When conducting intravenous therapy through a peripheral venous catheter (PVC), complications are excluded if the following basic conditions are met: the method should not be used occasionally (become permanent and habitual in practice), the catheter should be provided with impeccable care. Well-chosen venous access is essential to successful intravenous therapy.

STEP 1. Selecting the puncture site

When selecting a catheterization site, consideration should be given to patient preference, ease of access to the puncture site, and suitability of the vessel for catheterization.

Peripheral venous cannulas are intended for use in peripheral veins only. Priorities for choosing a vein for puncture:

1. Well visualized veins with well developed collaterals.
2. Veins on the non-dominant side of the body (right-handed - left, left-handed - right).
3. Use distal veins first
4. Use veins that are soft and elastic to the touch
5. Veins on the side opposite to the surgical intervention.
6. Veins with the largest diameter.
7. The presence of a straight section of vein along the length corresponding to the length of the cannula.

The most suitable veins and areas for installation of PVC are: the back of the hand, the inner surface of the forearm.

The following veins are considered unsuitable for cannulation:

1. Veins of the lower extremities (low blood flow velocity in the veins of the lower extremities leads to increased danger thrombosis).
2. Places where limbs bend (periarticular areas).
3. Previously catheterized veins (damage to the inner wall of the vessel is possible).
4. Veins located close to arteries (possibility of arterial puncture).
5. Median ulnar vein (Vena mediana cubiti). Puncture of this vein according to the protocols is permissible in 2 cases - taking blood for analysis, when providing emergency assistance and poor expression of the remaining veins.
6. Veins of the palmar surface of the hands (risk of vascular damage).
7. Veins in a limb that has undergone surgery or chemotherapy.
8. Veins of the injured limb.
9. Poorly visualized superficial veins.
10. Fragile and sclerotic veins.
11. Areas of lymphadenopathy.
12. Infected areas and areas of damaged skin.
13. Deep veins.

Table 1

Parameters and scope various types peripheral venous catheters

STEP 2. Selecting the type and size of catheter

When choosing a catheter, you must focus on the following criteria:

1. Vein diameter;
2. Required speed of solution introduction;
3. Potential residence time of the catheter in the vein;
4. Properties of the injected solution;
5. Under no circumstances should the cannula completely occlude the vein.

The main principle for choosing a catheter is to use the smallest size that provides the required insertion rate in the largest available peripheral vein.

All PVCs are divided into ported (with an additional injection port) and non-ported (without a port). Ported PVCs have an additional injection port for administering drugs without additional puncture. With its help, needle-free bolus (intermittent) administration of drugs without interruption is possible intravenous infusion.

Their structure always contains such basic elements as a catheter, a guide needle, a plug and a protective cap. A venesection is performed using a needle, and a catheter is inserted at the same time. The plug is used to close the catheter opening when infusion therapy is not performed (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 has the shape of a cone.

In addition, catheters may be accompanied by an additional design element - “wings”. Not only do they securely secure the PVC to the skin, but they also reduce the risk of bacterial contamination by preventing direct contact between the back of the catheter plug and the skin.

STEP 3. Placement of a peripheral venous catheter

1. Wash your hands;
2. Assemble a standard venous catheterization kit, including several catheters of various diameters;
3. Check the integrity of the packaging and shelf life of the equipment;
4. Make sure that in front of you is the patient who is scheduled for venous catheterization;
5. Provide good lighting, help the patient find a comfortable position;
6. Explain to the patient the essence of the upcoming procedure, create an atmosphere of trust, provide the opportunity to ask questions, determine the patient’s preferences regarding the location of the catheter;
7. Have a sharps disposal container available within easy reach;
8. Wash your hands thoroughly and dry them;
9. Apply a tourniquet 10-15 cm above the intended catheterization area;
10. Ask the patient to clench and unclench his fingers to improve the filling of the veins with blood;
11. Select a vein by palpation;
12. Remove the tourniquet;
13. Select the smallest catheter, taking into account: vein size, required insertion rate, intravenous therapy schedule, infusate viscosity;
14. Re-clean your hands using an antiseptic and put on gloves;
15. Apply a tourniquet 10-15 cm above the selected area;
16. Treat the catheterization site with a skin antiseptic for 30-60 seconds without touching untreated areas of the skin and let it dry on its own; DO NOT RE-PALPATE THE VEIN;
17. Secure the vein by pressing it with your finger below the intended catheter insertion site;
18. Take a catheter of the selected diameter using one of the grip options (longitudinal or transverse) and remove the protective cover. If there is an additional plug on the case, do not throw away the case, but hold it between the fingers of your free hand;
19. Make sure that the cut of the PVK needle is in the upper position;
20. Insert the catheter on the needle at an angle of 15 degrees to the skin, observing the appearance of blood in the indicator chamber;
21. If blood appears in the indicator chamber, further advancement of the needle must be stopped;
22. Fix the stylet needle, and slowly move the cannula completely from the needle into the vein (the stylet needle is not completely removed from the catheter yet);
23. Remove the tourniquet. DO NOT INSERT THE NEEDLE INTO THE CATHETER AFTER IT IS DISPLACED FROM THE NEEDLE INTO THE VEIN
24. Clamp the vein along its length to reduce bleeding and finally remove the needle from the catheter;
25. Dispose of the needle in a safe manner;
26. If, after removing the needle, it turns out that the vein is lost, it is necessary to completely remove the catheter from under the surface of the skin, then, under visual control, assemble the PVC (put the catheter on the needle), and then repeat the entire procedure for installing the PVC from the beginning;
27. Remove the plug from the protective sheath and close the catheter by inserting a heparin plug through the port or connecting the infusion set;
28. Secure the catheter to the limb;
29. Register the vein catheterization procedure according to the requirements of the medical institution;
30. Dispose of waste in accordance with safety regulations and sanitary and epidemiological regulations.

Standard set for peripheral vein catheterization:

1. Sterile tray
2. Garbage tray
3. Syringe with heparinized solution 10 ml (1:100)
4. Sterile cotton balls and wipes
5. Adhesive bandage and/or adhesive bandage
6. Skin antiseptic
7. Peripheral IV catheters in several sizes
8. Adapter and/or connecting tube or obturator
9. Sterile gloves
10. Scissors
11. Langeta
12. Medium bandage
13. 3% hydrogen peroxide solution

STEP 4. Removal of the venous catheter

1. Wash your hands
2. Stop infusion or remove protective bandage (if present)
3. Treat your hands with antiseptic and wear gloves
4. From the periphery to the center, remove the fixing bandage without using scissors
5. Slowly and carefully remove the catheter from the vein
6. Apply gentle pressure to the catheterization site with a sterile gauze pad for 2-3 minutes
7. Treat the catheterization site with a skin antiseptic, apply a sterile pressure bandage to the catheterization site and secure it with a bandage. Recommend not to remove the bandage or wet the catheterization site for 24 hours
8. Check the integrity of the catheter cannula. If there is a blood clot or the catheter is suspected of being infected, cut off the tip of the cannula with sterile scissors, place it in a sterile tube and send it to a bacteriological laboratory for examination (as prescribed by a doctor)
9. Document the time, date, and reason for catheter removal.
10. Dispose of waste in accordance with safety and sanitary regulations

Venous catheter removal kit

1. Sterile gloves
2. Sterile gauze balls
3. Band-Aid
4. Scissors
5. Skin antiseptic
6. Garbage tray
7. Sterile tube, scissors and tray (used if the catheter is clotted or if infection of the catheter is suspected)

STEP 5. Subsequent venipunctures

If there is a need to perform several PVK placements, change them due to the end of the recommended period of PVK stay in the vein or the occurrence of complications, there are recommendations regarding the choice of venipuncture site:

1. It is recommended to change the catheterization site every 48-72 hours.
2. Each subsequent venipuncture is performed on the opposite arm or proximal (higher along the vein) of the previous venipuncture.

STEP 6. Daily catheter care

1. Each catheter connection is a gateway for infection. Avoid repeatedly touching the equipment with your hands. Strictly observe asepsis, work only with sterile gloves.
2. Change sterile plugs frequently and never use plugs whose interior surfaces may be infected.
3. Immediately after administration of antibiotics, concentrated solutions glucose, blood products, flush the catheter with a small amount of saline.
4. Monitor the condition of the fixing bandage and change it if necessary or every three days.
5. Regularly inspect the puncture site for early detection of complications. If swelling, redness, local fever, obstruction of the catheter, leakage, or pain during drug administration occur, notify the doctor and remove the catheter.
6. When changing an adhesive bandage, do not use scissors. There is a danger for the catheter to be cut off, causing the catheter to enter the bloodstream.
7. To prevent thrombophlebitis, apply a thin layer of thrombolytic ointments (for example, Traumeel, Heparin, Troxevasin) to the vein above the puncture site.
8. The catheter should be flushed before and after each infusion session with a heparinized solution (5 ml of isotonic sodium chloride solution + 2500 units of heparin) through the port.

Possible complications:

Despite the fact that catheterization of peripheral veins is significantly less dangerous procedure Compared to central venous catheterization, it carries the potential for complications, as does any procedure that compromises the integrity of the skin. Most complications can be avoided thanks to the nurse's good manipulation technique, strict adherence to the rules of asepsis and antisepsis, and proper care of the catheter.

table 2

Possible complications and their prevention

STEP 7. Central catheter care

Puncture catheterization of the central vessels is a medical procedure. The subclavian vein, jugular and femoral vein, both left and right. The central venous catheter can function and remain uninfected for many weeks. This is achieved through strict adherence to the rules of catheter care, including adherence to aseptic rules during its installation, precautions when performing infusions and injections.

If the catheter is left in the PV for a long time, the following complications may occur:

Vein thrombosis;

Catheter thrombosis;

Thrombo- and air embolism;

Infectious complications (5 - 40%), such as suppuration, sepsis, etc.

That is why central venous catheterization requires careful adherence to the rules of care and monitoring of the catheter:

1. Before all manipulations, you should wash your hands with soap, dry them and treat them with 70% alcohol, and put on sterile rubber gloves.

2. The skin around the catheter is inspected daily and treated with 70% alcohol and 2% iodine solution or 1% brilliant green solution.

3. The dressing is changed daily and as it gets dirty.

4. Before the start of the event infusion therapy ask the patient to inhale and hold his breath. Remove the rubber stopper, attach a syringe with 0.5 ml of saline solution to the catheter, pull the piston towards you and make sure that blood flows freely into the syringe. Connect an intravenous infusion system to the catheter, allow the patient to breathe, and adjust the frequency of drops. Pour the blood from the syringe into the tray.

5. After completion of infusion therapy, it is necessary to place a heparin lock as follows:

Ask the patient to inhale and hold his breath;

Plug the catheter with a rubber stopper and allow the patient to breathe;

Through a stopper pre-treated with alcohol, inject 5 ml of solution with an intradermal needle: 2500 units (0.5 ml) of heparin + 4.5 ml of saline;

Secure the plug to the catheter with adhesive tape.

6. Be sure to rinse the catheter with the same solution as when installing a heparin lock in the following cases:

After injecting the drug through a catheter;

When blood appears in the catheter.

7. It is prohibited to bend the catheter, place clamps on the catheter that are not intended for the design, or allow air to enter the catheter.

8. If problems associated with the catheter are detected: pain, swelling of the arm, the bandage gets wet with blood, exudate or infusion medium, fever, catheter breaks, immediately inform your doctor.

9. The catheter is removed by the attending physician or anesthesiology service staff, followed by a note in the medical history.

10. It is prohibited to leave the hospital premises with a catheter! If referred to another medical institution, the patient must be accompanied by a health worker; In the discharge summary, a note is made about the presence of a subclavian catheter in the patient.

V.L. GOLOVCHENKO, L.M. ROMANOVA

Performed:

midwife of the OBS department - 4

Gorbatenko Marina.

Belgorod 2011.

Peripheral venous catheter care

Selection of catheterization area

Relevance of the problem of catheterization of peripheral veins

Catheterization of peripheral veins is a method of establishing access to the bloodstream for a long period of time through peripheral veins through the installation of a peripheral intravenous catheter.

A peripheral intravenous (venous) catheter (PVC) is a device inserted into a peripheral vein and providing access to the bloodstream.

Vein catheterization has long become routine medical procedure. In one year, over 500 million peripheral venous catheters are installed worldwide. With the advent of high-quality intravenous catheters on the domestic market in Ukraine, the method of conducting infusion therapy using a cannula installed in a peripheral vessel is receiving increasing recognition from medical workers and patients every year. The number of central venous catheterizations began to decrease in favor of an increase in peripheral ones. As modern practice shows, most types of intravenous therapy, previously carried out through central catheters, are more appropriate and safe to carry out through peripheral intravenous catheters. Wide Application infusion cannulas due to the advantages they have compared to the usual method carrying out infusion therapy using a metal needle - the catheter will not come out of the vessel and will not pierce it through, causing the development of infiltration or hematoma.

Delivering intravenous therapy through a peripheral venous catheter has a number of advantages for both healthcare providers and patients. The method assumes reliable and accessible venous access, facilitates the rapid effective administration of an accurate dose of drugs, saves the time of medical personnel spent on venipuncture during frequent intravenous injections, which also minimizes the psychological burden on the patient, ensures motor activity and patient comfort. In addition, this simple manipulation is associated with a minimum number of severe life-threatening complications, provided that basic conditions are met: the method must become permanent and habitual in practice and, as with any invasive medical procedure, impeccable care must be provided.

Comparative characteristics of peripheral venous catheters

Depending on the material from which the catheter is made, metal (the part of the cannula remaining in the vein is made of metal alloys) and plastic catheters can be distinguished.

Metal catheters consist of a needle connected to a connector. After puncture, the needle remains in the vein, performing the function of a catheter. Connectors can be transparent plastic or metal and have wings, for example, VENOFIX® (Fig. 1), BUTTERFLY®.

Rice. 1. Modern metal catheters VENOFIX9 (butterfly needles). The catheter is a needle made of chromium-nickel alloy with a microsiliconized cut, integrated between plastic fastened wings. On the other hand, a transparent flexible tube 30 cm long is connected to the needle through the wings, at the end of which there is a Luer lock type connection with a hydrophobic plug. Catheters come in different sizes with different needle lengths

This is the most optimal option for intravenous catheters with a steel needle for long-term use (approximately 24 hours). Of all the metal intravenous catheters, they are the most commonly used. Among these catheters, the following modifications are distinguished:

catheters with reduced cut length and needle length (to reduce mechanical irritation);

with a flexible tube between the needle and the connector (also to reduce mechanical irritation - forced manipulations of the connector are not transmitted to the sharp tip of the needle);

with wings made of soft plastic, between which the needle is integrated, which ensures safe puncture even in difficult-to-reach veins.

In modern practice, steel catheters are used extremely rarely, since they are not suitable for long-term stay in the vein due to the high incidence of complications associated with their use. The rigidity of the needle causes mechanical irritation (with further development of phlebitis or thrombosis), trauma and necrosis of sections of the vein wall, followed by extravasal administration of the drug, the formation of infiltration and hematoma. Infusion media introduced through these catheters are poured into the vein not along the blood flow, but at an angle to it, which creates conditions for chemical irritation of the intima of the vessel. The sharp needle creates an abrasive effect on inner surface vessel. To reduce the incidence of these complications when working with steel catheters, their reliable fixation is required, and achieving this condition limits the patient’s motor activity and creates additional discomfort for him.

However, there are advantages to using steel catheters. When they are installed, the risk is reduced infectious complications, since steel prevents the penetration of microorganisms through the catheter. In addition, due to their rigidity, manipulation of the puncture of difficult-to-visualize and thin veins is facilitated. In pediatrics and neonatology they are the catheters of choice.

Plastic catheters consist of an interconnected plastic cannula and a transparent connector, pushed onto a guide steel needle. The transition from a steel needle to a plastic tube in modern catheters is smooth or with a slight conical design, so that at the time of venipuncture the needle moves without resistance (Fig. 2).

Fig.2. Transition between catheter and guide needle

Unlike catheters with metal intravenous elements, plastic ones follow the route of the vein, which reduces the risk of vein trauma, infiltration and thrombotic complications, and increases the time the catheter remains in the vessel. Thanks to the flexibility of the plastic, patients can allow greater physical activity, which contributes to their comfort.

Today, various models of plastic intravenous catheters are offered. They may have an additional injection port (ported, Fig. 3) or not (non-ported, Fig. 1), they can be equipped with fixation wings or models without them can be produced.

peripheral venous catheter installation

Fig.3. Plastic intravenous catheter with injection port and protective clip on the guide needle

To protect against needle sticks and the risk of infection, cannulas with a self-activating protective clip mounted on the needle have been developed. To reduce the risk of contamination, catheters are produced with removable injection elements. To better monitor the catheter, which is in the vein, X-ray contrast strips are integrated into the transparent cannula tube. The sharpening of the piercing cut of the guide needle also helps to facilitate the puncture - it can be lanceolate or angular. Leading PVC manufacturers are developing a special position of the injection port above the fixation wings of the connector, which reduces the risk of cannula displacement when performing additional injections. In addition, some catheters have special holes in them to ventilate areas of the skin located under the fixing wings.

Thus, the following types of cannulas should be distinguished:

1. A cannula without an additional port for bolus injections is a catheter mounted on a stylet needle. After entering the vein, the cannula is moved from the stylet into the vein.

2. A cannula with an additional port expands the possibilities of its use, facilitates maintenance, and therefore extends the period of its installation.

There are two modifications of this cannula. The first modification is the most common configuration. Convenience during placement and fixation, the presence of an upper port for short-term insertions and heparinization of the cannula during infusion breaks have earned the love of doctors.

A wide variety of brands from different manufacturers is distinguished only by the quality of the product. But despite the apparent simplicity of the design, not everyone manages to combine the triad of qualities:

1) needle sharpness and optimal sharpening angle;

2) atraumatic transition from needle to cannula;

3) low resistance to insertion of the catheter through the tissue.

Manufacturers of such cannulas include B. Braun and VOS Ohmeda (part of the BD concern).

In the process of peripheral vein cannulation, sometimes the first attempt may fail for one reason or another. Invisible “scratches” on the cannula, as a rule, do not allow it to be reused or shorten the period of use to one day.

HMD has released a new material for the traditional cannula, which potentially allows it to be used if the first cannulation attempt fails without reducing placement time, and makes the cannula more resistant to sticking when kinked. This cannula is registered under the brand name "Cathy".

The second modification of the cannula with an additional port was developed by Wallace Ltd (a subsidiary of SIMS Portex Ltd) together with a Cambridge doctor, J. Farman.

The presence of a silicone insert in the cannula body and a silicone injection port on a flexible lead makes the cannula absolutely safe with respect to contact with the patient’s blood containing hepatitis or AIDS viruses. While retaining all the advantages of its predecessors, it is “bloodless” and, having a flexible outlet, allows you to manipulate infusion access without the risk of developing “mechanical” phlebitis.

Since the development of plastic catheters, the composition of the polymer used for their production has also changed. Previously, polyethylene and polypropylene were the most commonly used materials for the manufacture of intravenous catheters. The first is a flexible, non-looping, inert material, the easiest to process, but the catheter tube is relatively thick-walled, has increased thrombogenicity, causes irritation of the inner lining of blood vessels, and, due to its rigidity, is capable of perforating the vascular wall. The second is suitable for the manufacture of thin-walled catheters, but is a very rigid material, used mainly for arterial access or insertion of other catheters. Today, these materials are used only for the insertion of other catheters (“guide catheters”). Currently, three plastic compositions are commonly used: polytetrafluorethylene (PTFE), fluoroethylenepropylene-copolymer (FEP), polyurethane (PUR).

PTFE is one of the embedding materials with a very high level of organic tolerance. Catheters made from PTFE glide well and pose minimal risk of blood clots. Thin-walled models may form loops and become compressed.

FEP (Teflon): In addition to the positive characteristics of PTFE, copo polymer also increases the stability and controllability of the catheter. A radiopaque contrast medium can be integrated into the material, which helps localize the catheter in the blood vessel.

The hardness of PUR depends on temperature (thermoelastic). When cooled, PUR becomes rigid and allows easy insertion of the catheter. When heated by body temperature, PUR becomes soft, resulting in increased tolerance. Experience with the use of PUR for the production of central venous catheters demonstrates the tolerance of this material to venous tissue, as well as low rates of thrombus formation. Therefore, there is a growing trend towards using PUR for the manufacture of intravenous catheters.

In recent years, active measures have been taken to prevent the risk of transmission (to the user, medical personnel) of dangerous diseases through contact with blood ( viral hepatitis, AIDS). Particularly in the USA, in order to avoid needle damage, protective fasteners are used that are attached to needles* and catheters, and active and passive protection systems are used. In passive protection systems, when the steel needle is removed, an automatic system surrounding the tip of the needle is activated, thus protecting the user from injury. Thus, the protective clip on some peripheral venous catheters self-activates when the guide needle is removed from the cannula (Fig. 3). In addition to the fact that this type of protection protects medical personnel from injury from a used needle, the opened clip in no way returns to its original “inactive” state, which makes it impossible to re-insert the guide needle into the catheter.

Defense mechanism active systems the user must activate manually.

These are expensive systems and are currently only used in situations high risk. Thus, WHO supports and promotes the use of this type of product in some African countries.

The flexulle design has also changed over the years. The absolute leader in sales of intravenous catheters, the company B. Braun Melsungen AG, received the European Design Award "Columbus Egg" in 2004.

Catheters with injection ports are the absolute standard in Western Europe, where 90% of all peripheral venous access catheters used are Braunulen. This type of catheter has a valve that prevents the infused solution from flowing back into the injection port (Fig. 4).

Fig.4. Diagram of the movement of the drug when administered through the injection port

A syringe without a needle can be directly attached to the injection port. This allows an additional injection to be performed at any time during the infusion, which is why such catheters are most widely used in anesthesiology and intensive care.

The scope of application of non-ported (Fig. 5) catheters is much wider. They are applicable in almost all branches of medicine and account for 90% of the total number of catheters used in the world.

Fig.5. Modern plastic internal catalyzer without injection port

These cannulas have their advantages over ported catheters. They are more economical, more compact, and pose less of a contamination risk because the IV access system's detachable injection unit is changed daily. However, an additional injection is not possible when using catheters of this type, and a separate puncture is required for each injection.

Technique for catheterization of peripheral veins and catheter placement

Catheterization kit:

1. Sterile tray.

2. Garbage tray.

3. Syringe with heparinized solution 10 ml (1: 100).

4. Sterile cotton balls and napkins.

5. Adhesive plaster and/or adhesive bandage such as Leoderm, etc.

6.70% ethyl alcohol or leather preparation.

7. Peripheral intravenous catheters (several pieces of different sizes).

8. Adapters or connecting tube (or obturator).

10. Gloves.

11. Scissors.

12. Langeta.

13. Medium bandage.

14. Hydrogen peroxide solution 3%.

Before placing a PVC, a health worker must take care of creating comfortable conditions for his work. This is facilitated by organizing order in the workplace, creating optimal lighting, and observing personal hygiene rules. Always check the expiration date of the materials and medicines used, as well as the integrity of the packaging in which they are located! A medical employee must look neat, dress cleanly and neatly. A dirty gown on a nurse does not make the patient want to “allow” such a health worker to see him. Make sure that the patient in front of you is the one scheduled for catheterization. One should not neglect the psychological aspects of preparation for the placement of peripheral venous catheter, especially if it is performed on the patient for the first time. It is always necessary to warn what type of manipulation he is supposed to perform. If the patient demands to explain the essence of the procedure, the purpose of its implementation, as well as all the incomprehensible points of interest related to the manipulation, you need to give meaningful answers in a calm, friendly tone. You should also find out the reason for the anxiety of restless patients. If this is a previous unsuccessful catheterization, avoid inserting a catheter into the same vein. The patient may have preferences regarding the choice of vein for catheterization, these should be taken into account. Verbal contact contributes to the formation of a favorable psychological microclimate and trust in medical personnel; accordingly, it creates the necessary conditions for the work of the nurse and the comfort of the patient.

After you have chosen a vein for catheterization and decided on the required size of the PVC, you need to assemble a standard catheterization kit and put on a mask. The patient must be seated in such a way that he does not experience discomfort and the nurse feels comfortable working.

Peripheral venous catheter care

To promptly detect the first signs of complications, it is necessary to inspect the site of the catheter daily. Wet or soiled dressings should be changed immediately.

Redness and swelling of the tissue at the site of catheter installation indicate a local inflammatory reaction and indicate the need for urgent removal of the PVK. During manipulations with the PVC and infusion system, it is very important to avoid contamination and strictly adhere to the rules of asepsis. The timing of catheter placement must be recorded in writing; in adults, the PVK must be changed every 48-72 hours, and when using blood products - after 24 hours (in children, the placement site is changed only in case of complications), the infusion system is changed every 24-48 hours. To flush catheters, use heparinized isotonic sodium chloride solution.

The purpose of caring for an installed peripheral venous catheter is to ensure its functioning and prevent possible complications. To achieve success, it is necessary to comply with all points of high-quality use of the cannula.

Each catheter connection represents an additional gateway for infection, so you can touch the equipment only in cases of justifiable need. Avoid repeatedly touching the equipment with your hands. Strictly observe asepsis, work only with sterile gloves.

Change sterile plugs frequently and never use plugs whose interior surfaces may be infected.

Immediately after administering antibiotics, concentrated glucose solutions, or blood products, rinse the catheter with a small amount of saline.

To prevent thrombosis and prolong the functioning of the catheter in the vein, additionally rinse the catheter with saline during the day, between infusions. After administering the saline solution, do not forget to administer the heparinized solution! Monitor the condition of the fixation bandage and change it if necessary.

Do not use scissors when caring for the catheter!

Regularly inspect the puncture site for early detection of complications. If swelling, redness, local fever, obstruction of the catheter, leakage, or pain during drug administration occur, notify the doctor and remove the catheter.

When changing an adhesive bandage, do not use scissors. There is a danger for the catheter to be cut off, causing the catheter to enter the bloodstream.

To prevent thrombophlebitis, apply a thin layer of thrombolytic ointments (for example, Lyoton Gel) to the vein above the puncture site.

Closely monitor a small child who may unknowingly remove the dressing and damage the catheter.

When adverse reactions on the drug (pallor, nausea, rash, difficulty breathing, fever) - call a doctor. Interruption of infusion. For intermittent use (eg, injections, short infusions, etc.), the catheter should be kept open (patent). Several methods are used to achieve this goal.

1. Slow infusions - when the actual infusion is interrupted and replaced by an infusion that does not have any active effect and serves solely to keep the catheter open. It is necessary to take into account additional costs when using this method - for administration.

2. Heparin block: the lumen of the catheter tube is filled with a heparin solution at a dilution of 1: 100; after introducing the solution, the catheter must be “plugged” (screw the plug onto the catheter). This prevents blood from flowing back through the cannula and causing clots to form in the catheter tube. Disadvantages of this method: the cost of unnecessary use of heparin.

3. Stilettos - plastic obturators specially made for intravenous catheters of appropriate size, equipped with a plug screw (Fig. 6).

Fig.6. Short peripheral intravenous catheter G 18 with stylet on a hydrophobic plug for interrupting infusion

They are inserted into the lumen of the catheter tube and secured with a screw notch. They completely occupy the lumen space. The tip of the stylet is rounded so as not to damage the walls of blood vessels. They are safe because they provide additional stabilization of catheters.

Removing the catheter. Wash your hands thoroughly. Remove any dressings securing the catheter. Do not use scissors because this may result in catheter cutting and embolism from the cut portion of the catheter. Cover the catheter site with a dry, sterile cotton cloth. Remove the catheter by pressing the area where it was located for 3-4 minutes. Make sure there is no bleeding. If bleeding continues, raise the patient's arm up. If necessary, apply a sterile dressing to the area where the catheter was located. Always check the integrity of the removed catheter.

Complications and their prevention during catheterization of peripheral veins

Most common reasons failures and complications during catheterization of peripheral veins are due to the lack of practical skills among medical personnel, as well as violation of the technique for placing a venous catheter and caring for it.

All complications associated with peripheral vein catheterization can be divided into general and local. Local ones develop at the site of catheter installation or in the immediate vicinity of it (for example, along the vein in which the PVK is located), these include hematoma, infiltration, phlebitis and vein thrombosis. General complications are associated with the generalization of local complications or initially develop away from the location of the intravenous catheter (this air embolism, thromboembolism, catheter sepsis). They cause severe disruption of the general condition of the body.

Local complications.

A hematoma is an accumulation of blood in tissues. A hematoma can form as a result of blood leaking from a vessel into the tissues adjacent to the site of the catheter. This can occur as a result of unsuccessful vein puncture immediately at the time of establishing PVC or as a result of next deletion catheter. Therefore, in order to avoid the formation of a hematoma caused by the installation of a PVK, it is necessary to ensure adequate filling of the vein, as well as to carefully select the location of the catheter.

Prevention: do not perform venipuncture on poorly contoured vessels. The formation of a hematoma when removing the catheter can be avoided by applying pressure to the venipuncture site for 3-4 minutes after removing the PVK. You can also elevate the limb.

Vein thrombosis (Fig. 7) occurs when a blood clot forms in the lumen of the vessel. This can happen if there is a mismatch between the diameter of the vein and the size of the catheter, or defects in care.

Fig.7. Diagram of thrombosis of the vein in which the PVC is located

Prevention. To avoid the development of thrombosis, it is necessary to perform right choice the size of the catheter in accordance with the size of the punctured vein, adhere to the rules of care. Cannulas made of high-quality materials (polyurethane, polytetrafluoroethylene, fluoroethylenepropylene copolymer) are less thrombogenic than polyethylene and polypropylene catheters. Prevention of thrombosis is also to lubricate the skin area above the site where the catheter is supposed to be in the vein with heparin gels (Lioton).

Infiltration occurs when medications or infused solutions go under the skin and not into the vein. Penetration of certain solutions into tissue, such as hypertonic, alkaline or cytostatic solutions, can cause tissue necrosis. Therefore, it is very important to identify infiltration on early stages. When the first signs of infiltration occur, the PVC should be removed immediately. To avoid infiltration, use flexible capillary catheters and secure them carefully.

Prevention. Use a tourniquet to stabilize the catheter if the last one is installed at a bend. Check for decreased tissue temperature and any swelling around the catheter insertion site.

Phlebitis is an inflammation of the intima of a vein, which can occur as a result of chemical, mechanical irritation or infection. The most common causative agents of catheter infections are coagulase-negative staphylococci and Staphylococcus aureus, enterococci, Candida (often against the background of antibiotic therapy), resistant to many antimicrobial drugs.

In addition to inflammation, a blood clot can also form, which leads to the development of thrombophlebitis. Of all the factors that contribute to the development of phlebitis (such as the size of the catheter, the site of venipuncture, etc.), the length of time the catheter remains in the vein and the type of fluid that is injected are especially important. The osmolarity of the drug is important (severe phlebitis develops at an osmolarity of more than 600 mOsm/l, Table 8.1) and the pH of the injected solution (limiting pH values ​​affect the development of phlebitis). All intravenous access should be regularly monitored for symptoms of phlebitis. Any case of phlebitis should be documented. Typically, the incidence of phlebitis is 5% or less.

The first signs of phlebitis are redness and pain at the catheter site. In later stages, swelling and the formation of a palpable “venous cord” are observed. An increase in skin temperature at the site of the catheter may indicate the presence of a local infection. In particularly severe cases, the erythema extends more than 5 cm proximal to the end of the catheter, and pus may be discharged at the site of insertion and removal of the catheter. This can lead to purulent phlebitis and/or septicemia, which are one of the most severe complications of intravenous therapy and cause high level mortality. If there is a blood clot and/or infection of the catheter is suspected, after removing it, the tip of the cannula is excised with sterile scissors, placed in a sterile tube and sent to a bacteriological laboratory for examination. If purulent phlebitis or septicemia occurs, it is necessary to take a blood culture and examine the cito! To prevent phlebitis: when performing PVC, one should strictly adhere to the rules of asepsis and antiseptics; give preference to the smallest possible catheter size for a specific therapy program; ensure reliable fixation of the PVK; choose high quality catheters; Before administering medications, dilute them and practice slow infusion; lubricate the skin above the site where the catheter is supposed to be located in the vein with anti-inflammatory agents in combination with heparinized gels (Fastum-gel, Lyoton); before applying the gel, degrease the skin alcohol solution. For preventive purposes, it is also recommended to regularly change the vein in which the peripheral venous catheter is located (every 48-72 hours), however, in a clinical setting this requirement is difficult to comply with, so if there are no signs of phlebitis or other complications, modern high-quality peripheral venous catheters can be kept in vein all the time necessary to carry out infusion therapy.

General complications

Thromboembolism occurs when a blood clot on a catheter or vein wall breaks off and travels through the bloodstream to the heart or pulmonary circulatory system. The risk of blood clots can be significantly reduced by using a small catheter to ensure satisfactory blood flow around the catheter at all times.

Prevention. Avoid inserting PVK into the veins of the lower extremities, because in this case the risk of thrombosis is higher. If the infusion is stopped due to the formation of a blood clot at the end of the catheter, it should be removed and a new one inserted according to the scheme for changing the location of its installation. Flushing a catheter obstructed by a thrombus can lead to the clot breaking off and migrating towards the heart.

Air embolism can occur with any type of intravenous therapy. However, with peripheral catheterization, the risk of air embolism is limited by positive peripheral venous pressure. Negative pressure can form in the peripheral veins if the catheter is installed above the level of the heart.

Prevention. Air must be completely removed from all elements of the infusion system before connecting it to the PVC. You can remove air by lowering the system's initial opening below the level of the infusion bottle and draining some of the solution, thereby stopping the flow of air into the infusion system. In addition, reliable fixation of all Luer-Lock connections plays an important role in preventing air embolism.

The most rare complication is the rupture and migration of a peripheral venous catheter.

Principles for choosing venous access and catheter size

If the veins are not visible or are difficult to palpate, it is necessary to apply methods that improve their visualization. This is helped by applying a tourniquet 5-10 cm above the site of intended catheterization, asking the patient to alternately clench and unclench his hand in a fist for a while, pat or stroke the vein, lower the hand down, provide a warm bath for the limb or apply a heating pad to it.

It is necessary to achieve good palpation of the vein being catheterized. Taking into account its size, the required catheter size is selected, which will be optimal in a specific clinical situation (characteristics of injected solutions, required rate of intravenous therapy). For a puncture in the area of ​​the dorsal veins (back of the hand), special cannulas for the dorsal veins (18G short needle) are used - shorter than catheters of the appropriate size (Fig. 8).

Fig.8. Peripheral venous catheter Vasofix G 18: a short version of the cannula designed for catheterization of the veins of the dorsum of the hand

Taking these factors into account, you should choose the smallest catheter size possible (short catheters have a greater capacity than long catheters of the same diameter). In addition, PVCs of the same size from different manufacturers may have differences in throughput, which depends on the material from which the catheter is made, as well as the presence of a special coating that reduces resistance (microsiliconization). Size, length, and capacity information is included on each catheter package.

The definition of Gauge measurement comes from the AAMI (Association for the Advancement of Medical Instrumentation). The gauge determines how many cannulas fit into a 1" internal diameter tube (1 inch = 25.4 mm). AAMI uses only even numbers(18, 20, 22, etc.). A similar size definition exists in the UK, and here it is known as SWG (Standard Wire Gauge). SWG uses sequential numbers 13 to 24 and is the more common method for measuring catheter sizes in Europe. Charrieres (Charriere3 Ch), better known as French units (Fr), refer directly to the size of the catheters: 1 Fr = 0.33 mm (Table 1).

When injecting solutions at high speed or administering drugs with an irritating effect on the vessel, large patent veins with good blood flow should be selected for placing a peripheral venous catheter. The smaller the diameter of the catheter, the better the blood flow around it and, therefore, the higher the dilution of the drug in blood. Large-diameter cannulas can close the lumen of the vein or damage its inner lining (Fig. 2).

Selection of catheterization area

Selection of catheterization area:

1. distal veins are used first; if catheterization is unsuccessful, it is carried out proximal to the site of the previous intervention;

2. veins are used, soft and elastic to the touch;

3. If possible, well-visualized large veins with well-developed collaterals are used;

4. venipuncture is performed on the side opposite to the surgical intervention;

5. veins are used, the length of the straight section of which corresponds to the length of the catheter;

6. veins are used on the patient’s non-dominant (not “working”) limb;

7. ease of access to the puncture site.

Areas to avoid during peripheral venous catheterization:

Veins that are hard and sclerotic to the touch;

Veins in the area of ​​the flexor surfaces of the joints;

Veins close to arteries/projections of arteries;

Deep veins;

Veins of the lower extremities;

Veins that show signs of irritation from previous injections;

Limbs with fractures;

Small, visible but not palpable veins;

Veins of the palmar surface of the hand;

Intermediate veins of the elbow; median cubital vein (v. mediana cubiti), which is used for blood sampling;

Areas near existing skin lesions, infected areas;

Limbs that have been removed The lymph nodes or have undergone radiotherapy.

Contraindications to peripheral venous catheterization

Contraindications for peripheral venous catheterization:

There are no contraindications to peripheral venous catheterization that prohibit peripheral venous access. There are conditions that prohibit puncture of a vein in this area or indicate a preference for central venous access in a particular clinical situation.

1. Contraindications indicating preference for central venous access:

· administration of solutions and medications that cause irritation of the vascular wall (for example, solutions with high osmolarity);

· transfusion of large volumes of blood and its components;

· the need for rapid infusion (at a rate of over 200 ml/min.);

· all superficial veins of the arm are not visualized or palpated after applying a tourniquet.

2. Contraindications that require choosing a different site for peripheral vein catheterization:

the presence of phlebitis or inflammation of soft tissues on the arm;

the arm vein is not visualized or palpated after applying a tourniquet.

Indications for catheterization of peripheral veins

Indications:

1. The first stage before placing a central venous catheter.

2. Support and/or correction of water and electrolyte balance.

3. Intravenous administration of drugs in cases where this cannot be done orally (the need for rapid and accurate administration of the drug into effective dose, impossibility of administering the drug orally, lack of a dosage form of the drug that allows its administration orally).

4. Carrying out frequent courses of intravenous therapy for chronic patients, the need for long-term infusion therapy.

5. Rehydration of the body.

6. Jet (bolus) administration of drugs, for example, administration of antibiotics (according to the instructions for use from the manufacturer of the drug).

7. Access to the bloodstream in emergency conditions (fast venous access if it is necessary to simultaneously carry out emergency infusions of drugs or high speed administration of solutions).

8. Transfusion of blood products.

9. Parenteral nutrition(except for the introduction of nutritional mixtures containing lipids).

10. Blood collection for clinical trials(to determine blood group and Rh, blood gas composition, liver function indicators, urea and electrolytes, blood formula, glucose tolerance, determination of drug content, narcotic substances, alcohol in blood plasma, etc.).

11. Invasive blood pressure monitoring.

12. Anesthetic management (anesthesia, regional anesthesia).

Performed:

midwife of the OBS department - 4

Gorbatenko Marina.

Belgorod 2011.

Technique for catheterization of peripheral veins and catheter placement

Peripheral venous catheter care

Complications and their prevention during catheterization of peripheral veins

Principles for choosing venous access and catheter size

Selection of catheterization area

Contraindications to peripheral venous catheterization

Indications for catheterization of peripheral veins

Relevance of the problem of catheterization of peripheral veins

Catheterization of peripheral veins is a method of establishing access to the bloodstream for a long period of time through peripheral veins through the installation of a peripheral intravenous catheter.

A peripheral intravenous (venous) catheter (PVC) is a device inserted into a peripheral vein and providing access to the bloodstream.

Vein catheterization has long become a routine medical procedure. In one year, over 500 million peripheral venous catheters are installed worldwide. With the advent of high-quality intravenous catheters on the domestic market in Ukraine, the method of conducting infusion therapy using a cannula installed in a peripheral vessel is receiving increasing recognition from medical workers and patients every year. The number of central venous catheterizations began to decrease in favor of an increase in peripheral ones. As modern practice shows, most types of intravenous therapy, previously carried out through central catheters, are more appropriate and safe to carry out through peripheral intravenous catheters. The widespread use of infusion cannulas is explained by the advantages they have over the conventional method of infusion therapy using a metal needle - the catheter will not come out of the vessel and will not pierce it through, causing the development of infiltration or hematoma.

Delivering intravenous therapy through a peripheral venous catheter has a number of advantages for both healthcare providers and patients. The method assumes reliable and accessible venous access, facilitates the rapid effective administration of an accurate dose of drugs, saves the time of medical personnel spent on venipuncture during frequent intravenous injections, which also minimizes the psychological burden on the patient, ensures motor activity and patient comfort. In addition, this simple manipulation is associated with a minimum number of severe life-threatening complications, provided that basic conditions are met: the method must become permanent and habitual in practice and, as with any invasive medical procedure, impeccable care must be provided.

Comparative characteristics of peripheral venous catheters

Depending on the material from which the catheter is made, metal (the part of the cannula remaining in the vein is made of metal alloys) and plastic catheters can be distinguished.

Metal catheters consist of a needle connected to a connector. After puncture, the needle remains in the vein, performing the function of a catheter. Connectors can be transparent plastic or metal and have wings, for example, VENOFIX® (Fig. 1), BUTTERFLY®.

Rice. 1. Modern metal catheters VENOFIX9 (butterfly needles). The catheter is a needle made of chromium-nickel alloy with a microsiliconized cut, integrated between plastic fastened wings. On the other hand, a transparent flexible tube 30 cm long is connected to the needle through the wings, at the end of which there is a Luer lock type connection with a hydrophobic plug. Catheters come in different sizes with different needle lengths

This is the most optimal option for intravenous catheters with a steel needle for long-term use (approximately 24 hours). Of all the metal intravenous catheters, they are the most commonly used. Among these catheters, the following modifications are distinguished:

catheters with reduced cut length and needle length (to reduce mechanical irritation);

with a flexible tube between the needle and the connector (also to reduce mechanical irritation - forced manipulations of the connector are not transmitted to the sharp tip of the needle);

with wings made of soft plastic, between which the needle is integrated, which ensures safe puncture even in difficult-to-reach veins.

In modern practice, steel catheters are used extremely rarely, since they are not suitable for long-term stay in the vein due to the high incidence of complications associated with their use. The rigidity of the needle causes mechanical irritation (with further development of phlebitis or thrombosis), trauma and necrosis of sections of the vein wall, followed by extravasal administration of the drug, the formation of infiltration and hematoma. Infusion media introduced through these catheters are poured into the vein not along the blood flow, but at an angle to it, which creates conditions for chemical irritation of the intima of the vessel. A sharp needle creates an abrasive effect on the inner surface of the vessel. To reduce the incidence of these complications when working with steel catheters, their reliable fixation is required, and achieving this condition limits the patient’s motor activity and creates additional discomfort for him.

However, there are advantages to using steel catheters. When they are installed, the risk of infectious complications is reduced, since the steel prevents the penetration of microorganisms through the catheter. In addition, due to their rigidity, manipulation of the puncture of difficult-to-visualize and thin veins is facilitated. In pediatrics and neonatology they are the catheters of choice.

Plastic catheters consist of an interconnected plastic cannula and a transparent connector, pushed onto a guide steel needle. The transition from a steel needle to a plastic tube in modern catheters is smooth or with a slight conical design, so that at the time of venipuncture the needle moves without resistance (Fig. 2).

Fig.2. Transition between catheter and guide needle

Unlike catheters with metal intravenous elements, plastic ones follow the route of the vein, which reduces the risk of vein trauma, infiltration and thrombotic complications, and increases the time the catheter remains in the vessel. Thanks to the flexibility of the plastic, patients can allow greater physical activity, which contributes to their comfort.

Today, various models of plastic intravenous catheters are offered. They may have an additional injection port (ported, Fig. 3) or not (non-ported, Fig. 1), they can be equipped with fixation wings or models without them can be produced.

peripheral venous catheter installation

Fig.3. Plastic intravenous catheter with injection port and protective clip on the guide needle

To protect against needle sticks and the risk of infection, cannulas with a self-activating protective clip mounted on the needle have been developed. To reduce the risk of contamination, catheters are produced with removable injection elements. To better monitor the catheter, which is in the vein, X-ray contrast strips are integrated into the transparent cannula tube. The sharpening of the piercing cut of the guide needle also helps to facilitate the puncture - it can be lanceolate or angular. Leading PVC manufacturers are developing a special position of the injection port above the fixation wings of the connector, which reduces the risk of cannula displacement when performing additional injections. In addition, some catheters have special holes in them to ventilate areas of the skin located under the fixing wings.

Thus, the following types of cannulas should be distinguished:

1. A cannula without an additional port for bolus injections is a catheter mounted on a stylet needle. After entering the vein, the cannula is moved from the stylet into the vein.

2. A cannula with an additional port expands the possibilities of its use, facilitates maintenance, and therefore extends the period of its installation.

There are two modifications of this cannula. The first modification is the most common configuration. Convenience during placement and fixation, the presence of an upper port for short-term insertions and heparinization of the cannula during infusion breaks have earned the love of doctors.

A wide variety of brands from different manufacturers is distinguished only by the quality of the product. But despite the apparent simplicity of the design, not everyone manages to combine the triad of qualities:

1) needle sharpness and optimal sharpening angle;

2) atraumatic transition from needle to cannula;

3) low resistance to insertion of the catheter through the tissue.

Manufacturers of such cannulas include B. Braun and VOS Ohmeda (part of the BD concern).

In the process of peripheral vein cannulation, sometimes the first attempt may fail for one reason or another. Invisible “scratches” on the cannula, as a rule, do not allow it to be reused or shorten the period of use to one day.

HMD has released a new material for the traditional cannula, which potentially allows it to be used if the first cannulation attempt fails without reducing placement time, and makes the cannula more resistant to sticking when kinked. This cannula is registered under the brand name "Cathy".

Target: A peripheral venous catheter is inserted into a peripheral vein and provides access to the bloodstream, allows for long-term infusion therapy, and reduces the incidence of psychological trauma (especially in children) associated with numerous punctures of peripheral veins.

When choosing a catheter, the following rules should be considered: :

ü The catheter should cause the least discomfort to the patient;

ü Ensure optimal infusion rate (drug administration);

ü The length of the catheter must correspond to the length of the straight section of the vein being used;

ü The diameter of the catheter must correspond to the diameter of the selected vein (catheters of smaller diameter give ...
the possibility of better blood flow around the catheter and dilution of the drug with blood; large-diameter catheters can close the lumen of the vein or damage the inner lining of the vein).

ü Orange– for rapid blood transfusion;

ü Grey— for transfusion of blood and its components;

ü Green– for blood transfusion or administration of sick volumes of fluid;

ü Pink– for the administration of large volumes of liquid, rapid administration of contrast agents during diagnostic procedures;

ü Blue– for long-term intravenous drug therapy in children and adults (small veins);

ü Yellow– for newborns, chemotherapy.

The duration of operation of one catheter is 3 days. When operating the boat, strictly follow the rules of asepsis and antiseptics. The connection points of the catheter with the system for intravenous drips and the plug must be thoroughly cleaned of blood residues and covered with a sterile napkin. Monitor the condition of the vein and skin in the puncture area. To avoid thrombosis of the catheter with a blood clot, fill it with heparin solution. To avoid migration of the catheter, constantly monitor the reliability of its fixation.

Indications: 1. administration of medications to patients who cannot take them orally; if the drug must be administered in an effective concentration and accurately, especially if the drug can change its properties when taken orally;

2. Cases when emergency administration of a drug or solution may be required;

3. Frequent intravenous administration of drugs;

4. Blood collection for clinical studies carried out at time intervals (for example, determination of glucose tolerance, drug levels in plasma and blood;

5. Transfusion of blood products;

6. Parenteral nutrition (except for the administration of nutritional mixtures containing lipids);

7. Rehydration of the body (restoration of water and electrolyte balance).

Contraindications: The catheter should not be inserted into: 1. Veins that are hard to the touch and sclerotic (their inner lining may be damaged); 2. Veins of the flexor surfaces of the joints (high risk of mechanical damage); 3. Veins located close to arteries or their projections (there is a risk of puncture of the artery); 4. Veins of the lower extremities; 5. Previously catheterized veins (damage to the inner wall of the vessel is possible); 6. Small visible but not palpable veins; 7. Veins of the surface of the arms, median ulnar veins (usually they are used to draw blood for testing); 8. Veins in a limb that has undergone surgery or chemotherapy.

Workplace equipment: sterile gloves, clean gloves, mask, protective glasses, a waterproof apron, a bottle with a drug for intravenous administration, a bottle with 0.9% sodium chloride solutions, heparin, a file for opening ampoules, scissors, sterile tweezers, sterile dressing material in a package (cotton balls, gauze pads), adhesive plaster, two sterile disposable syringe with a volume of 0.5 ml., a bottle with disinfectant solutions for treating ampoules and vials, a bottle with an antiseptic for treating the patient’s skin and the hands of medical staff, containers with a disinfectant solution for disinfecting waste material, containers for waste material, a splint, an instrument table, containers with a disinfectant solution for treating surfaces, clean rags, a hemostatic clamp.

Possible complications:

Are common: septicemia, embolism (catheter embolism), air embolism, anaphylactic shock.

Local: phlebitis (inflammation of a vein), thrombophlebitis (inflammation of a vein with the formation of a blood clot), tissue infiltration and necrosis, hematoma, catheter blockage, venous spasm, damage to a nearby nerve.

Medicines can be administered directly into the blood using intravenous catheters. They are installed once and can be used many times. Thanks to this, there is no need to constantly prick your hands in search of veins.

Principle of catheter design

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

A catheter for intravenous drug administration is a thin, hollow tube. It is inserted into the bloodstream.

This can be done in the arms, neck or head. But inserting catheters into the vessels of the legs is not recommended.

These devices are installed so that there is no need to constantly pierce the veins. After all, this can cause them to become injured and inflamed. Constant damage to their walls leads to thrombus formation.

Types of devices

Medical facilities may use one of four types of catheters. The following types are distinguished:

Models intended for short-term use;

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

Tunneled catheters, which are inserted into wide bloodstreams, such as the vena cava;

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

Depending on the materials used in the manufacture of these devices, metal and plastic models are distinguished. The choice of the appropriate option in each specific case is made only by a doctor.

A metal catheter for intravenous infusions 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 a transparent connector that are pushed onto a steel needle. Such options are used much more often. After all, they can be used longer than metal catheters. The transition from a steel needle to a plastic tube is smooth or cone-shaped.

Steel catheters

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

There are several modifications of such catheters.

So, they can be with a short cut and a small needle or with a flexible tube installed between the connector and the needle. This is intended to reduce the mechanical irritation that occurs when a steel IV catheter is used. A photo of such a device makes it possible to understand that there is nothing terrible if they install 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 in hidden and hard-to-reach veins.

Disadvantages and advantages of metal models

In modern medical practice, steel options are used extremely rarely. After all, their service life is quite short - they can remain in the vein for no more than 24 hours. In addition, hard needles cause vein irritation. Because of this, thrombosis or phlebitis may develop. Also, the possibility of trauma or necrosis of part of the vein wall cannot be excluded. And this may cause extravasal administration of the drug.

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

To prevent the possibility of complications when working with steel intravenous catheters, they must be firmly 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 does not allow microorganisms to enter the bloodstream. In addition, they are easier to install in thin veins that are difficult to visualize. Therefore, their use is practiced in neonatology and pediatrics.

Modern devices

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, a plastic peripheral intravenous catheter can follow the bends of the vein. Thanks to this, the risk of injury is significantly reduced. The likelihood of blood clots and infiltrates is also minimized. In this case, the time that such a catheter remains in the vessel increases significantly.

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

Varieties of plastic models

Doctors can choose which catheter to place in a patient. You can find models on sale with or without additional injection ports. They can also be equipped with special fixing wings.

To protect against accidental punctures and 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 medications, an intravenous catheter with an additional port can be used. Many manufacturers place it above the wings designed for additional fixation of the device. When administering medications into such a port, there is no risk of cannula displacement.

When purchasing catheters, you should follow the recommendations of doctors. After all, these devices, although externally similar, can differ significantly in quality. It is important that the transition from needle to cannula is atraumatic, and that there is minimal resistance when inserting the catheter through the tissue. The sharpness of the needle and its sharpening angle are also important.

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

Materials used

The first plastic models were not very different from steel catheters. Polyethylene could have been used in their manufacture. The result was thick-walled catheters, 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 a loop, 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, which are used in the production of these medical devices. Thus, the most popular materials are: PTFE, FEP, PUR.

The first of them 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 of this material can be compressed and form loops.

FEP (fluoroethylene propylene copolymer), also known as Teflon, has the same positive characteristics as PTFE. But, in addition, this material allows for better control of the catheter and increases its stability. A radiopaque contrast medium can be injected into such an intravenous device, which will allow it to be seen in the bloodstream.

PUR material is a well-known polyurethane. Its hardness depends on temperature. The warmer it is, the softer and more elastic it becomes. It is often used to make central intravenous catheters.

Advantages and disadvantages of ports

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

If this is not required, a regular intravenous catheter can be installed.

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 using them, 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 and anesthesiology, preference is given to ported catheters. In all other areas of medicine, it is enough to establish the usual option.

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

Dimensions of plastic models

The patient should not choose which intravenous catheter he needs to buy.

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 - heych. In accordance with their size and throughput, a unified color marking has been established.

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

The green catheter (87G) is installed in those patients who are routinely receiving red blood cell (blood) transfusions. It operates at a speed of 80 ml/min.

Patients who undergo long-term daily intravenous therapy (2-3 liters of solutions per day are infused) are recommended to use the pink model (20G). When installed, 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. It passes 31 ml of fluid every minute.

To install a catheter in thin sclerotic veins, yellow (24G) or purple (26G) catheters can be used in pediatrics and oncology. 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.

Carrying out the installation

Every nurse should know how to place an intravenous catheter. To do this, the injection site is pre-treated, a tourniquet is applied and measures are taken to ensure that the vein is filled 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 the blood that should fill the catheter imaging chamber. It is important to remember: the larger its diameter, the faster this biological fluid will appear there.

Because of this, thin catheters are considered more difficult to work with. The cannula should be inserted more slowly, and the nurse should also focus on tactile sensations. When the needle enters the vein, a hole is felt.

After contact, you need to push the device further into the vein with one hand, and fix the guide needle with the other. After completion of catheter insertion, the guide needle is removed. It cannot be reattached to the part remaining under the skin. If the vein has been lost, the entire device is removed and the insertion procedure is repeated again.

It is also important to know how intravenous catheters are secured. This is done using an adhesive plaster or a special bandage. The site of entry into the skin itself 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 unported variants) or through a special port. The device is also washed after each infusion. This is necessary in order to prevent the formation of blood clots in a vessel with an installed catheter. It also prevents the development of a number of complications.

There are certain rules for working with devices for intravenous drug administration.

All health care workers who will select or install an intravenous catheter should know them. 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 next installation(if necessary long-term treatment) is done on the opposite hand. The catheter is inserted higher along the vein. Compliance with this rule allows you to minimize the likelihood of developing phlebitis.

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