Question

For subcutaneous, intramuscular, and intradermal injections, research and describe the following: sites of administration, maximum volumes for each injection type, needle length and gauge ranges, type of syringe needed, and angles of needle insertion. How do you locate the injection sites? Why is it important to be sure that the correct needle size is used and to insert at the proper angle? Describe in detail what you would do if your dosage calculation exceeded the maximum volume allowed for the injection type and site

Answer 1

# There are different routes of drug administration . Some of these are :-

- oral

- intravenous

- intramuscular

- intradermal

- subcutaneous

- intraocular

- intranasal

Describing some of these :-

1. Subcutaneous injection is administered into the subcutaneous tissue , the layer below the epidermis and dermis . The angle of administration is 45° to 60° . The maximum volume of drug injected by this route is. ,the needle used is small and short . The maximum volume of drug given through subcutaneous route is 1.5ml . The common drugs given by this route are insulin ,heparin , female hormones etc

To give a subcutaneous injection, the following steps should be used :-

- Choose fatty area of the body, such as the abdomen, back of the arm, or thigh: If you are giving several injections or have to do daily injections, rotate the sites to allow each area to heal between injections

- Wash hands before cleaning the area with an alcohol pad: Wait for the area to completely dry before the next step.

- Take the cap off the needle: Draw medication into the syringe, according to the directions on the vial. This usually means turning the vial upside down then pulling the plunger back to suck in the medication. Tap the syringe to get rid of air bubbles.

- Pinch a fold of skin: Pinch the fatty area about 2-inches thick in between the thumb and a finger.

- While holding the needle like a dart, slide it into the skin at an angle of 90 degrees: Needles used for subcutaneous injection are usually short and small and should go all the way into the skin.

- Push the plunger all the way down quickly: Do not push forcefully.

- Cover the needle: Dispose of the needle in a needle-safe container.

# Commonly chosen locations include:

the backs or sides of the arms

the fatty part of the stomach

the front of the thighs

the top of the buttocks, where there is more fat than muscle

Some subcutaneous injections come in the form of an auto-injector. An auto-injector is a self-contained device that does not require drawing the medication up first. People can follow the instructions on the package if they are using an auto-injector.

2. Intrdermal injection is the administration of injection into the dermal layer of skin . Syringes used are Tuberculin syringe calibrated in tenths and hundredths of a millilitre and a 1/4 to 1/2 in. The gauge of needle used for ID is 26 or 27 . The maximum volume of drug given through ID is 0.5 - 1ml . It is used for TB skin test and allergy testing . The site's used for intradermal injection are inner forearm and upper back . Angle used for intradermal injection is 5°-15° . It is the route of slowest absorption.

To give intradermal injection ,the following steps has to be followed :-

- Wash hands before cleaning the area with an alcohol pad: Wait for the area to completely dry before the next step.

- Take the cap off the needle: Draw medication into the syringe, according to the directions on the vial. This usually means turning the vial upside down then pulling the plunger back to suck in the medication. Tap the syringe to get rid of air bubbles.

- Locate the site free of hair and vein , stretch the skin , inject the bevel up and a bleb will be formed . Encircle the bleb , mark the medicine name , time and check after 72hours for induration .

- Instruct the patient not to massage and not to aspirate the site .

3. Intramuscular injection is the administration of drug into the muscle tissue . It is the route of fastest absorption . The angle used for giving intramuscular injection is 90° . The maximum volume of drug injected by intramuscular route is 3ml. 22- 25 gauge needle is used for IM injection . The length of the needle is 2inch and the syringes used are 2 ml and 5 ml . Analgesics like voveron, denoting etc is given by this route . Z track method is used for giving IM injections.

To give intramuscular injection ,the following steps has to be followed :-

- Wash hands before cleaning the area with an alcohol pad: Wait for the area to completely dry before the next step.

- Take the cap off the needle: Draw medication into the syringe, according to the directions on the vial. This usually means turning the vial upside down then pulling the plunger back to suck in the medication. Tap the syringe to get rid of air bubbles.

- Change the needle for giving the injection

- The different sites for giving intramuscular injection are vastus lateralis , ventrogluteal , rectus muscle , deltoid muscle and dorsogluteal muscle ( least preferred because of the risk of sciatic nerve damage )

- Locate the site : if you are giving the injection in the right ventrogluteal muscle then keep your left hand over right buttocks ,first finger-pointing to greater trochanter and stretch the middle finger as much as possible and thumb pointing towards iliac crest . The middle point between first and middle finger is the site of IM injection . Clean the site with spirit and allow it to dry . Z track method is used while giving IM injection by stretching 2-3 inches of skin from the site of injection ,it prevents the back flow of medicine, and prevents irritation .

- Inject drug at 90° angle , remove the needle after injecting medicine and press the site , don't massage the site .

​​​​​​# If the calculated dose exceeds the allowed maximum volume allowed for the injection type and site then the physician is informed about the dose exceeding and the dose is modified according to the weight and reference dose of that medication. Further to avoid the exceeding dose , the total dose might be divided into various doses that is q6-8hourly , q6-12hourly etc