Gas anesthesia for animals reviews. New service - gas (inhalation) anesthesia

The main task veterinarian- preserving the life of the animal. Doesn't matter we're talking about about diseases internal organs: liver, kidneys, of cardio-vascular system; lesions of the musculoskeletal system or other organs and systems. Some diseases can be cured conservative methods(drugs that are administered orally and by injection), but some require surgery. In this case, there is a need for anesthesia.

In our clinic, anesthesiological care is entrusted to an anesthesiologist, whose main task is to ensure that during medicated sleep the life and health of the animal were safe. To reduce the risks associated with the administration of anesthesia drugs before surgery, it is necessary to conduct a minimum set of studies, which includes general analysis blood, blood biochemistry and ultrasound examination of the heart (echocardiography). In some cases it is required additional research: Ultrasound of organs abdominal cavity, radiography chest, general urine test or other. Especially relevant preoperative examination for middle-aged and elderly animals.

A veterinary anesthesiologist conducts a preoperative clinical examination and analyzes data laboratory research and the animal's medical history. After this, the doctor determines the optimal combinations of drugs for sedation, routes and methods of their administration, which depends on the condition of the animal, its age, anatomical and physiological characteristics, complexity and duration of the planned operation, the required depth of medicated sleep and the level of anesthesia. Our clinic has a full arsenal available drugs to provide high-quality anesthesiological support to the patient. Monitoring is carried out during medicated sleep the following indicators: ECG, blood oxygen saturation, level carbon dioxide in the blood, respiratory rate, heart rate, pulse pattern, blood pressure.

The most convenient, controlled and safe is gas anesthesia for cats and dogs. The clinic has modern equipment for its implementation: anesthesia machine, artificial ventilation lungs, oxygen concentrator, patient monitor with capnometry module.

General view of the anesthesia machine and patient monitor.

Our clinic is one of the few in Nizhny Novgorod introduced into clinical practice and has mastered the technique of gas anesthesia in animals. Greatest Reasons for its use in elderly animals, in animals with pathologies of the liver, kidneys, cardiovascular system, during long-term and technical complex operations: on the abdominal organs and chest cavity, spinal column, head organs. To achieve complete analgesia, our doctors have the technique of animal epidural anesthesia, when an anesthetic is injected into the space around spinal cord, blocking the conduction of impulses through it. In this case, the animal not only does not feel pain, but also does not perceive any discomfort from the area of ​​operation.

After inhalation anesthesia, animals quickly come to their senses, after about an hour they can move independently, feel normal and are able to go home with the owner, which makes possible to carry out some operations are performed on an outpatient basis.

Our doctors take full responsibility for general anesthesia(anesthesia), realize possible risks and constantly strive to improve the safety of this procedure, create comfortable conditions for animals during and after medicated sleep.

Merkulova A.S., veterinary anesthesiologist at the Clinic of Neurology, Traumatology and intensive care Doctor Sotnikov V.V."

Problems we were afraid to face:

This type of anesthesia is dangerous for doctors and pollutes the air in the operating room.

Requires expensive equipment and consumables.

Difficulties in monitoring, difficulty in operation and provision of consumables.

Our practice has shown that these fears are not true. Today, to provide inhalation anesthesia, we use:

Inhalation anesthetic (isoflurane) anesthesia device (vet.qvip 38427);

Breathing circuit (we use a closed circuit);

Oxygen source (oxygen cylinder); carbon dioxide absorbent;

Intubation tubes and masks, breathing bags of different volumes.

1. The technique of inhalation anesthesia is as follows: oxygen flows from the cylinder into the evaporator, which contains isoflurane. Then the resulting mixture follows the contour: lungs - arterial blood- brain - deoxygenated blood- lungs - breathing circuit.

Depending on where the exhaled mixture moves next, the contours are divided into:

Reversible (the exhaled mixture goes into the breathing circuit or absorbent);

Irreversible (the exhaled mixture goes into the atmosphere);

Partially reversible (the exhaled mixture goes into the atmosphere, breathing circuit or absorbent).

As can be seen from Table 1 and as our practice shows, the most convenient to use is a closed circuit, since with a minimum consumption of anesthetic, maximum precision in controlling the depth of anesthesia can be achieved. In this case, there is no air pollution in the operating room or breathing circuits.

Table 1. Characteristics of breathing circuits

When exhaling, to prevent hypercapnia (carbon dioxide poisoning) it is necessary to remove CO2 from the exhaled mixture. For this we use an absorbent with a pH indicator. The change in color of the indicator is due to an increase in the concentration of hydrogen ions, signaling the depletion of the absorbent. It should be changed if 50-70% of the volume has changed color. It is necessary to pay attention to the fact that the changed granules can return to their original color after a certain pause, and the absorption capacity is not restored.

Advantages of inhalation anesthesia:

Predictable pharmacokinetics, pharmacodynamics, hemodynamics. If we compare this method anesthesia with intravenous administration propofol, then achieve the desired stable concentration Propofol for the entire duration of the operation (which is sometimes 2-4 hours), without disturbing hemodynamics, is more difficult. Propofol should be given via an infusion pump rather than as a bolus, as is often practiced. With isoflurane this does not happen due to self-dosing.

Self-dosing. Due to the fact that the patient is breathing spontaneously, mortality during the operation is minimized.

Rare anaphylactoid reactions.

Good handling. In a matter of seconds, the gas concentration can be increased or decreased, or the isoflurane supply can be stopped altogether.

Sleep guarantee. Isoflurane induction time is 5 minutes, awakening time is 6-8 minutes.

Isoflurane is less toxic than propofol. It is practically not metabolized in the body and is excreted through the lungs.

Quite low cost (compared to propofol).

Associated disadvantages of inhalation anesthesia:

Malignant hyperthermia (extremely rare, reports from colleagues; no such cases were observed in our practice);

Promotion intracranial pressure(not exactly established);

Pathologies of the pulmonary system limit the use of inhalation anesthesia;

Systemic hypotension (may occur with insufficient and untimely monitoring, as well as insufficient preoperative preparation patient. We have not encountered it in our practice).

A limiting factor in the use of inhalation anesthesia is the need for a gas analyzer.

As you can see, most of the missing ones are either rare, or the presence is not precisely established; unfortunately, almost no one mentions this when describing this type anesthesia.

2. During our work with isoflurane, we were convinced economic feasibility i applications. For a year, we kept a protocol for the use of the drug, in which we recorded each operation performed under gas anesthesia, its type, the duration of the amount of anesthesia and various nuances. For clear example economically feasible, we will consider the operation of biceps-sartorio transposition, carried out in case of a rupture of the anterior cruciate ligament. As a result of the study, it was found that 100 ml of isoflurane is enough to carry out 12 such operations average duration 35 minutes for dogs different breeds with a body weight of 35-40 kg with monopathology.

As can be seen from the table, the ratio of propofol to isoflurane is 1:10. The cost of propofol for a dog owner will be 2 thousand rubles, and only 250 rubles will be the cost of isoflurane if the dog is operated under gas anesthesia.

Rice. 2. Schematic representation of the cost of propofol to isoflurane.

RM-9000 portable medical monitor monitors:

3. Anesthesia monitoring. When working with gas anesthesia, we use a Mindrey RM-9000E type monitor.

It performs many functions such as visual and audible alarms, storage and printing of trend data, NIBP measurements blood pressure), alarms, oxycardiorespirogram, viewing data from one monitor from another. There is also a function for calculating the dose of drugs.

The mandatory minimum set of indicators by which the patient’s condition is monitored during anesthesia must include:

Capnometry;

Pulse oximetry;

Blood pressure measurement;

Electrocardiography.

The Harvard monitoring standard (Eichhorn et al, 1986) can also be used.

Today in veterinary medicine, capnometry is the main indicator of patient monitoring during anesthesia.

Using CO2 monitoring allows you to:

Quickly determine the correctness of tracheal intubation;

Quickly identify disturbances in the air tract;

Objectively, continuously, non-invasively monitor the adequacy of ventilation;

Recognize disturbances in gas exchange, pulmonary circulation and metabolism;

Reduce the need for blood gas tests since the Pet-C02 trend reflects the PaC02 trend. Blood gas analysis becomes necessary in cases significant deviation trend PetC02.

In second place is pulse oximetry. High saturation does not mean that oxygen has reached the body tissues. Today's experience, which is already generally recognized in foreign veterinary medicine, has proven that the electrocardiogram is not information monitoring during the administration of anesthesia. In our clinic, inhalation anesthesia is used in approximately 50% of patients. Regardless of the type of anesthesia offered, the preoperative examination is always standard and includes:

Taking anamnesis (duration of illness, appetite, night cough, vomit, past illnesses etc.).

Clinical examination.

General clinical analysis blood. It is especially important to establish the level of hemoglobin, the number of leukocytes and red blood cells.

Blood chemistry. Especially the determination of urea, creatinine, transaminase activity and alkaline phosphatase. It is also advisable to evaluate protein metabolism.

Determination of blood clotting according to indications.

If chronic heart failure is suspected and if there is pathology on the ECG, a general cardiological examination (Rg-CG and ECHO-CG) is performed. If you suspect renal failure based on anamnesis, biochemical and clinical signs it is necessary to determine the filtration function of the kidneys and perform an ultrasound.

The choice of premedication drugs for each patient is carried out individually. We never use alpha 2 agonist drugs (xylazine), since these drugs significantly disrupt peripheral circulation and create conditions for the development of oxygen debt. This in turn can cause the death of the patient several days after anesthesia.

The formation of an oxygen debt is possible even when oxygen is used during anesthesia with alpha 2 agonists. It must be said that in Russia many clinics are not equipped with oxygen lines; they do not have oxygen cylinders or oxygen concentrators. Rampant premedication with atropine is typical for many veterinary anesthesiologists, but its inappropriateness was established 25 years ago in the USA and in 1994 by Bunyatyan (1).

In our clinic, atropine is used only strictly according to indications (persistent bradycardia, excessive saltation). Propofol is used for tracheal intubation and transition to inhalation anesthesia. Before the operation, it is necessary to ensure the integrity of the intubation cuff and the strong sealing of the endotracheal tube with the contour of the device. It is important not to forget that the induction time of isoflurane at the highest values ​​is on average 3-5 minutes. It is possible to use isoflurane in mono mode, but most often we use combined anesthesia, combining isoflurane with ketamine or butorphanol. For certain operations, the anesthesia machine works together with an artificial ventilation device (we use the “phase-5” device as the latter). For apnea, an Ambu bag is used.

4. As for maintenance, consumables are Russian market presented in required quantity, and prices are affordable for most clinics. The WEST MEDICA company offers devices for inhalation anesthesia at a price of about 100 thousand rubles. During the 1.5 years of operation of our clinic, no technical support was required with such equipment, and any practicing doctor can replace the consumables.

Cost of consumables:

Cylinder with 100% 02-100 rub;

100 ml of isoflurane - 2500 rubles;

Absorbent - 400 rubles;

A set of intubation tubes - 100 rubles.

Inhalation anesthesia is a significant breakthrough in veterinary anesthesiology for our country. The equipment pays for itself within a few months.

A significant reason for using this method of anesthesia is sharp decrease anesthetic risk reduction in mortality. For the managers of veterinary clinics, another reason will be undeniable - more operated patients and satisfied clients, which accordingly leads to increased financial profits.

When working with gas anesthesia, it should be remembered that most often the death of patients during anesthesia is associated with various types breathing problems, even stopping. More than 90% of deaths during operations are the result of incorrect actions of the veterinarian in such situations. Effective monitoring, especially of carbon dioxide in exhaled air, will help to identify inadequacy in time spontaneous breathing, because availability breathing movements does not mean adequate breathing. You can complete an internship or learn how to use this type of anesthesia at the Clinic of Neurology, Traumatology and Intensive Care of Dr. Sotnikov.

References.

“Guide to Anesthesiology, ed. A. A. Bunyatyan. ed. Medicine, Moscow, 1994.

"Modern aspects of inhalation anesthesia." A.G. Yavorovsky. PHI RAMS, Moscow.

"Movement and problems safe in modern anesthesiology." A. Bunyatyan. RSCH RAMS, Moscow.

"Basics of CO2 monitoring. Practical guide"(based on Datex materials). Novosibirsk 1995.

29.09.0010

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Benefits of gas anesthesia
To date inhalation anesthesia animals - the most safe look anesthesia The drug (isoflurane) enters the animal’s body with inhalation and is eliminated by exhalation; the animal quickly falls asleep and wakes up very quickly after anesthesia. The animal receives the minimum required dose of anesthetic and an overdose of anesthesia is almost impossible.Thus, inhalation anesthesia has minimal side effects on the animal’s body and ensures a quick recovery for your pet after surgery.
At the Aibolit clinic, gas anesthesia is used not only for surgical operations, but also for diagnostic manipulations, which makes it possible to increase their effectiveness by eliminating the factor of pain and stress.This is the only type of anesthesia that can be used on animals in serious condition, as well as aged animals. Gas anesthesia does not affect liver and kidney function, and an older animal may have chronic diseases these organs.
Rodents are very sensitive to anesthesia and gas anesthesia for them is the safest, and often the only type of anesthesia.
The intensity of inhalation anesthesia is easy to control during surgery, that is, increase or decrease the concentration of the drug in the mixture inhaled by the animals. Thus, the animal can be brought out of anesthesia almost instantly, unlike other types of anesthesia.
How to prepare an animal for anesthesia
The day before, you need to remove food and water from your pet 10 hours before. If the animal has chronic diseases and is older than 5 years or a breed that has more high risks complications after anesthesia (Abessinian, Bengal, British, Scottish, Persian cats, Maine Coons, Sphynxes and their mixed breeds; dogs - English and french bulldogs, Dobermans, Greyhounds, Irish Wolfhounds, Shepherds, Yorkies, Pugs, Dachshunds, Poodles, Collies, Shar-Peis, Shih Tzus, Chihuahuas), then the animal must be examined before using anesthesia. And any animal is not immune from hidden diseases. Therefore, before anesthesia, it is advisable for a dog or cat to undergo a cardiac examination (ECG, chest and neck x-rays), and a blood test.
Anesthesia for a cat or dog
The type of drug depends on the age of the animal, the type of operation and its duration. For simple manipulations (anesthesia for castration of a cat, anesthesia for sterilization of a cat, haircut or castration of a male dog), propofol, zoletil and local anesthesia, epidural anesthesia. For more complex operations (osteosynthesis, tumor removal, intestinal surgery, C-section) gentle gas anesthesia is usually used.
Isoflurane is administered through Airways. Before administering the main anesthesia, premedication and induction of anesthesia are used, which allows the animal to be smoothly introduced into anesthesia. With a smooth entry, the exit from anesthesia will be softer. Premedication calms the animal, reduces salivation, improves cardiac activity, and prevents side effects in a sick or old animal.
The cat or dog under anesthesia remains asleep during the entire period of the operation and does not feel pain. Her muscles are relaxed and her consciousness is turned off. An animal under anesthesia cannot close its eyes on its own, this is due to the fact that all the muscles are relaxed, and closing the eyelids requires their tension. After the operation is completed, the animal quickly and easily wakes up.
How do dogs and cats feel after anesthesia?
The dog after anesthesia quickly (within half an hour), and if used inhalation anesthesia, then almost instantly comes to consciousness. Depending on the severity of the operation, you may feel normal within the next few hours. At heavy operations The dog's recovery from anesthesia may take longer.
Cats may become frightened after anesthesia sharp sounds and light, so you need to place the animal on a bedding spread on the floor in a dimly lit room, cover it and not disturb it. At first the cat sleeps after anesthesia, and after about half an hour it begins to walk. Within an hour, coordination may be impaired. The cat may be lethargic throughout the day and sometimes vomit after anesthesia. All these symptoms disappear completely within the first day.
IN in rare cases Complications are possible in cats and dogs after the use of anesthesia. But if the animal is properly prepared, examined before anesthesia and used good drugs for anesthesia, then they are unlikely. Complications occur in seriously ill animals, as an individual reaction to anesthesia, in animals with asymptomatic diseases of the heart, lungs, and brain.
Complications in cats after anesthesia can manifest themselves in exacerbation of chronic diseases, acute disorder blood circulation of the heart muscle and brain. When using inhalation anesthesia, all these risks are minimal compared to all other drugs (even propofol), since gas anesthesia is removed from the body's lungs quickly and does not provide harmful effects to internal organs.
Caring for cats and dogs after anesthesia
Caring for a cat after anesthesia consists of not disturbing it in the first hours. It is necessary to prepare a warm bedding, it should be placed on the floor so that the animal does not get injured when it wakes up from a fall from a height. Food can be offered after 8-10 hours. The food should be familiar, preferably the one that the animal likes best. There are special diets for more quick recovery animal after operations (for example, Royal Canin Recovery).
Caring for a dog after anesthesia consists of providing warm bedding on the floor, personal support from a beloved owner and minimal disturbance. You can feed in a few hours a small amount usual food.
The cat or dog completely recovers from anesthesia within the next few hours after the operation (up to 24 hours). Consciousness and coordination are finally restored quite quickly. Full time recovery depends on the severity of the operation. Anesthesia after sterilization is usually the easiest for cats to tolerate because it is a simple elective surgery, which is done to a healthy animal.
Gas anesthesia for rabbits, ferrets and rodents (rats, hamsters, guinea pigs, chinchillas)
To prepare for anesthesia, the animal is not fed for several hours. Gas anesthesia is most often used for anesthesia in ferrets, rabbits and rodents. After anesthesia, a rabbit or rodent remains in a hospital in an oxygen chamber until it fully regains consciousness. At home, you need to remove the shelves from the cage and provide hay and water. Place the cage in a warm, semi-dark place, avoid stress.
Gas anesthesia for rabbits is used for the same manipulations, as well as for filing back teeth in restless animals (since a rabbit can even die from the stress of fixation).
You need to remove the hammock from the ferret's cage. Gas anesthesia is given to ferrets for castration, sterilization, removal of anal glands, intestinal operations, and osteosynthesis.
Gas anesthesia for chinchillas is the only type of anesthesia that can be used practically safely in these animals. Other drugs used for dogs and cats are, for the most part, contraindicated for them.
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