Overview of Ultrasound-Guided Intercostal Nerve Block
An intercostal nerve blockade is a type of regional pain relief that can be easily done in a hospital room, with or without the use of ultrasound to guide the doctor. It’s a procedure used for both diagnosing and treating certain conditions. This treatment can relieve pain or enhance anaesthesia in different situations, including after chest injury, chest wall surgery, or a condition called postherpetic neuralgia, which is a complication of shingles.
On the whole, patients handle this procedure well, and complications are minimal, especially when ultrasound is used to guide the doctor. This makes it a safe and effective way to manage pain in a variety of situations.
Anatomy and Physiology of Ultrasound-Guided Intercostal Nerve Block
The intercostal nerves are a set of nerves that run from your spinal cord, specifically between your T1 and T11 vertebrae. These nerves are involved in both sensing and controlling movements (motor control) in specific areas of your body. The sensory side of these nerves helps you feel things on your chest and stomach walls, and around your ribs. The motor side helps control the muscles in similar locations. The intercostal nerves are located near the bottom edge of each rib.
The nerve that comes from the T12 spinal vertebra, found at the bottom of your rib cage, is called the “subcostal nerve.” There are also so-called “atypical” intercostal nerves that do more than just control the chest and stomach area and extend to other parts of your body.
Each of these intercostal nerves splits into smaller branches that have different functions. Some connect to parts of your body’s fight-or-flight response system (sympathetic ganglion), while others control the movements and sense the muscular section of your body (the torso). Some branches even provide sensation to parts of your skin on your chest.
The nerves that run from your third to sixth rib (T3 to T6) are known as “typical” intercostal nerves. These control the layer lining the inside of your chest (the parietal pleura).
About half of the intercostal nerves are considered “atypical.” These nerves have functions extending beyond the chest region. For instance, the first intercostal nerve, which originates from the T1 spinal cord, splits into two branches that control different areas in the upper body, including the arm. Some other intercostal nerves provide sensation and motor control to the muscles and skin of the stomach and abdomen area.
It’s important to note that, with the exception of the first and subcostal nerves, intercostal nerves do not form a network (plexus) and each follows its specific path.
Why do People Need Ultrasound-Guided Intercostal Nerve Block
Intercostal nerve blockade, a procedure where the sensation from the skin and tissues surrounding your ribs is blocked, can be used for various purposes. This method can be used to bring relief for conditions causing pain in the chest area including costochondritis (inflammation of chest cartilages), shingles (painful viral rash), and postherpetic neuralgia (a nerve pain complication of shingles).
In addition, it can be used after surgeries to decrease pain, especially in surgeries involving the chest wall and breast tissue. For example, it has been found to be effective in reducing pain after lumpectomy (surgery to remove cancer or other abnormal tissue from your breast), partial or complete mastectomy (surgery to remove all breast tissue from a breast), and breast reconstruction.
The procedure is simple enough that it can be performed right at your bedside in the emergency room. This makes it a great option in treating blunt force trauma to the chest, sternal (breastbone) fractures, and fractures of multiple ribs. It also serves as an effective form of anesthesia for the insertion of a chest tube (a tube inserted between the ribs to remove fluid, blood or air from the space around the lungs).
For patients suffering from pain stemming from the thoracic spine (the part of the spine that corresponds to the chest), or uncharacteristic pains in the chest wall, the intercostal nerve blockade might also be beneficial. In cases of these unusual chest wall pains, the procedure may help both in identifying (diagnostic) and easing (therapeutic) the pain.
When a Person Should Avoid Ultrasound-Guided Intercostal Nerve Block
Before treating pain in the ribs with a method called an intercostal nerve blockade, doctors need to consider several factors. This technique blocks the nerves between the ribs to help manage pain, but it might not be safe for all people.
Certain situations, or “absolute contraindications,” often mean people cannot have this procedure. This can include people not wanting the procedure, having an infection where the injection would be made, being allergic to the local anesthetics used, or hospitals not having sterile equipment. High risk of local anesthetic toxicity, which is harmful reactions to the medicines used to numb the area, also prevents the use of this technique. Also, the doctor or nurse must be skilled enough to perform it and a kit for restarting the heart must be available.
There are also situations called “relative contraindications” where it might not be recommended. If a patient cannot alert their doctor of toxicity symptoms, has a blood condition that makes them bleed easily, or takes medications to thin their blood, the risk can be higher. If there’s a threat of reduced blood supply to the far end of an arm or leg or an organ, or if a patient has existing nerve diseases, it may also not be safe. Lastly, it’s also usually not recommended for children and patients with dementia or severe agitation, since they might not be able to communicate properly during the procedure.
Equipment used for Ultrasound-Guided Intercostal Nerve Block
For a procedure known as an intercostal nerve block, the following materials are needed:
* A high-frequency ultrasound machine which acts as our medical radar to locate the areas we need to focus on.
* A sterile cover for the ultrasound to maintain cleanliness and avoid any infections.
* A marking pen to mark the targeted area on your skin.
* Sterile gloves for cleanliness.
* Clear drapes to keep the surrounding skin surface around the operation area clean.
* A special skin cleaner called 2% chlorhexidine gluconate to disinfect your skin before the procedure.
* A 20- to 22-gauge needle that’s between 4 to 5 centimeters long for performing the actual nerve block.
* Lidocaine 1%, a local anesthetic that numbs the area we’re working on.
* 2-inch gauze to cover and protect the area after the needle has been inserted.
* Syringes of various sizes (3, 12 and 20 mL) to administer the necessary drugs.
We also setup additional equipment such as:
* Standard American Society of Anesthesiologists (ASA) monitors. These include a 3-lead ECG to monitor your heart, a blood pressure monitor to keep an eye on your blood pressure, pulse oximetry equipment to measure how much oxygen your blood is carrying, and a nasal cannula with an EtCO2 detector to measure carbon dioxide levels you breathe out.
* Resuscitation equipment and ACLS medications just in case we need to treat any emergency situations.
* Lipid Emulsion 20%, which is a treatment for a severe local anesthetic overdose. We also have drugs like epinephrine and benzodiazepines on hand if needed.
Who is needed to perform Ultrasound-Guided Intercostal Nerve Block?
The process of blocking the nerves in the rib area (this is called an intercostal nerve blockade) is usually done by a very experienced doctor who specializes in anesthesia. This doctor uses a special ultrasound machine to guide them during the procedure and make sure it’s done safely and effectively. Usually, this doctor will have another skilled medical professional helping them.
Preparing for Ultrasound-Guided Intercostal Nerve Block
To lower the chances of complications from regional anesthesia, such as when the needle accidentally punctures a nerve, medical professionals use special monitors. These monitors include a one-time-use device that keeps track of the pressure when local anesthetic is being injected. Recording the details of each step of this procedure is vital in all healthcare facilities where they provide regional anesthesia. This helps maintain safe and effective practices.
How is Ultrasound-Guided Intercostal Nerve Block performed
Intercostal nerve blocks are a type of pain relief treatment where a doctor injects medicine to block off the nerves between the ribs. They can be performed with ultrasound guidance or without it.
Intercostal Nerve Block Without Ultrasound Guidance
If you are having an intercostal nerve block without ultrasound, these are the steps your doctor will follow:
1. They will put you in a comfortable sitting, lying on your side, or face-down
position. If seated, you will be asked to lean forward over a support to broaden your back.
2. They will clean the treatment area with an antiseptic solution to prevent infection.
3. The doctor will mark the treatment spots that are about 6 to 8 cm from your spine.
4. They will numb the site with a local anesthetic.
5. The needle will be inserted straight in, aiming for the lower edge of a rib to reach a groove beneath it.
6. A small amount of anesthetic will be injected to numb the tissue around the bone.
7. The needle will be moved a bit further (2 to 3 mm), and you might feel a “pop” sensation as the needle passes through a layer of tissue.
8. Your doctor will then draw back the needle slightly to make sure it isn’t in a blood vessel.
9. Finally, they will inject 3 to 5 mL of local anesthetic. This process may be repeated to spread the anesthetic.
Intercostal Nerve Block With Ultrasound Guidance
If you are having an intercostal nerve block with ultrasound guidance, these are the steps your doctor will follow:
1. Positioning, cleaning, and marking the sites are similar to the process without ultrasound.
2. The doctor will use a special tool called a high-frequency linear transducer to see the muscles around your ribs.
3. They will use the ultrasound to pinpoint the blood vessels.
4. They will find the edge of a rib with a long view.
5. The doctor will insert the needle aligned with the ultrasound view, aiming for the middle.
6. Again, they will check that the needle isn’t in a blood vessel.
7. The anesthetic will be injected between two layers of muscle.
8. The ultrasound pays a critical role in showing where the medicine spreads.
Following this, depending on the level of pain relief needed, the doctor might use more needles to insert anesthetic at multiple levels. The amount of local anesthetic used comes with a maximum limit since it can quickly reach high levels in the bloodstream.
The dose is usually 0.1 to 0.15 mL/kg per space between the ribs, not exceeding 2 to 3 mL per space. The most common medicines used are ropivacaine 0.2%, levobupivacaine 0.25%, or bupivacaine 0.25%. Liposomal bupivacaine can be used to manage severe pain in patients receiving certain surgeries.
Possible Complications of Ultrasound-Guided Intercostal Nerve Block
Getting an intercostal nerve block, which is a type of pain relief method, is generally safe. However, like all medical procedures, it can have some risks. These could involve injuries to nearby body parts like the chest artery, nerves, protective layers of the lungs which can lead to lung collapse (pneumothorax) or blood accumulation in the chest (hemothorax), and muscle tears. Some people might feel pain during the procedure, and sometimes, it might not completely take away the pain as planned. There’s also a chance of getting an infection where the injection is given.
Something called local anesthetic systemic toxicity (LAST) is an uncommon risk that can happen due to the anesthesia. This condition occurs if too much anesthetic enters the bloodstream and disrupts the normal operation of the heart and brain. Doctors are always on the lookout for this, but luckily it’s quite rare.
Remember, the doctors carrying out the procedure are very attentive to perform the technique correctly and follow all safety measures to lower these risks as much as possible.
What Else Should I Know About Ultrasound-Guided Intercostal Nerve Block?
An intercostal nerve blockade is a type of pain control method often used after surgery. It directly targets the nerves between the ribs to ease pain, typically for about 8 to 12 hours, and is known to have fewer complications compared to other similar procedures or epidural injections. If a special type of medication called liposomal bupivacaine is used during the procedure, the pain relief can last for up to 72 hours. This method also helps reduce the need for strong painkillers, known as opioids, after surgery.
