Syringe

A syringe is a common name for tools that are used in the field of technology, cooking and medicine. Let’s consider the last option in more detail. Medical syringes are necessary for the collection of biological fluids, the introduction of medicinal solutions and the installation of droppers. In practice, several unique types of syringes are used that have been developed for specific purposes (for example, the Janet syringe). What do you need to know about the device, on what principle does it work, and what rules should be taken into account during the injection?

General characteristics

Most syringes are a hollow cylinder, which is marked with a special scale. A needle is placed on the base of the cylinder, and a piston is connected to the reverse side. It regulates the intensity of the introduction or intake of fluids due to the simplest mechanism. The stronger and more intensively the doctor presses on the plunger, the more fluid/biological material will be injected or received.

The design and specificity of syringes has gone from a hollow tube to disposable sterile instruments. Only one thing remained unchanged – the use of a press and a needle (in various variations that depended on time). Now the most popular are disposable syringes made of plastic with a stainless steel needle. They are sold in pharmacies, used in specialized medical institutions due to their low cost, sterility, ease of use. The invention of the first disposable syringe belongs to the pharmacist and veterinarian Colin Murdoch. At the time of opening (1956) he was only 27 years old.

A Brief Historical Reference

A curious fact is that intravenous injections have been carried out since the 1853th century, but the invention of syringes dates back only to the XNUMXth century. In XNUMX, an incredible idea was visited by two scientists at once – the Scotsman Alexander Wood and the Frenchman Charles-Gabriel Pravas. Scientists worked independently of each other, and the world community calls this fact an amazing coincidence.

The Pravas syringe consisted of three elements. This is a glass cylinder with a metal frame, a cannula for a tubular needle of silver or gold, a graduated metal plunger of durite, asbestos or vulcanized rubber. Wood’s medical instrument also consisted of a hollow needle and a cylinder, but was not used for surgical purposes, but for subcutaneous injections. Wood wanted to alleviate the fate of his own patients, who did not tolerate anesthesia well or did not feel its effects at all. He began injecting opiates into pain points and waiting for the patient’s response. Substances quickly spread through the bloodstream and blocked pain, which significantly increased the effectiveness of therapy.

The invention of disposable syringes

New Zealander Colin Murdoch was able to bring the idea of ​​a disposable syringe to life. He trained as a pharmacist, but decided to work as a veterinarian for a while. Murdoch faced the problem of safe injections for animals. Reusable glass devices were fraught with many dangers, which the New Zealander was able to neutralize in 1956. It was at this time that he patented the first disposable medical syringe, which is still used throughout the world. Murdoch’s invention remains one of the most used medical items, with shipments running into the billions.

Modern science is trying to invent a truly disposable syringe, physically depriving the design of the possibility of reuse. The demand and importance of the task is due to the rapid spread of HIV and other infections that threaten human life. Some scientists have made significant progress in research and even received patents for existing developments. But there is still no reliable and cost-effective solution to the issue.

In many countries of the world, charitable organizations are engaged in the exchange of syringes, their disposal, and carry out educational work among the population in order to reduce the spread of infections.

The principle of operation and design of the tool

All syringes operate on a single mechanism. The needle is placed in a vessel with liquid. Then the person raises the piston, due to which a vacuum is created between the device and the surface. A biological fluid or a special substance rushes out of its vessel under the influence of atmospheric pressure and enters a closed cylinder. Later, the cylinder is removed, and the liquid is used for the desired purposes. Let us consider in more detail the design, specifics, features and sequence of the tool.

Two piece construction

The two-component device is based on a cylinder and a piston. The main disadvantage of this design is tightness. To achieve it, the diameter of the piston must exceed the size of the cylinder in which it is located and on which it will slide during the injection. In motion, the piston literally strips polypropylene microparticles from the cylinder, which can affect the test result.

Moreover, the two-piece design requires a lot of effort from the healthcare worker. The nurse exerts considerable force to push the plunger, loses control of the process, injects the medicine in jerks, causes pain to the patient, and feels discomfort in the arm being used.

XNUMX piece construction

The three-component design, in addition to the piston and cylinder, provides for a rubber seal. The element is attached to the piston to reduce friction and greatly facilitate the use of the tool. The seal is made not only from natural rubber, but also rubber, latex impurities and other things. The composition depends on the manufacturer, the cost of materials and the specifics of use.

The needle is not the third component of the syringe. This is a common misconception among both ordinary consumers and medical professionals.

Rubber seals have affected not only comfort or safety, but also the accuracy of the procedure. The piston does not touch the plastic particles of the cylinder, which means they cannot get into the sample fluid or drug substance.

Varieties of medical syringes

Volume classification:

1. Small (0,3; 0,5; 1 milliliter). Used in neonatology, phthisiology and endocrinology. Also, with the help of small syringes, vaccinations are carried out, allergological intradermal tests are done.
2. Standard (from 2 to 22 milliliters). Used in all branches of medicine for subcutaneous, intramuscular and intravenous injections.
3. Large (30, 50, 60, 100 milliliters). A large volume is needed to aspirate fluid, introduce specific nutrients, and flush body cavities (eg, Janet’s ear wash syringe).

Classification according to the type of needle attachment:

1. Luer. The most common type of attachment. The shape of the cylinder provides a special protruding part to which the needle is attached before use. Luer is used in most syringes from 1 to 100 milliliters.
2. Luer-lock. If during luer-fastening the needle is “put on” the syringe, then luer-rock provides for its screwing. It is most often used in devices for injections and droppers, when the most durable fastening of the needle to the syringe is necessary.
3. Non-removable needle, which is integrated into the body of the device. Fixed needles are most often used in small volume syringes – up to 1 milliliter.

Classification according to the position of the tip-cone on the cylinder:

1. concentric. The tip into which the needle is inserted or screwed is located in the center of the device. This is the most comfortable position for both the medical staff and the patient. It is necessary for subcutaneous / intramuscular injections, the volume of which does not exceed 10 milliliters.
2. Eccentric. The tip is slightly offset to the left or right side of the cylinder. It is found in syringes with a volume of about 20 milliliters, which are used to collect venous blood from the elbow area.

Janet’s syringe

It is intended for suction of liquids and washing of internal cavities. It can also be used for enteral nutrition (introduction of mixtures and liquid products through the oral cavity) or emergency evacuation of air in case of accumulation of gases inside the body. It is also possible to use a Janet syringe for intravenous / intraperitoneal infusions. The volume of the device can reach 250 milliliters, which makes it the “largest” of all syringes used in medical practice.

Insulin syringe

Used to administer insulin. A feature of the device is a relatively short needle that does not cause pain to the patient. This aspect is extremely important, since in most cases a person injects insulin on their own. The cylinder scale is marked not only in standard milliliters, but also in units for hormone dosage. Insulin is administered in small quantities, so a specific piston shape has been developed for the convenience of patients. It allows you to easily collect and inject the medicine in the required amount.

Carpool syringe

It is used for the introduction of carpool anesthesia during dental procedures. The device is made of stainless steel or titanium, less often glass. Carpool syringes are reusable, disinfecting before and after each client. The device consists of a cylindrical body, a hermetic plug and several holders. It is held with three fingers in order to clearly and accurately control the introduction of the needle.

Syringe dart

Used in veterinary medicine to administer drugs to animals. The cylinder is connected to a special gun, directed at the animal and a shot is fired, which delivers a needle with medication to the body. A syringe gun works on a similar principle. A suitable syringe is connected to it, which is precisely fixed in the structure, and a shot is fired. Manufacturers claim that the manipulations are carried out so quickly and accurately that the patient does not feel pain at all.

Self-disrupting syringe

A self-destructive or self-locking device is a modern version of a disposable syringe. Their design is non-reusable, which can reduce the risk of infection. Syringes have been developed for large and routine population immunization programs but have not yet been widely adopted.

How to use a syringe correctly

The main aspect in the process of using medical instruments is sterility. They come into contact with the blood, which means they can cause rapid infection of the entire body. How to avoid it? Before using a needle and a disposable syringe, make sure that their packaging is intact. Some firms apply special indicators to the container, which show the degree of sterility of the instrument. Reusable syringes are used much less frequently in medical practice, but the process of their sterilization is also important and necessary. The device is thoroughly boiled in water, treated with special means and the rules for storing medical equipment are followed.

Immediately before injection, the syringe barrel is placed in a container with a drug. The medical worker pulls the piston of the device towards himself, after which he draws the required amount of medicine into the cylinder. It is important that there are no air bubbles in the collected preparation.

To do this, the device is directed with the needle up, slightly pressed on the piston and the remaining air is “expelled” from it with a small part of the medicine.

The injection site is wiped with alcohol, after which the needle is inserted into the blood vessel, under the skin or inside the muscle, depending on the therapeutic goals. Then the nurse presses the piston, moves the medication from the cylinder directly into the patient’s body, carefully removes the needle and once again treats the formed wound.

Do not self-medicate. Perform injections or sampling of biological material only in specialized institutions under the supervision of physicians. Do not risk your own health and use the benefits of modern medicine.

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