Types of Anesthesia - An Overview

Introduction

A precise anesthesia definition can be complex. However, in simple terms, a medical intervention that is given to patients to reduce their discomfort and pain during a surgical procedure and certain screening procedures is termed anesthesia. Healthcare professionals who are specialized in giving anesthesia are called ‘anesthesiologists’. The medicines administered are termed anesthetics. Anesthesia is given in various forms, like inhalational, intravenous, as an injection, etc., depending on the requirement. This article deals with the different types of anesthesia.

What Is Anesthesia?

Drugs that are given to prevent one from feeling pain or discomfort during a surgical procedure or complex diagnostic procedures are called anesthesia. An anesthesiologist has to be consulted prior to the surgery to get proper guidance on the patient’s health status and help them decide what type of anesthesia and types of anesthesia drugs are suitable for the patient.

Before the evolvement of anesthesia, about 175 years ago, surgeries were rare and were used as the last resort. The patients who underwent surgeries were fully aware of what was happening and had to bear the pain. With the advancement in the field of medical science, anesthesia was introduced, and even life-saving surgeries became more feasible. Though the anesthesia used in the modern world is safe, there are also risks like breathing problems, allergic reactions, and general confusion after the surgery.

What Are the Types of Anesthesia?

There are different types of anesthesia. The type of anesthesia required will depend on the type of procedure, the health status of the patient, and other factors. The different types of anesthesia for surgery include:

1. General Anesthesia: This makes the patient fall asleep or unconscious and unable to move. It is usually preferred for time-consuming, complex surgical procedures, like spinal surgery. The anesthesia medicine is given inhalational (breathed through a mask) or through an intravenous (IV) line. A breathing tube might be used in the windpipe to facilitate breathing during the surgical procedure. The medicine is stopped after the procedure, and the patient is shifted to a recovery room for observation.

2. Monitored Sedation: This is similar to general anesthesia, as it relaxes the body and makes the patient sleep. However, in monitored sedation, the patient might be conscious. They might even be able to talk, depending on the level of sedation given. In procedures like colonoscopies (a procedure to examine the colon), monitored sedation is coupled with painkillers to reduce procedural discomfort. They are usually given through an intravenous line.

3. Regional Anesthesia: In this type of anesthesia, only the area where the surgical procedure is done, like an arm, a leg, or the area below the waist, is made numb. Hand and joint surgeries, cesarean section, etc., are some examples where regional anesthesia is used. The patient is conscious but does not feel the pain in regional anesthesia. The anesthetic medicine is given either through a catheter or an injection. There are two forms of regional anesthesia, which include:

   • Spinal Anesthesia: This type of anesthesia is used in surgeries in the lower abdominal, pelvic, rectal, or lower extremities. The anesthetic agent is injected as a single dose into the region near the spinal cord. It is usually given in the lower back, causing numbness in the lower body. Surgical procedures of the legs or hips use this type of anesthesia.

   • Epidural Anesthetic: This is similar to spinal anesthesia, but the anesthesia is given continuously through a catheter placed in the area near the spinal cord in the lower back. It causes numbness in the lower back. Epidural anesthesia can be used in chest and abdominal surgeries. In these surgeries, the anesthesia is delivered to a higher area of the spine. Labor, cesarean sections, and surgeries of the colon and gastrointestinal tract usually use this type of anesthesia for surgery.

4. Local Anesthesia: This type of anesthesia works only on only one part of the body. For example, it can be used to prevent pain during tooth removal by blocking a nerve that supplies the tooth. The patient receiving local anesthesia will be aware of what happens around them during the procedure and be comfortable. Different types of local anesthesia can be given in various forms like injection, topical lotion or spray, eye drops, or skin patches.

What Is Laryngeal Mask Airway?

In some cases, the anesthesiologist would prefer to use a method called laryngeal mask airway (LMA) instead of intubating the patient. This method works faster and causes less discomfort to the patient. It consists of a tube with an inflatable cuff, which can be inserted into the upper part of the patient’s windpipe (pharynx). It is also called a ‘supraglottic airway device.’ It temporarily provides an airway while the patient is under anesthesia. It is also used as an immediate life-saving method when the airways fail to function.

How Does Anesthesia Work?

Different types of general anesthesia work to stop pain by stopping the nerve signals from being passed to the brain. Though the exact mechanism of how anesthesia works might not be clear, some of the mechanisms how they work can include:

• Altering the Release of Neurotransmitters: The chemical messengers that help pass signals from one neuron to another are called neurotransmitters. They can either cause a signal to be passed or block a signal from being transmitted. Some anesthetic agents block the transmission of signals, while others release an inhibitory neurotransmitter. This prevents the pain signals from being passed, anesthetizing the area.

• Altering the Ion Channel Release: The ion channel proteins pass through the nerves to cause the normal transmission of signals. The anesthetic agent prevents the passage of ion channel proteins, which prevent the passage of signals. As a result, the signals do not reach the brain and prevent the sensation of pain.

Conclusion

Different types of anesthesia have made life-saving surgical procedures feasible with lesser patient discomfort. Procedures that were considered as the last resort have now become more common with the advent of different types of anesthesia for surgery. The different types of anesthesia drugs can remain in one’s body for about 24 hours. Patients are advised not to drive or do any complex activities unless the general anesthesia medicine is completely eliminated from the body. However, the patient can return to normal activities (to an extent with the physician’s consent) after local or regional anesthesia in many cases.