste in the mouth, dizziness, cardiac arrhythmias (irregular heartbeat), and in rare cases, seizures.Nerve puncture: In rare cases, the needle may accidentally puncture the nerve or cause direct trauma, which may result in pain, weakness, or loss of sensation.Systemic complications:Allergic reaction to the anaesthetic: Though uncommon, some patients may have an allergic reaction to the local anaesthetic. This might result in symptoms like rash, swelling, or more severe reactions (e.g., anaphylaxis).Accidental intravenous injection: If the needle is placed in or near a blood vessel, the anaesthetic might be inadvertently injected into the bloodstream, potentially causing systemic effects like dizziness, seizures, or irregular heartbeat.Respiratory depression or paralysis: Certain blocks, especially those around the neck or spinal cord (e.g., epidural, cervical blocks) might affect respiratory function or cause paralysis if the anaesthetic spreads to unintended areas (e.g., the diaphragm or spinal cord).Complications specific to certain blocks:Pneumothorax: Accidental puncture of the lung while performing interscalene or supraclavicular blocks can result in the leakage of air from the lungs into the space between the lung and chest wall (pleural space), causing a collapsed lung (pneumothorax), which may require immediate intervention.Diaphragm paralysis: If the anaesthetic spreads to the phrenic nerve when performing the phrenic nerve block, it can cause diaphragm paralysis, resulting in respiratory difficulty.Weakness and clot formation: Motor 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. Additionally, the femoral artery or vein could be accidentally punctured during the procedure, leading to bleeding or clot formation.Low blood pressure (hypotension) and injury to other structures: The celiac plexus controls many abdominal organs and can blocking the same can potentially lead to a drop in blood pressure (hypotension). Further, 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. This can happen if the anaesthetic is not delivered correctly, or if the nerve is not adequately targeted.Post-operative pain: Some patients may experience delayed pain or residual discomfort after the block wears off, especially if the block was only partially successful.Psychological effects: In rare cases, patients may experience anxiety or psychological distress due to the nerve block procedure, particularly if they have a fear of needles or medical procedures.Long-term complications (rare):Chronic nerve pain: In rare cases, nerve blocks can lead to chronic pain or neuropathy as a result of nerve damage or irritation from the anaesthetic injection.Fibrosis or scarring: Over time, scarring or fibrosis at the injection site may occur, potentially leading to difficulties with future procedures.