Overview of respiratory anesthesies

The article was consulted professionally by Master, Dr Ta Quang Hung – General Department of General Medicine – Share99 Da Nang International Hospital.

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If preparing to undergo an operation, the patient is usually anesthetic to fall asleep, temporarily forgetting the painful sensation. The doctor usually anesthesihets with prolonged surgeries or surgeries that require the patient to be fixed in an uncomfortable position. There are 2 main anesthesies: respiratory anesthesiologist and intravenous anesthesia.

1. When to do anesthesia?

The anesthesia helps the patient fall asleep and feel no pain during the operation. At the end of the operation, the doctor will give the medicines to help the patient wake up quickly and the patient also does not have any memories of the process just underwent. If the patient has to ventilator during surgical anesthesia, when the conditions are adequate, the patient will be disconnected from the ventilator so that it can breathe naturally as usual safely. After that, the patient is taken into the resuscitation room for close monitoring and the use of painkillers as prescribed. Patients may feel a little letharmed, drowsy, nauseous after surgery but this feeling will soon disappear. When the body gradually stabilizes, the patient will be transferred to the usual disease room or home.

pancreatic excipient surgery

Pre-surgery anesthesia

2. What are anesthesies?

Anesthesiology drugs are inhibitors that restore the central nervous system at therapeutic doses. Has the effect of losing consciousness, loss of sensation (pain, heat, cold …), loss of reflexes, muscle dilation but does not disturb the function of respiration and respiration.

Anesthesiology drugs inhibit the central nervous system in order: Mediasions on the cortex – cortex – under the cerebral cortex and spinal cord.

According to the course of use, anesthesies are divided into 2 types:

  • Respiratory anesthesies: Ether Ethylic, Nitrogen oxyd (N2O), Cloroform, Desfluran, Halothan, Enfluran, Isofluran, Methoxyfluran, Sevofluran …
  • Intravenous anesthesies: Thiopental, Propofol, Ketamin (Ketalar), Fentanyl, Etomidat, Gamma OH …

Halothan Anesthetic

Halothan Anesthetic

3. Criteria for evaluation of anesthesies

An ideal anesthetic needs to meet the following requirements:

  • Has a strong enough anesthesia effect and is sufficiently used in surgery
  • Quick anesthesia, soothing effect, quick wake-up
  • Loss of reflexes and muscle relaxion to an appropriate level for surgery, without affecting the respiratory and 3 respiratory systems.
  • High level of safety, no side effects at therapeutic doses, less toxicity
  • Non-flammable, easy to preserve, reasonable cost

However, no anesthetic can fully meet all of the above standards, so in one operation it is common to combine both forms of respiratory anesthesia with intravenous anesthesia to increase the effectiveness of anesthesia.

4. Effects of anesthesies through the respiratory tract

Respiratory anesthesies commonly used to maintain anesthesia can also be used to initiate anesthesia (especially in children). Respiratory anesthesies are usually in the form of gas or volatile liquids. When the patient inhales the anesthetic, it will go from nose to lung, diffusing into the bloodstream and then the central nerve and causing an inhibitory effect. The patient will have signs: sedation, muscle relaxion, decreased consciousness, loss of reflexes, insymity and an infatuation appears.

With its liquid and gas properties, respiratory anesthesies have advantages: easy to use, easy to adjust the dose, quick absorption, quick elimination (elimination through the lungs should help eliminate accidents).

In addition, anesthesies also work on the following agencies:

  • For the respiratory system: Most respiratory anesthesia drugs cause respiratory inhibition to varying degrees. Among the strongest inhibitors are Enfluran and Isofluran.
  • For the brain: because anesthesies reduce the conversion in the brain but increase blood flow to the brain, it also contributes to increased cranial pressure (especially in people with head injuries or brain tumors). Nitrogen Oxyd is the drug that limits the increase in cranial pressure.
  • For the cardiovascular system: Generally anesthesiological drugs (Halothan) cause heart suppression, varicose dilators and hypotension. However, some drugs such as Isofluran, Methoxyfluran and enfluran can cause increased heart rate.
  • For muscles: Most respiratory anesthesies have a muscle relaxer effect
  • For the kidneys: All anesthesies reduce the rate of dialysis and blood flow through the kidneys due to increased renal vascular resistance, however each has a different degree of influence.


Respiratory anesthesietic drugs that cause respiratory inhibition

5. Classification of respiratory anesthesies

5.1. Diethyl Ether

Is a transparent, colorless, insoluble liquid in water, has a special aroma, is explosive. When encountering air, Ether light converts to very toxic Peroxyd Ethyl.

  • Advantages: Slow, safe anesthesia. Proper stretching at stage 3, wide safety limits and little effect on the heart.
  • Disadvantages: in the dose of Ether anesthesia mild stimulation of the sympathetic nerve releases catecholamin should cause a slight increase in heart rate and blood pressure, while also causing dilators of the brain, increasing cranial pressure.

Ether causes mild dilation of the intestum but strongly stimulates the respiratory mucosa so it can increase sputum secretion, causing reflexes of the lumbar spasm, causing vomiting. Due to the prolonged coma effect, which is prone to vomiting and irritation, Ether is now less used.

In addition: Anesthesia for small, short surgery, in coordination with other anesthesies to reduce the dose. Contraint prescribed for surgery for more than 90 minutes.

5.2. Halothan

Halothan is colorless, volatile liquid, pleasant aroma, non-explosive, less soluble in water.

  • Advantages: Due to the relatively high anesthesia activity, the anesthesia effect is fast, strong (4 times more than Ether), patients are awake quickly (<1 giờ), không gây kích thích. The drug also does not irritate the respiratory tract, does not increase secretion and has a smooth dilated effect on the in the air.
  • Cons: Poor analgesic and sedative abilities should often be combined with painkillers and sedatives.

Halothan also causes respiratory inhibition, reducing respiratory flow, so if deep anesthesia is prone to hypoxia of tissues, blood acidity and apnea, oxygen breathing must be combined.

Like other anesthesies, Halothan increases blood flow to the brain leading to increased cranial pressure and arrhythmias.

Halothan causes an immune response and should limit repeated use, if repeated, it must be at least 3 months apart.

Contraindicing: In the following cases: malignant high fever, used in obstetrics (except for cases where diling of the uterus is required), does not coordinate with the enzyme monoamine oxidase inhibitor (MAO).

Diethyl Ether

Diethyl Ether Respiratory Anesthetic

5.3. Enfluran

Enfluran is colorless, volatile, insoluble in water, fragrant, non-explosive.

  • Pros: Halothan-like strong anesthesia, rapid anesthesia. Good muscle dilation, less respiratory effects, less toxic to the liver and kidneys. Enfluran is considered a new respiratory anesthetic, widely used.
  • Disadvantages: Prolonged anesthesia can cause respiratory failure, biltitular failure, arrhythmias. May cause nausea reactions, post-surgical vomiting (lighter than Halothan). If used repeatedly can cause liver toxicity, kinh.

5.4. Isofluran

  • Advantages: Rapid anesthesia, good maintenance of cardiovascular re-veins. Rarely arrhythmias occur, increasing the effect of muscle relaxers. Less toxic to the liver than Enfluran. As a respiratory anesthetic is widely used in therapy.
  • Disadvantages: When taking high concentrations can cause respiratory failure or hypotension. When used in childbirth can prolong the period of childbirth and post-birth bleeding (due to good muscle dilation).

Isofluran Anesthesihet

Isofluran Anesthesihet

6. Complications when taking anesthesies

6.1. Complications during anesthesia

  • On the respiratory system: Spasms of the remand, increased respiratory secretion, respiratory discontinuation due to reflexes.
  • On the cardiovascular system: Fainting due to reflex cardiac arrest, hypotension, drug-in-medicine shock, arrhythmias (tachycardia).
  • On the digestion: Nausea, vomiting clog the respiratory tract when vomit overflows the lungs.

6.2. Complications after anesthesia

  • On the respiratory system: Inflammation of the respiratory tract (gas, bronchitis, pneumonia …) usually caused by Ether.
  • On the cardiovascular system: The risk of heart failure due to prolonged anesthesia inhibits the activity of the heart, the heart is poisoned.
  • On other muscles: Liver, kidney, intestinal paralysis, bladder paralysis due to the dilated effect of anesthesies.

Part of the respiratory anesthetic is converted in the liver that is toxic to the liver. Respiratory anesthesies are also released through the kidneys, which can be toxic to the kidneys.

Master. Dr Ta Quang Hung has over 10 years of experience in teaching and practice in the field of Resuscitation Anesthesia. Currently, he is an anesthesithesithesisithesiist, General Department – Share99 Da Nang International Health Hub

Customers can directly go to Share99 Health System nationwide for examination or contact the hotline here for assistance.

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About: Minh Quynh

b1ffdb54307529964874ff53a5c5de33?s=90&d=identicon&r=gI am the author of Share99.net. I had been working in Vinmec International General Hospital for over 10 years. I dedicate my passion on every post in this site.


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