Pharmacodynamics is one of the parts of pharmacology (the science of drugs) that studies the effect of the body on drugs, i.e. how drugs enter the body, are adsorbed into the bloodstream, transported to organs and tissues, metabolized and excreted from it. One of the important issues that pharmacodynamics considers is the route of drug administration. All routes of administration are divided into integral (through the gastrointestinal tract) and parenteral (bypassing the gastrointestinal tract). And if everything is more or less clear with the former, then the parenteral administration of drugs raises a lot of questions in patients.

Injection routes of administration

Among the injection routes, the most common are intravenous and intramuscular. In addition to them, there are also subcutaneous, intradermal, intraarterial and intraosseous. Let's take a look, parenterally - how is it?

Intravenous administration of drugs is perhaps the most common among injections. Combining relative simplicity, it provides fast delivery of the drug to organs and tissues with 100% bioavailability. Parenteral administration is both a unique opportunity to deliver minimal volumes of drugs, and to produce a round-the-clock infusion using an installed venous catheter and a special device. In addition, the intravenous route is the only way to administer drugs in critical conditions and in cases where the patient is unconscious, and also makes it possible to administer drugs that are poorly soluble in the gastrointestinal tract.

In addition to all the advantages, the intravenous route of administration has its own disadvantages. Thus, only a parenteral agent, which is an aqueous solution or suspension on an aqueous basis, can be administered intravenously, and during manipulation it is necessary to avoid getting air into the blood vessel, as this can lead to the development of embolism.

Intramuscular administration, at first glance, may seem equivalent to intravenous, but this is far from being the case. In addition to lower bioavailability, intramuscular administration is not carried out in critical conditions, as this reduces central hemodynamics, blood supply to muscle tissue decreases and, accordingly, drug delivery decreases. Also, do not inject more than 10 ml of solutions intramuscularly.

Intra-arterial administration has found its application in cardiac surgery and angiology, as well as diagnostic procedures. In this case, parenteral administration is like a new breakthrough in medicine, because in this way, for example, contrast agents are administered to study the vascular system and determine the scope of further therapeutic measures. This, in turn, allows you to take a fresh look at the diagnostic process.

Parenterally - how is it?

Among the non-injection routes, it is necessary to note transdermal, intravaginal, intratracheal, as well as intranasal, etc.

The transdermal route is the penetration of drugs through the skin. This path for an adult can only cause a local effect from the administered drug (for example, in the form of creams or ointments), but in a child, medicinal substances may have a systemic effect. This is due to the fact that the child's skin has a high sorption capacity, which causes the penetration of drugs into the bloodstream.

Intratracheal administration refers to inhalation routes. In this case, the introduction of the drug occurs through the trachea into the bronchial tree. As a rule, this method is used to administer drugs that affect the respiratory system.

Intranasal administration in the form of sprays and drops, as well as the use of drugs in the form of eye drops, has become widespread.

Which way to choose?

The question of choice is always relevant. If possible, the oral route should be limited to them, and when choosing the parenteral administration of drugs, it is necessary to focus on the severity of the patient's condition and the drug itself.

Conclusion

Parenteral drugs are drugs intended for administration to the human body, bypassing the gastrointestinal tract. The choice of this route of administration should be based on the principles of rationality, as well as extreme necessity for the patient, since in any case this type of administration is associated with certain risks.

Subcutaneous injection technique:
Purpose: curative, preventive
Indications: determined by the doctor
The subcutaneous injection is deeper than the intradermal injection and is made to a depth of 15 mm.

Rice. Subcutaneous injection: needle position.

The subcutaneous tissue has a good blood supply, so drugs are absorbed and act faster. The maximum effect of a subcutaneously administered drug usually occurs after 30 minutes.

Injection sites for subcutaneous injection: upper third of the outer surface of the shoulder, back (subscapular region), anterolateral surface of the thigh, lateral surface of the abdominal wall.

Prepare equipment:
- soap, individual towel, gloves, mask, skin antiseptic (for example: Lizanin, AHD-200 Special)
- an ampoule with a drug, a nail file for opening the ampoule
- sterile tray, waste tray
- a disposable syringe with a volume of 2 - 5 ml, (a needle with a diameter of 0.5 mm and a length of 16 mm is recommended)
- cotton balls in 70% alcohol
- first-aid kit "Anti-HIV", as well as containers with des. solutions (3% solution of chloramine, 5% solution of chloramine), rags

Preparation for manipulation:
1. Explain to the patient the purpose, the course of the upcoming manipulation, obtain the patient's consent to perform the manipulation.
2. Treat your hands at a hygienic level.
3.Help the patient into position.

Subcutaneous Injection Algorithm:
1. Check the expiration date and tightness of the syringe package. Open the package, assemble the syringe and place it in a sterile patch.
2. Check the expiration date, name, physical properties and dosage of the drug. Check with destination sheet.
3. Take 2 cotton balls with alcohol with sterile tweezers, process and open the ampoule.
4. Draw the required amount of the drug into the syringe, release the air and put the syringe in a sterile patch.
5. Lay out 3 cotton balls with sterile tweezers.
6. Put on gloves and rub the ball in 70% alcohol, drop the balls into the waste tray.
7. Treat a large area of ​​skin with the first ball in alcohol centrifugally (or in the direction from bottom to top), treat the puncture site directly with the second ball, wait until the skin dries from alcohol.
8. Discard the balls into the waste tray.
9. With your left hand, grasp the skin at the injection site in the warehouse.
10. Bring the needle under the skin at the base of the skin fold at an angle of 45 degrees to the skin surface with a cut to a depth of 15 mm or 2/3 of the needle length (depending on the length of the needle, the indicator may be different); index finger; hold the cannula of the needle with your index finger.
11. Move the hand that fixes the fold to the plunger and slowly inject the drug, try not to shift the syringe from hand to hand.
12. Remove the needle, continuing to hold it by the cannula, hold the puncture site with a sterile cotton swab moistened with alcohol. Put the needle in a special container; if a disposable syringe is used, break the needle and cannula of the syringe; take off your gloves.
13. Make sure that the patient feels comfortable, take the 3 balloon from him and escort the patient.

Rules for the introduction of oil solutions. Oily solutions are often administered subcutaneously; intravenous administration is prohibited.

Drops of the oil solution, falling into the vessel, clog it. The nutrition of surrounding tissues is disturbed, their necrosis develops. With the blood flow, oil emboli can enter the vessels of the lungs and cause blockage, which is accompanied by severe suffocation and can cause the death of the patient. Oily solutions are poorly absorbed, so an infiltrate may develop at the injection site. Warm oily solutions before administration to a temperature of 38 ° C; before administering the medicine, pull the plunger towards you and make sure that blood does not enter the syringe, that is, you do not enter the blood vessel. Only then slowly inject the solution. Apply to the injection site heating pad or warm compress: this will help prevent infiltration.

- It is a blood sugar lowering drug that is dosed in units of insulin (IU). Produced in vials of 5 ml, 1 ml of insulin contains 40 IU, 80 IU or 100 IU - look carefully at the bottle label.

Insulin is administered with a special disposable insulin syringe of 1 ml.

On one side of the scale on the cylinder - divisions for ml, on the other - divisions for EI, on it and carry out a set of the drug, after evaluating the scale of division. Insulin is administered s / c, in / in.

Target: therapeutic - to lower the level of glucose in the blood.

Contraindications:

2. Allergic reaction.

Equipment:

Sterile: a tray with gauze tuffs or cotton balls, an insulin syringe with a needle, a 2nd needle (if the needle is changed on the syringe), alcohol 70%, an insulin preparation, gloves.

Non-sterile: scissors, couch or chair, containers for disinfection of needles, syringes, dressings.

Patient and drug preparation:

1. Explain to the patient the need to comply with the diet when receiving insulin. Short-acting insulin is administered 15-20 minutes before meals, its hypoglycemic effect begins after 20-30 minutes, reaches its maximum effect after 1.5-2.5 hours, the total duration of action is 5-6 hours.

2. The needle can be inserted into the vial with insulin and s / c only after the stopper of the vial and the injection site are dry from 70% alcohol, because. alcohol reduces the activity of insulin.

3. When drawing insulin solution into a syringe, draw 2 UI more than the dose prescribed by the doctor, because. it is necessary to compensate for losses during the removal of air and checking the second needle (provided that the needle is removable).

4. Vials with insulin are stored in the refrigerator, preventing them from freezing; direct sunlight is excluded; warm to room temperature before administration.

5. After opening, the bottle can be stored for 1 month, do not tear off the metal cap, but bend it.

Execution algorithm:

1. Explain to the patient the course of the manipulation, get his consent.

2. Put on a clean gown, mask, clean your hands at a hygienic level, put on gloves.

3. Read the name of the insulin, dosage (40,80,100 IU per 1 ml) - must correspond to the doctor's prescription.

4. Look at the date, expiration date - must match.

5. Check the integrity of the packaging.

6. Open the package with the selected sterile insulin syringe, put it in a sterile tray.

7. Open the aluminum cover by treating it with 70% alcohol twice.

8. Pierce the rubber cap of the vial after the alcohol has dried, draw up insulin (the dose prescribed by the doctor plus 2 units).

9. Change the needle. Release the air from the syringe (2 units will go into the needle).

10. Put the syringe on a sterile tray, prepare 3 sterile, cotton balls (2 moistened with 70% alcohol, the 3rd dry).

11. Treat the skin first with the 1st, then with the 2nd cotton ball (with alcohol), hold the 3rd (dry) in your left hand.

12. Gather the skin into a triangular fold.

13. Insert the needle into the base of the fold at an angle of 45° to a depth of 1-2 cm (2/3 of the needle), holding the syringe in your right hand.

14. Inject insulin.

15. Apply pressure to the injection site dry cotton ball.

16. Remove the needle by holding it by the cannula.

17. Discard the disposable syringe and needle in a container of 3% chloramine for 60 minutes.

18. Remove gloves, place in a container with a disinfectant solution.

19. Wash hands, dry.

Possible complications with insulin administration:

1. Lipodystrophy (disappearance of adipose tissue at the site of numerous injections, scarring).

2. Allergic reaction (redness, urticaria, angioedema).

3. Hypoglycemic state (in case of overdose). Observed: irritability, sweating, hunger. (Help for hypoglycemia: give the patient sugar, honey, sweet drink, biscuits).

The subcutaneous fat layer is well supplied with blood vessels, therefore, subcutaneous injections (s / c) are used for a faster action of the medicinal substance. Subcutaneously administered medicinal substances are absorbed faster than when administered through the mouth. Subcutaneous injections are made with a needle to a depth of 15 mm and up to 2 ml of drugs are injected, which are quickly absorbed in loose subcutaneous tissue and do not have a harmful effect on it.

Characteristics of needles, syringes for s / c injections :

Needle length -20 mm

Cross section -0.4 mm

Syringe volume - 1; 2 ml Sites for subcutaneous injection:

The middle third of the anterolateral surface of the shoulder;

The middle third of the anterolateral surface of the thigh;

Subscapular region;

Anterior abdominal wall.

In these places, the skin is easily captured in the fold and there is no danger of damage to blood vessels, nerves and periosteum. It is not recommended to make injections: in places with edematous subcutaneous fat; in seals from poorly absorbed previous injections.

Equipment:

Execution algorithm:

Put on a clean gown, mask, treat your hands at a hygienic level, put on gloves.

Take the medicine, release the air from the syringe, put it in the tray.

Sit or lay the patient down, depending on the choice of injection site and drug.

Inspect and palpate the injection site.

Treat the injection site sequentially in one direction with 2 cotton balls moistened with a 70% alcohol solution: first a large area, then the second ball directly at the injection site, put it under the little finger of the left hand.

Take the syringe in your right hand (hold the cannula of the needle with the index finger of the right hand, hold the syringe plunger with the little finger, hold the cylinder with fingers 1,3,4).

With your left hand, gather the skin into a triangular fold, base down.

Insert the needle at an angle of 45° with the cut up into the base of the skin fold to a depth of 1-2 cm (2/3 of the length of the needle), hold the cannula of the needle with your index finger.

Place your left hand on the plunger and inject the drug (do not switch the syringe from one hand to the other).

Remove gloves, place in

Wash hands, dry.

Note. During the injection and after it, after 15-30 minutes, ask the patient about his well-being and about the reaction to the injected drug (detection of complications and reactions).

Fig.1.Places for s / c injections

Fig.2. Technique of subcutaneous injection.

The introduction of oil solutions subcutaneously.

Target: medical.

Indications: the introduction of hormonal drugs, solutions of fat-soluble vitamin preparations.

Equipment:

Sterile: a tray with gauze tuffs or cotton balls, a 1.0 or 2.0 ml syringe, 2 needles, 70% alcohol, drugs, gloves.

Non-sterile: scissors, couch or chair, containers for disinfection of needles, syringes, dressings.

Execution algorithm:

Explain to the patient the course of the manipulation, get his consent.

Put on a clean gown, mask, treat your hands at a hygienic level, put on gloves.

Before use, dip the ampoule into a container with warm water, heat it up to 38 ° C.

Draw the medicine into the syringe, release the air from the syringe.

Treat the tufikomi injection site twice with 70% alcohol.

Inject with a needle, pull the piston towards you - make sure that no blood enters the syringe - prevention of drug embolism (oil).

Slowly inject the solution (t° oil solution 38°C).

Press the injection site with a cotton ball with 70% alcohol.

Remove the needle by holding it by the cannula.

Discard the disposable syringe and needle in a container of 3% chloramine for 60 minutes.

Remove gloves, place a container with a disinfectant solution.

Wash hands, dry.

Subcutaneous injections are a highly demanded medical procedure. The technique for its implementation differs from the method of administering drugs intramuscularly, although the preparation algorithm is similar.

The injection should be made subcutaneously less deeply: it is enough to insert the needle inside only 15 mm. Subcutaneous tissue has a good blood supply, which leads to a high rate of absorption and, accordingly, the action of drugs. Just 30 minutes after the administration of the drug solution, the maximum effect of its action is observed.

The most convenient places for the introduction of drugs subcutaneously:

• shoulder (its outer region or middle third);
• anterior surface of the thighs;
• lateral part of the abdominal wall;
• subscapular region in the presence of pronounced subcutaneous fat.

Preparatory stage

The algorithm for performing any medical manipulation, as a result of which the integrity of the patient's tissues is violated, begins with preparation. Before giving an injection, you should disinfect your hands: wash them with antibacterial soap or treat with an antiseptic.

Important: In order to protect their own health, the standard algorithm for the work of medical personnel in all types of contact with patients provides for the wearing of sterile gloves.

Preparation of instruments and preparations:

• sterile tray (ceramic plate clean and disinfected by wiping) and waste tray;
• a syringe with a volume of 1 or 2 ml with a needle 2 to 3 cm long and not more than 0.5 mm in diameter;
• sterile wipes (cotton swabs) - 4 pcs.;
• prescribed drug;
• alcohol 70%.

Everything that will be used during the procedure should be on a sterile tray. You should check the expiration date and the tightness of the packaging of the medicine and the syringe.

The place where the injection is planned to be inspected for the presence of:

1. mechanical damage;
2. edema;
3. signs of dermatological diseases;
4. manifestation of allergy.

If the selected area has the above problems, the intervention site should be changed.

Medication withdrawal

The algorithm for taking the prescribed drug into the syringe is standard:

• checking the compliance of the medicine contained in the ampoule prescribed by the doctor;
• clarification of the dosage;
• disinfection of the neck at the point of its transition from a wide part to a narrow one and notching with a special nail file supplied in one box with the medicine. Sometimes ampoules have specially weakened places for opening, made in a factory way. Then on the vessel in the indicated area there will be a mark - a colored horizontal stripe. The removed tip of the ampoule is placed in the waste tray;
• the ampoule is opened by grabbing the neck with a sterile swab and breaking it away from you;
• the syringe is opened, its cannula is combined with the needle, after which the case is removed from it;
• the needle is placed in the opened ampoule;
• the syringe plunger is retracted with the thumb, fluid is taken;
• the syringe is raised with the needle up, the cylinder should be lightly tapped with a finger to force out the air. Squeeze the medicine with a piston until a drop appears on the tip of the needle;
• put on the needle case.

Before making subcutaneous injections, it is necessary to disinfect the operating field (side, shoulder): with one (large) swab dipped in alcohol, a large surface is treated, the second (middle) place where the injection is directly planned. Technique of sterilization of the working area: moving the swab centrifugally or from top to bottom. The injection site should be dry with alcohol.

Manipulation algorithm:

• the syringe is taken in the right hand. The index finger is placed on the cannula, the little finger is placed on the piston, the rest will be on the cylinder;
• with the left hand - thumb and forefinger - grab the skin. You should get a skin fold;
• to make an injection, the needle is inserted with a cut up at an angle of 40-45º for 2/3 of the length into the base of the resulting skin fold;
• the index finger of the right hand maintains its position on the cannula, and the left hand is transferred to the piston and begins to squeeze it, slowly injecting the medicine;
• a swab dipped in alcohol is easily pressed against the insertion site of the needle, which can now be removed. Safety precautions provide that in the process of removing the tip, you should hold the place where the needle is attached to the syringe;
• after the injection is finished, the patient must hold the cotton ball for another 5 minutes, the used syringe is separated from the needle. The syringe is ejected, the cannula and needle break.

Important: Before injecting, you need to comfortably position the patient. In the process of performing the injection, it is necessary to continuously monitor the condition of the person, his reaction to the intervention. Sometimes it is better to inject when the patient is lying down.

When you are done giving the injection, remove your gloves if you have worn them, and disinfect your hands again: wash or wipe with an antiseptic.

If you fully comply with the algorithm for performing this manipulation, then the risk of infections, infiltrates and other negative consequences is sharply reduced.

Oil solutions

It is forbidden to make intravenous injections with oily solutions: such substances clog blood vessels, disrupting the nutrition of adjacent tissues, causing their necrosis. Oil emboli may well end up in the vessels of the lungs, clogging them, which will lead to severe suffocation, followed by death.

Oily preparations are poorly absorbed, therefore, infiltrates are not uncommon at the injection site.

Tip: To prevent the occurrence of infiltration to the injection site, you can put a heating pad (make a warm compress).

The algorithm for introducing an oil solution provides for preheating the drug to 38ºС. Before injecting and administering the medicine, you should insert the needle under the patient's skin, pull the plunger of the syringe towards you and make sure that the blood vessel has not been damaged. If blood has entered the cylinder, lightly press the needle insertion site with a sterile swab, remove the needle and try again in another place. In this case, safety precautions require replacing the needle, because. already used is not sterile.

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