Collection, sterilization, embalming, immobilization and preservation experiments on dead bodies
Collection, sterilization, embalming, immobilization and preservation experiments on dead bodies
The scientific understanding of human structure cannot be separated from the practice of cadaver dissection. Corruption of cadavers, on the other hand, restricts anatomical research. Therefore, the method of preserving corpses against decay should be improved continuously in order to create good conditions for teaching and research in anatomy.
The collection of corpses not only involves the quality of preservation of corpses, but also relates to policies, laws and traditional folk customs. Therefore, the collection of corpses should be carried out by specialized personnel in a serious and conscientious manner so as to avoid all kinds of disturbances and adverse social impacts. Immediately after collection, the body should be registered, sterilized, embalmed, fixed and preserved.
Operation method
Collection, sterilization, embalming, immobilization and preservation experiments on dead bodies
Materials and Instruments
Carcasses. Move I. Registration of bodies Formaldehyde-free mixtures generally do not have a strong irritating odor, and the bodies are softer, but are less effective at antiseptic fixation. For more product details, please visit Aladdin Scientific website.
70% alcohol, Lysol, Neosporin, formalin, carbolic acid, glycerin, ammonia, muscimol.
Dissecting apparatus Slinger Syringe Needle Y-shaped glass tube Injection catheter Rubber tubing Rubber gloves Isolation gowns Masks Long rubber shoes Plastic registration tags Line
Bodies must be registered in accordance with the relevant government regulations before disposal, and there should be a special registration book or registration card. For unclaimed corpses, photographs should be taken for reference. The registration shall include the following items: number, name, sex, age, place of origin, source, cause of death, time since death (estimated to end at the time of injection), physical characteristics of the body (with or without disabilities, deformities, traumas, etc.), the site of embalming, the formula of the antiseptic and the amount of injection, the date of the injection, the name of the person who performed the injection, the method of preservation, the unit that received the body, the date, and the person who handled it.
After registration, each body in the earlobe and ankle part of the separate tie number plate, number plate can choose acid and alkali resistance, not easy to corrode the plastic sheet, can also choose cloth. In order to avoid the long mold fall off and not recognizable, the number of plastic pieces of organic solvents can be used with oil paint writing, cloth can be written in carbon ink with alcohol after wetting and drying, it will be able to long-term preservation will not be decolorized.
Second, the cleaning and sterilization of the body
Before handling the corpses, the staff should wear isolation clothes, caps, masks, rubber gloves and long rubber shoes. Pay attention to avoid infectious diseases and their intermediate host vector of infection. The carcass is first rinsed with tap water, while being cleaned with a soft bristle brush, and then sprayed with disinfectant. Disinfectants are usually 3% to 5% Lysol or 0.1% to 0.2% Neosporin or 70% to 75% alcohol. It is best to shave the hair and pubic hair after disinfecting.
Cleaning, disinfecting and perfusion of cadavers should be carried out in the processing room near the cadaveric vault or in the laboratory autopsy room, and processing in other places is contraindicated. After the disposal of the corpse, the workplace and the used clothes and utensils should be cleaned and sterilized. The clothing of the deceased should be incinerated in a timely manner.
III. Embalming and fixing of corpses
After the death of a person or animal, if the body is not embalmed and fixed treatment, it will soon occur tissue autolysis, corruption, gradual disintegration, producing a variety of amines, indole, methyl indole, hydrogen sulfide and other toxic products with a strong odor. The principle of embalming and fixation is mainly to make protein denaturation and coagulation. Organizational corruption and autolysis to have enzyme participation, and the essence of the enzyme is protein, bacteria are also composed of protein. Therefore, all can make protein denaturation or coagulation of physical and chemical factors, can make the enzyme lose catalytic activity, inhibit or kill bacteria, in order to prevent tissue corruption, autolysis, to achieve the purpose of embalming and fixing the body. Commonly used chemical preservatives such as phenols, alcohols, aldehydes, heavy metal salts or physical heating, ultraviolet light, drying and dehydration, etc., all have the role of embalming and fixation. In the work of embalming and fixing and preservation of corpses, chemical preservatives are mostly used.
Fourth, commonly used antiseptic fixed agent formula
(a) A single antiseptic fixative
Fixation of cadaver specimen formaldehyde solution as a single antiseptic fixative. Formaldehyde chemical structure formula for HCHO, its 35% ~ 40% saturated aqueous solution of the commercial name is usually called formalin (formalin) or formaldehyde solution. The common concentration of formalin used to immobilize cadavers is 10% formalin, or 4% formaldehyde. With formalin perfusion of the body, about 7 d can penetrate the whole body, but to achieve a more complete fixation to the degree suitable for anatomical operations, it will take about 120 ~ 180 d.
Formalin has the advantages of low price, strong bactericidal ability, good antiseptic fixation effect, so it is more commonly used. Its disadvantage is that the specimen tissue fixed with formalin is easy to become hard, brittle, irritating and so on.
(ii) Mixed antiseptic fixative
Mixed antiseptic fixative has many formulations, each with its own advantages and disadvantages. Mixed formula, the principle of increasing or decreasing the drug is based on the need to give full play to the strengths of various drugs, to overcome their shortcomings, to avoid adverse chemical reactions. Here are some commonly used formulations, for reference only.
1. Formaldehyde-containing mixed antiseptic fixative 
Formaldehyde-containing fixative are irritating odor, the use of formaldehyde mixed with ammonia to generate cyclic hexamethylenetetramine (urotropine), can reduce the irritation and toxicity of formaldehyde, the formula is as follows:
2. Mixed antiseptic fixative without formaldehyde
Fifth, the body of the embalming fixed treatment
Embalming fixed method, there are two kinds of immersion and perfusion method. Immersion method is to soak the specimen in the embalming fluid. Drugs penetrate into the internal organs to achieve the purpose of antiseptic fixation. Due to direct penetration can only reach a certain depth, and therefore only suitable for small pieces of isolated organs, the overall preservation of embalming is commonly used perfusion method, the antiseptic fixation of drugs injected into the blood vessels, so that it flows through the blood vessels all over the body, penetrate into all the tissues and organs.
1. Selection of perfusion site Adult cadaver perfusion site should be selected in the less damaged parts of the structure, easy to expose the superficial arteries, such as the flexor artery, femoral artery, carotid artery and the carotid artery. Such as flexor artery, femoral artery, common carotid artery, brachial artery or dorsalis pedis artery. Children's corpses because of the small limb arteries, the operation is more difficult. Most of the carotid artery. Infant corpses because the body is small, subcutaneous fat, in the limbs or the neck are not suitable for perfusion, if the umbilical cord still exists, can be used for large syringe perfusion through the umbilical vein; if the umbilical cord has been dislodged. The embalming fluid can be injected into the thoracic and abdominal cavities, and then put into the cadaver trough to be immersed in the embalming fluid.
For perfusion, a longitudinal incision can be delineated according to the body position of the artery, the incision is about 4 cm long, and after cutting through the skin, the artery is identified by blunt dissection, and the artery is incised longitudinally FIGURE 22 The wall of the arterial Fig. 22 Hanging bucket perfusion method. The distal end of the perfusion hose is connected to two injection catheters (metal, glass, or plastic can be used) with a Y-shaped tube, and the end of the catheter is preferably made into a potbelly shape, which makes it easy to be ligated and less likely to slip off (two syringe tips can also be connected). The two catheters or needles are inserted into the arteriotomy in the distal and proximal directions respectively, so as to perfuse in both distal and proximal directions at the same time.
After the cadaver is perfused, the morphologic position will be basically stereotyped, especially after the contraction of the two hands in the shape of a fist, it is difficult to correct, and it is inconvenient for anatomical operation: therefore, attention should be paid to the cadaver according to the anatomical position of the cadaver should be set up at the time of perfusion, i.e.: the cadaver lying on its back, the head placed in the right place, the upper limbs straightened, the palms of the hands facing upward, the fingers straightened, the lower limbs straightened and separated by about 30 degrees, and special attention should be paid to make the fingers straightened and avoided to be curled. In order to prevent the fingers from bending and shrinking, the palms and fingers can be pressurized by placing objects on them.
3. The amount of embalming fluid to be injected should be decided according to the condition of the corpse and different fixation fluids, generally about 20% of the body weight. Some corpses may have cavities in the lungs or for other reasons, and in the process of infusion, more liquid flows out of the mouth and nose, and if the blockage is ineffective, the height of the bucket can be appropriately lowered, and the infusion can be performed under reduced pressure or intermittent infusion. Perfusion to what extent is considered to meet the requirements, can be determined in the following way: when the perfusion to meet the requirements, the subcutaneous edema, hand pressure has a solid sense of elasticity, chest and abdomen full, the mouth and nose out of the foamy liquid; if the antiseptic solution within the carbolic acid component, the antiseptic solution has reached the skin area will appear white spots, and to the surrounding areas to expand. The above phenomena can be used as a sign that the perfusion has met the requirements.
If the perfusion that some localization is not up to the perfusion requirements, can be used to perfuse the bucket of needles directly into the required parts of the local re-injection, can also be used to localize the direct supplemental injection syringe. Cadaver perfusion is completed, should be set aside for 1 ~ 2 d, so that the antiseptic fluid in the arteries penetrate into the tissue interstitial space, and then moved into the pool for immersion.
Sixth, the preservation of the body
Cadaver by embalming fixed treatment, but also have proper preservation measures to avoid evaporation of water, the body dry stiffness, surface mold and so on. There are many methods of preservation of the body, now only introduces the commonly used preservation methods.
(A) wet preservation
Wet preservation is the body will be immersed in the preservation of liquid in the body tank, body box or body pool. This method is simple, low cost and effective. Antiseptic fixation drugs can be used alone or mixed as preservation fluid, with reliable efficacy, and is a commonly used preservation fluid.
1. formaldehyde solution commonly used 5% formalin solution. In order to reduce the irritating odor and toxicity of formaldehyde, ammonia infusion can be used to improve the teaching environment. The method is to instill 1000 ml of 25% ammonia into the arteries of the fixed cadaver, and 200 ml into each of the thoracic, abdominal and pelvic cavities.
2. Phenol solution is commonly used with a concentration of 2% to 3% phenol. Phenol solution antiseptic anti-mold effect is good, irritating odor is small, but the fixed peripheral nerve endings have a detrimental effect, after a long time, there will be yellow-brown mud-like sediment in the cadaver pool.
3. PM antimicrobial antiseptic solution PM is 2-pyridyl-n-oxide iso-thiourea hydrobromide (2-pyridyl-n-oxide iso-thiourea hydrobromide) for short. PM is a light gray or milky yellow crystalline or crystalline powder, decomposition at 155-158 ℃, soluble in water, slightly soluble in methanol, ethanol. It has the advantages of wide antimicrobial spectrum, strong antimicrobial force, good antiseptic and antibacterial effect, small irritation, weak toxicity, good water solubility. Often 0.05% of PM plus 10% alcohol configuration of the preservation solution to save the body, mold preservation and anticorrosion effect is good. The preservation liquid is clear and moderately priced, which is a new and more ideal preservation liquid for corpses.
Wet preserved corpses should be checked regularly, at least twice a year. Inspection should pay attention to whether the exposed part of the corpse is rotten, whether the liquid surface has moldy lumps. If the body is found to have decay or moldy lumps on the surface of the liquid, timely measures should be taken to replace or replenish the liquid.
(ii) Dry storage in plastic bags
After embalming the fixed body, in the body pool immersed in 30 ~ 90 d, so that the surface is fixed, removed into the size of a suitable plastic bag, the bag to stay a small amount of preservation of formalin or phenol-containing preservation of the liquid, seal the mouth of the bag, placed on the shelf for storage.