(1) Inhalation anesthesia

(2) Non-inhalational anesthesia

Drugs that block nerve conduction are used to localize the anesthetic effect to a certain part of the body, causing local pain to disappear. At the same time, the motor nerves are blocked, causing muscle movement to weaken or completely relax.

Local anesthesia can be divided into topical anesthesia, local infiltration anesthesia, regional block anesthesia, and nerve block anesthesia. ☆

Local anesthetic is injected into the spinal canal to block part of the spinal nerves, causing anesthesia in the corresponding areas innervated by the spinal nerves. According to the injection gap, it can be divided into subarachnoid space block anesthesia (spinal anesthesia) and epidural space block anesthesia.

The simultaneous use of multiple anesthetic drugs and anesthetic methods to coordinate with each other to achieve better results than a single anesthetic method is called compound anesthesia.

ASA disease classification standards

ASA rating Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ Ⅵ

Note: For emergency surgical cases, add "urgent" or "E" after the corresponding level.

(1) Relieve mental stress and fear and achieve a preoperative state of sleep or drowsiness. (2) Control adverse reactions, reduce basal metabolism, reduce oxygen consumption, and reduce respiratory gland secretion, which is beneficial to the smooth induction of anesthesia. (3) Raise the pain threshold, enhance the anesthetic effect, reduce the dosage of anesthetics, and facilitate the maintenance of anesthesia. (4) Combat the adverse reactions of anesthetics and reduce the toxicity of anesthetics.

(1) Hypnotics: Commonly used drugs are barbiturates.

(2) Narcotic analgesics can increase pain threshold and enhance anesthetic and analgesic effects. Commonly used drugs include morphine, pethidine, fentanyl and analgesics.

(3) Sedatives and tranquillizers have the effects of anti-anxiety and controlling emotional stress. They can enhance the effects of hypnotics, anesthetics and analgesics, reduce basal metabolism, and prevent intraoperative nausea, vomiting and central muscle relaxation. Commonly used drugs include benzodiazepines, such as diazepam, midazolam, etc.; butyramide benzene, such as droperidol, haloperidol, etc.; phenothiazines, such as chlorpromazine, promethazine wait.

(4) Anticholinergic drugs have the effect of inhibiting the secretion of respiratory glands. Commonly used drugs include atropine and scopolamine.

(5) Special drugs: Use corresponding drugs according to different conditions before surgery. For those with bronchial asthma or a history of allergies, antihistamines can be added; for those with diabetes, insulin can be used; for those with high fever, antipyretics can be used.

The method of using a highly permeable local anesthetic to contact the mucosa to produce mucosal pain loss is called mucosal surface anesthesia, also known as mucosal anesthesia. It is commonly used for superficial surgery or endoscopy of the eyes, nose, throat, trachea and urethra.

Commonly used topical anesthetics include 0.5% to 2% tetracaine and 2% to 4% lidocaine.

Local anesthetic is injected in layers along the surgical incision line to block nerve endings in the tissue, which is called local infiltration anesthesia. Local infiltration anesthesia is suitable for various small and medium-sized surgeries, as well as local analgesia for various closed treatments and special punctures.

The local anesthetics commonly used for infiltration anesthesia are procaine and lidocaine, generally using 0.5% to 2% solutions.

Infiltrating local anesthetic around and at the base of the surgical site to block the nerve branches and nerve endings entering the surgical area is called regional block anesthesia. This method is most suitable for the removal of small subcutaneous cysts, biopsy of small superficial masses, surgeries on the tongue, penis or pedunculated masses, and breast surgeries. Commonly used local anesthetics are the same as infiltration anesthesia.

Injecting local anesthetic around a nerve trunk to anesthetize the area innervated by the nerve trunk is called nerve block anesthesia.

(1) Cervical plexus block Cervical plexus block is suitable for subtotal cervical thyroidectomy, thyroid adenoma removal, trachea, larynx and other surgeries.

(2) Brachial plexus block: Brachial plexus block methods include interscalene path puncture, supraclavicular path puncture, and axillary path puncture.

1. Clinical manifestations: Mainly in the central nervous system and cardiovascular system. Local anesthetics have a downward inhibitory effect on the central nervous system. Clinically, an overexcited state often occurs first, such as fear and restlessness, mania, nausea and vomiting, chills, and convulsions. Then it quickly enters a severe depression stage, causing coma and even respiratory arrest. The cardiovascular inhibition caused by local anesthetics is manifested as weak myocardial contraction, reduced cardiac output, decreased arterial blood pressure, atrioventricular block, and even atrial fibrillation or asystole.

2. Prevention

3. Treatment

1. Clinical manifestations: rash or urticaria on the skin and mucous membranes, conjunctival congestion, facial edema, etc.; angioedema, manifested in mucosal edema and spasm in the larynx and bronchi, bronchial asthma and dyspnea may occur; in severe cases, allergies may occur Sexual shock.

2. Prevention

3. Treatment

When signs of severe poisoning occur after using a small dose of local anesthetic, it is called an idiosyncratic reaction, also known as a hypersensitivity reaction. Once it occurs, it should be treated as a poisoning reaction.

1.Indications (1) Lower abdominal and pelvic surgery (2) Lower limb surgery (3) Anal and perineal surgery

2.Contraindications (1) Progressive diseases of the central nervous system, such as multiple sclerosis, meningitis, progressive anterior horn poliomyelitis, spinal cord metastasis cancer, etc. (2) Severe systemic infection or inflammatory infection at the puncture site should be disabled in order to prevent inflammation from being introduced into the subarachnoid space and causing acute cerebrospinal meningitis. (3) Elderly people, those who are thin, frail, have high blood pressure, severe anemia, etc. are prone to a sharp drop in blood pressure and should be used with caution or banned. (4) Hypovolemic shock, when the blood volume is not replenished. (5) Pregnancy, huge abdominal tumors, severe ascites, etc. (6) Those with spinal deformity or severe low back pain.

1. Once you have a headache after surgery (so there is no pillow after surgery), you must lie absolutely flat to reduce the pressure of cerebrospinal fluid and reduce cerebrospinal fluid extravasation; those with headaches can be treated with acupuncture and take painkillers. 2. Low back pain 3. Urinary retention: Acupuncture Zhongji, Guanyuan, Qihai, Sanyinjiao and other points; seal the Changqiang points with 1% procaine; in severe cases, catheterization may be performed. 4. Paralysis of lower limbs

1. Indications: It is suitable for surgeries on the chest wall, upper limbs, lower limbs, abdomen and anus-perineum area. It is also suitable for the treatment of acute and chronic pain such as cervical spondylosis, low back pain and leg pain.

2.Contraindications (1) Severe shock or bleeding that cannot be corrected. (2) Those with infection at the puncture site or severe systemic infection. (3) Central nervous system diseases. (4) Disorders of coagulation mechanism. (5) Hypotension or severe hypertension. (6) Chronic low back pain or history of headache before surgery. (7) Spinal deformity or spinal rheumatoid arthritis. (8) Those who are mentally ill and unable to cooperate.

1. Intraoperative complications: Total spinal anesthesia, toxic reactions of local anesthetics, drop in blood pressure, respiratory depression, nausea and vomiting, etc. 2. Postoperative complications: nerve damage, epidural hematoma, epidural abscess, anterior spinal artery syndrome, etc.