absorb

distributed

metabolism

eliminate

Interfere with the function of ligand-gated ion channels, targeting GABAa receptors, NMDA receptors, glycine receptors, opioid receptors and neuronal nicotinic receptors

The first phase (analgesic phase)

The second period (exciting period)

Anesthesia induction period: no surgery

The third phase (surgical anesthesia phase)

The fourth stage (bulbar anesthesia stage)

After the surgery is completed and the medication is stopped, the patient will gradually recover in the reverse order of anesthesia, but usually there will be no second phase of excitement.

anesthetic ether

Halothane

Enflurane and isoflurane

Nitrous oxide (laughing gas)

Features: High fat solubility, redistribution blood→brain (onset of effect)→fat (invalidation), quick onset of action, but short maintenance time, significant inhibitory effect on the respiratory center

Application: Clinically, it is mainly used for short-term operations such as induction anesthesia, basic anesthesia, incision and drainage of abscesses, closed reduction of fractures and prolapse, etc.

Disabled: Disabled for newborns, infants and young children It can easily induce spasm of the larynx and bronchus, and is contraindicated in patients with bronchial asthma.

Features: Dissociative anesthesia, obvious analgesic effect on body surface, poor analgesic effect on viscera, but rapid induction. It has a slight impact on breathing and has a significant stimulating effect on cardiovascular systems.

Application: Used for short-term minor surface surgeries, such as burn debridement, scabectomy, skin grafting, etc.

Mechanism: It exerts sedative and hypnotic effects by activating GABA receptor-chloride ion complex. Its anesthetic potency is 1.8 times that of thiopental sodium

Features: 1. It can inhibit the laryngeal reflex, facilitate intubation, and rarely cause laryngospasm. 2. Has an inhibitory effect on the circulatory system 3. Reduce intracranial pressure and intraocular pressure, reduce cerebral oxygen consumption and cerebral blood flow, and have very weak analgesic effect

Application: Can be used as an auxiliary for spinal and epidural anesthesia

Mechanism: It is a powerful, short-acting non-barbiturate intravenous general anesthetic. It may also act on GABA receptors, blocking synaptic transmission and inhibiting the brainstem reticular formation activating system.

Features: 1. Intravenous administration, rapid onset of action, and immediate suppression of the cerebral cortex to cause loss of consciousness. 2. The induction is smooth, and its intensity is about 12 times that of thiopental sodium. 3. Has no analgesic effect, but can enhance the analgesic effect of other anesthetics 4. It has the effect of reducing cerebral oxygen consumption, reducing cerebral blood flow and reducing intracranial pressure. 5. It has slight suppression of circulation and respiratory function and a large safety margin, so it is mainly used for patients who are not suitable for thiopental sodium for induction of general anesthesia and tracheal intubation.

Application: Suitable for patients with coronary heart disease, valvular disease, and other poor heart functions

Take a sleeping pill the night before surgery: phenobarbital or diazepam Injection 30 minutes before surgery: phenobarbital sodium, atropine, opioid

Preoperative intramuscular injection of a large dose of barbiturate sodium to put the patient into a deep sleep state

Use sodium thiopental or N2O to quickly enter the surgical anesthesia period, and then use other drugs to maintain it.

Add succinylcholine during anesthesia

Combined with chlorpromazine, physical cooling → body temperature 28~30℃

Use short-acting vasodilators (such as sodium nitroprusside) to moderate BP, elevate the surgical site (such as the brain), and reduce bleeding.

Neuroleptics (droperidol) analgesics (fentanyl) iv: confusion, cessation of voluntary movements, loss of pain sensation →Suitable for minor surgeries, plus N2O and muscle relaxants: achieve surgical anesthesia