MindMap Gallery intravenous general anesthesia
Its metabolite norsufentanil has an analgesic effect similar to that of fentanyl, so its action time is longer and its circulation is more stable than fentanyl. It is more suitable for cardiovascular and elderly patients' surgery, but it has adverse reactions. Comparable to fentanyl.
Edited at 2022-01-04 16:48:39This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
intravenous general anesthesia
Biggest disadvantage
Poor controllability
continuous administration
It takes 5 drug half-lives to achieve stable blood concentrations
midazolam
The only water-soluble BZ with the shortest half-life; long-acting (diazepam, diazepam)
internal processes
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)
Pharmacological effects
dose dependent
Effective in eradicating intraoperative awareness and producing good anterograde amnesia
Sodium thiopental (barbiturates), retrograde amnesia; combined with mida, the amnestic effects of both are enhanced
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
Contraindications
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)
Flumazenil
BZ blocking drugs, antagonize BZ
Dexmedetomidine
New sedative-hypnotic drug can wake up during surgery
Pharmacological effects
a2 adrenoceptor agonist
presynaptic a2 receptor
Inhibits the release of NE
Terminates the release of pain signals
Reduce vasoconstriction and reduce BP
postsynaptic a2 receptor
Peripheral vasoconstriction (temporary BP increase only occurs when infusion is too large and too fast)
Inhibit sympathetic nerves, decrease BP and HR
Acts on a2 receptors in the spinal cord to produce analgesia, sedation, and anxiety relief
Sympathetic suppression, analgesia, sedation
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)
anaesthetization
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
internal processes
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)
Adverse reactions
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)
Note the contraindications: high vagal tone, diabetes, HBP, advanced age, bradycardia, poor liver and kidneys
Ketamine
The only intravenous anesthetic with strong analgesic effect
可单独使用于一些短小手术
·
支气管哮喘病人的麻醉
anaesthetization
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.
It can be intubated with muscle relaxants and used for patients with congenital heart disease with right-to-left shunt.
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
Contraindications
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
complication
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
Can cause respiratory obstruction
Routine preoperative use of anticholinergics
Fentanyl and its derivatives
opioid agonists
sufentanil
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
Large dose: 8~50ug/kg, cardiothoracic surgery, neurosurgery
Medium dose: 2~8ug/kg, more complex general surgery
Low dose: 0.1~2ug/kg, induction of general anesthesia (intubation: 0.3~0.6ug/kg) or minor outpatient surgery
Fentanyl
Anesthesia method
induce
Commonly used dosage: 0.1~0.2mg (can inhibit the stress response during intubation), half-life: 4.2h
large dose
6ug/kg: Inhibit cardiovascular response during intubation
20ug/kg: Because it has little impact on circulation and is conducive to circulatory recovery in postoperative patients, it can be used in large doses for neovisceral and large vessel surgeries, or non-cardiac surgeries for patients with cardiac insufficiency. The total dosage can reach 50~100ug. /kg
maintain
Generally, 0.05~0.1 mg is added before the operation or every 30~60 minutes during the operation to suppress the body's excessive stress response.
internal processes
"Quick" --- takes effect in 1 minute; "short" --- lasts for 10 minutes; "strong" --- strong analgesia (the strongest is sufentanil)
Liver metabolism, renal excretion
Precautions
There are fentanyls
cycle
It has a slight effect on circulatory function, does not inhibit myocardial contractility, but excites the medulla oblongata vagus nerve>>HR increases
Bradycardia and conduction block can be corrected with atropine
At large doses, BP and HR decrease, blood vessels dilate, and circulating blood volume is relatively insufficient. At this time, slow down the fentanyl infusion rate and replenish blood volume appropriately.
BP may increase during surgical stimulation or light anesthesia.
breathe
Choking and coughing during IV IV too quickly: It is harmful to poor heart function and intracranial hypertension.
Respiratory depression: reduced frequency, reduced tidal volume when the dose is too high
Respiratory amnesia: After repeated and large amounts >> 3~4 hours, fentanyl is redistributed in the stomach wall and lung tissue, causing respiratory depression. At this time, respiratory control and antagonist drugs are required
other
No release of histamine, postoperative nausea, vomiting, and skin itching
Muscle stiffness: Chest wall and abdominal wall muscles >> will cause CVP and intracranial pressure to increase, hinder ventilation, and require muscle relaxant relief
Prevention: Give muscle relaxants before applying fentanyl to slow down the IV rate
Contraindications
Bronchial asthma, myasthenia gravis, coma caused by brain tumors or craniocerebral trauma, children under 2 years old
remifentanil
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
After sedation and muscle relaxation, iv, 2~4ug/kg can inhibit the intubation stress response.
maintain
15~120ug/(kg*h), which can enhance the anesthetic effect of isoflurane and reduce its MAC, and the degree is related to age.
Metabolism
U-type opioid receptor agonists, because they have ester bonds, can be rapidly hydrolyzed by non-specific esterases. Therefore, they have a short action time, rapid recovery, and no accumulation.
Advantages: 1. Accurately adjust the dose, smooth anesthesia, and easy to reverse; 2. Few side effects; 3. Not dependent on liver and kidney; 4. No accumulation after repeated use.
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.
Propofol
Mechanism
Combined with GABA (r-aminobutyric acid), it increases the influx of Cl ions and produces hyperpolarization.
Anesthesia method
induce
Adults: 1.5~2.5mg/kg; complete injection within 30s~45s; one arm-brain circulation time (10~40s) to take effect; single IV anesthetic effect lasts 5~10min; reaches peak value in 90s; half-life 0.5~1.5h
Pediatrics: Due to the large apparent volume of distribution and high clearance rate, the induction dose is moderately increased.
maintain
4~12mg/(kg*h)
metabolism, excretion
Metabolized by liver, excreted by kidneys
It is well controlled, completely awake and without accumulation, and the incidence of postoperative nausea and vomiting is low.
Pharmacological effects
dose dependence
CNS
loss of sense of consciousness
Can be reduced
Used for surgical procedures
cerebral blood flow
cerebral oxygen metabolic rate
intracranial pressure
Normal: 80~120; >200 is considered intracranial hypertension
suppress breathing
Frequency reduction
Decreased tidal volume
IV, reduce the sensitivity of the respiratory center to CO2
inhibit cycle
Inhibit myocardial contraction
Dilate peripheral blood vessels
Decreased blood pressure and heart rate
When injected slowly, the inhibitory effect may be weakened, but the anesthetic effect may be reduced
Adverse reactions and precautions
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)
Contraindications
Allergies, hyperlipidemia, severe circulatory insufficiency, pregnant and lactating women, children under 3 years old, patients with mental illness, and epilepsy
Etomidate
Non-barbiturate intravenous anesthetics with little effect on circulatory function
induce
0.1~0.4mg/kg, half for the elderly and infirm
internal processes
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
Pharmacological effects
cycle
The impact is small, BP slightly decreases
But it is also suitable for coronary heart disease due to diastolic coronary blood vessels.
CNS
Similar to propofol, but does not affect cerebral perfusion pressure and has a protective effect on hypoxic brain injury
breathe
Small impact, fast IV, inhibited by large doses
Adverse reactions
Nausea and vomiting, worsened when combined with fentanyl
Inhibits adrenocortical function, no clinical significance, injection pain