Intravenous catheters: sizes, types, fixation. Intravenous peripheral catheter

Medicines can be injected into the body in various ways, depending on the indications: enterally (by mouth) medications are administered in the form of tablets, powders, solutions, mixtures, capsules; rectally (into the rectum) - in the form of suppositories, enemas; parenterally (bypassing the gastrointestinal tract) - in the form of injections or by applying drugs to the skin, mucous membranes.

This article will discuss the parenteral method of administering drugs under the skin and into the muscle using a syringe, as well as into a vein using an intravenous catheter.

General rules for performing injections

Injection - the introduction of a drug by injecting it under pressure into a particular environment or tissue of the body with a violation of the integrity of the skin. This is one of the most dangerous uses of medications. An incorrect injection can damage nerves, bones, tissues, blood vessels, or the body becomes infected with microflora.

There are the following types of injections: intradermal, subcutaneous, intramuscular, intravenous, intraarterial, intraarticular, intraosseous, intracardiac, subdural, subarachnoid (spinal injection), intrapleural, intraperitoneal.

To perform injections, sterile instruments are required - a syringe and a needle, intravenous catheters of various sizes, infusion (drip) systems, as well as alcohol balls, injection solutions, tourniquets, etc. When using each element, it is important to adhere to certain rules.

Figure: 1. Syringes of various sizes (from 1 to 50 ml) used in veterinary medicine

Syringes... Before starting work, it is necessary to check the integrity of the syringe package, then sterilely open it from the side of the piston, take the syringe by the piston and, without removing it from the package, insert it into the needle.

Needles... First of all, the integrity of the package is checked. Then it is opened sterile from the side of the cannula, the needle is carefully removed from the cap.

Infusion systems... Manipulations are performed in the following order:

1. the package is opened in the direction of the arrow;
2. close the roller clamp;
3. remove the protective cap from the vial needle and insert the needle completely into the infusion solution vial;
4. suspend the bottle with the solution and squeeze the needle container so that it is ½ filled;
5. open the roller clamp and release the air from the system;
6. connected with a needle or intravenous catheter;
7. open the roller clamp and adjust the flow rate.

A set of a drug in a syringe from an ampoule
First of all, you need to familiarize yourself with the information on the ampoule: the name of the drug, its concentration, expiration date.
Make sure that the medicinal product is suitable for use: there is no sediment, the color does not differ from the standard one.
Knock on the narrow part of the ampoule so that all the drug is in its wide part.
Before sawing off the neck of the ampoule, you need to treat it with a cotton ball with a disinfectant solution. Cover the ampoule with a napkin to protect yourself from debris. Break off the neck of the ampoule with a confident movement.
Insert a needle into it and collect the required amount of the drug. Ampoules with wide bore should not be inverted (Fig. 2). It is necessary to ensure that when dialing the drug, the needle is always in the solution: in this case, air will not enter the syringe.
Make sure there is no air in the syringe. If there are air bubbles on the walls, you should slightly pull back the plunger of the syringe, “turn” the syringe several times in a horizontal plane and squeeze out the air.

Figure: 2. Ampoules with a wide "neck" should not be turned over to avoid leakage of the drug

A set of drugs in a syringe from a vial closed with an aluminum cap
As in the case of the ampoule, first of all, you need to read the name of the drug, concentration, expiration date on the bottle; make sure the color is the same as the standard one.
Vials with solutions are checked for intact packaging and contamination.
Then, with non-sterile tweezers (scissors, etc.), part of the bottle cap covering the rubber stopper is folded back.
Wipe the rubber stopper with a cotton / gauze ball moistened with an antiseptic.
Insert the needle at an angle of 90 ° into the vial and draw the required amount of the drug from the vial into the syringe.
Separate sterile needles and syringes are used at each withdrawal of the contents from the vial.
Opened multi-dose vials are stored in the refrigerator for no more than 6 hours, unless otherwise indicated in the instructions.

Figure: 3. A set of the drug from a vial with a rubber stopper rolled up with an aluminum cap

Injection technique

When performing injections, it is very important to follow certain rules.

Subcutaneous injection... With this method, the medicinal substance is injected directly into the subcutaneous tissue, preferably in an area that is well supplied with blood. Subcutaneous injections are less painful than intramuscular injections. The groin crease and withers are the most suitable sites for subcutaneous injections. Before injection, the skin is collected in a fold to determine the thickness of the subcutaneous tissue. Grasping the skin with thumb and forefinger, an injection is made into the formed triangle. To correctly administer the medicine, it is necessary to accurately calculate the length of the fold and the thickness of the subcutaneous tissue. The needle is inserted at an angle of 45 ° to 90 ° to the skin surface.

Intramuscular injection... This method is used to introduce those medicinal substances that, when injected subcutaneously, give severe irritation (for example, magnesium sulfate) or are slowly absorbed. The drug is injected into the posterior femoral muscle group or the muscles of the shoulder.

Intravenous injection... They are carried out both with a syringe with a needle and by pre-installing an intravenous catheter. In veterinary medicine, due to the mobility of patients, it is optimal to use catheters. When choosing a catheterization site, it is necessary to take into account the ease of access to the puncture site and the suitability of the vessel for catheterization. There are practically no complications if the basic rules are followed. The catheter must be cared for perfectly.

Vein catheterization rules

Indications for venous catheterization... A peripheral intravenous catheter is an instrument inserted into a peripheral vein to provide access to the bloodstream.

Figure: 4. Intravenous catheters

Indications for the use of an intravenous boat:

• emergency conditions in which quick access to the bloodstream is required (for example, if you need to urgently and at high speed to inject drugs);
• prescribed parenteral nutrition;
• overhydration or hydration of the body;
• transfusion of blood products (whole blood, erythrocyte mass);
• the need for rapid and accurate administration of the drug in an effective concentration (especially when the drug can change its properties when taken orally).

A well-chosen venous approach contributes greatly to the success of intravenous therapy.

Vein and catheter selection criteria... With intravenous injections, the advantage remains with the peripheral veins. Veins should be soft and elastic, without seals and knots. It is better to inject drugs into large veins, in a straight section corresponding to the length of the catheter.

When choosing a catheter (Fig. 4), you must focus on the following criteria:

• diameter of the vein (the diameter of the catheter should be less than the diameter of the vein);
• the required rate of solution introduction (the larger the catheter size, the higher the rate of solution introduction);
• potential time the catheter is in the vein (no more than 5 days).

When catheterizing veins, preference should be given to modern Teflon and polyurethane catheters. Their use significantly reduces the frequency of complications and, with high-quality care, their service life is much longer.
The most common cause of failures and complications in peripheral vein catheterization is the lack of practical skills of the staff, violation of the technique of inserting a venous catheter and its care. This is largely due to the absence in veterinary medicine of generally accepted standards for peripheral vein catheterization and rules for catheter care.

A standard set for catheterization of a peripheral vein (Fig. 5) includes a sterile tray, sterile napkins soaked in disinfectant solution, adhesive plaster, peripheral intravenous catheters of several sizes, tourniquet, sterile gloves, scissors, gauze or self-fixing elastic bandage.

Figure: 5. Standard kit for peripheral vein catheterization

Placement of a peripheral catheter... They start by providing good illumination of the manipulation site. Then hands are thoroughly washed and dried. A standard vein catheterization kit is assembled, with several catheters of different diameters in the kit.
A tourniquet is applied 10-15 cm above the expected catheterization zone. The vein is selected by palpation.
An optimal catheter is selected, taking into account the size of the vein, the required injection rate, and the schedule of intravenous therapy.
Put on gloves.
The catheterization site is treated with a skin antiseptic for 30-60 seconds and allowed to dry.
Having fixed the vein (it is pressed with a finger below the intended site of catheter insertion), a catheter of the selected diameter is taken and the protective cover is removed from it. If there is an additional plug on the cover, the cover is not thrown away, but held between the fingers of the free hand.
The catheter is inserted on the needle at an angle of 15 ° to the skin, observing the indicator chamber. When blood appears in it, the angle of inclination of the stylet needle is reduced and the needle is inserted into the vein by a few millimeters (Fig. 6). Having fixed the stylet needle, slowly move the cannula from the needle into the vein to the end (the stylet needle is not completely removed from the catheter until it is completely removed). Remove the tourniquet.
Do not insert the needle all the way into the catheter after it has been displaced from the needle into the vein! This will injure the vessel walls.
The vein is clamped to reduce bleeding and the needle is permanently removed from the catheter.
The needle is disposed of in a safe manner.
Remove the plug from the protective sheath and close the catheter or attach an infusion set.
The catheter is fixed on the limb with adhesive tape (Fig. 7).

Figure: 6. Installation of an intravenous catheter for a cat. The assistant compresses the vein above the catheter insertion with the thumb. The catheter tube is in the vein, the stylet needle is halfway out.

Figure: 7. The installed catheter is fixed on the paw with an adhesive plaster.

Catheter care rules
Each catheter connection is a gateway for infection. It is necessary to avoid repeatedly touching the instruments with your hands. It is recommended to change sterile plugs more often, never to use plugs, the inner surface of which could be infected.

Immediately after the administration of antibiotics, concentrated glucose solutions, blood preparations, the catheter is washed with a small amount of saline.

To prevent thrombosis and prolong the life of the catheter in the vein, it is recommended to flush the catheter with saline additionally - during the day, between infusions.

Complications after vein catheterization are divided into mechanical (5-9%), thrombotic (5-26%), infectious (2-26%).

It is necessary to monitor the condition of the fixation bandage and change it if necessary, as well as regularly examine the puncture site in order to identify complications as soon as possible. When edema appears (Fig. 7), redness, local temperature rise, catheter obstruction, leakage, as well as painful sensations of the animal to which the drug is injected, remove the catheter and install a new one.

Figure: 7. Swelling of a limb in an animal with improper fixation of the catheter (the paw is very tightly tightened with a plaster)

When changing the adhesive bandage, do not use scissors, because you can cut off the catheter, causing it to enter the bloodstream. The place of catheterization is recommended to be changed every 48-72 hours. To remove the venous catheter, you need a tray, a ball soaked in disinfectant solution, a bandage, and scissors.

Conclusion

Despite the fact that catheterization of peripheral veins is a much less dangerous procedure than catheterization of central veins, if the rules are violated, it can cause a complex of complications, like any procedure that violates the integrity of the skin. Most complications can be avoided with good manipulation techniques of the staff, strict adherence to the rules of asepsis and antisepsis, and proper care of the catheter.

Literature

1. A guide for a nurse in a treatment room. - SPb .: "Printing house" Beresta ", 2007.
2. Mitin V.N. First aid for small pets. - M .: KolosS, 2005.
3. Handbook for nurses of the intensive care unit // Ed. AND I. Grinenko. - SPb .: Committee on Health of the Leningrad Region, Association of Nurses, 2007.

S. V. Panfilova, veterinary clinic "Biocontrol"
at the Russian Cancer Research Center named after N.N. Blokhin (Moscow)

Thanks to him, you can avoid injury to blood vessels, and therefore inflammatory processes and thrombus formation.

What is a venous catheter

The instrument is a thin, hollow tube (cannula) equipped with a trocar (hard pin with a sharp end) to facilitate its introduction into the vessel. After the introduction, only the cannula is left, through which the medicinal solution enters the bloodstream, and the trocar is removed.

Before setting, the doctor conducts an examination of the patient, which includes:

How long does the installation take? The procedure takes about 40 minutes on average. Anesthesia of the insertion site may be required when a tunnel catheter is inserted.

After the installation of the instrument, it takes about one hour to rehabilitate the patient, the sutures are removed after seven days.

Indications

A venous catheter is necessary if long-term intravenous administration of drugs is required. It is used in chemotherapy in cancer patients, in hemodialysis in people with renal failure, in the case of long-term treatment antibiotics.

Classification

Intravenous catheters are classified in many ways.

By appointment

There are two types: central venous (CVC) and peripheral venous (PVK).

CVCs are intended for catheterization of large veins, such as subclavian, internal jugular, and femoral. With such a tool, drugs and nutrients are injected, blood is taken.

PVC is installed in peripheral vessels... As a rule, these are the veins of the extremities.

Comfortable peripheral venous butterfly catheters with soft plastic wings to attach to the skin

Butterfly is used for short-term infusions (up to 1 hour), since the needle is constantly in the vessel and can damage the vein if kept longer. Usually they are used in pediatrics and outpatient practice for puncturing small veins.

By size

The size of venous catheters is measured in gauges and is designated by the letter G. The thinner the instrument, the greater the value in gauges. Each size has its own color, which is the same for all manufacturers. The size is selected depending on the application.

By model

There are ported and non-ported catheters. Ported ones differ from non-ported ones in that they are equipped with an additional port for the introduction of liquid.

By design

Single-lumen catheters have one lumen and end in one or more holes. They are used for periodic and continuous administration of medicinal solutions. They are used in both emergency and long-term therapy.

Multichannel catheters have 2 to 4 channels. Used for the simultaneous infusion of incompatible drugs, blood sampling and transfusion, hemodynamic monitoring, for visualization of the structure of blood vessels and heart. They are often used for chemotherapy and long-term administration of antibacterial drugs.

By material

• Slippery surface
• Rigidity

• Frequent cases of blood clots

• High permeability to oxygen and carbon dioxide
• High strength
• Not wetted with lipids and fats
• Sufficiently resistant to chemicals

• Stable change of shape in places of folds

• Thrombotic resistance
• Biocompatibility
• Flexibility and softness
• Slippery surface
• Resistant to chemicals
• Non-wetting

• Change in shape and the possibility of rupture with increasing pressure
• Hard under the skin
• Possibility of entanglement inside the vessel

• Unpredictable on contact with liquids (changes in size and stiffness)

• Biocompatibility
• Thrombosis
• Wear resistant
• Rigidity
• Resistant to chemicals
• Return to the previous form after kinks
• Easy insertion under the skin
• Hard at room temperature, soft at body temperature

• Abrasion resistance
• Hard at room temperature, soft at body temperature

• Frequent thrombosis
• The plasticizer can be washed out into the blood
• High absorption of certain drugs

Central venous catheter

It is a long tube that is inserted into a large vessel to transport medicines and nutrients. There are three access points for its installation: the internal jugular, subclavian and femoral veins. The first option is most often used.

When a catheter is inserted into the internal jugular vein, there are fewer complications, pneumothorax occurs less often, it is easier to stop bleeding if it occurs.

With a subclavian approach, there is a high risk of pneumothorax and damage to the arteries.

When accessing through the femoral vein after catheterization, the patient will remain immobile and there is a risk of catheter infection. Of the advantages, one can note an easy entrance to a large vein, which is important in case of emergency assistance, as well as the possibility of installing a temporary pacemaker

There are several types of central catheters:

• Peripheral central. It is passed through a vein in the upper limb until it reaches a large vein near the heart.
• Tunneling. It is injected into a large jugular vein, through which blood returns to the heart, and is excreted at a distance of 12 cm from the injection site through the skin.
• Non-tunneling. It is installed in a large vein of the lower limb or neck.
• Port catheter. Inserted into a vein in the neck or shoulder. The titanium port is installed under the skin. It is equipped with a membrane that is pierced with a special needle through which fluids can be injected for a week.

Indications for use

A central venous catheter is installed in the following cases:

• For the introduction of food, if its entry through the digestive tract is impossible.
• With chemotherapy behavior.
• For fast injection of large volumes of solution.
• With prolonged administration of fluids or drugs.
• With hemodialysis.
• In case of inaccessibility of veins in the arms.
• With the introduction of substances that irritate peripheral veins.
• With blood transfusion.
• With periodic blood sampling.

Contraindications

There are several contraindications to central venous catheterization, which are relative, therefore, according to vital indications, the CVC will be installed in any case.

The main contraindications include:

• Inflammatory processes at the injection site.
• Blood clotting disorder.
• Bilateral pneumothorax.
• Clavicle injuries.

Order of introduction

A vascular surgeon or interventional radiologist places a central catheter. The nurse prepares workplace and patient, helps the doctor put on sterile overalls. To prevent complications, not only installation is important, but also its care.

After installation, it can stand in a vein for several weeks or even months.

Before installation, preparatory measures are required:

• find out if the patient is allergic to drugs;
• conduct a blood clotting test;
• stop taking certain medications a week before catheterization;
• take blood thinning medications;
• find out if there is pregnancy.

The procedure is performed in a hospital or on an outpatient basis in the following order:

1. Hand disinfection.
2. Choice of catheterization site and skin disinfection.
3. Determination of the location of the vein by anatomical features or using ultrasound equipment.
4. Local anesthesia and incision.
5. Reducing the catheter to the required length and flushing it in saline.
6. Guiding the catheter into a vein with a guidewire, which is then removed.
7. Fixation of the instrument on the skin with adhesive plaster and installation of the cap at its end.
8. Catheter dressing and insertion date.
9. When a port catheter is inserted, a cavity is formed under the skin for its placement, the incision is sutured with an absorbable suture.
10. Check the injection site (whether it hurts, whether there is bleeding and fluid discharge).

Proper care of the central venous catheter is very important to prevent suppurative infections:

• At least once every three days, it is necessary to process the opening of the catheter introduction and change the dressing.
• The junction of the dropper with the catheter must be wrapped with a sterile tissue.
• After administration of the solution, wrap the free end of the catheter with sterile material.
• Try not to touch the infusion set.
• Change infusion sets daily.
• Do not bend the catheter.

• Keep the puncture site dry, clean and bandaged.
• Do not touch the catheter with unwashed and unsanitary hands.
• Do not swim or wash with the installed tool.
• Do not let anyone touch him.
• Do not engage in activities that could weaken the catheter.
• Check the puncture site daily for signs of infection.
• Flush the catheter with saline.

Complications after the installation of the CVC

Central vein catheterization can lead to complications, including:

• Puncture of the lungs with accumulation of air in the pleural cavity.
• Accumulation of blood in the pleural cavity.
• Puncture of the artery (vertebral, carotid, subclavian).
• Pulmonary embolism.
• Misplaced catheter.
• Puncture of the lymphatic vessels.
• Catheter infection, sepsis.
• Abnormal heart rhythm during catheter advancement.
• Thrombosis.
• Nerve damage.

Peripheral catheter

A peripheral venous catheter is installed for the following indications:

• Inability to take oral fluids.
• Transfusion of blood and its components.
• Parenteral nutrition (nutrient administration).
• The need for frequent administration of drugs into the vein.
• Anesthesia during surgery.

PVK cannot be used if it is required to inject solutions that irritate the inner surface of the vessels, a high infusion rate is required, as well as when transfusing large volumes of blood

How veins are chosen

A peripheral venous catheter can only be inserted into peripheral vessels and cannot be inserted into central vessels. It is usually placed on the back of the hand and on the inside of the forearm. Vessel selection rules:

• Well-visible veins.
• Vessels that are not on the dominant side, for example, for right-handers should be selected on the left side).
• On the other side of the surgical site.
• If there is a straight section of the vessel corresponding to the length of the cannula.
• Vessels with a large diameter.

Do not put PVCC in the following vessels:

• In the veins of the legs (high risk of thrombosis due to low blood flow velocity).
• On the folds of the arms, near the joints.
• Into a vein close to the artery.
• In the median ulnar.
• In poorly visible saphenous veins.
• Weakened sclerosed.
• Deeply buried.
• On infected skin areas.

How to put

Peripheral venous catheter placement may be performed by a qualified nurse. There are two ways to take it in your hand: longitudinal grip and transverse. The first option is more often used, which makes it possible to more reliably fix the needle in relation to the catheter tube and prevent it from going into the cannula. The second option is usually preferred by nurses who are accustomed to performing a vein puncture with a needle.

Algorithm for setting a peripheral venous catheter:

1. The puncture site is treated with alcohol or alcohol-chlorhexidine mixture.
2. A tourniquet is applied, after filling the vein with blood, the skin is pulled and the cannula is set at a slight angle.
3. Venipuncture is performed (if blood appears in the imaging chamber, then the needle is in a vein).
4. After the appearance of blood in the imaging chamber, the advancement of the needle stops, it must now be removed.
5. If after removing the needle the vein is lost, re-insertion of the needle into the catheter is unacceptable, you need to pull out the catheter completely, connect it to the needle and re-insert.
6. After the needle is removed and the catheter is in the vein, you need to put a plug on the free end of the catheter, fix it on the skin with a special bandage or adhesive tape, and rinse the catheter through the additional port, if it is ported, and the attached system, if not ported. Flushing is required after each infusion of fluid.

The care of the peripheral venous catheter is carried out approximately according to the same rules as for the central one. It is important to be aseptic, wear gloves, avoid touching the catheter, change plugs more often, and flush the instrument after each infusion. The bandage should be monitored, changed every three days, and scissors should not be used when changing the bandage. The puncture site should be closely monitored.

Although catheterization of peripheral veins is considered less dangerous than central ones, if the rules of installation and care are not followed, unpleasant consequences are possible

Complications

Nowadays, the consequences after a catheter are less and less frequent, thanks to improved models of instruments and safe and low-traumatic methods of their installation.

Of the complications that can happen, the following can be distinguished:

• bruising, swelling, bleeding at the insertion site;
• infection in the area where the catheter is inserted;
• inflammation of the walls of the veins (phlebitis);
• thrombus formation in the vessel.

Conclusion

Intravenous catheterization can lead to various complications, such as phlebitis, hematoma, infiltration and others, therefore, the installation technique, sanitary standards and rules for caring for the instrument should be strictly observed.

Peripheral catheter placement indications contraindications

N. B. Yarko, B. P. Gromovik, E. N. Eliseeva, N. V. Galayko, Lviv National medical University them. D. Galitsky, Odessa State Medical University

Peripheral intravenous catheters (infusion cannulas, PVVK) are used for patients who need immediate and / or intensive long-term infusion therapy, as well as for patients with "severe", poorly visualized veins. The use of infusion cannulas at the pre-hospital stage makes it possible to comfortably transport the patient without fear that the needle will "come out" of the vessel or pierce its opposite wall and complicate the patient's condition with infiltration or hematoma.

Taking into account the disappointing results of the questionnaire survey of pharmacists and nurses regarding the consumer properties of PVVK, the purpose of this publication was to summarize data on indications, contraindications, structure and features of the use of infusion cannulas.

As can be seen from the data in Table 1, there are four main types of indications and three groups of contraindications for intravenous catheters.

The presence of a wide range of PVHCs necessitated the development of their classification depending on the material of manufacture, structure, size and color coding (Fig. 1).

Materials for the manufacture of PVHC are thermoplastic and strong, have a high degree of biocompatibility and a low coefficient of friction. They help ensure that catheters can be used for 48–120 hours with proper care. Depending on the material of manufacture, there are polyurethane (vialon) and fluoroplastic (Teflon) PVVK. In this case, two types of fluoroplastic are used: polytetrafluoroethylene (PTFE-Teflon) and an analogue of Teflon - fluorinated ethylene propylene (FEP-Teflon).

According to its structure, PVVKs are port and non-port. In their structure, such basic elements as a catheter, a guide-needle, a plug and a protective cap are always present. With the help of a needle, venesection is performed, while a catheter is inserted. The plug serves to close the catheter opening when infusion therapy is not performed (in order to avoid contamination), the protective cap protects the needle and catheter and is removed immediately before manipulation. For easy insertion of a catheter (cannula) into a vein, the tip of the catheter is shaped like a cone. The ratio of the tip of the catheter to the beginning of the needle cut or the amount of trim is specific to each catheter size.

Port PVHCs have an additional injection port for drug administration without additional puncture. With its help, needleless bolus (intermittent) administration of drugs is possible without interruption of intravenous infusion.

In addition, catheters can be accompanied by an additional structural element - "wings". With their help, PVHCs are not only securely fixed to the skin, but also reduce the risk of bacterial contamination, since they do not allow direct contact between the back of the catheter plug and the skin.

Table 1: Indications and contraindications for the use of PVVK

Some manufacturers offer accessories: mandrel or obturator (used to protect the inner lumen of the catheter from blood clotting and blood clots after infusion), additional Luer-Loc plugs, sterile dressings.

In order to reduce friction, which means painful sensations during installation, the catheter and needle are coated with a lubricant (silicone). Some manufacturers equip catheters with a radio-opaque strip to provide effective control over their position in the vein.

PVICs are characterized by size, which is understood as the outer diameter of the catheter (needle) and the length of the cannula (in mm). In this case, according to the measurement system of the American Association of Manufacturers of Medical Instruments, the outer diameter of the catheter (needle) is supplied in gauges (gauge - G), and its length in inches (inch - in). The size in gauges (for example, 14 G) corresponds to the number of cannulas (in our case - 14) that fit in a tube with an inner diameter of 1 inch. In turn, 1 in is equal to 25.4 mm, that is, the 14 Gx1.77 in catheter is 45 mm long.

For all PVHCs, depending on the size, color coding is mandatory according to the ISO 10555 standard. It should also be noted that the size of the catheter is directly related to the scope of its use, as well as to the flow rate (outflow) of the liquid, which, depending on the manufacturer, the PVHCs have the same sizes can be different.

Since the investigated catheters belong to “single-use” products, they must be sterile, pyrogen-free, non-toxic, and since they come into direct contact with blood, they must be biocompatible and hypoallergenic. In addition to general quality requirements, a number of functional requirements are imposed: the needle must be sharp, elastic, without burrs; the plug should not be unauthorizedly disconnected from the catheter sleeve; the injection port cover should open and close without applying force.

Taking into account the insufficient level of knowledge of pharmacists and nurses in the care of PVHC, we have developed a block diagram of pharmaceutical care when using catheters in the departments of a medical institution, aimed at doctors and nurses. As you can see from the data in Figure 2, pharmaceutical care can be divided into eight stages.

Block diagram of pharmaceutical care using PVHC in the departments of a medical institution

The patient's informed consent to the manipulation is certified by his signature, must be entered into the hospital patient's medical record (form No. 003–0) and is the second stage in the choice of PVHC. Before manipulation, a patient should be tested for allergies to the drugs being administered.

At the third stage, the issues of choosing a catheter are considered depending on the material of manufacture, structure and size, as well as the recommended areas of application of certain catheters, the possibility of additional administration of drugs and the duration of the necessary cannulation.

The corresponding PVVK is selected taking into account:

• the size, condition and blood flow of the available veins, since the cannula should never completely block the vein;
• the length of the cannula, which should correspond to the approximate length of the straight section of the corresponding vein; local anatomy;
• the required infusion rate: a high infusion rate necessitates the installation of a PVVK in a vein of a larger diameter;
• the type of fluid to be injected, since potent irritating drugs must be injected into larger vessels for more intense blood dilution;
• the predicted duration of administration, since the use of a smaller PVAC will minimize irritation of the vein

The fourth stage is the choice of the venipuncture site. PVVK should be installed in veins:

• well palpable with high blood filling;
• limbs of the non-dominant side of the body;
• from the side opposite to the one where the surgery was performed;
• with the largest possible diameter.

Avoid bending points (joints), veins lower limbsclose to arteries, irritated as a result of previous catheterization, brittle and sclerized veins, areas of lymphodenoma, infected areas and skin fissures, as well as the median cubital vein, which must be left for collection of venous blood samples.

The fifth stage covers the installation of PVVK, for which it is necessary to check its sterility and shelf life, as well as prepare all the necessary auxiliary materials (as a rule, a sterile tray is prepared containing cotton wool, a disinfectant for skin, a syringe with 0.9% sodium chloride solution, sterile bandages and plaster). According to the appointment sheet, the doctor ( nurse) must identify the patient, thoroughly wash, cover all lesions on the skin, put on protective gloves (latex, latex-free, chain mail), treat them with a disinfectant, if necessary, wear a medical mask and glasses, take a comfortable position and start the process of installing the PVHC. The venipuncture site and adjacent skin areas should be carefully treated twice with a disinfectant solution. In this case, the area of \u200b\u200bthe skin should correspond to the size of the future bandage. The treatment is carried out from the place of the planned installation of the catheter in one direction or in circular movements outward from it and wait until the antiseptic dries. Do not touch the treated area.

Once again making sure that the packaging is not damaged and that the PVVK is not expired, using the symbols (marking), open the packaging in the manner prescribed by the manufacturer. If necessary, unfold the "wings" and take the PVVK in the most convenient way. It is strictly forbidden to remove the needle from the catheter before venipuncture, since not only the trim is disturbed, and venipuncture will be difficult to perform, and the patient will have severe pain, but the catheter itself may be damaged. Next, the vein is fixed and inserted at a small angle of the PVHC, while the cut of the needle should be directed upward. Successful venipuncture, which means that the needle is in the vein, is indicated by the appearance of blood in the reverse flow imaging chamber.

After that, the PVHC is slowly advanced together with the needle a few millimeters further into the vein, into which the tip of the cannula enters, after which the guide needle is fixed with one hand, and the catheter is advanced with the other, thus removing it from the guide needle, or the needle is slowly pulled back - guide and advance the cannula into the vein faster. If you used a tourniquet, then it must be removed. Do not re-insert the guide needle into the cannula while it is in a vein, as this may damage the cannula walls. In order to prevent blood from flowing from the PVHC, it is necessary to press the vein with a finger slightly above the tip of the cannula. Then the guide-needle is completely removed and the infusion system is connected to the PVHC or closed with a plug. For disposal, the guide needle is placed in a sharps container. To confirm the efficiency of functioning and the correct position of the PVHC, it should be flushed (best of all with 0.9% sodium chloride solution). To ensure the dryness of the installation site, the absence of possible infection and mechanical phlebitis, as well as the appropriate service life of the PVHC, a sterile dressing should be applied.

Catheterization of veins - central and peripheral: indications, rules and algorithm for catheter placement

Vein catheterization (central or peripheral) is a manipulation that allows you to provide full venous access to the bloodstream in patients requiring long-term or continuous intravenous infusions, as well as in order to provide faster emergency care.

Venous catheters are central and peripheral, respectively, the former are used to puncture the central veins (subclavian, jugular or femoral) and can only be installed by a resuscitator-anesthesiologist, and the latter are installed in the lumen of the peripheral (ulnar) vein. The last manipulation can be performed not only by a doctor, but also by a nurse or anesthetist.

A central venous catheter is a long, flexible tube (okolosm) that is firmly placed in the lumen of a large vein. In this case, a special access is carried out, because the central veins are located rather deep, in contrast to the peripheral saphenous veins.

The peripheral catheter is represented by a shorter hollow needle with a thin stylet needle located inside, which punctures the skin and venous wall. Subsequently, the stylet needle is removed, and a thin catheter remains in the lumen of the peripheral vein. Access to the saphenous vein is usually not difficult, so the procedure can be performed by a nurse.

Advantages and disadvantages of the technique

The undoubted advantage of catheterization is the implementation of quick access to the patient's bloodstream. In addition, when placing a catheter, the need for daily vein puncture is eliminated for the purpose of intravenous drip infusion. That is, it is enough for the patient to insert a catheter once instead of having to "prick" the vein again every morning.

Also, the advantages include sufficient activity and mobility of the patient with the catheter, since the patient can move after the infusion, and there are no restrictions on the movement of the hand with the catheter installed.

The disadvantages include the impossibility of long-term presence of the catheter in the peripheral vein (no more than three days), as well as the risk of complications (albeit extremely low).

Indications for placing a catheter into a vein

Often in emergency conditions, access to the patient's vascular bed is impossible by other methods for many reasons (shock, collapse, low blood pressure, collapsed veins, etc.). In this case, in order to save the life of a severe patient, it is necessary to administer medications so that they enter the bloodstream immediately. And this is where central venous catheterization comes in. Thus, the main indication for placing a catheter in central vein is the provision of emergency and urgent care in the conditions of the intensive care unit or ward, where intensive therapy is carried out for patients with severe illnesses and disorders of vital functions.

Sometimes catheterization can be done femoral vein, for example, if doctors are performing cardiopulmonary resuscitation (artificial ventilation + chest compressions), and another doctor is providing venous access, and at the same time does not interfere with his colleagues by manipulating the chest. Also, femoral vein catheterization can be attempted in an ambulance when peripheral veins cannot be found and drugs are required in an emergency mode.

central vein catheterization

In addition, there are the following indications for central venous catheter placement:

• Open heart surgery using a heart-lung machine (AIC).
• Access to the bloodstream in severe patients in intensive care and intensive care.
• Installing a pacemaker.
• Introduction of the probe into the heart chambers.
• Measurement of central venous pressure (CVP).
• Conducting X-ray contrast studies of the cardiovascular system.

Installation of a peripheral catheter is indicated in the following cases:

• Early start infusion therapy at the stage of ambulance. When a patient is admitted to a hospital with a catheter already installed, the treatment is continued, thereby saving time for setting a dropper.
• Installation of a catheter for patients who are planning abundant and / or round-the-clock infusions of medicines and medical solutions (saline, glucose, Ringer's solution).
• Intravenous infusions for patients in a surgical hospital, when surgery may be required at any time.
• The use of intravenous anesthesia for minor surgical interventions.
• Installation of a catheter for women in labor at the beginning of labor so that there are no problems with venous access during labor.
• The need for multiple sampling of venous blood for research.
• Blood transfusions, especially multiple ones.
• Inability to feed the patient through the mouth, and then with the help of a venous catheter, it is possible to carry out parenteral nutrition.
• Intravenous rehydration for dehydration and electrolyte changes in the patient.

Contraindications for venous catheterization

Installation of a central venous catheter is contraindicated if the patient has inflammatory changes on the skin of the subclavian region, in case of bleeding disorders or injury to the clavicle. Due to the fact that catheterization of the subclavian vein can be carried out both on the right and on the left, the presence of a unilateral process will not prevent the installation of the catheter on the healthy side.

Of the contraindications for a peripheral venous catheter, it can be noted that the patient has thrombophlebitis of the ulnar vein, but again, if there is a need for catheterization, then manipulation can be performed on the healthy arm.

How is the procedure performed?

Special preparation for catheterization of both central and peripheral veins is not required. The only condition when starting to work with a catheter is full adherence to the rules of asepsis and antisepsis, including the treatment of the hands of the personnel installing the catheter, and careful treatment of the skin in the area where the vein puncture will be performed. Working with the catheter, of course, is necessary with the help of sterile instruments - a catheterization kit.

Central venous catheterization

Subclavian vein catheterization

During catheterization of the subclavian vein (with "subclavian", in the slang of anesthesiologists), the following algorithm is performed:

subclavian vein catheterization

Lay the patient on his back with the head turned in the direction opposite to the catheterization and with the hand lying along the body on the side of the catheterization,

Conduct local anesthesia of the skin according to the type of infiltration (lidocaine, novocaine) below the collarbone on the border between its inner and middle thirds,

With a long needle, into the lumen of which a guidewire (introducer) is inserted, make an injection between the first rib and the clavicle and thus ensure entry into the subclavian vein - this is the basis for the Seldinger method of central vein catheterization (insertion of a catheter with a guidewire),

Check for venous blood in the syringe,

Remove the needle from the vein,

Insert the catheter into the vein along the guidewire and fix the outer part of the catheter with several sutures to the skin.

Video: Subclavian Vein Catheterization - Training Video

Internal jugular vein catheterization

internal catheterization jugular vein

Internal jugular vein catheterization is slightly different in technique:

• Patient position and pain relief are the same as for subclavian vein catheterization,
• The doctor, being at the patient's head, determines the puncture site - a triangle formed by the legs of the sternocleidomastoid muscle, but 0.5-1 cm outward from the sternal edge of the clavicle,
• The needle is inserted at an angle of degrees towards the navel,
• The rest of the steps in the manipulation are the same as in the catheterization of the subclavian vein.

Femoral vein catheterization

Femoral vein catheterization differs significantly from those described above:

1. The patient is placed on his back with the thigh extended outwards,
2. Visually measure the distance between the anterior iliac spine and the pubic symphysis (pubic symphysis),
3. The resulting value is divided by three-thirds,
4. Find the border between the inner and middle thirds,
5. Determine the pulsation of the femoral artery in the inguinal fossa at the obtained point,
6. The femoral vein is located 1-2 cm closer to the genitals,
7. Venous access is performed using a needle and a guidewire at an angle of degrees towards the navel.

Video: Central Vein Catheterization - Instructional Film

Peripheral vein catheterization

Of the peripheral veins, the most preferred in terms of puncture are the lateral and medial veins of the forearm, the intermediate ulnar vein, and also the vein on the back of the hand.

peripheral vein catheterization

The algorithm for introducing a catheter into a vein in the arm is as follows:

• After treating the hands with antiseptic solutions, the required catheter is selected. Typically, catheters are marked according to size and have different colors - purple for the shortest catheters with a small diameter, and orange for the longest with a large diameter.
• A tourniquet is applied to the patient's upper arm above the catheterization site.
• The patient is asked to "work" with the fist, clenching and unclenching the fingers.
• After palpation of the vein, the skin is treated with an antiseptic.
• Puncture of the skin and veins is performed with a stylet needle.
• The stiletto needle is pulled out of the vein while the catheter cannula is inserted into the vein.
• Next, an intravenous infusion system is connected to the catheter, and medicinal solutions are infused.

Video: puncture and catheterization of the cubital vein

Catheter care

In order to minimize the risks of complications, the catheter should be proper care.

First, a peripheral catheter should be placed for no more than three days. That is, the catheter can stay in the vein for no more than 72 hours. If the patient requires additional infusion of fluids, the first catheter should be removed and the second placed on the other arm or vein. Unlike peripheral, a central venous catheter can be in a vein for up to two to three months, but subject to weekly replacement of the catheter with a new one.

Secondly, the plug on the catheter should be flushed with heparinized solution every 6-8 hours. This is to prevent blood clots in the lumen of the catheter.

Thirdly, any manipulations with the catheter should be carried out in accordance with the rules of asepsis and antiseptics - personnel should carefully handle their hands and work with gloves, and the catheterization site should be protected with a sterile bandage.

Fourthly, in order to prevent accidental cutting of the catheter, it is strictly forbidden to use scissors when working with the catheter, for example, to trim the adhesive plaster with which the bandage is fixed to the skin.

The listed rules when working with a catheter can significantly reduce the incidence of thromboembolic and infectious complications.

Are complications possible during venous catheterization?

Due to the fact that vein catheterization is an intervention in the human body, it is impossible to predict how the body will react to this intervention. Of course, the vast majority of patients do not have any complications, but in extremely rare cases this is possible.

So, when installing a central catheter, rare complications are damage to neighboring organs - the subclavian, carotid or femoral artery, brachial plexus, perforation (perforation) of the pleural dome with air penetration into the pleural cavity (pneumothorax), damage to the trachea or esophagus. Air embolism also belongs to this kind of complications - the penetration of air bubbles from the environment into the bloodstream. Prevention of complications is technically correct central venous catheterization.

When installing both central and peripheral catheters, thromboembolic and infectious complications are formidable. In the first case, thrombophlebitis and thrombosis may develop, in the second - systemic inflammation up to sepsis (blood poisoning). Prevention of complications is careful observation of the catheterization area and timely removal of the catheter at the slightest local or general changes - pain along the catheterized vein, redness and swelling at the puncture site, increased body temperature.

In conclusion, it should be noted that in most cases, catheterization of veins, especially peripheral ones, passes for the patient without a trace, without any complications. But the therapeutic value of catheterization can hardly be overestimated, because the venous catheter allows for the volume of treatment that is necessary for the patient in each individual case.

Algorithm for setting a peripheral venous catheter

Assemble a standard kit for vein catheterization, which includes: a sterile tray, a trash tray, a syringe with 10 ml of heparinized solution (1: 100), sterile cotton balls and wipes, an adhesive plaster or an adhesive bandage, skin antiseptic, peripheral intravenous catheters of several sizes, adapter or connecting tube or obturator, tourniquet, sterile gloves, scissors, splint, medium-width bandage, 3% hydrogen peroxide solution.

Check the integrity of the packaging and the shelf life of the equipment.

Make sure you have a patient in front of you who is scheduled for vein catheterization.

Provide good lighting, help the patient to get comfortable.

Explain to the patient the essence of the upcoming procedure, create an atmosphere of trust, give him the opportunity to ask questions, determine the patient's preferences in relation to the place of insertion of the catheter.

Prepare a sharps disposal container.

Select the site of the proposed catheterization of the vein: apply a tourniquet above the proposed catheterization zone; ask the patient to squeeze and unclench the fingers of the hand to improve the filling of the veins with blood; select the vein by palpation, taking into account the characteristics of the infusate, remove the tourniquet.

Select the smallest catheter, taking into account the size of the vein, the required injection rate, the schedule of intravenous therapy, the viscosity of the infusate.

Hand sanitize your hands and wear gloves.

Reapply the tourniquet above the selected area.

Treat the catheterization site with a skin antiseptic for a few seconds, and let it dry. DO NOT TOUCH THE TREATED AREA!

Secure the vein by pressing it with your finger below the intended insertion site.

Take the catheter of the chosen diameter and remove the protective sheath. If the cover has an additional plug, do not throw the cover away, but hold it between the fingers of your free hand.

Insert the catheter on the needle at a 15 ° angle to the skin, observing the appearance of blood in the indicator chamber.

When blood appears in the indicator chamber, reduce the angle of inclination of the needle-stylet and insert the needle into the vein by a few millimeters.

Fix the stylet needle, and slowly slide the cannula from the needle into the vein to the end (the stylet needle is completely removed from the catheter).

Remove the harness. Do not allow the insertion of the stylet needle into the catheter after its displacement into the vein!

Pinch the vein to reduce bleeding and permanently remove the needle from the catheter, dispose of the needle safely.

Remove the plug from the protective sheath and close the catheter or attach an infusion set.

Secure the catheter with a fixation bandage.

Register the vein catheterization procedure as required by the hospital.

Dispose of waste in accordance with safety regulations and sanitary and epidemiological regulations.

Daily catheter care

It must be remembered that maximum attention to the choice of a catheter, the process of its placement and high-quality care of it are the main conditions for the success of treatment and prevention of complications. Observe the rules for using the catheter. Time spent on thorough preparation is never wasted!

Each catheter connection is a gateway for infection. Touch the catheter as little as possible, strictly follow the rules of asepsis, work only with sterile gloves.

Change sterile plugs often, never use plugs that might have infected the inside.

Immediately after the administration of antibiotics, concentrated glucose solutions, blood products, flush the catheter with a small amount of saline.

To prevent thrombosis and prolong the functioning of the catheter in the vein, additionally flush it with saline during the day between infusions. After the introduction of saline, do not forget to enter the heparinized solution (in the ratio of 2.5 thousand units of sodium heparin per 100 ml of saline).

Monitor the condition of the fixation bandage, change it if necessary.

Check the puncture site regularly for early detection of complications. If swelling, redness, local temperature rise, catheter obstruction, painful sensations during the administration of drugs and their leakage occur, the catheter must be removed.

When changing an adhesive bandage, do not use scissors, as this can cut off the catheter and enter the bloodstream.

For the prevention of thrombophlebitis, thrombolytic ointments (Lioton-1000, heparin, troxevasin) should be applied to the vein above the function site with a thin layer.

If your patient small child, be careful not to remove the dressing and damage the catheter.

When adverse reactions for a drug (pallor, nausea, rash, difficulty breathing, fever), call a doctor.

Regularly record information on the volume of drugs administered per day, the rate of their administration in the patient observation card in order to monitor the effectiveness of infusion therapy.

Puncture and catheterization of peripheral veins is a widely used method of intravenous therapy, which has a number of advantages for both the patient and the medical staff.

For peripheral vein catheterization, the vein of the elbow of the right or left arm is usually used. Manipulation is performed with a needle with a plastic cannula put on it - a catheter for catheterization of peripheral veins.

A peripheral intravenous (venous) catheter is a device for long-term intravenous drug administration, transfusion, or blood collection.

Indications

Indications for peripheral venous catheterization are:

1. The need for long-term repeated intravenous administration of drugs;

2. transfusion or repeated blood sampling;

3. preliminary stage before central venous catheterization;

4. the need for anesthesia or regional anesthesia (for small operations);

5. support and correction of the patient's body water balance;

6. the need for venous access in urgent emergency conditions.

7. parenteral nutrition.

Technique

The technique for performing catheterization of peripheral veins is quite simple, this explains the popularity of this method.

1. Carry out the necessary preparation: choose a catheter that is suitable in terms of size and capacity, treat hands, put on gloves and prepare instruments and preparations, check their expiration date;

2. Apply a tourniquet 10-15 centimeters above the intended puncture and ask the patient to clench and unclench his fist, which will ensure that the vein is filled with blood;

3. Choose the most suitable and well visualized peripheral vein;

4. Treat the punctured site with a skin antiseptic;

5. Puncture the skin and vein with a needle and catheter. Blood should appear in the indicator chamber, so the puncture can be stopped;

6. Remove the tourniquet and remove the needle from the catheter, put the plug;

7. Fix the catheter to the skin with a plaster.

The algorithm for peripheral vein catheterization and placement of a peripheral catheter can be clearly seen in this video.

Advantages and disadvantages

The advantages of peripheral vein catheterization include the following possibilities of this manipulation:

Reliability and convenience of access to the vein;

Ability to take blood samples for analysis without unnecessary injections;

The ability to use for short operations;

The patient can walk with a catheter in a vein when there is no IV line. A plug is placed on the catheter, in other words, a rubber stopper.

The disadvantage of this procedure is that you can use it for no more than 2-3 days.

Complications

The algorithm for performing catheterization of peripheral veins is quite simple, but since manipulation is associated with a violation of the skin, complications are possible.

1. Phlebitis - inflammation of a vein associated with irritation of its wall with drugs, either due to mechanical action, or the appearance of an infection.

2. Thrombophlebitis - inflammation of a vein with the appearance of a blood clot.

3. Thromboembolism and thrombosis - sudden blockage of a vessel by a thrombus (blood clot).

4. Kinked catheter.

To prevent catheter thrombosis, proper care of the peripheral venous catheter is essential. It should be periodically flushed with saline heparin solution every 4 to 6 hours.

For the convenience of the staff, a three-way tap - tee is often used. This allows you to connect another dropper in parallel if necessary, or to enter medications and drugs for anesthesia, measure venous pressure.

The tee is attached to the cannula of the catheter, a dropper is attached to it, and medication is injected through the side entrance. As you can see from the figure, there is a switch on the tee, i.e. you can shut off the drip and inject drugs directly. The tee is used with a subclavian catheter and in other cases.

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You can inject drugs directly into the blood using intravenous catheters. They are installed once and can be operated multiple times. This eliminates the need to constantly prick your hands in search of veins.

The principle of the device of catheters

First of all, the medical staff should know how to give an intravenous infusion of medicines. But if patients know the information about the procedure, then they may be less afraid.

An intravenous drug catheter is a thin, hollow tube. It is inserted into the bloodstream.

This can be done on the arms, neck, or head. But it is not recommended to insert catheters into the vessels of the legs.

These devices are installed so that there is no need to constantly pierce the veins. After all, from this they can be injured, inflamed. Permanent damage to their walls leads to thrombus formation.

Types of devices

Health care facilities can use one of four types of catheters. There are the following types:

Models for short-term use;

Central peripheral intravenous catheters, which are placed in the veins of the arms;

Tunneling catheters, which are inserted into wide blood vessels, such as the vena cava

Subcutaneous venous catheters inserted in the area chest under the skin.

Depending on the materials used in the manufacture of these devices, metal and plastic models are distinguished. The choice of the option required in each case is carried out only by the doctor.

A metal catheter for intravenous infusion is a needle that is connected to a special connector. The latter can be metal or plastic, some of them are equipped with wings. Such models are not used very often.

Plastic catheters are a connected plastic cannula and transparent connector that are pulled over a steel needle. Such options are used much more often. After all, they can be used longer than metal catheters. Their transition from a steel needle to a plastic tube is smooth or tapered.

Steel catheters

There are several metal variants of models designed for intravenous drug administration. The most popular among them are butterfly catheters. They are a needle made of a chromium-nickel alloy that is integrated between two plastic wings. On the other side of them comes a flexible transparent tube. Its length is about 30 cm.

There are several modifications of these catheters.

So, they can be with a shortened cut and a small needle or with a flexible tube installed between the connector and the needle. This is intended to reduce mechanical irritation that occurs when an intravenous steel catheter is used. A photo of such a device makes it possible to understand that there is nothing terrible if they put it on you. The picture shows that the needles in them are quite short.

A special peripheral intravenous catheter with soft wings can ensure the safety of a puncture even with hidden and hard-to-reach veins.

Disadvantages and advantages of metal models

In modern medical practice, steel options are rarely used. After all, their service life is rather short - they can stay in a vein for no more than 24 hours. In addition, stiff needles irritate the veins. Because of this, thrombosis or phlebitis may develop. Also, the likelihood of trauma or necrosis of a part of the vein wall cannot be ruled out. And this can cause extravasal administration of the drug.

Through such catheters, solutions are injected not along the flow of blood, but at a certain angle. This becomes the cause of chemical irritation of the inner layer of the vessel.

To prevent the likelihood of complications when working with steel intravenous catheters, they must be rigidly fixed. And this limits the mobility of patients.

But, despite all the disadvantages described, they also have a number of advantages. The use of metal catheters reduces the risk of developing infectious lesions, because steel prevents microorganisms from entering the bloodstream. In addition, they are easier to insert into thin, difficult to visualize veins. Therefore, their use is practiced in neonatology and pediatrics.

Modern gadgets

In medical practice, catheters with steel needles are currently practically not used, because the comfort and safety of the patient come to the fore. Unlike the metal model, the plastic intravenous peripheral catheter can follow the bends of the vein. Thanks to this, the risk of her injury is significantly reduced. The likelihood of blood clots and infiltrates is also minimized. In this case, the residence time of such a catheter in the vessel is significantly increased.

Patients who have such a plastic device installed can move without fear of damaging their veins.

Varieties of plastic models

Doctors can choose which catheter to place in a patient. On the market, you can find models with or without additional injection ports. They can also be equipped with special fixation wings.

To protect against accidental injections and to prevent the risk of infection, special cannulas have been developed. They are equipped with a protective self-activating clip, which is installed on the needle.

For the convenience of injecting drugs, an intravenous catheter with an additional port can be used. Many manufacturers place it over the wings, designed for additional fixation of the device. There is no risk of cannula displacement when injecting medication into such a port.

When purchasing catheters, you should be guided by the recommendations of doctors. After all, these devices, with external similarity, can significantly differ in quality. It is important that the transition from the needle to the cannula is atraumatic and there is minimal resistance when the catheter is inserted through the tissues. The sharpness of the needle and the angle of its sharpening are also important.

An intravenous catheter with a Braunulen port has become the standard for developed countries. It is equipped with a special valve, due to which the possibility of a reverse movement of the solution introduced into the injection compartment is prevented.

Materials used

The first plastic models did not differ much from steel catheters. In their manufacture, polyethylene could be used. As a result, thick-walled catheters were obtained, which irritated the inner walls of blood vessels and led to the formation of blood clots. In addition, they were so rigid that they could even lead to perforation of the vessel walls. Although polyethylene itself is a flexible, inert material that does not form loops, it is very easy to process.

Polypropylene can also be used in the production of catheters. Thin-walled models are made from it, but they are too rigid. They were mainly used to access arteries or to insert other catheters.

Later, other plastic compounds were developed that are used in the manufacture of these medical devices. So, the most popular materials are PTFE, FEP, PUR.

The first is polytetrafluoroethylene. Catheters made from it glide well and do not lead to thrombus formation. They have a high level of organic tolerance and are therefore well tolerated. But thin-walled models made from this material can squeeze and form loops.

FEP (Fluoroethylene Propylene Copolymer), also known as Teflon, has the same benefits as PTFE. But, in addition, this material allows better control of the catheter and increases its stability. Such an intravenous device can be injected with a radiopaque medium, which will allow it to be seen in the bloodstream.

PUR material is known to many polyurethane. Its hardness is temperature dependent. The warmer, the softer and more elastic it becomes. It is often used for central intravenous catheters.

Advantages and disadvantages of ports

Manufacturers produce several types of devices for intravenous administration of medicinal solutions. According to many, it is preferable to use a cannula equipped with a special port. But it's not always the case. They are necessary if the treatment involves additional jet injection of medications.

If this is not required, a conventional intravenous catheter can be inserted.

A photo of such a device makes it possible to see that it is very compact. Devices without additional ports are cheaper. But this is not their only advantage. When used, there is less chance of contamination. This is due to the fact that the injection element of this system is separated and changed daily.

In intensive care, anesthesiology, preference is given to ported catheters. In all other fields of medicine, it is sufficient to establish the usual variant.

By the way, in pediatrics, they can install a catheter with a port for jet injection of drugs, even in cases where children do not need to install an IV. So antibiotics can be injected, replacing injections into the muscle with intravenous administration. This not only increases the effectiveness of the treatment, but also makes the procedure easier. It is easier to insert the cannula once and almost imperceptibly inject the medicine through the port than to make painful injections several times a day.

Sizes of plastic models

The patient does not have to choose which one he needs to buy an intravenous catheter.

The size and type of these devices are selected by the doctor depending on the purposes for which they will be used. After all, each of them has its own purpose.

The size of catheters is determined in special units - gauges. In accordance with their size and capacity, a unified color marking is installed.

The maximum size for an orange catheter is 14G. This corresponds to 2.0 x 45 mm. 270 ml of solution can be passed through it per minute. It is installed in cases where transfusion of significant volumes of blood products or other fluids is required. For the same purposes, gray (16G) and white (17G) intravenous catheters are used. They are capable of passing 180 and 125 ml / min, respectively.

A green catheter (87G) is placed in those patients who are routinely receiving red blood cell (blood product) transfusions. It runs at 80 ml / min.

Patients undergoing long-term daily intravenous therapy (infused from 2-3 liters of solutions per day) are recommended to use the pink model (20G). When installed, the infusion can be carried out at a rate of 54 ml / min.

For cancer patients, children, and patients who require long-term intravenous therapy, a blue catheter (22G) can be inserted. He passes 31 ml of liquid every minute.

In pediatrics and oncology, yellow (24G) or purple (26G) catheters can be used to insert a catheter into thin sclerosed veins. The size of the first is 0.7 * 19 mm, and the second is 0.6 * 19 mm. Their capacity is 13 and 12 ml, respectively.

Installing

Every nurse should know how to insert an intravenous catheter. For this, the injection site is pre-processed, a tourniquet is applied and measures are taken to fill the vein with blood. After this, the cannula, which the nurse takes in the hand with a longitudinal or transverse grip, is inserted into the vessel. The success of venipuncture is indicated by blood, which must fill the imaging chamber of the catheter. It is important to remember: the larger its diameter, the faster this biological fluid will appear there.

Because of this, it is believed that working with thin catheters is more difficult. The cannula should be inserted more slowly and the nurse should be sensitive to tactile sensations as well. When the needle enters the vein, a dip is felt.

After hitting, it is necessary to push the device further into the vein with one hand, and fix the guide needle with the other. Once the catheter has been inserted, the guide needle is removed. You cannot reattach it to the part remaining under the skin. If the vein has been lost, then the entire device is removed, and the insertion procedure is repeated again.

It is also important to know how the intravenous catheters are fixed. This is done with an adhesive plaster or a special bandage. The very place of entry into the skin is not sealed, as this can lead to the development of infectious phlebitis.

The final step is flushing the installed catheter. This is done through the installed system (for non-ported variants) or through a dedicated port. The device is also rinsed after each infusion. This is necessary in order to prevent the formation of blood clots in the vessel with the installed catheter. It also prevents the development of a number of complications.

There are certain rules for working with intravenous drug devices.

They should be known to all health care providers who will select or place an intravenous catheter. The algorithm for their use provides that the first installation is carried out from the non-dominant side at a distal distance. That is, the best option is the back of the hand. Each subsequent installation (if long-term treatment is necessary) is done on the opposite arm. The catheter is inserted upstream of the vein. Compliance with this rule minimizes the likelihood of developing phlebitis.

If the patient will undergo surgery, it is better to install a green catheter. It is the thinnest of those through which blood products can be transfused.

In the largest peripheral vein available.

The main thing is to take the largest catheter that provides the required rate of solution injection

The material of the catheter is essential. Domestic catheters are mainly made of polyethylene. This is the easiest material to process, however, it has increased thrombogenicity, irritates the inner membrane blood vessels, due to its rigidity, is capable of perforating them. Teflon and polyurethane catheters are preferred. When using them, there are significantly fewer complications; if you provide them with high-quality care, their service life is much longer than polyethylene ones. This has a significant economic effect despite the relatively high cost of these catheters.

The most common causes of failures and complications in peripheral vein catheterization are the lack of practical skills of medical personnel, violation of the technique for inserting and caring for a venous catheter.

Equipment: sterile tray, syringe with 10 ml of heparinized solution, adhesive plaster, ethyl alcohol 70%, tourniquet, peripheral catheters of various sizes, sterile gloves, scissors, garbage tray

Stages	Justification
1. Carry out hygienic hand washing. Wear a mask
2. Assemble a standard peripheral venous catheterization kit	Ensuring the clarity and efficiency of the procedure
3. Explain to the patient the purpose and course of the procedure, create an atmosphere of trust, obtain the patient's consent	Ensuring the patient's right to information
4. Provide good lighting and help the patient to get into a comfortable sitting or lying position.	Ensuring patient safety and comfort
5. Conduct hygienic hand antiseptic. To do this, apply 3 ml of 70% ethyl alcohol on your hands and rub the preparation for 1 min.	Ensuring infectious safety
6. Select the site of the proposed catheterization zone. To do this · Apply a venous tourniquet · Ask the patient to squeeze and unclench the fingers to improve the filling of the veins with blood · Select a suitable vein by palpation, taking into account the characteristics of the infusion solution · Relax the tourniquet	Preparation for the procedure. Selection of the optimal vein for catheterization.
7. Select, if possible, the largest diameter of the catheter, taking into account the size of the vein, the required rate of introduction, the viscosity of the infusion solution.	Selection of the optimal size of the peripheral venous catheter.
8. Conduct surgical hand antisepsis. To do this, apply 5 ml of 70% ethyl alcohol to your hands and rub the preparation for 1 min, repeat the treatment of your hands again. Wear sterile gloves	Ensuring infectious safety
9. Apply a venous tourniquet	Ensuring ease of entry into the vein
10. Treat the catheterization site with 70% ethyl alcohol twice, with two sterile swabs with an interval of 1 min.	Ensuring infectious safety
11.Open the catheter of the selected size.	Preparation for the procedure
12.Fix the vein by pressing it with a finger below the intended site of catheter insertion	Vein fixation for easy catheter insertion
13. Insert the catheter parallel to the vein, observing the appearance of blood in the indicator chamber.	Controlling needle entry into the vein
14.When blood appears in the indicator chamber, insert a catheter a few mm into the vein	Ensuring the required depth of needle insertion into the vein
15.Fix the needle-stylet, and slowly move the cannula from the needle into the vein to the end	Ensuring the required depth of cannula insertion into the vein
16. Remove the venous tourniquet
17. Pinch the vein to reduce bleeding and permanently remove the needle from the catheter	Reduced bleeding
18.Cover the catheter with the plug	Prevention possible complications
19. Fix the catheter with an adhesive plaster or fixing bandage	Preventing catheter displacement
20.Carry out the registration of vein catheterization according to the requirements of the medical institution	Ensuring continuity in work