Overview of Pectoralis Nerve Block
The Pecs block I and II are newer techniques that help in numbing certain nerves in the chest region, including the pectoral nerves, intercostal nerves 3 to 6, intercostobrachial nerves, and the long thoracic nerve. These methods are particularly helpful in managing pain for surgeries performed on the front wall of the chest, like breast surgery. These blocks are easily performed by doctors and most of the time patients require little or no sedation beforehand.
The Pecs I block was first introduced in 2011 by Blanco and his colleagues. They defined it as a technique that involves injecting a high amount of local anesthetic between the pectoralis major and minor muscles, mainly targeting the lateral pectoral nerves.
In 2012, Blanco and his team introduced the modified version of the Pecs block, called the Pecs II block. This second version, like Pecs I, targets the area between the pectoralis major and minor muscle, but it also focuses on the area between the pectoralis minor and the serratus anterior muscle. The aim is to numb intercostal nerves 3 to 6, intercostobrachial, and the long thoracic nerves, which are all significant for surgery involving axillary node dissection- a procedure where the lymph nodes in the armpit are removed.
A recent meta-analysis (a statistical method where results from multiple scientific studies are combined) compared 14 randomized trials of Pecs II block versus another technique called paravertebral blocks. The results showed that there were no significant differences in the usage of pain relievers or the reported pain levels between the two methods in patients who had undergone breast cancer surgery. Also, the study found that when it comes to 24-hour morphine usage and post-surgery pain intensity, Pecs II blocks are just as good as paravertebral blocks. When compared with only using systemic analgesia, or pain relief medicine that works on the whole body, both block types were found to be better.
Anatomy and Physiology of Pectoralis Nerve Block
A Pecs I block is a procedure that requires an injection of local anesthetic between two chest muscles, called the pectoralis major and pectoralis minor, at the level of your third rib. This achieves numbness by blocking the signals to both the medial pectoral nerve and lateral pectoral nerve, which provide sensation to that area. This process is guided by an ultrasound, which helps locate key structures such as the pectoralis major muscle, pectoralis minor muscle, and a certain artery, called the thoracoacromial artery.
The Pecs II block is a bit different but can be achieved using the same needle stick used for the Pecs I block. The anesthetic is placed in the same area as before, in addition to another space located between the pectoralis minor and another chest muscle known as the serratus anterior. This added step successfully numbs other nerves, blocking the sensation in an even larger area, which includes the skin covering the ribs (from 3rd to the 6th), the intercostobrachial nerves, and the long thoracic nerve. The similar landmarks identified by the ultrasound in this procedure include the pectoralis major muscle, pectoralis minor muscle, serratus anterior muscle, and the thoracoacromial artery again.
Why do People Need Pectoralis Nerve Block
The Pecs I and II techniques can be used to provide localized pain relief for a wide range of surgeries. These surgeries can include placing breast expanders and under-the-muscle prostheses, insertion of small medical devices like ports, pacemakers, and implantable heart defibrillators, front-chest surgical openings, front shoulder surgeries, tumor removal, breast removal surgeries, biopsy of a sentinel lymph node (the first lymph node to which cancer cells are most likely to spread from a primary tumor), and axillary dissection (surgery to remove lymph nodes found in the armpit region).
When a Person Should Avoid Pectoralis Nerve Block
There are certain situations where a Pecs block, a type of numbing injection for pain relief in the chest wall, should not be performed. If a patient does not want the procedure, or if there is an infection where the injection would be given, it cannot be done.
When a patient is taking medications that slow their body’s ability to form clots (called anticoagulants), it could potentially be unsafe to perform a Pecs block. However, there are no specific guidelines for this situation. In 2018, the American Society of Regional Anesthesia didn’t provide a clear rule for combining Pecs blocks and anticoagulants.
Equipment used for Pectoralis Nerve Block
The following equipment and products are used in a procedure known as Pecs Block that helps to numb the chest area, making you uncomfortable during the procedure. The provisions include the following:
– Chlorhexidine gluconate, which is an antiseptic that kills bacteria and viruses on your skin before a medical procedure to prevent infection.
– Sterile gloves are used to maintain cleanliness and avoid contamination during the procedure.
– A high-frequency linear ultrasound probe with a sterile cover and gel. This is a tool that helps the doctor to see images of the inside of your body during the procedure.
– 22G regional block needle, 50 to 100 mm. This is a special kind of thin, long needle used for numbing part of your body.
– Pecs Block local anesthetic solution (0.25% bupivacaine or 0.5% ropivacaine 20 to 40 ml). This is a medication that is given to you to numb the area where the procedure will be done.
– An Epidural catheter (optional). This is a small tube that might be placed in your back to give you pain medicine.
Who is needed to perform Pectoralis Nerve Block?
It’s best to have a specialized doctor, known as an anesthesiologist, who has skills in regional anesthesia and the use of ultrasound. Regional anesthesia refers to numbing a specific area of the body so you don’t feel any pain during the procedure. Ultrasound is simply a device that uses sound waves to create images of the inside of your body. Additionally, having an extra person on hand to help, like a nurse or another doctor, is highly recommended.
Preparing for Pectoralis Nerve Block
Before undergoing any medical procedure, patients need to be fully informed about what will happen. This includes understanding the risks and benefits. This information helps the patient make an educated decision about their treatment plan.
In order to protect patient safety, doctors and medical staff will take a “time out” to double-check critical details about the procedure, like what exactly will be done, where, and making sure there are no reasons why the procedure shouldn’t happen.
As part of standard procedure, patients’ health will be continuously monitored during the procedure. This includes tracking heart patterns with an electrocardiogram (ECG), checking oxygen levels in the blood using pulse oximetry, and constantly noting changes in blood pressure. Patients will also have a line put into a vein to allow for quick access if medications or fluids need to be given during the procedure. Equipment for sudden emergency situations, like those needed to handle unexpected reactions to local anesthetics and a tube to help with breathing (intubation), will also be kept on standby.
Particular care is taken to avoid any kind of infection. Doctors bathe the area where the surgery will be conducted in an antiseptic solution, chlorhexidine gluconate. Strict cleanliness protocols are maintained throughout the process. All medical staff will wear masks, head coverings, and sterile gloves to keep the area as clean as possible. Even equipment used for imaging, like an ultrasound probe, will have a sterile cover on.
How is Pectoralis Nerve Block performed
The Pecs I and Pecs II blocks are techniques used by doctors to numb certain areas of the body for pain relief, typically during or after surgical procedures in the chest area. They both involve the use of ultrasound guidance for safety and efficiency, and administering an anesthetic drug via injection or catheter to block the pain.
In a Pecs I block, you will be asked to lie flat on your back with your arm either straight by your side or bent at a right angle. Using ultrasound imaging, the doctor will locate a part of your body called the coracoid process. The ultrasound machine is then angled a little to the side. This helps your doctor see the path where the needle would go, and also helps them avoid a small artery in that area. After that, the anesthetic drug- usually 0.2 mL/kg of a 0.25% solution of either bupivacaine or ropivacaine- is injected into the area between two chest muscles, the pectoralis major and pectoralis minor.
The Pecs II block is done in a similar position to the Pecs I block, with the same anesthetic drug used. The difference is that in a Pecs II block, the anesthetic is injected in two separate spots. The first spot is the area between the pectoralis major and pectoralis minor muscles, just like in a Pecs I block. The needle is then repositioned under ultrasound guidance to the second injection site, which is between another pair of muscles, the pectoralis minor and the serratus anterior. These injections are typically 1 to 3 cm deep for the first spot, and 3 to 6 cm deep for the second spot.
To prevent accidental injection into a blood vessel, the anesthetic should be injected in small amounts of 5 cc each time, and your doctor should take out some fluid from the injection site to make sure it’s not blood before injecting more. If you’re likely to need pain relief for a long time after surgery, the doctor might introduce a catheter (a small plastic tubing) into the areas where the anesthetic is injected. The last 10 cc of anesthetic can be injected into the catheter to ensure that it’s properly positioned and not inside a blood vessel. The Pecs II block is sometimes done by targeting the deeper injection spot first, and then withdrawing the needle to the shallower spot.
Possible Complications of Pectoralis Nerve Block
Using ultrasound guidance during medical procedures helps to lower risks because your doctor can clearly see your lung covering and major blood vessels the entire time. Despite this, complications are not entirely ruled out, but they are quite rare.
The most common issues that can arise include a pneumothorax, which is when air gets into the space between your lung and chest wall causing your lung to collapse. Other possible complications include infection, having an allergic reaction or toxic response to the local anesthetic, accidentally hitting a blood vessel, or the treatment not working as intended.
What Else Should I Know About Pectoralis Nerve Block?
The Pecs block is a recent advancement in pain control methods used for surgeries that involve the chest wall. It can help relieve pain and potentially bypass the need for more complicated procedures like paravertebral blockades, which are techniques used to numb specific areas of the body. Doctors who specialize in anesthetics have used Pecs blocks to manage pain for a range of procedures, from the insertion of a port (a small medical device that allows easy access to veins) to radical mastectomies (complete removal of one or both breasts as a form of breast cancer treatment).