ADMINISTRATION OF DRUGS BY PARENTERAL ROUTE (INJECTION)

Objectives

1. Outline the importance for giving drugs by injection
2. List the routes of giving drugs by injection.
3. Identify the requirements for giving drugs by injection.
4. Describe the appropriate technique forgiving drugs by injection.
5. Outline the complications of intravenous infusion.

Aim

To prevent the patient from infecting others (cross infection)

This is a bed for patients who have infectious conditions.

Routes

The routes by which injections are given areas follows; –

1. intradermal
2. intramuscular
3. intrathecal
4. intra-articular
5. Hypodermic
6. Intravenous
7. intra-arterial
8. Intraosseous.

Advantages of parenteral route

• The drug acts quicker than the oral route. For this reason it is very useful in emergencies.
• It is the route of choice when the patient is unconscious or when there is nausea and vomiting.
• The route is useful for uncooperative patients who refuse to take drugs orally (e.g. some psychiatric patients).
• For drugs which are not absorbed by gastro-intestinal tract or are made inactive by digestive juices, the parenteral route may be the only choice e.g. insulin.
• The desired dosage can be determined more accurately.
• Some patients get psychological satisfaction with injections.
• Small doses of powerful drugs can be administered efficiently.

Disadvantages

• Syringes and needles which are needed for this technique are expensive.
• Injections are painful and some patients especially children may be tense prior to an injection.
• An abscess may occur at the site of injection if sterility is not maintained during the procedure.
• Drugs given by this means may be difficult to neutralize if any undesirable effect occurs.
• If the injection site is not carefully selected nerves may be injured resulting in paralysis.
• Air embolism may occur is air is not completely expelled from the syringe before giving an injection.
• Irreversible side effects may occur if an over dose is given.

Syringes and needles

Administration of drugs by parenteral route involves the use of sterile syringes and needles. A syringe consists of a barrel made of glass or plastic with the nozzle to which the needle is attached. The barrel has graduations of the dose.

Within the barrel is the plunger (piston) which can be drawn up to a spirate fluid into the syringe through the needle or depressed to expel its contents.

The usual sizes of syringes are: 0.1ml, 2ml, 5ml, 10ml, 20ml, 30ml, 50ml e.t.c the most commonly used sizes are 2ml and 5ml. The insulin and tuberculin syringes are specially designed and calibrated for specialized use. Needles come in various lengths and gauges. Needles should be selected according to: –

• Route of administration.
• Site of injection.
• Amount of drug to be administered.
• Viscosity of the drug
• Amount of muscle and fat at the injection site.

Rules for parenteral route administration

1. Aseptic technique must be ensured while giving injections.
2. All patients undergoing an injection should be educated and counseled before the injection is given. For example the type of drug, indication, side effects, for possible adverse events following the administration of the injection and total number of doses given by injection.
3. An injection is given when ordered by the doctor and written on the patients’ treatment sheet.
4. The drug must be checked by a trained nurse and can only be given by a student nurse under supervision of such a person.
5. The right patient, correct drug, dose and route must be checked with the patient’s treatment sheet by a trained member of the ward staff and then checked by a person.
6. All needles must be inspected before use for patency.
7. The drug is always recorded and signed for.
8. Needles must not be recapped at all.
9. All used syringes and needles or any other sharps are discarded in a secure container and sealed when three quarters full at the point of use.
10. Discard medications that are visibly bleached, contaminated, cracked or leaking.
11. A patient should be kept for at least five minutes after the injection and be observed for any possible adverse events.

Procedure forgiving injections

Preparation that should be done by the nurse.

1. Get the doctor’s prescription.
2. Review the patient’s diagnosis and make sure you know the indications for the drug, dose, intended effects and route of administration.
3. Wash and dry hands.
4. Check the nurse’s record to find out the time at which the last dose was given.
5. Check the necessity for giving a test dose.
6. Check the consciousness of the patient and ability to follow directions.
7. Check the site of injection where the last dose was given for the following: redness, pain, itching, indurations, skin lesions, sloughing or abscess formation.

If any of these signs are present, report it to the in-charge nurse and use a different site.

Requirements for one patient

A tray with the following;

• 2 syringes
• A gallipot with swabs.
• An ampoule or viral containing the drug.
• An ampoule file.
• Prescription or patient’s chart.
• Clean gloves
• Safety box
• Needles
• A gallipot with antiseptic solution.
• Sterile water for injection.
• Sharps safety box.
• Injection dish.
• At bed side.

Requirements when giving injections to many patients

Trolley

• Small tray
• Sterile syringes and needles
• Drugs to be injected.
• Gallipot with swabs
• Antiseptic solution
• Ampoule solution
• Sterile water for injection
• Injection dishes, clean gloves.
• Sharps safety box
• Receiver for used swabs
• Patient’s charts and medicine lists
• Handwashing equipment
• screen

For intravenous injection add the following: –

• Tourniquet
• Cannula of appropriate gauge.
• Small pillow for supporting the arm.
• Mackintosh and towel.
• Strapping
• Pair of scissors.

Intradermal or intracutaneous injection.

In intradermal injections the drug is introduced between the layers of the skin. Only a small amount of drug is injected. It is commonly used for sensitivity tests and BCG vaccination.

Sites for intradermal injections

1. Inner surface of the arm, midway between wrist and elbow.
2. Outer surface of the upper.
3. On the front of the upper chest.
4. On the back of the shoulder blade.

Technique/method of administration

1. A tuberculin syringe or 1ml syringe is used and needles.
2. Identify the patient, help him to lie in a comfortable position and expose the selected site.
3. Clean the skin with an antiseptic swab and allow the site to dry.
4. If is BCG vaccination clean the site with water.
5. Stretch the patient’s skin, draw it tight and introduce the needle at an angle parallel to the skin.
6. Gently and slowly inject the drug while observing for a small wheal to appear.
7. Carefully with draw the needle. Do not massage the site after removing the needle as it may alter the test results.
8. Circle the area with a pen and record time and date if it was for diagnosis purpose e.g. Mantoux test.
9. Instruct the patient not to wash the area until it is assessed for the intended outcome.
10. Inspect for signs of reaction when the stated duration of time has reached.
11. Report and record results.
12. Clean away the used equipment.

Angle of needle for intradermal

Subcutaneous injection or hypodermic

By this route the drug is injected in the subcutaneous tissues which lie just beneath the skin. Quantities up to 2ml can be given.

It is a good route for watery solutions but not suspensions or oily substances. It takes 15-20 minutes for the drug to be absorbed.

Suitable sites

• Outer aspect of the upper arm.
• Anterior and lateral aspects of the thigh.
• Upper back.
• Any other sites where there is no bony prominence and where it is free from big blood vessels and nerves.
• Examples of drugs given by this route.

-Insulin

-Heparin.

• Sites should be rotated in order to make sure the injections are not given in the same site within a short interval.

Procedure

1. Identify the patient
2. Check the prescription and collect the drug.
3. Choose a suitable needle gauge; take a 1ml or 2ml syringe depending on the dosage.
4. Draw the drug into the syringe.
5. Expel the air by holding the syringe with the needle pointing up.
6. Place the syringe in the sterile receiver or injection dish.
7. Explain the procedure to the patient asking him/her not to move while the injection is being given.
8. Select the site and clean it with an antiseptic swab and let the area dry first.
9. Pinch or squeeze the patient’s skin gently between the finger and thumb of your left hand and insert the needle at angle of 45⁰, pull back the piston plunger and if no blood appears inject the drug slowly. If blood appears in the needle with draw the needle and look for a fresh site.
10. When the drug has been injected completely, place a swab over the needle and withdraw the needle quickly and smoothly.
11. If there is any bleeding at the site apply a firm gentle pressure with a swab until it stops.
12. Make the patient comfortable and record the drug given on the patient’s treatment sheet.
13. Clear away the equipment.

Intramuscular injection

1. The drug is injected deep into the muscle tissue. This route is popularly used for the following reasons: –
2. Drugs which are too irritating to the subcutaneous tissue are less irritating when given into the muscle because deep muscles have fewer nerve endings.
3. The muscles can tolerate volumes of drug then the subcutaneous route. Up to 5nls of drug can be injected on one side.
4. The vascularity of the muscle area enables absorption to take place faster than via the subcutaneous route.

Points to remember

1. Blood vessels are readily entered so the precaution of withdrawing the piston before giving the drug must never be omitted.
2. The site is selected with care to avoid the possibility of injuring the nerves and other structures.
3. If antibiotics like penicillin or streptomycin are being given by this route the possibility of sensitization to the drug must be kept in mind and the antidote must be at hand for emergency.
4. The nurse may contract severe dermatitis as a result of repeated exposure to drugs (fingers and face) by spay so protective precautions should be taken.
5. If multiple injections have to be given site should be regularly changed as constant injections in the same place may lead to necrosis.
6. Very thin patients and children need special care since the available muscle is small.
7. Very fat patients have their muscle deeper below the skin than normal and along enough needle to reach it must be chosen. Eedematous patients should have the edema fluid pressed away from the site selected before giving the injection.
8. An injection must never be given to a restless patient or child until movement has been absolutely controlled. This is to avoid breaking the needle and giving the injection at wrong site/angle during the injection.

Sites for intramuscular injections

Selection of a suitable site is very important in order giving the injection into blood vessel, nerve or periosteum.

The safest sites are:-

1. The gluteal muscle

The outer upper quadrant of the buttock. This is the safest site. The sciatic nerve runs beneath the inner and lower parts of the buttocks and so great care must be taken to avoid piercing it.

2. The thigh muscles

The upper outer third of the muscles of the thigh. Injections in this area are often painful especially for those who have to walk and the site should only be used by a trained nurse.

3. The deltoid muscle

Muscles of the shoulder may be used for small injections up to 2mls if the patient has enough muscle but this site is best avoided.

Procedure

1. Review the general rules of nursing procedures; –

1. Explain the procedures to the patient
2. Ensure privacy
3. Bring prepared tray/trolley to the bedside.

2. Wash hands.
3. Read the prescription carefully and check the drug with the other nurse including the amount to be given.
4. Assemble the syringe and needle.
5. Break open the top of the ampoule (by using a gauze swab or a file) or remove the top of the rubber cap.
6. Reconstitute powdered drugs according to the instructions on the bottle.
7. Draw up the prescribed dose of the drug.
8. Expel the air and remember that with antibiotics and multidose vials the air is expelled into the container. The distal ring of the rubber plunger should be level with the graduation mark. 
9. Choose the site for the injection, clean the skin and draw it tight and introduce the needle at an angle of 90⁰.
10. Withdraw the piston a little to make sure that the needle is not in a blood vessel.
11. If blood is with drawn the needle must be withdrawn a little and the direction changed. If no blood appears then insert the drug gradually by pushing the piston slowly and steadily.
12. Withdraw the needle while pressing firmly round it with a swab.
13. Massage the area to distribute the drug.
14. Thank the patient and leave him comfortable.
15. Record the drug and clear away.

Likely complications associated with intramuscular injection.

Abscess formation:

When unsterile needles and syringes are used an abscess may be formed at the injection site or when oily substances are not injected deep enough.

Abscess formation can be prevented by use of aseptic technique and avoiding injecting irritating substances superficially.

Nerve injury:

Can be avoided by establishing correct land marks for the injection site chosen.

Cysts and necrosis:

The injection site may be changed regularly for patients who are on injections for a long time in order to prevent cysts and necrosis e.g. streptomycin therapy.

Injecting the drug into a blood vessel:

This can be prevented by withdrawing the piston and checking for the presence or absence of blood in the syringe when giving intramuscular injection.

The needle may break.

Intravenous injection

Objectives

1. Define the term intravenous injection.
2. Outline the indications of intravenous injection.
3. Identify the requirements for administering intravenous drugs.
4. Describe the appropriate technique for giving drugs intravenously.

Definition:

This is when a drug is injected into the blood stream through a vein.

This method is used:

• When a rapid effect is needed.
• To inject drugs which cannot be injected into the tissues.
• When a larger amount is to be given as intransfusion.
• For certain drugs that will be irritating to the muscles or subcutaneous tissue.

Sites commonly used for intravenous injection

• The basic and cephalic veins.
• The accessory cephalic or the median ante brachial vein.
• The dorsal metacarpal veins.
• Saphenous and femoral veins.

Procedure

1. Prepare the injection tray and take to the patient’s bedside.
2. Identify the patient.
3. Explain the procedure to the patient.
4. Provide privacy.
5. Place a small pillow and a protective sheet under the patient’s arm.
6. Expose the patient’s fore arm and anterior surface of elbow.
7. Inspect the selected vein and if it is visible and clear; distend it by applying a tourniquet about 8 to 10cm above the site and ask the patient to close and open his fist for a minute or until the vein is enlarged. Alternatively apply the sphygmomanometer cuff around the vein.

Tapping the site gently helps to distend the vein.

8. Clean the area with an antiseptic and dry with a sterile swab.
9. Make sure that air is expelled from the syringe.
10. Hold the patient’s arm and with your left thumb exert pressure about 3cm below the chosen site and make the skin tight.
11. Insert the needle at an angle of 15⁰-45⁰ degrees with its be vel up then quickly and steadily insert in to the vein. Pull back the piston slightly if blood is aspirated, it indicates that the needle is in the vein.
12. Remove the tourniquet or deflate the cuff and inject the drug slowly.
13. When the drug is injected put a swab over the site and withdraw the needle.
14. Apply pressure at the site with a swab for some seconds to make sure there is no bleeding. If oozing continues apply a swab and a piece of strapping.
15. Record the drug in the patient’s chart and clear away.

Hazard associated with intravenous injections

1. Necrosis occurs if the drug is injected into the surrounding tissues.
2. Damage the arteries if the drug injected accidently into the arteries.
3. If the drug is given rapidly without following the doctor’s instructions undesired effects may occur.
4. Sclerosis occurs if the veins are used frequently.

Points to remember

1. The thinner the skin the easier it becomes to locate the vein.
2. Start choosing site which is distal to the heart and more proximally only when you fail to get a good vein.
3. Select the size of the needle which corresponds to the vein.
4. Avoid choosing damaged veins.
5. For right handed patients select veins of the left first and vice versa.

Intra–Arterial injection

This route is used by doctors to introduce a drug directly into an artery in some forms of carcinoma. Pressure is needed to inject the drug and therefore a pump is always needed.

Intra Articular

This is an injection given into the joints.

Additional requirements:

-Longer needles.

-Local anaesthia.

Intrathecal injection

After lumbar puncture has been performed drugs may be given into the cerebral spinal fluid and this site is used.

When the drug does not penetrate into the cerebral spinal fluid if administered by any other route.

To give low dose injections.

Intra Osseous

Intra osseous is to get access to general circulation via the bone marrow. It is recommended for emergency administration of fluids and drugs in infants and children.

Sites recommended

The tibia, the femur, the iliac crest.

This procedure is performed by a doctor and it is a sterile procedure.

Equipment

• Dressing pack.
• iodine
• Strapping
• Sterile swabs
• Sterile gloves.
• Intraosseous needle/large gauge needle.

Intravenous infusion

Objectives

1. Outline the indications for intravenous infusion.
2. Identify the requirements for intravenous infusion
3. Describe the appropriate care for patients receiving intravenous fluids.
4. Outline the complications for intravenous infusion.

Definition

Intravenous infusion is a method of giving fluids and nutrients directly into the body of a patient via a vein by means of a Cannula or scalpel vein needle.

Indications.

1. To replace water and electrolyte losses when other routes cannot supply as rapid or efficiently as required.
2. To supply the body with nutritional requirements such as glucose, amino acids, protein hydrolysates when the patient is unable to get the morally.
3. To supply one or more components such as plasma, plasma substitute or cell suspensions.
4. Administration of some drugs.

Types of fluids

• Normal saline (sodium chloride) 0.9% solution.
• Dextrose 5%.
• Hartman’s solution/ringers lactate and ½ strength Darrows solution contain addition electrolytes like potassium and calcium.
• Dextran solution acts as volume expander.
• Blood.

Some commonly recommended veins include: –

1. Back of the hand

-Dorsal metacarpal veins:

This site allows arm movement and if a problem arises at the site another site can be chosen.

2. Fore arm

-Basilic vein

Cephalic vein

3. Inner aspect of the elbow (antecubital fossa)

-Medial basilica vein

-Median cephalic vein

These veins are larger and can be entered more easily but flexion of the elbow or movement of the arm may dislodge the needle. Always insist on choosing the site below the elbow crease.

4. Lower extremity

-Femoral and saphenous vein in the thigh.

Dorsal venous plexus, medial and lateral marginal veins in the foot.

5. Scalp veins

These may be used in infants and elderly patients.

Procedure

1. Explain the procedure to the patient
2. Screen the bed and put the patient in a comfortable position.
3. If necessary shave the infusion site.
4. Support the patient’s fore arm on a pillow covered with the mackintosh.
5. Prepare the prescribed infusion, fluid, check the fluid for particles and expiry date before putting up.
6. Attach the bottle holder if necessary.
7. Remove the cap of the bottle if necessary.
8. Remove the sheath from the piercing needle.
9. Insert the piercing needle of the giving set in to the rubber seal. If there is no air in let available, another needle may be used to make an inlet next to the piercing needle. Remove the sheath from the other end of the giving set.
10. Allow fluid to run through the giving set to the receiver until all air has been expelled. Then fill the fluid chamber to halfway.
11. Use the tourniquet or sphygmomanometer to locate the vein more easily.
12. Request the patient to open and close his fist in order to distend the veins.

Gently tap the area over the selected vein then palpate and note suitability of the vein.

13. Clean the skin with an antiseptic and arrange the sterile Cannula or scalp vein needle into the vein, when in situ release the tourniquet.
14. With their other, hold the patient’s arm and“ anchor” the vein with your thumb just below the selected site to prevent it from moving when punctured.
15. Holding the Cannula with the sharp beveled and facing upwards at an angle of 20 to 30 degrees either directly over the vein or just to one side of it, insert the Cannula through the skin and into the vein.
16. Stop advancing the Cannula as soon as it is in the vein and lower the angle of the Cannula.
17. Hold the needle part of the Cannula with one hand to stop it advancing any further. Slide the Cannula off the needle and into the vein with the other hand.
18. Apply pressure to the vein immediately above the end of the Cannula to minimize blood flow.
19. Remove the needle and connect the apparatus to the Cannula and the rate of flow is regulated by the clip.
20. Clean up any blood and apply a sterile dressing ensuring that the Cannula is held securely in place.
21. Place sterile gauze under the Cannula and strips of strapping keep the tubing in place and lightly padded splint is bandaged into position.
22. Regulate the rate of flow as prescribed by the doctor.
23. Record the date and time of starting the infusion.
24. Leave the patient comfortable.

The following is a useful formula for calculating the drop rate

Number of ml x Drops per ml

Ordered (drop factor) = Drops to infuse per minute.

Number of hours 60 minutes

Example:

The doctor has ordered 1000mls of 5% dextrose infusion to run in 10 hours’ time. How many drops per minute will you regulate if your infusion set has a“ drop factor” of 20 ?

1000 x 20 = 33.3

1060 (33 drops per minute)

If the rate is not specified, the normal rate is 40 drops per minute.

Frequently Asked Questions (FAQs)

1. What is parenteral drug administration?

Parenteral drug administration is the delivery of medications into the body through routes other than the gastrointestinal tract, usually by injection. It allows drugs to be introduced directly into tissues, veins, muscles, or other body spaces.

2. What are the routes of parenteral drug administration?

The main routes of parenteral drug administration include:

• Intradermal injection
• Subcutaneous (hypodermic) injection
• Intramuscular injection
• Intravenous injection
• Intrathecal injection
• Intra-articular injection
• Intra-arterial injection
• Intraosseous injection

3. What are the advantages of the parenteral route?

Advantages include:

• Faster drug action compared with oral administration
• Useful during emergencies
• Suitable for unconscious patients or those with vomiting
• Allows accurate dosage administration
• Useful for drugs not absorbed through the gastrointestinal tract, such as insulin

4. What are the disadvantages of parenteral drug administration?

Common disadvantages include:

• Pain during injection
• Expensive equipment such as syringes and needles
• Risk of infection and abscess formation
• Possible nerve injury
• Risk of serious effects if an incorrect dose is administered

5. What are the principles of safe injection practice?

Safe injection practice involves:

• Maintaining aseptic technique
• Checking the correct patient, drug, dose, and route
• Using sterile equipment
• Avoiding needle recapping
• Proper disposal of sharps
• Recording medication administration
• Monitoring the patient after injection

6. What is an intradermal injection?

An intradermal injection is a technique where a small amount of medication is introduced between the layers of the skin. It is commonly used for sensitivity testing and BCG vaccination.

7. What is a subcutaneous injection?

A subcutaneous injection involves introducing medication into the tissue beneath the skin. It is commonly used for drugs such as insulin and heparin.

8. What is an intramuscular injection?

An intramuscular injection is the administration of medication deep into muscle tissue. It allows faster absorption than subcutaneous injections and can accommodate larger volumes of medication.

9. What are the common sites for intramuscular injections?

Common intramuscular injection sites include:

• Gluteal muscle (upper outer quadrant of buttock)
• Thigh muscles
• Deltoid muscle

10. What complications can occur after intramuscular injection?

Possible complications include:

• Abscess formation
• Nerve injury
• Cysts and tissue necrosis
• Accidental injection into blood vessels
• Needle breakage

11. What is intravenous injection?

Intravenous injection is the administration of medication directly into the bloodstream through a vein. It is used when rapid drug action is required or when drugs cannot be given through tissues.

12. What are the complications of intravenous injection?

Complications may include:

• Tissue necrosis due to leakage of medication
• Arterial damage
• Unwanted effects from rapid administration
• Vein sclerosis from repeated use

13. What is intravenous infusion?

Intravenous infusion is a method of delivering fluids, nutrients, blood products, or medications directly into the body through a vein using a cannula or vein needle.

14. What fluids are commonly used for intravenous infusion?

Common intravenous fluids include:

• Normal saline (0.9% sodium chloride)
• 5% dextrose solution
• Hartmann’s solution (Ringer’s lactate)
• Dextran solution
• Blood products

15. Why is aseptic technique important during injections?

Aseptic technique prevents contamination and reduces the risk of infection, abscess formation, and cross-infection between patients.