Saddle Anesthetic Block (Saddle block)

Overview of Saddle Anesthetic Block

Using medication to numb certain areas of the body by injection into the spine has been a common practice for over 100 years. One specific type of this procedure is called ‘saddle block anesthesia’. It’s named this way because it numbs the areas where you would feel if you were sitting on a saddle, like your thighs, the back of your legs, and areas around your bottom.

This procedure uses different numbing drugs such as procaine, bupivacaine, cocaine, among others. Some long-lasting drugs like pontocaine and cinchocaine are used to ensure the numbing effect lasts for a longer time. Compared to general anesthesia (where the whole body is numb) and subarachnoid block anesthesia (a type of spinal anesthesia that affects a large area), saddle block anesthesia is preferred because it produces numbness in a more selective area.

This technique is commonly used for childbirth, surgeries related to the urinary system, rectum, and for providing relief from pain before, during or after surgeries. It is also becoming popular for use during childbirth because it needs a lower dose of drugs, providing complete relief from labor pains without affecting the baby.

Other benefits such as quick effect, strong numbing, early patient movement, and shorter hospital stay make the saddle block procedure preferred for surgeries around the bottom area. This is especially noticed in day surgery centers that perform lots of surgeries per day.

Anatomy and Physiology of Saddle Anesthetic Block

When a doctor gives a patient a spinal saddle block, which is a type of anesthesia, they need to understand the structure of the spine and spinal cord. The spinal canal is a long tube-like space that is formed by the alignment of holes in the vertebrae, the bones in the spine. This canal houses the spinal cord which starts at the base of the brain and ends around the first vertebra in the lower back in adults, but extends to the second one in infants. The spinal cord is about 45 cm long and is surrounded by three layers called the meninges.

The layers from outside to the inside include the dura mater, arachnoid mater, and pia mater. There is a small low-pressure space between the dura mater and the spinal canal. This is known as the epidural space and it contains a mix of loose connective tissue, fat, lymph vessels, arteries, and a network of veins. There is also another potential space, the subdural space, between the dura mater and the arachnoid mater.

The dura mater extends below the spinal cord and along each nerve, eventually merging with the outer layer of the spinal nerves. The space between the arachnoid and pia mater, known as the subarachnoid space, is filled with cerebrospinal fluid. This is the area where anesthetic drugs are often injected. In adults, this space ends at the second bone in the sacrum, part of the lower spine, and extends a bit lower in children.

One way doctors locate the correct spot for the injection can be through a landmark called the Tuffier line, an imaginary line that connects the tops of the hip bones on both sides. This line generally lines up with the fourth lumbar vertebra in your lower back.

Why do People Need Saddle Anesthetic Block

A saddle block is a type of anesthesia often used for several different types of surgeries. This technique can numb the lower part of your body, while you remain awake. It’s commonly used in the following situations:

In maternity care, it’s used during:

• Regular childbirth
• Childbirth involving the use of forceps during the final stages of delivery
• Repairs of an episiotomy, which is a surgical cut made at the opening of the vagina during childbirth to aid a difficult delivery and prevent rupture of tissues

In urology, where it’s commonly used during:

• TURP, which stands for transurethral resection of the prostate, a procedure often used to solve urine blockage due to an enlarged prostate
• Fournier’s gangrene, a severe infection of the genital area which requires surgery

In surgery involving the rectal or anal area:

• Hemorrhoids, which are swollen veins in the lowest part of the rectum and anus that can be painful and cause bleeding
• Pilonidal sinus, a small hole or ‘tunnel’ in the skin at the top of the buttocks where they divide (the cleft). If it becomes infected, it usually needs surgery

When a Person Should Avoid Saddle Anesthetic Block

Saddle anesthesia is a type of numbing treatment often used in medical procedures that can provide many benefits. However, there are some cases where it cannot be administered. Some of those reasons are highlighted below.

There are some absolute no-go situations, including:

• If there’s an infection in the place where the numbing medication would be injected, it’s too dangerous to give saddle anesthesia.
• Coagulopathy, a condition that affects the blood’s ability to clot, can make the procedure too risky.
• If the patient doesn’t want the treatment, the doctors will not go ahead with it.
• If in the past, the patient had an allergic reaction to the medicine used in this treatment, they shouldn’t have it again.

There are also some other situations where doctors need to be extra careful when considering this treatment, such as:

• If the patient is suffering from a body-wide infection, it may not be safe to administer the anesthesia.
• People with neurological diseases or conditions related to the brain and nerves would need more careful assessment.
• If the patient has any spinal abnormalities, there could be risks involved.
• If the patient have had a specific type of headache in the past—known as a post-dural puncture headache—after a similar procedure, the doctors would need to proceed cautiously.
• If the pressure inside the patient’s skull is higher than normal, doctors need to weigh up the potential dangers.

Equipment used for Saddle Anesthetic Block

The tools needed for this operation typically include surgical gloves for cleanliness, a substance that kills bacteria paired with clean medical gauze to clean the area, a special needle called a “quincke spinal needle” that is sized between 22-25G, an ordinary needle for injections, and medications to numb the area.

Who is needed to perform Saddle Anesthetic Block?

An expert doctor known as an anesthesiologist, along with a surgical assistant and a nursing assistant, are needed to do the operation. A radiologist, who is another kind of doctor that uses medical images to diagnose and treat illnesses, can use an ultrasound (a tool that uses sound waves to create pictures of the inside of the body) to guide a special type of anesthesia called a saddle block. This helps to make sure the operation is done safely and successfully.

Preparing for Saddle Anesthetic Block

When a patient is in the operation room, a doctor will insert a large needle into a vein to help deliver vital fluids and medication during the procedure. The patient is then comfortably situated in a sitting position and hooked up to monitors that keep track of essential body functions. These machines measure heart rate, blood pressure, the amount of oxygen in the blood and even the average pressure in the arteries during a heartbeat.

The surgical team makes a note of these measurements before any drugs are given. This is important as it gives the doctors a benchmark to reference, helping them ensure the patient is stable and healthy during the operation. These numbers are checked frequently, usually every 5 minutes, to keep an eye on any changes.

Unlike some other procedures, patients are not given any medication before this type of surgery. That’s because the local anesthesia used (called a ‘saddle block’) won’t cause unnecessary changes in blood pressure and other bodily functions. This also means there’s no need to give the patient a medication called a vasopressor, which is sometimes used to increase blood pressure, before the surgery starts.

During the operation, the team makes sure that emergency drugs are readily available. If the patient’s average pressure in their arteries (known as MAP) falls too low, the surgical team will give a vasopressor. If the heart rate slows (a condition known as bradycardia), they’ll give a medication called atropine. This helps keep the patient stable throughout the procedure.

A clean, bacteria-free area, known as a sterile field, is established using antibacterial solution. This helps to minimize the risk of infections. The patient remains in a sitting position during this process.

How is Saddle Anesthetic Block performed

A subarachnoid block is a type of anesthesia that works at or below the chest area (specifically at the fourth thoracic vertebra or T4). This is because the highest point of the curve between your chest and lower back is at the T4 level. The anesthesia goes to this level when you’re lying on your back. A specific kind of this anesthesia, called a saddle spinal block, is focused on your lower back region. This leaves your body’s ‘fight-or-flight’ response unaffected and has little impact on your blood circulation.

The spot where the anesthesia is injected is very important. It needs to be right for you to get the right amount of numbness and to avoid injury to the lower end of your spinal cord. To find this spot, doctors draw an imaginary line joining the tops of your hip bones and locate the point on your spine that aligns with this line. This is usually level with the fourth bone in your lower back or L4. Doctors then find the gap between L3 and L4 bones in your lower back. All spinal blocks should be done at or below this space to prevent any possible injury to the spine.

When doing the procedure, doctors take special care to keep everything clean and sterile. They then inject a needle into the middle line of your skin to numb the space between the third and fourth bones in your lower back. This results in a small raised area on your skin’s surface. A special spinal needle is then inserted at the level of the gap with the patient in a sitting position. The needle goes through the skin and the layers underneath until two ‘pop’ sounds are heard. The first pop is when the needle penetrates a thick tissue in the lower back region. The second pop is when the needle pierces the protective layers of the spinal cord.

Doctors confirm that the needle has successfully pierced the spinal cord by pulling back the needle and seeing clear brain-spinal fluid leaking out of it. If the needle is thin, doctors might need to pull back the fluid themselves to make sure the needle is in the right place. They then attach a syringe with the anesthetic to the needle and pull back some fluid to make sure the needle hasn’t moved. If the needle has moved, they’ll need to reposition it. After the anesthetic is injected, the patient should stay in the same sitting position for 3 to 10 minutes.

Doctors then check the level of numbness by using a cold alcohol swab or doing a pinprick test on both sides of the body. They also test if there’s any weakness in the movement by using a tool called the Bromage scale.

Possible Complications of Saddle Anesthetic Block

Saddle block anesthesia is a type of pain relief used during surgery. It’s generally safe, easy to do, and doesn’t cause many problems. However, there can be some downsides. After getting this type of anesthesia, you might need to sit for a long time, which could lead to trouble peeing after the surgery. But this can be helped by moving you into a different position just a minute after the drugs are given.
It might take a little extra time for the anesthesia to start working, which could delay the start of the surgery. Also, the pain relief might not last as long as we want it to. To solve this, we can add different pain relief drugs into the mix. Using these add-ons helps make the anesthesia last longer, uses less local anesthetic, and makes it easier for you to start moving and peeing after surgery.

Of course, like any medical procedure, there can be some risks. If the doctor giving the anesthesia isn’t experienced, it could lead to nerve damage, back pain, loss of bowel or bladder control, or numbness in your private parts. Rarely, they could accidentally inject into a blood vessel, causing bleeding. Headaches and backaches are fairly common. There’s always the risk of infection, too, or that the anesthesia just doesn’t work as well as it should.

What Else Should I Know About Saddle Anesthetic Block?

Saddle block is a method of providing pain relief during and after surgeries in areas such as the birth canal, urinary tract, and the area around the anus. The advantage of spinal anesthesia methods like the saddle block, over general anesthesia, is that they don’t require the patient’s airway to be opened with a tube, which can lead to irritation and breathing problems.

Saddle block also requires less use of strong painkillers after the surgery. An important concern during anesthesia is a significant decrease in blood pressure due to the altering of nerve function. This can be complicated in older patients or those with existing heart and lung conditions, particularly if their circulation has been overloaded due to the fluids and medication to adjust the blood pressure.

However, with saddle block, this concern is less pronounced as it doesn’t lead to an over-inhibition of the sympathetic nervous system, that system which regulates unconscious actions such as heartbeat and blood pressure. Another advantage of saddle block is that patients can move about soon after their operation, especially a benefit for day surgeries. For pregnant women, this technique is very beneficial as it allows the newborn to breathe on its own more naturally and there is less likelihood of complications for both mother and baby.