Pharmacological properties: ① The smaller the MAC value, the stronger the anesthetic effect ② Blood/gas distribution coefficient: proportional to the intensity of anesthesia / the lower it is, the shorter the time to reach equilibrium and the easier it is to control

Factors affecting the alveolar concentration of drugs: ① The ventilation effect is proportional ② The concentration effect is proportional ③ CO: the increase slows down the rise, the greater the blood gas distribution coefficient, the increase in CO causes a significant decrease ④ The lower the blood/gas distribution coefficient, the FA increases during the induction period The faster, the faster the recovery period decreases ⑤F (A-V): The larger it is, the more the pulmonary circulation absorbs and the more drugs are taken away

Metabolism and toxicity: High fat solubility, liver, cytochrome P450 Fluoride ion concentration <50 does not cause nephrotoxicity, 50-100 possible, >100 definitely

Commonly used inhalation anesthetics

① Ketamine: selectively inhibits brain communication pathways and the thalamus-neocortex system, excites the limbic system, has less inhibition on the reticular structure, excites the sympathetic system, accelerates heart rate, and increases blood pressure and pulmonary artery pressure. Significant respiratory depression, increased bronchial secretions, and relaxation of bronchial smooth muscles. Hepatic metabolism, norketamine is active. Used for induction and basic anesthesia in children. Side effects: increased intraocular pressure and intracranial pressure.

② Etomidate: short-acting hypnosis, no analgesia, used for induction, myoclonus occurs after injection, and repeated use can inhibit adrenocortical function.

③ Propofol: sedative and hypnotic, significantly inhibits the cardiovascular system, directly inhibits the myocardium, causes vasodilation, decreases blood pressure, slows heart rate, decreases peripheral resistance, and decreases cardiac output. Significant respiratory depression. for induction.

④Midazolam: induction and maintenance.

⑤ Dexmedetomidine: auxiliary medication

1. Classification and mechanism of action: ① Depolarizing muscle relaxant, succinylcholine has strong affinity with receptors, causing continuous depolarization of the postsynaptic membrane. Characteristics of action: Continuous depolarization of the posterior membrane, muscle fiber bundle tremor (uncoordinated contraction), cholinesterase inhibitors cannot antagonize, but enhance it. ②Non-depolarizing muscle relaxants: tubocurarine, which binds to receptors but does not cause depolarization. The blocking site is at the neuromuscular junction and occupies acetylcholine receptors. When excited, the amount of acetylcholine does not decrease, but it cannot It does not function as muscle fiber bundles and can be inhibited by cholinesterase inhibitors.

2. Commonly used muscle relaxants

Precautions

① Morphine and opioids act on the limbic system and significantly inhibit the respiratory center. The release of histamine causes bronchospasm, dilation of arterioles and veins, etc., resulting in a drop in blood pressure, but has no obvious inhibitory effect on the myocardium. ② Pethidine is analgesic, hypnotic, and relieves smooth muscle spasm. It should not be used by children under two years old. ③Fentanyl, respiratory depression ④Remifentanil, a standard analgesic, dose-dependent respiratory depression, high incidence of muscle rigidity, used to induce and maintain analgesia during surgery, and inhibit the reaction during tracheal intubation . ⑤Sufentanil, respiratory depression