CN108938141A - Circulating inhalation anaesthesia apparatus - Google Patents

Abstract

The invention discloses a circulating inhalation anesthesia device, which comprises an oxygen tank, a first gas flow meter, an anesthetic gas volatilization tank, a mask and a waste gas absorption tank; the outlet of the oxygen tank is connected with the inlet of the first gas flow meter, and the first gas The outlet of the flow meter is connected to the inlet of the anesthetic gas volatilization tank; the outlet of the anesthetic gas volatilization tank merges with the outlet of the micro-vacuum pump and is connected to the inlet of the second gas flow meter and the mask, and the pipeline before the second gas flow meter is equipped with a large storage tank. air bag. The outlet of the mask is connected to the inlet of the exhaust gas absorption tank and the inlet of the circulating gas filter box respectively, and the outlet of the circulating gas filter box is connected in series with the micro vacuum pump and then merged with the outlet of the anesthetic gas volatilization tank to enter the anesthesia channel again for circulation. The anesthesia device has good sealing performance, reliable anesthesia effect, high safety, little impact on animal physiological indicators, recyclable gas, high anesthesia efficiency, easy control of anesthesia and recovery time, and is suitable for anesthesia operation of small animals.

Description

Cyclic inhalation anesthesia device

technical field

The invention relates to an anesthesia device, in particular to a circulating inhalation anesthesia device for small animals, which is mainly used for anesthesizing experimental animals in scientific research and teaching experiments in life sciences, medicine, pharmacology, food science, veterinary medicine, etc. The invention belongs to the field of anesthesia devices for small animals.

Background technique

Animal experiments are an indispensable part of scientific research and teaching experiments in life sciences, medicine, pharmacology, food science, veterinary medicine, etc. Rats are commonly used experimental animals in animal medical research. Rats are commonly used as experimental animal models in the research of disease, hematology, tumor, radiation biology and immunology. However, in the process of scientific research, it was found that rats that did not enter a good anesthesia state often had stress reactions such as struggling and commotion because they could not tolerate the strong painful stimulation in surgery, making it difficult for researchers to complete the research process. Even sometimes the quality of animal safety and anesthesia directly determines the success or failure of scientific research.

The study found that the heart rate and blood oxygen concentration of rats using inhalational anesthesia are more stable, and the animal's cardiac function level can be better maintained during the operation, and the inhalational anesthesia method also has the advantages of short induction time, fast anesthesia, fast recovery, and easy control of the depth of anesthesia Inhalation anesthesia has gradually replaced injection anesthesia as the preferred method of general anesthesia.

Most of the existing inhalation anesthesia devices are suitable for medium and large animals such as dogs and cats. During the anesthesia process, a tracheal intubation tube is suitable for connecting with the animal's trachea, but it is not suitable for small animals such as rats. Although there are some small inhalation anesthesia devices suitable for small animals, most of these devices are fully open or semi-open, resulting in the unused gas of animals being discharged directly into the atmosphere without filtering and recycling, resulting in waste of resources and pollution of the environment.

Most of the face shields used in existing inhalation anesthesia devices on the market are suitable for medium and large animals such as dogs and cats, and the degree of sealing is insufficient, so that the nose and mouth of the animal are easily exposed from the face shield. During the general anesthesia of small animals, the head of the animal is usually placed in the mask, and then anesthesia gas is injected to maintain anesthesia, but the head of the animal cannot be closely connected with the mask during this process, so that the anesthesia gas leaks into the air, Then pollute the environment and endanger the health of operators. Although there are reports of oral tracheal intubation in rats, the operation is difficult and not easy to popularize (Tomasello G1, Damiani F, Cassata G, Palumbo VD, Sinagra E, Damiani P, Bruno A, Cicero L, Cupido F, Carini F, Lo Monte AI. Simple and fast orotracheal intubation procedure in rats. Acta Biomed. 2016, 87(1):13-5.). Most of the masks suitable for small animals such as rats are fully open, and the anesthesia gas that is not used by rats is not recycled and is directly discharged into the air, resulting in waste and pollution.

Therefore, although the simple rat breathing anesthesia device in the prior art can basically meet the purpose of anesthetizing rat anesthesia, yet all exist the following deficiencies in varying degrees:

(1) The speed of anesthesia is slow, the efficiency of anesthesia is low, and the anesthesia process cannot be accurately controlled in real time.

(2) Although there is a waste gas recovery bottle, the anesthetic gas cannot be recycled, which greatly reduces the utilization rate of the anesthetic;

(3) The airtightness of the existing device is not good, especially the mask part, which easily causes the anesthetic to diffuse into the air, which not only wastes the anesthetic, but also endangers the health of the experimenters.

In view of the current situation, it is urgent to develop a multi-channel inhalation anesthesia device for small animals with good sealing, high safety, recyclable gas and high anesthesia efficiency.

Contents of the invention

In order to overcome the above-mentioned shortcomings of the existing rat anesthesia device, the present invention provides a circulating inhalation anesthesia device suitable for rats with good sealing, high safety, recyclable gas and high anesthesia efficiency. A circulating inhalation anesthesia device with good airtightness, high anesthesia efficiency and safe use.

For realizing above-mentioned purpose, the technical scheme that the present invention takes is:

A circulating inhalation anesthesia device, comprising an oxygen tank, a first gas flow meter, an anesthetic gas volatilization tank, a mask and a waste gas absorption tank; wherein, the outlet of the oxygen tank passes through an oxygen pressure reducer and a pipeline and the inlet of the first gas flow meter Connect, the outlet of the first gas flow meter is connected with the inlet of the anesthetic gas volatilization tank through the pipeline, and the outlet of the anesthetic gas volatilization tank is connected with the entrance of the mask through the second gas flow meter and the pipeline; the outlet of the mask is connected with the waste gas absorption tank; Wherein the outlet of the anesthesia gas volatilization tank is also connected with the outlet of a micro vacuum pump and then connected with the inlet of the second gas flowmeter and the face mask; Connection; a large air storage bag is installed on the outlet pipe of the miniature vacuum pump.

Due to the small tidal volume of the rats, most of the oxygen and isoflurane are not inhaled by the rats, so this anesthesia device is equipped with a miniature vacuum pump, a circulating gas filter box and an exhaust gas absorption tank. An anesthetic gas circulation device is formed, which can recycle unabsorbed anesthetic gas and oxygen in rats; by installing a miniature vacuum pump at the outlet of the circulating gas filter box, a certain suction force can be given to the circulating gas filter box, so that the gas can maintain a one-way circulation; The circulating gas that does not enter the circulating gas filter box enters the exhaust gas absorption tank through the pipeline and is absorbed by the activated carbon in it; therefore, this anesthesia device can completely absorb the CO ₂ exhaled by animals, and can repeatedly inhale anesthetic gas and anesthetic drugs, humidify, warm It can soften the airway, protect the tracheal mucosa, and has the characteristics and advantages of a semi-closed breathing circuit.

During anesthesia maintenance, adjust the flow meter of the drug administration part so that the oxygen input flow rate is 0.15 L/min; at the same time, adjust the gas flow rate of the mask part flow meter to 0.2 L/min, and adjust the concentration of isoflurane to 2.5%, and then A digital pressure gauge is connected to the end of the exhaust gas absorption tube. By adjusting the flow rate of the micro vacuum pump, the pressure at the end of the exhaust gas absorption tube is close to 0, and then the exhaust gas absorption tube is connected to the exhaust gas absorption tank, so that the anesthesia gas that is not inhaled by the rats Reuse, thereby reducing waste gas emission and loss of anesthetic gas, and improving the utilization rate of anesthetic gas. During the surgical verification, it was found that the rats were maintained under anesthesia in this way, the rats were in good respiratory condition, the breathing was stable, the color of the visible mucosa was normal, and the blood oxygen could be maintained above 98%.

As a preferred embodiment of the circulating inhalation anesthesia device of the present invention, the circulating gas filter box is preferably an acrylic box, and a partition is used between the two ends of the acrylic box to divide it into two chambers. The chambers are connected with each other, and the two chambers are filled with soda lime.

As a preferred embodiment of the circulation type inhalation anesthesia device of the present invention, it also includes an anesthesia induction box, which is provided with an air inlet and an air outlet, and the air inlet is connected to the large air storage bag and the second air outlet through a pipeline. The three-way valve on the pipeline between the gas flow meters is connected, and the gas outlet is connected to the three-way valve on the pipeline arranged between the outlet of the face mask and the inlet of the circulating gas filter box through the pipeline. The anesthesia induction box is preferably a closed acrylic box, and the bottom of the anesthesia induction box is covered with soda lime.

As a preferred embodiment of the circulating inhalation anesthesia device of the present invention, the mask is an umbrella-shaped mask, and the center of the bottom surface of the umbrella-shaped mask is provided with a central hole sealed with an elastic material, and the central hole is preferably conical. ; Further preferably, the umbrella-shaped mask is composed of a conical main body and a bottom surface made of rubber, and a central hole that fits the upper and lower jaws of the rat through elastic deformation is provided in the middle of the bottom surface; in the conical main body There are inlets and outlets on the mask, and a small air storage bag on the top of the mask.

The face mask of the circulating inhalation anesthesia device of the present invention is an umbrella-shaped breathing mask, and the central hole is sealed with an elastic material for fixing the upper and lower jaws of rats. Because the central hole is elastic, not only the tension is very good, but also the mouth and nose of the rat can be firmly fixed in the mask, which can not only ensure airtightness, but also will not cause the animal to suffocate. The outlet of the mask is connected to the recovery tank, and the gas that the rat has not absorbed will pass through the recovery tank to absorb carbon dioxide and water, leaving isoflurane and oxygen to join the new anesthetic gas for reuse by the rat. The effects of resource saving and safety are achieved.

As a preferred embodiment of the circulating inhalation anesthesia device of the present invention, a digital pressure gauge is installed at the inlet of the exhaust gas absorption tank; activated carbon is installed in the exhaust gas absorption tank.

The circulating inhalation anesthesia device of the present invention is mainly composed of three parts, that is, a drug administration part, an induction part and a mask part. The induction part is an airtight container with an inlet and outlet connected to the drug administration part. The mask part is assembled with a three-way connection, and an umbrella-shaped breathing mask is connected to the end, sealed with rubber, and a small hole is left for the animal's head. Because the rubber has Elasticity ensures airtightness without suffocating the animal. The inlet and outlet passages of the mask part are respectively connected with the administration part. The administration part consists of an anesthetic volatilizer and a gas flow meter. When administering medicine, connect the oxygen tank, the oxygen mixed with the anesthetic is delivered to the induction box of the induction part through the anesthetic volatilization tank, and the gas exhaled by the animal in the induction box passes through the gas recovery bottle to absorb carbon dioxide, and the remaining gas is mixed with fresh oxygen and After the anesthetic is mixed, it enters the delivery channel again, and the cycle repeats. The mask part and the induction part go through two different pathways. When in use, the anesthesia pathway of the induction part can be blocked and connected to the mask part, and vice versa, the induction part can be connected to block the anesthesia pathway of the mask part. The entire system is also equipped with a gas pressure gauge to monitor the air pressure in the channel, which is convenient for adjustment at any time. At the same time, there is a flow meter in each branch to control the opening and closing of the channel, which can ensure the anesthesia volume of each anesthesia channel. The device is also equipped with an exhaust gas absorption tank to prevent the exhaust gas from entering the air and causing pollution and endangering the health of the experimenters.

In order to verify the anesthesia effect of the anesthesia device of the present invention, the present invention uses the device to perform surgical verification of the anesthesia effect on rats. Use this device to anesthetize rats for routine operations (laparotomy and gastrotomy), record the time of each stage of anesthesia during the operation, and use a physiological monitor to continuously and dynamically monitor the rat's respiration (RR), heart rate (HR), blood Oxygen (SpO ₂ ), systolic blood pressure (SBP), mean arterial pressure (MAP) and body temperature (T), while observing the effects of sedation, analgesia and muscle relaxation in rats, to evaluate the safety and usability of the anesthesia device. Observation results found that the time for anesthesia induction of rats with the anesthesia device of the present invention was 2.20 ± 0.45min, the time required to reach surgical anesthesia was 2.12 ± 0.36min, and the anesthesia maintenance and recovery time were 45.18 ± 0.12min and 2.40 ± 0.55, respectively. The total anesthesia time was 51.40±0.24min. During the operation, the sedative, analgesic, and muscle relaxation effects of the rats were good. At the 10th, 20th, 30th, and 45th minute of the operation, HR, SpO ₂ , RR, T, SBP, and MAP all remained stable. There was no significant difference (p>0.05). The test results prove that the inhalation anesthesia device of the present invention has a reliable, safe and controllable anesthesia effect on rats, and the anesthesia induction and recovery time are fast, which can fully meet the anesthesia requirements of the operation.

The circulating type inhalation anesthesia device of the present invention mainly has the beneficial effects of the following aspects:

(1) In this anesthesia device, an elastic rubber mask is used to replace the traditional mask, which solves the problem of poor airtightness at the opening of the mask; the mask is an umbrella-shaped breathing mask with a rubber hole in the center, and the rubber mouth is fixedly placed on the upper body of the rat. The position of the mandible not only ensures good airtightness of the mask, but also prevents the mask from being too tight to hinder the rats from breathing.

(2) The mask of this anesthesia device is an umbrella-shaped breathing mask with a rubber hole in the center, and a small air bag is installed on the upper part, which can buffer the gas pressure entering the mask and also play the role of pressure indication, which can effectively avoid the positive air in the mask. Avoid excessive pressure and avoid affecting the breathing of the rats or causing damage to the lungs.

(3) The anesthesia device consists of an anesthetic gas circulation unit through a circulating gas filter box, a micro vacuum pump and a waste gas absorption tank, which can recycle unabsorbed anesthetic gas and oxygen for rats.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the embodiment of the present invention;

Fig. 2 is the axial sectional view of mask of the present invention;

Fig. 3 is an explanatory diagram of the working principle of the mask of the present invention.

Description of reference signs: 1. Oxygen tank, 2. Oxygen pressure reducer, 3. First gas flowmeter, 4. Anesthetic gas volatilization tank, 5. Three-way valve between the large air storage bag and the first gas flowmeter , 6. Anesthesia induction box, 7. A three-way valve between the outlet of the mask and the circulating gas filter box, 8. The circulating gas filter box, 81. Partition plate, 82. Connecting pipe, 9. Micro vacuum pump, 10. Large storage Air bag, 11. Second gas flow meter, 12. Mask, 121. Conical body of mask, 122. Bottom surface of mask, 123. Center hole, 124. Air inlet of mask, 125. Air outlet of mask, 13. Small air storage bag, 14. waste gas absorption tank, 15. digital pressure gauge.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings, and the advantages and features of the present invention will become clearer along with the description. However, these embodiments are only exemplary and do not constitute any limitation to the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the present invention can be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the protection scope of the present invention.

Referring to Fig. 1, a circulating inhalation anesthesia device of the present invention comprises an oxygen tank 1, a first gas flow meter 3, an anesthetic gas volatilization tank 4, an anesthesia induction box 6, a circulating gas filter box 8, a miniature vacuum pump 9, and a large air storage bag 10. A second gas flowmeter 11, a mask 12, a small air storage bag 13 and an exhaust gas absorption tank 14; wherein, the outlet of the oxygen tank 1 is connected to the inlet of the first gas flowmeter 3 through an oxygen pressure reducer 2 and a pipeline, and the first The outlet of the gas flow meter 3 is connected to the inlet of the anesthetic gas volatilization tank 4 through a pipeline, and the outlet of the anesthetic gas volatilization tank 4 is connected with three loops: the first road is connected with the outlet of the miniature vacuum pump 9, and the inlet of the miniature vacuum pump 9 is connected with a The circulating gas filter box 8 is connected in series with the outlet of the face mask 12, the outlet of the anesthesia induction box 6, and the inlet of the waste gas absorption tank 14; The outlet of box 6 is connected with the outlet of mask 12 and the inlet of circulating gas filter box 8 by another three-way valve 7; It is connected with exhaust gas absorption tank 14. Large air storage bag 10 is housed on the outlet pipeline of this miniature vacuum pump 9, and small air storage bag 13 is housed on this face shield 12. A digital pressure gauge 15 is installed at the entrance of the waste gas absorption tank 14 . Activated carbon is housed in the exhaust gas absorption tank 14 .

The anesthesia device is provided with a micro-vacuum pump 9, a circulating gas filter box 8 and a waste gas absorption tank 14. These devices form an anesthesia gas circulation device with an anesthesia gas volatilization tank 4 and a mask 12, which can circulate the unabsorbed anesthesia gas and oxygen in rats. use. By installing a micro-vacuum pump at the outlet of the circulating gas filter box, a certain suction force can be given to the circulating gas filter box 8, so that the gas can maintain a one-way circulation; the circulating gas that does not enter the circulating gas filter box 8 enters the exhaust gas absorption tank 14 through the pipeline and is absorbed. The activated carbon in it is adsorbed.

When maintaining anesthesia, adjust the first gas flow meter 3 of the administration part so that the oxygen input flow rate is 0.15L/min; simultaneously adjust the gas flow rate of the second gas flow meter 11 near the face mask 12 to be 0.2L/min, and Adjust the concentration of isoflurane to 2.5%, and then connect a digital pressure gauge to the end of the waste gas absorption pipe, adjust the flow rate of the micro vacuum pump 9 to make the pressure at the end of the waste gas absorption pipe close to 0, and then connect the waste gas absorption pipe to the waste gas absorption tank 14. In this way, the anesthetic gas not inhaled by rats can be reused, thereby reducing waste gas emission and loss of anesthetic gas, and improving the utilization rate of anesthetic gas. During the surgical verification, it was found that the rats were maintained under anesthesia in this way, the rats were in good respiratory condition, the breathing was stable, the color of the visible mucosa was normal, and the blood oxygen could be maintained above 98%.

As a preferred embodiment of the present invention, the circulating gas filter box 8 adopts an acrylic box, and a partition is used to divide the two ends of the acrylic box into two chambers. The connecting pipe is connected, and soda lime is filled in the two chambers. A series structure of two chambers is formed to enhance the filtering effect.

As a preferred embodiment of the present invention, the anesthesia induction box is a closed acrylic box, and the bottom of the anesthesia induction box is covered with soda lime.

Referring to Fig. 2 and Fig. 3, described mask 12 is made up of conical main body 121 and the bottom surface 122 that rubber is made, is provided with the center hole 123 that can be matched with upper and lower jaw of rat by elastic deformation in the middle part of bottom surface 122; The conical body 121 is provided with an inlet 124 and an outlet 125, and is connected with the small air storage bag 13 through a separate channel. The conical main body 121 can be made of plastic, and the whole mask 12 can also be made of rubber. Since the central hole 123 of the bottom surface 122 is conical (or other shapes with very thin edges), its edges can be elastically deformed under the condition of applying a small pressure, so when in use, once the mouth A of the rat to be tested is inserted into the Behind the central hole 123, the edge of the central hole 123 is bent and deformed upwards (see FIG. 3 ), and fits tightly with the upper and lower jaws of the rat. The anesthetic gas in the mask 12 will basically not leak from the central hole 123. Because the central hole 123 is elastic, not only the tension is very good, but also the mouth and nose of the rat can be firmly fixed in the mask 12, which can ensure airtightness without causing the animal to suffocate. The outlet of the mask 12 is connected to the circulating gas filter box 8 and the waste gas absorption tank 14, and the gas not absorbed by the rat will pass through the circulating gas filter box 8 to absorb carbon dioxide and water, leaving isoflurane and oxygen to merge with the new anesthetic gas, Let the rats be reused to achieve the effect of saving resources and safety.

The working principle of the present invention is: the anesthesia device is divided into two parts, an anesthesia induction circulation pathway and an anesthesia maintenance circulation pathway, which are respectively described as follows:

1. Anesthesia induction circulation pathway:

The anesthesia induction circulation path is as follows: the output end of the oxygen tank 1 is connected to the input end of the first gas flow meter 3 through a pipeline, the output end of the first gas flow meter 3 is connected to the input end of the anesthetic gas volatilization tank 4 through a conduit, and the anesthetic gas The output end of the vaporizer 4 merges with the output end of the micro vacuum pump 9. After the anesthetic gas is stored and buffered by the large air storage bag 10, it enters the anesthesia induction box 6 through the control of the three-way valve 5. After the oxygen and anesthetic agent are inhaled by the rat, the exhaled _CO2 and the remaining gas are controlled by the three-way valve 7 to enter the circulating gas filter box 8 to filter the _CO2 , and the remaining oxygen and anesthetic gas are sucked by the micro-vacuum pump 9 and re-enter the anesthesia induction channel for recycling. The mixed gas that is not sucked into the circulating gas filter box 8 by the micro-vacuum pump 9 is absorbed by the waste gas absorption tank 14 . Connect the digital pressure gauge 15 at the inlet (M end) of the waste gas absorbing tank 14, by adjusting the suction flow of the miniature vacuum pump 9, so that the output of the mixed gas at the M end is close to 0kPa, this operation can reduce the pressure of the mixed gas as much as possible. discharged to increase its utilization.

2. Anesthesia maintenance circulation path: the output end of the oxygen tank 1 is connected to the input end of the first gas flow meter 3 through a pipeline, and the output end of the first gas flow meter 3 is connected to the input end of the anesthetic gas volatilization tank 4 through a catheter, and the anesthesia The output end of the gas volatilization tank 4 merges with the output end of the micro vacuum pump 9. After being stored and buffered by the large air storage bag 10, it is controlled by the three-way valve 5 and enters the second gas flow meter 11. The oxygen and anesthetic are inhaled by the rat in the mask 12. Finally, the exhaled _CO2 and remaining gas are controlled by the three-way valve 7 to enter the circulating gas filter box 8 to filter the _CO2 , and the remaining oxygen and anesthetic gas are sucked by the micro vacuum pump 9 and re-enter the anesthesia maintenance channel for recycling. The small air storage bag 13 on the face mask 12 plays the role of pressure buffer and indication.

Test example 1 uses the anesthesia device of the present invention to carry out routine anesthesia operation verification to rats

1 Materials and methods

1.1 Materials

1.1.1 Experimental animals

Ten SD rats, half male and half male, weighing 258±23 g, were purchased from Weitong Lihua Experimental Animal Co., Ltd., and were bred under the same conditions for 15 days for the experiment.

1.1.2 Main Consumables

Gas vaporization tank (Beijing Yianji Medical Technology Co., Ltd.), exhaust gas absorption tank (Hefei Jinnaoren Photoelectric Instrument Co., Ltd.), gas flow meter (Changzhou Shuanghuan Instrument Co., Ltd.), micro vacuum pump (Shanghai Carmel Technology Co., Ltd.), Intelligent digital pressure gauge (Hangzhou Miko Sensing Technology Co., Ltd.), acrylic plate (Beijing Yongshengkang Acrylic Products Co., Ltd.).

1.1.3 Drugs and instruments

Isoflurane (Hebei Jiupai Pharmaceutical Co., Ltd.), medical soda lime (Shanghai Nahui Dry Reagent Factory), medical oxygen (Beijing Beiyang Lilai Gas Co., Ltd.), physiological index monitor (Softtron, BP-2010, Beijing Soft Long Biotechnology Corporation).

1.2 Surgical verification method

1.2.1 Rat laparotomy and gastrotomy

It can be seen from the preliminary anesthesia test that the device of the present invention can produce a good anesthesia effect on rats when the oxygen flow rate is 0.15 L/min and the isoflurane concentration is 2.5%. In this experiment, 10 SD rats were selected for laparotomy and gastrotomy under these conditions. Put the rats in a supine position, shave and disinfect the rat abdomen, lay a towel for isolation, use a scalpel to incise the skin along the midline folds of the abdomen, separate the subcutaneous tissue, muscle and peritoneum, and expose the abdominal cavity. Observe the appearance of each viscera in the abdominal cavity to judge whether there is any abnormality; explore the abdominal cavity of the rat with fingers, and simultaneously pull each viscera or tissue to observe the pain response of the rat. After the abdominal cavity was explored, traction lines were drawn at both ends of the incision line on the stomach wall where there were few blood vessels, the gastric wall was sharply cut open, the incision was rinsed after the gastric cavity was explored, and the gastric wall was returned to the abdominal cavity with double-layer suture. Finally, the abdominal wall incision was routinely closed.

1.2.2 Evaluation of anesthesia effect

(1) Evaluation of sedative effect

The effects of sedation, analgesia and muscle relaxation on rats were recorded every 10 min during laparotomy and gastrotomy to evaluate the availability of anesthesia devices. A good sedation effect must meet the need for no obvious response to external sounds during the operation, and the operation goes smoothly.

(2) Evaluation of analgesic effect

A good analgesic effect needs to meet the following conditions: no pain response to skin incision; no pain response to blunt subcutaneous tissue separation; no pain response to blunt or sharp muscle separation; no pain response to stretching organs and mesentery; no pain response to cavity There was no pain response to organ cutting, exploration, and suture; no pain response to clamping, cutting, and suturing of the peritoneum; no pain response to suturing the skin; no obvious pain after the animal woke up after the operation.

(3) Evaluation of muscle relaxation effect

A good muscle relaxation effect needs to be met when the skin is cut and the muscles are separated during the operation, there is no tension in the muscles; the viscera after incision of the peritoneum remains in the original position, and there is no phenomenon of viscera gushing out; when the viscera is stretched, the retraction force of the viscera is very small.

1.2.3 Intraoperative monitoring of physiological indicators

During the laparotomy and gastrotomy, the physiological indicators of the rats were monitored with a physiological monitor, and the respiration (RR), heart rate (HR), blood oxygen (SpO ₂ ) and systolic blood pressure (SBP) were recorded every 10 minutes. ), mean arterial pressure (MAP) and body temperature (T) to evaluate the safety of the anesthesia device.

12.4 Statistical Analysis

SPSS17.0 statistical software was used for statistical analysis of data, and the significance of difference was analyzed by one-way ANOVA, and the comparison of data at different time points was performed by LSD test, and the data were expressed as mean ± standard deviation express.

2 test results

2.1 Statistics of anesthesia time for rat surgery

This device can produce a good anesthesia effect on rats at a concentration of 2.5% isoflurane. During the verification process of laparotomy and gastrotomy, the time for rats to induce anesthesia and reach surgical anesthesia is relatively fast, and the operation lasts for 45 minutes Afterwards, the rats could quickly wake up from anesthesia (see Table 1). The anesthesia device has the obvious advantages of precise and controllable anesthesia maintenance time, fast induction and recovery time, etc.

Table 1. Statistics of anesthesia time of rats by laparotomy and gastrotomy

2.2 Effects of sedation, analgesia and muscle relaxation in rats during operation

It can be seen from Table 2 that the rats were anesthetized by using the anesthesia device (2.5% isoflurane concentration) for laparotomy and gastrotomy, and the rats had good sedation and muscle relaxation effects during the operation, and had no pain response, which can fully meet the needs of the rats. Anesthesia requirements for surgery (see Table 2).

Table 2. Observation of the effects of sedation, analgesia and muscle relaxation during laparotomy and gastrotomy (n=10)

2.3 Changes of physiological indicators of rats during operation

Under the concentration of 2.5% isoflurane, the device was used to anesthetize the rats, and the laparotomy and gastrotomy were verified. During the operation, various physiological indicators of the rats were monitored. The results showed that the rats HR, SpO ₂ , RR, T, SBP, and MAP did not fluctuate significantly at the 10th, 20th, 30th, and 45th minute of operation, and each physiological index had no significant difference at each time point (p>0.05), which indicated that the anesthesia device had Rats undergo surgery after anesthesia, and the main physiological indicators during the operation can be kept stable (see Table 3).

Table 3. Effects of laparotomy and gastrotomy on physiological indicators in rats ( n=10)

During anesthesia maintenance, adjust the flow meter of the drug administration part so that the oxygen input flow rate is 0.15 L/min; at the same time, adjust the gas flow rate of the mask part flow meter to 0.2 L/min, and adjust the concentration of isoflurane to 2.5%, and then A digital pressure gauge is connected to the end of the exhaust gas absorption tube. By adjusting the flow rate of the micro vacuum pump, the pressure at the end of the exhaust gas absorption tube is close to 0, and then the exhaust gas absorption tube is connected to the exhaust gas absorption tank, so that the anesthesia gas that is not inhaled by the rats Reuse, thereby reducing waste gas emission and loss of anesthetic gas, and improving the utilization rate of anesthetic gas. During the surgical verification, it was found that the rats were maintained under anesthesia in this way, the rats were in good respiratory condition, the breathing was stable, the color of the visible mucosa was normal, and the blood oxygen could be maintained above 98%. Compared with similar anesthesia methods abroad, the changes in physiological indicators such as body temperature, blood pressure, heart rate and blood oxygen in rats are basically the same as the recovery time from anesthesia.

Claims (10)

1. A circulating inhalation anesthesia device, comprising an oxygen tank (1), a first gas flow meter (3), an anesthetic gas volatilization tank (4), a face mask (12) and a waste gas absorption tank (14); wherein, the oxygen tank The outlet of (1) is connected with the inlet of the first gas flowmeter (3) through the oxygen pressure reducer (2) and the pipeline, and the outlet of the first gas flowmeter (3) is connected with the inlet of the anesthetic gas volatilization tank (4) through the pipeline Connect, the outlet of this anesthesia gas volatilization tank (4) is connected with the inlet of face mask (12) by the second gas flow meter (11) and pipeline; The outlet of face mask (12) is connected with waste gas absorption tank (14); It is characterized in that , the outlet of the anesthetic gas volatilization tank (4) merges with the gas outlet of a miniature vacuum pump (9) and then is connected with the inlet of the second gas flowmeter (11) and the face mask (12) successively; the miniature vacuum pump (9) The air inlet of the air inlet is connected with the air outlet of the circulating gas filter box (8) by the pipeline, and the air inlet of the circulating air filter box (8) is connected with the outlet (125) of the face mask (12) by the pipeline; in the miniature vacuum pump (9) A large air storage bag (10) is housed on the pipeline between the gas outlet of the gas outlet and the second gas flow meter (11). 2. circulation type inhalation anesthesia device according to claim 1, is characterized in that, is also provided with an anesthesia induction box (6), and this anesthesia induction box (6) is provided with air inlet and air outlet, and its air inlet Link to each other with the three-way valve (5) that is arranged on the pipeline between the large air storage bag (10) and the second gas flow meter (11), and its gas outlet is connected with the outlet (125) that is arranged on the face mask (12) and the circulating gas The three-way valve (7) on the pipeline between the air inlets of the filter boxes (8) is connected. 3. The circulating inhalation anesthesia device according to claim 1 or 2, characterized in that, the circulating gas filter box (8) is an acrylic box, and a partition is used between the two ends of the acrylic box (8) (81) is divided into two chambers, communicates with connecting pipe (82) between two chambers, fills up soda lime in two chambers. 4. The circulating inhalation anesthesia device according to claim 2, characterized in that the anesthesia induction box (6) is a closed acrylic box, and the bottom of the anesthesia induction box (6) is covered with soda lime. 5. circulation type inhalation anesthesia device according to claim 1, is characterized in that, described face mask (12) is an umbrella-shaped mask, and the center of the bottom surface of umbrella-shaped mask is provided with the center hole (123) of sealing with elastic material . 6. The circulating inhalation anesthesia device according to claim 1 or 5, characterized in that, the face shield (12) is an umbrella-shaped body consisting of a conical main body (121) and a bottom surface (122) made of rubber The face shield is provided with a central hole (123) in the middle part of the bottom surface (122) which fits the upper and lower jaws of the rat through elastic deformation; the conical main body (121) is provided with an inlet (124) and an outlet (125). 7. The circulating inhalation anesthesia device according to claim 6, characterized in that a small air storage bag (13) is provided on the top of the conical main body of the mask (12). 8. The circulating inhalation anesthesia device according to claim 6, characterized in that, the central hole (123) is conical. 9. The circulating inhalation anesthesia device according to claim 1, characterized in that a digital pressure gauge (15) is installed at the entrance of the exhaust gas absorption tank (14). 10. The circulating inhalation anesthesia device according to claim 1, characterized in that activated carbon is housed in the exhaust gas absorption tank (14).