Acts on GABA, Cl ion inflow, hyperpolarization

General anesthesia induction: 0.05~0.2 mg/kg, IV within 15~20 seconds. In renal failure, due to the decrease in plasma protein in the body and the increase in free drugs, the drug dose can be appropriately reduced.

Medication before anesthesia: 0.02~0.04mg/kg, fast onset and short duration (2~3h, related to its redistribution and fast metabolism)

Intramuscular injection: 5~10mg, rapid and complete absorption; half-life: 2~3h

Other administration methods: high first-pass elimination and low bioavailability (diazepam, diazepam, is suitable for oral administration)

dose dependent

Effective in eradicating intraoperative awareness and producing good anterograde amnesia

Can enhance the effect of anesthetics and reduce dosage

Anti-anxiety (BZ is preferred), anti-convulsant, hypnosis, muscle relaxant

The effect on the brain is the same as that of propofol and reffen

Suppression of breathing is related to IV speed. Combined use of opioids is prone to respiratory amnesia.

Reduce intraocular pressure; but it cannot prevent the increase in intraocular pressure caused by skolin intubation, but diazepam can

Allergies, depression, organic brain injury, pregnant women, angle-closure glaucoma, and patients with severe uncontrolled pain

Schizophrenia (strong neuroleptics, antipsychotics, phenothiazines, and cetacetin are available)

BZ blocking drugs, antagonize BZ

a2 adrenoceptor agonist

Some diuretic effect

It does not inhibit breathing and has a protective effect on the heart, brain and kidneys.

Circulation: Mainly slows down HR, or even stops; reduces peripheral resistance >> BP decreases (severe conduction block, disabled in severe cardiac insufficiency)

Continuous infusion before anesthesia induction: 0.5~1.0ug/kg (10~15min) can make the induction smooth and reduce intubation reaction. Excessive dosage can temporarily constrict blood vessels and slow down HR.

Maintenance: 0.2~0.4ug/(kg*h), easy to wake up during surgery when used alone

Sedation for critically ill patients: 0.2~0.7ug/(kg*h), which can not only make the patient quiet and comfortable, but also wake the patient up at any time to cooperate with treatment

Liver metabolism, renal excretion

Large dose, acts on a2 receptors, significantly shrinks peripheral blood vessels

The longer the continuous infusion time, the longer the half-life, and the more difficult it is to wake up after surgery, so the drug needs to be stopped early (40 minutes to 1 hour before the end of the surgery)

Continuous infusion can lead to hypotension, bradycardia, and dry mouth (at this time, reduce the amount of dextromethamine, increase the intravenous fluid flow rate, elevate the lower limbs, and apply vasopressors)

可单独使用于一些短小手术

·

Because ketamine can cause psychological side effects after anesthesia, it is generally not used in adults (if used, it should be combined with central sedatives), and is widely used in pediatric anesthesia.

Because of its strong analgesic effect, it is often combined with sodium oxybutyrate, diazepam and other pediatric anesthesia that has strong sedation but weak analgesia. IV maintenance is interrupted during the operation.

1. Intramuscular injection: 4~6 mg/kg for minor surgery in children, aged under 2 years old, with large body fluids, increase the dose to 6~8, onset of action in 2~5 minutes, and maintained for 30 minutes; 2. Intravenous infusion: first iv 1~2mg/kg, and then continue to drip 0.1% ketamine solution for maintenance, first quickly and then slowly, which is easy to accumulate the drug, so use sparingly; 3. Intravenous injection method: 1~2mg/kg iv for the first time, slowly iv for 1 minute, the effect lasts for 10~ 15 minutes, used for pediatric surgeries that do not require muscle relaxation, or short adult surgeries that require minimal muscle relaxation, such as artificial abortion and dressing changes for burns; 4. Sub-anesthetic dose: <0.4mg/kg, used for dural and nerve block sedation. When the pain effect is not good

Severe hypertension, high intracranial pressure, high intraocular pressure (can cause temporary blindness); hyperthyroidism, pheochromocytoma, insufficient cardiac function compensation; throat and oral surgery, intubation is strictly prohibited; epilepsy and mental illness

Psychiatric and neurological symptoms: seen when ketamine is used alone. After waking up from anesthesia, looking forward, mania, moaning, mental confusion, severe convulsions or convulsions, in adults, women, and short surgeries. Benzodiazepines are used before the end of anesthesia to have a preventive effect.

Circulation: directly inhibits myocardial contraction, but excites the cardiovascular center and sensory nerves. Generally, excitement dominates, and BP and HR increase.

Intracranial pressure: dilates cerebral blood vessels, increases brain tissue metabolic rate and oxygen consumption

Respiration: Inhibited

increased secretions

The strongest analgesic effect

Its metabolite norsufentanil has an analgesic effect similar to that of fentanyl, so its action time is longer.

Compared with fentanyl, the circulation is more stable and more suitable for cardiovascular and elderly patients' surgery, but the adverse effects are equivalent to fentanyl

Dosage

Anesthesia method

internal processes

Precautions

Contraindications

The shortest half-life is 9 minutes; the half-life of continuous infusion is 3~5 minutes; and it is not metabolized by the liver and kidneys.

induce

maintain

Metabolism

Refine can also constrict cerebral blood vessels, reduce cerebral blood flow, and subsequently significantly reduce intracranial pressure, making it suitable for craniocerebral surgery.

Postoperative pain: Because of its fast metabolism, pain occurs quickly after surgery. Severe pain can cause cardiovascular accidents.

Combined with GABA (r-aminobutyric acid), it increases the influx of Cl ions and produces hyperpolarization.

induce

maintain

Metabolized by liver, excreted by kidneys

dose dependence

CNS

suppress breathing

inhibit cycle

Use with caution if you are allergic to soybeans or eggs, or have fat metabolism disorders (hyperlipidemia)

Decreased BP, decreased HR, respiratory depression

Injection pain, thrombophlebitis, muscle spasm (can be controlled with diazepam, midazolam, and physostigmine)

Allergies, hyperlipidemia, severe circulatory insufficiency, pregnant and lactating women, children under 3 years old, patients with mental illness, and epilepsy

0.1~0.4mg/kg, half for the elderly and infirm

Liver metabolism, renal excretion

Does not affect liver and kidney function, does not release histamine

Rapidly lower intraocular pressure, which is beneficial for intraocular surgery

cycle

CNS

breathe

Nausea and vomiting, worsened when combined with fentanyl

Inhibits adrenocortical function, no clinical significance, injection pain