The term anesthesia originates from the Greek words "an" and "aesthetics," which means "loss of perception or sensation. Sensory loss can be localized, manifested in a certain part of the body, or systemic, manifested as a loss of sensation throughout the patient's body, unconscious. From a medical perspective, anesthesia refers to the temporary loss of sensation in a patient's entire or local area through medication or other methods, in order to achieve painlessness and provide conditions for surgical treatment or other medical examinations and treatments. Below, I will lead everyone to understand the classification and selection of anesthesia.
1、 Classification of anesthesia methods
1. General anesthesia: Anesthetics enter the body through inhalation or intravenous injection, inhibit the central nervous system, and cause loss of consciousness, collectively referred to as general anesthesia. Specifically, it can be divided into: (1) Inhalation anesthesia: using gas or volatile anesthetics inhaled into the lungs to achieve general anesthesia.
(2) Intravenous anesthesia: The use of intravenous anesthetics for general anesthesia.
(3) Basic anesthesia: Patients should first receive intramuscular or anal injection of an appropriate amount of anesthesia before entering the operating room to eliminate consciousness, which is beneficial for inducing smoothness after entering the room. It is mostly used for pediatric patients.
2. Local anesthesia: using local anesthetics to block spinal nerves, nerve plexuses, or nerve endings without causing loss of consciousness. Specifically, it can be divided into: (1) Spinal anesthesia: subarachnoid block anesthesia, epidural block anesthesia (including sacral block).
(2) Neural plexus block: such as cervical plexus and brachial plexus nerve block.
(3) Neural trunk block: such as intercostal nerve, sciatic nerve block, etc.
(4) Regional nerve block and local infiltration anesthesia.
(5) Surface anesthesia: submucosal peripheral nerve block.
(6) Local vein: After blocking the circulation of the limbs, local anesthetics are injected into the local vein.
3. Compound anesthesia:
(1) Inhalation compound anesthesia.
(2) Intravenous inhalation combined anesthesia.
(3) All rely on intravenous compound anesthesia.
(4) Local anesthesia combined with general anesthesia.
(5) Low temperature anesthesia and neuropathic analgesia anesthesia.
2、 The selection of anesthesia methods varies from general anesthesia, epidural nerve block anesthesia, lumbar anesthesia, local anesthesia, and compound anesthesia, including local anesthesia plus lumbar anesthesia, local anesthesia plus general anesthesia, etc.
The fundamental purpose of anesthesia is to enable patients to complete surgery smoothly and quickly without pain. Doctors choose anesthesia based on their own experience and surgical methods, and various anesthetics have their advantages and disadvantages.
(1) General anesthesia: Currently, this type of anesthesia is rarely used for general surgical methods for lumbar disc herniation. But when using microsurgical methods for nucleus pulposus removal, in order to keep the patient's surgical site immobile, general anesthesia is required.
(2) Epidural nerve block anesthesia: It can make patients painless during surgery, but there may be incomplete pain relief when pulling the nerve root. If there is a central type of intervertebral disc herniation, it is not appropriate to remove the nucleus pulposus by cutting open the dura mater. Due to the high concentration and high dose of epidural anesthesia drugs entering the subarachnoid space, excessive use of spinal anesthesia drugs can lead to anesthesia accidents.
(3) Lumbar anesthesia: produces the effect of spinal anesthesia, not only anesthetizing the affected nerves, but also anesthetizing the entire cauda equina nerve. Both types of anesthesia require accurate localization of nerve compression sites before and during surgery. At the same time, if the nerves are accidentally injured during the operation, it is not easy for the surgeon to detect.
(4) Local anesthesia: Surgery is performed under local infiltration anesthesia, and the patient experiences severe pain when the nerve root is pulled. Its advantage is to accurately locate the affected nerve roots based on intraoperative observations and the patient's clear sensory condition, and to detect nucleus pulposus protrusion missed by clinical and X-ray examinations, which can avoid accidental injury to nerve roots.
Due to the poor analgesic effect of local nerve root traction anesthesia, after determining the location and extent of the lesion, when removing the nucleus pulposus, procaine 50mg can be injected into the subarachnoid space for lumbar anesthesia or ketamine 50mg can be intravenously injected for general anesthesia, exerting a brief and complete analgesic effect. During this time, the nerve root is pulled apart and the nucleus pulposus is removed.