Overview of Pediatric Regional Anesthesia
Thanks to technology and new methods in the way anaesthesia (which helps with pain management during surgical procedures) is administered, we’ve seen major improvements in managing pain before, during, and after surgeries. One notable advancement is the use of an ultrasound machine, which has opened up new ways this procedure can be done. As a result, some types of pain control that we didn’t have before are now possible.
However, fear and misunderstandings about possible negative effects have meant these new techniques aren’t used as frequently in children as they are in adults. But, a growing amount of trustworthy evidence is showing that these modern methods are safe for children. This is also important because managing pain better can speed up a child’s recovery, and as a result, reduce the cost of healthcare.
Moreover, these methods of pain management with anesthesia are particularly significant today when we are dealing with a crisis related to the overuse of powerful painkillers, known as opioids. This summary will present the basic principles and practices of using these modern pain control methods in children.
Anatomy and Physiology of Pediatric Regional Anesthesia
The use of regional anesthesia techniques, specifically those involving the spinal cord, is common in children. The spinal anatomy and position of the spinal cord vary with a child’s age. It is generally believed that in infants, the spinal cord ends as low as the L3 vertebra, while in adults it ends at the L1 vertebra. Adult-like spinal cord end points are usually seen in kids around 6 years of age. However, recent studies suggest the spinal cord of infants may end even higher, at the L2 vertebra. Such information is very crucial when administering spinal anesthesia to newborns.
In babies, the line connecting the high points (the “intercristal line”) of the hip bones points to where the L4-L5 vertebrae are located, while in adults, this line points to the L3-L4 vertebrae. At birth, the spine has one curve, but as babies grow they develop additional curves in the neck and lower back regions, matching adult spines around their first birthday. At birth, the spine is not fully formed and made of cartilage, which can give in easily to needle insertion points. Hence doctors need to be very careful to avoid injury.
The section of the spinal cord enclosed by the dura, a tough protective membrane (the “dural sac”), extends further in neonates and infants, usually to the S3-S4 vertebrae, compared to the S1 vertebra in adults. Therefore, during procedures like caudal blocks, great care must be taken to avoid unintentionally puncturing the dural sac.
Newborns and toddlers often have a larger, more accessible opening into the epidural space, which is the area between the spinal cord and its outer covering, this makes anesthesia procedures easier. However, as the child grows, this opening becomes fully formed and angled differently making such procedures more challenging.
Due to incomplete development of nerve fibers in newborns, diluted local anesthetics can cause quicker and more intense effects, though the effects may not last as long as in adults. This is due to faster absorption of these drugs into the bloodstream, as well as their faster release from the nerve sheath.
Local anesthetics are often linked to plasma proteins, with any unlinked portion contributing to potential toxic effects. In babies, lower levels of these plasma proteins result in more unlinked anesthetics, which can increase the risk of toxicity. By their first birthday, children usually have adult levels of these proteins.
Lastly, the way children perceive pain is different from adults largely due to differences in their nervous system. As kids have a larger neuron receptive field, it makes it difficult for them to localize pain. Also, they have immature inhibitory pathways, which could lead to amplified pain signals. Therefore, careful management of pain in infants and children is critical.
Why do People Need Pediatric Regional Anesthesia
Doctors often use regional pain relief techniques to manage pain after surgery whenever they can. These same methods are also used to treat many ongoing pain conditions, both caused by cancer and other non-cancer conditions. These techniques play a key role in recovery plans and help reduce the need for strong pain medications, like opioids, after surgery. Managing pain immediately after surgery is crucial to prevent chronic, long-term pain.
When a Person Should Avoid Pediatric Regional Anesthesia
There are certain conditions in which regional anesthesia, a type of pain management used during surgeries, may not be suitable for use in children. These are similar to the conditions in adults. When a child or their parent does not agree to it or if there is an allergy to the local anesthetic drug, the use of regional anesthesia is strictly not advisable. An actual allergy to these medications is quite rare. Many reported “allergies” are responses to additional components in the drugs, such as preservatives. Some reactions might also be due to overdosing on the anesthetic drug.
Other cautionary conditions include when an infection is present in the area where the needle is to be inserted, an issue with blood clotting, severe illness or blood infections, and existing nerve issues. There are some precautions for children who are on blood-thinning medications, which are outlined by the American Society of Regional Anesthesia and Pain Medicine.
If there is instability in the child’s vital signs, it may make the use of a particular type of regional anesthesia, a neuraxial block (anesthesia given near the spinal cord), difficult. Another issue considered is the risk of a condition called acute compartment syndrome (ACS) after surgery on the limbs. Previously it was believed that regional anesthesia might hide pain, a key sign of this condition. However, there is proof to disprove this belief. If a low-strength anesthetic drug is used, increasing pain and an increasing need for pain medication are still signs indicating ACS.
Children undergoing major procedures like urological surgeries or orthopedic surgery on the lower limbs, might have significant abnormalities in their spinal structure. Thus, extra care should be taken while considering a neuraxial block for these children. Similarly, existing nerve issues could also be a limiting factor to consider as further issues could develop. It is best to decide whether to use the regional block on a child with these conditions on a case-by-case basis, considering both the advantages and the risks.
Equipment used for Pediatric Regional Anesthesia
For children, using the right size tools is crucial in safely and effectively carrying out regional procedures, like pain-blocking injections. Small needles are especially important when dealing with nerves in the spine (neuraxial procedures) or around the body (peripheral nerve blocks). It’s worth noting that most issues found by the French-Language Society of Pediatric Anesthesiologists (ADARPEF) were due to using inappropriate tools.
Regarding disinfectants to clean the skin before doing regional blocks, Chlorhexidine is most commonly used. It not only cleans the skin but also continues to work after application, mitigating bacterial buildup on long-term catheters. For children who are allergic to Chlorhexidine, Povidone-iodine can be used as an alternative. However, it should be carefully cleaned off with alcohol after it has dried on the skin to reduce the risk of aseptic chemical meningitis – a condition caused by non-bacterial inflammation of the membranes around the brain. Also remember that prolonged skin contact with Povidone-iodine could cause irritation.
Ultrasonography, a technique that uses sound waves to create images of structures inside the body, has become a key tool for anesthesiologists. This technology helps precisely locate nerves and gives doctors the ability to safely and effectively block those nerves by administering small doses of local anesthetics. Clear imaging made possible by ultrasound has opened doors for a variety of pain-blocking procedures, including transversus abdominis plane blocks (which numb the abdominal area) and erector spinae plane blocks (which numb the back muscles and surrounding areas). Properly sized pediatric probes further improve the visibility and precision of these procedures.
Who is needed to perform Pediatric Regional Anesthesia?
A doctor who is an expert in giving anesthesia (a type of medication to make you feel no pain) to children should be the one to give the anesthesia. If the doctor doesn’t have a lot of experience, there’s a higher chance of problems happening with the anesthesia. It’s very important to have a well-equipped place and trained nurses to watch over the child after the procedure, and while they’re waking up from the anesthesia.
Preparing for Pediatric Regional Anesthesia
In children, anesthetics are usually given before performing certain medical procedures. This isn’t typically the case with adults, who are generally more communicative and can signal if something feels wrong during a procedure. But communication can be difficult with kids, even when they’re awake. They might not be able to tell doctors if they’re feeling tingling sensation known as ‘paresthesia’ after nerve contact or nerve injection. Also, children might not show signs of side effects from anesthesia, like local anesthesia (LA) systemic toxicity. On top of this, if children suddenly move, they are at risk of hurting themselves. This is why around 93.7% of medical procedures on children are performed under general anesthesia (GA), according to the Pediatric Regional Anesthesia Network (PRAN). The risk of complications is higher when procedures are performed on awake children.
Anesthesia is typically given to older children who can cooperate with the procedure, or babies who need small-scale medical operations under spinal anesthesia. But in general, general anesthesia is given to children to make the procedure easier and safer for them. Ideal situation for this is achieved with or without neuromuscular blockade (NMB) and ultrasound guided/regional blocks.
Doctors have been using ultrasound imaging (USG) a lot more in recent years. They use it to closely watch nerves and figure out how to best place blocks, a medication that blocks nerves and decrease pain. But changes in children’s bodies as they grow can make it hard for doctors to find these nerves. The use of ultrasound has made it easier for doctors to successfully place these blocks and has helped bring down the amount of anesthesia needed. This approach has also lowered the risk of nerve damage in children.
There are several steps for ensuring a successful anesthesia procedure. For example, positioning the patient in a comfortable and safe way, maintaining an organized workspace, and checking a patient’s allergies, type of block, and consent for the procedure. Safety measures also include preparing the skin with sterilization and covering the ultrasound probe for safety, wearing sterile gloves, and using sterile equipment. Besides, the amount of anesthesia should be calculated beforehand to avoid any overdose.
Various specific instruments are used in different scenarios. For instance, blunt-tip needles are mostly used, nevertheless, sharp needles may be used for tissue plane blocks when necessary. Similarly, short, thin needles are used for spinal blocks in infants, and other types of needles used for other forms of anesthesia. Therefore, a variety of tools are at the disposal of medical professionals to ensure the safety and comfort of pediatric patients during procedures.
How is Pediatric Regional Anesthesia performed
There are methods used to provide anesthesia or numbness for surgery, either in the whole body or in one area. A technique called an ultrasound (USG) can be used to guide the needle to the right spot, allowing for the delivery of anesthesia to a particular nerve or set of nerves. This is especially useful for operations that only require a small part of the body to be numbed.
There’s also a method called “loss of resistance.” This involves using saline (sterile saltwater) to tell when the needle has reached the right spot in a space in your spine that’s used to deliver anesthesia. This is because tissue and ligaments in your back will provide resistance to the saline, but that resistance will suddenly disappear when the needle enters this space.
Delivering anesthesia to the lower parts of your spine, in particular, requires certain techniques. For example, the needle should be directed in line with your spine for the lower part, and tilted upward for the upper part.
Caudal block is a specific type of anesthesia often used in children. It involves delivering anesthesia to certain nerves in the very lower part of your spine. The volume and type of anesthetic drug used depends on the area they want to numb and the child’s size. It’s important to note that using these drugs must be tailored carefully to ensure it’s safe and effective.
The maximal allowable dose of anesthetic is dependent on the person’s ideal body weight and the specific drug used. Infants younger than 6 months old may require lower doses of these drugs. There are also limits to the amount of drug that can be given over a certain time period, and these limits are lower for infants.
There are possible side effects to these anesthetic drugs, which can affect either the nervous system or circulatory system, leading to symptoms such as tremors, seizures, or issues with heart rhythm. If these occur, immediate medical treatment will be provided.
To extend the effect of anesthesia, other medications can sometimes be added. These include other types of anesthetics or medications like clonidine and opioids. However, these also come with their own potential side effects and have to be used with caution.
Possible Complications of Pediatric Regional Anesthesia
The Pediatric Regional Anesthesia Network (PRAN) is a group of several children’s hospitals that work together to track and improve regional anaesthetic procedures in children. They collected data from 2007 to 2015 which included information on 91,701 pediatric patients who had a kind of block (a procedure to stop nerve signals in a specific area to control pain).
The most common type of single-shot nerve block was a caudal block (a type of epidural in the lower back), while the most common type of single-shot nerve block outside the spine was a femoral block (an anesthetic injection to numb the leg). The majority of the constant-dose injections (73%) were given around the spinal cord.
Common minor problems were related to the fluid delivery tubes (4%), including them coming loose, getting blocked, or disconnecting. Very few patients experienced neurological problems (2.4 out of 10,000 blocks) – these were typically issues with feeling or sensation which went away within 3 months. Thankfully, no patients experienced lasting issues with their motor nerves, which control the body’s muscles. The risk of neurological problems was the same regardless of the type of nerve block, location, or technique used.
The rate of serious side effects from the local anesthetic, such as seizures or heart arrest, was 7 out of 10,000 blocks. Most of these occurred in infants less than six months old after they received an initial high dose of local anaesthetic. One patient had a spinal cord abscess (a collection of pus near the spine), which required treatment but happily, it resolved without causing any lasting nerve damage.
Out of every 10,000 blocks, 53 patients developed skin infections, which were more common with nerve blocks that were administered around the spinal cord complex. Luckily, there were no reports of internal bleeding around the spinal cord. Potential risks such as fluid build-up around the brain (dural puncture) were rare, ranging from 10 to 86 incidents for every 10,000 blocks, depending on the technique. When continuous-dose morphine was delivered around the spinal cord, 14 out of 10,000 patients experienced difficulty breathing. Studies from other organizations also found a very low occurrence of complications.
Overall, these findings go a long way in ensuring and improving the safety of pediatric regional anesthesia.
What Else Should I Know About Pediatric Regional Anesthesia?
There are several reported benefits of using regional methods for post-surgery pain relief, according to different studies, especially those focused on adults. Methods like neuraxial anesthesia during surgery and epidural pain relief afterward have been shown to have benefits, including reducing the chances of death. An epidural, usually given in the middle of your back, can help balance the oxygen supply-demand in your heart, protecting it from damage or irregular heartbeat.
Untreated pain after surgeries in the belly area can harm breathing, leading to lung collapse (atelectasis) and infection (pneumonia). Using an epidural for major belly surgeries can greatly relieve pain and lessen the chances of post-surgery lung problems. Moreover, an epidural can help your digestive system get back to work quicker after major surgeries in the belly area. This is possible because of the epidural’s direct pain relief effect and its ability to lessen the need for opioids.
Neuraxial pain relief, which means anesthesia given in or around the spinal cord, can lessen the stress response to pain and the following overactive blood clotting after surgery. This reduces the chances of issues from blood clots (thromboembolic complications). Other benefits include lesser need for opioids (strong painkillers) and thus decreased chances of their side effects like drowsiness, nausea, and vomiting.
