What is the difference between general anesthesia and local anesthesia?

Anesthesia is an essential part of certain surgical operations and treatments. Anesthesia is the use of anesthetic drugs to temporarily deprive the patient of some or all sensations in order to ensure the success of the operation. There are many methods of anesthesia, which can be mainly divided into general anesthesia and local anesthesia. So what is the difference between these two methods of anesthesia? This article will give you the answer.

1. What is general anesthesia?

General anesthesia, abbreviated as general anesthesia, refers to the administration of anesthetic drugs into the body through intravenous injection, intramuscular injection, respiratory inhalation, etc. The drugs will temporarily inhibit the central nervous system, and the patient will experience loss of sensation, loss of consciousness, amnesia, etc. Simply put, after receiving general anesthesia, our body is like "sleeping", and we have no memory of the surgical process and will not feel any pain.

2. What is local anesthesia?

Local anesthesia is also called regional anesthesia, which means that a certain part or local area of ​​the body loses sensation. During the treatment, the patient is still conscious. There are many types of local anesthesia, which can be mainly divided into the following types.

2.1 Neuraxial anesthesia

Spinal anesthesia is also known as "partial anesthesia". The doctor will inject anesthetic drugs into the subarachnoid space or epidural space of the spinal canal. After the drug is injected, the spinal nerve roots will be blocked, thereby producing an anesthetic effect on the corresponding area. This type of anesthesia is mainly suitable for lower abdominal and lower limb surgeries, such as cesarean sections, appendectomies, hernia repairs, etc.

2.2 Nerve block anesthesia

Nerve block anesthesia refers to the injection of drugs into nerve trunks, nerve plexuses, areas around ganglia, etc. The drugs will block nerve conduction, thus producing an anesthetic effect. This type of anesthesia is mainly suitable for orthopedic surgery, thoracic surgery, various neuropathic pain, non-painful diseases, etc.

2.3 Local infiltration anesthesia

Local infiltration anesthesia refers to the injection of anesthetic drugs into the surgical site, subcutaneous tissue, mucous membranes, etc. The drugs will cause the sensory nerve endings or nerve trunks to lose the ability to conduct stimulation and sensation, thereby playing an anesthetic role. Local infiltration anesthesia is mainly suitable for minor surface surgeries, skin wound debridement, interventional examinations, etc.

3. What is the difference between general anesthesia and local anesthesia?

3.1 Different scope of action

General anesthesia mainly acts on the entire central nervous system. After anesthesia, the patient loses consciousness and sensation throughout the body, enters a deep sleep state, and does not respond significantly to external stimuli. Local anesthesia only acts on the surgical part and surrounding nerve tissue. The patient will feel no pain or sensation in the surgical area, but will remain awake throughout the operation. Anesthetic drugs will not affect the patient's consciousness and sensation in other parts of the body.

3.2 Different complications

Most anesthesia is safe when used correctly and closely monitored. However, due to the different range of action, general anesthesia is more likely to cause complications and is more dangerous than local anesthesia, such as circulatory disorders and respiratory depression. The complications of local anesthesia are generally rare, and even if they occur, they are relatively mild, such as nerve damage and drug toxicity.

3.3 Different scope of application

General anesthesia has a wide range of applications and can be used in almost all surgeries. During surgery, the patient's muscles relax well and the doctor can adjust the medication according to the patient's actual situation and surgical requirements. Local anesthesia has fewer indications and cannot be used in complex surgeries, but the patient can actively cooperate with the doctor during the operation.

3.4 Different comfort levels

General anesthesia is very comfortable, the patient stays asleep throughout the whole operation, has no memory of the whole operation, and has less psychological pressure. When local anesthesia is used, the patient will not feel pain in the operation or treatment area, but the patient often faces greater psychological pressure, such as tension, anxiety, fear, etc., and the comfort is relatively poor.

4. How to choose the anesthesia method that suits you?

General anesthesia and local anesthesia each have their own advantages and disadvantages, so how do we choose between the two anesthesia methods? When choosing an anesthesia method, we must first consider the needs of the surgery. Some surgeries can only be performed with general anesthesia, such as heart surgery, craniotomy, etc., while some surgeries can be performed with local anesthesia, such as limb fractures, cesarean sections, etc. When choosing an anesthesia method, the doctor's personal level and surgical safety must also be considered. If both anesthesia methods are available, patients need to choose an anesthesia method based on their personal needs and psychological tolerance to improve treatment compliance.

5. Do both general and local anesthesia require fasting and abstaining from water?

During general anesthesia, the patient is unconscious, and the drugs will affect the respiratory center and gastrointestinal motility. During surgery, gastric contents are likely to reflux into the respiratory tract, causing suffocation or severe pneumonia. Therefore, as long as it is general anesthesia, fasting and abstinence from water are required. In order to ensure the safety of the operation, local anesthesia such as spinal anesthesia and nerve block anesthesia also require fasting and abstinence from water. Generally, fasting for 6-8 hours and abstinence from water for 2-4 hours are required. Whether fasting and abstinence from water are necessary should be scientifically selected according to the doctor's instructions. If fasting and abstinence from water are required, be sure to avoid any food or drink before the operation. Don't take chances, so as not to affect the safety of the operation.

6. Will anesthesia make people stupid?

Many people worry that anesthesia will make people "stupid", especially that general anesthesia will affect the brain. In fact, there are many factors that affect memory and intelligence, such as the mental state and psychological pressure before surgery, the stress state caused by major surgery, psychological suggestion, etc. The general painlessness and loss of consciousness caused by anesthesia are temporary and reversible. After the anesthesia is over, the patient will gradually return to normal as the drug is metabolized. For example, when using inhalation anesthesia, the drug will be completely excreted from the body through breathing. After stopping the drug, the patient will be able to return to normal quickly, and it will not cause long-term effects on the patient's memory or intelligence.

7. Conclusion

Different anesthesia methods have different advantages and disadvantages. Before starting treatment, we need to choose the most suitable anesthesia method according to the doctor's advice, which can not only reduce the risk of surgery, but also improve our comfort. In addition, anesthesia is not as terrible as you think. Before receiving anesthesia, we must understand the knowledge related to anesthesia in advance and actively cooperate with medical staff to ensure smooth treatment.

Author: Luo Liu, Zhuzhou Hospital Affiliated to Xiangya School of Medicine, Central South University