Pharmacology and Venipuncture

PHARMACOLOGY AND VENIPUNCTURE 💉 REVIEW ON ROUTES OF DRUG ADMINISTRATION Mucous membranes absorb drugs much more readily – they are not keratinized ORAL ROUTE RECTAL ROUTE MC method; safest and most economical Advantages: Easiest retrieval of a drug in overdose situations May be retrieved by lavage or catharsis Disadvantages: May have an objectionable odor or taste; may be bulky to swallow May harm or discolor the teeth May irritate the gastric mucosa, causing nausea and vomiting May be aspirated by a seriously ill or uncooperative individual May be destroyed by digestive enzymes May be inappropriate for some patients (ex. For patients for are NPO) Advantages: When the stomach is nonretentive or traumatized When the medicine has an objectionable taste or odor When it can be changed by digestive enzymes Avoids irritation of the upper GIT INTRADERMAL (ID) METHOD Injection is made into the upper layers of the skin almost parallel to the skin surface SUBLINGUAL AND BUCCAL ROUTES Drug must dissolve readily and patient must be able to cooperate Not to be swallowed; taking a drink must be avoided until the drug has been absorbed TOPICAL ROUTE Following effects of this route: Astringent – vasoconstriction, tissue contraction, decreased secretions and sensitivity counteract inflammatory effects Antiseptic or bacteriostatic – inhibit growth and development of microorganisms Emollient – for soothing and softening effect to overcome dryness and hardness Cleansing – for the removal of dirt, debris, secretions, or crusts Anesthetic – to remove the sensation of pain Antihistamine – for manifestations caused by allergic reactions → Common sites: Medial forearm Upper back, especially scapular region Skin is thin and less hairy; fewer blood vessels SUBCUTANEOUS (SC) METHOD Beneath the layers of skin, yet above the muscle 25-gauge needle or , or even thinner Technique: withdraw the plunger of the syringe (aspirate) before injecting the drug → If (+) red streak a vessel has been tapped; reposition or replace the needle If not observed: SC immediately turns into intravenous or intraarterial Angle of insertion: 45-60 degrees depends on the needle length and depth of fat pads → PHARMACOLOGY AND VENIPUNCTURE 💉 REVIEW ON ROUTES OF DRUG ADMINISTRATION SUBCUTANEOUS (SC) METHOD Common sites: Fat pads of the abdomen Outer surface of the upper arm Anterior surface of the thigh Lower abdominal surface •Fewer large blood vessels, sensation is less keen •Massage part after SC inj absorption → to inc rate of INTRAMUSCULAR (IM) METHOD Larger doses can be given (up to 5ml) than SC inj Criteria for selection of a safe IM injection site: Distance from large, vulnerable nerves, bones, and blood vessels and from bruised, scarred, or swollen previous injection or infusion sites Usual gauge used is 21 to 23 Inramuscular injection sites: • (a) dorsogluteal site Anterior to the diagonal line from the trochanter to the posterior iliac spine; not recommended anymore • (b) ventrogluteal V fans out from the greater trochanter between the anterior iliac spine and iliac crest; site is at the base of the triangle • (c) vastus lateralis Midlateral thigh; handsbreadth below the greater trochanter and a handsbreadth above the knee and halfway between the front and side of the thigh • (d) mid-deltoid Below the acromion and lateral to the axilla PARENTERAL ROUTE Administered by injection using a syringe, needle, or catheter Intradermal, subcutaneous, intramuscular, intravenous Drugs must be sterile, soluble, absorbable, and nonirritating Requires aseptic technique, proper dosing, and skilled administration Possible adverse effects: infection, tissue damage, nerve injury, pain Errors in dose, site, or technique are difficult to correct PHARMACOLOGY AND VENIPUNCTURE 💉 REVIEW ON ROUTES OF DRUG ADMINISTRATION The larger the number, the finer the needle •Intravenous equipment: • IV CANNULA A flexible plastic tube inserted into a vein using a needle Components: INTRAVENOUS (IV) METHOD Needle (introducer) Flexible catheter (cannula) Hub Flashback chamber (confirms venous entry) Injection port Cannula sizes: smaller gauge number = larger diameter 18-20G commonly used for contrast injection immediate” effects of a drug or fluid is desired MC IV sites: Basilic or cephalic veins on the back of the hand Basilic vein on the medial, anterior forearm and elbow Cephalic vein on the lateral, anterior forearm and elbow Antecubital space – anterior recess of the elbow where these veins are located Intravenous equipment: Winged-tip or butterfly set MC IV needle used by imaging technologists for introduction of contrast Needles vary from ¼ to 1 ¼ inches in length and 18 to 27 gauge in diameter; 6 to 12 inches of tubing Some imaging procedures may require a slower “drip infusion” technique a bag or bottle of liquid containing a diluted percentage Avoid air embolism: make sure all air bubbles are out of the catheter before releasing the “drip” infusion → Advantages: Rapid drug delivery Continuous access to circulation Useful in emergencies Essential for imaging procedures PHARMACOLOGY AND VENIPUNCTURE 💉 REVIEW ON ROUTES OF DRUG ADMINISTRATION Possible complications: Infiltration/ contrast media extravasation Leakage of IV administered contrast media from the normal intravascular compartment into surrounding soft tissues A known complication of contrastenhanced CT; also occur in MRI but the complications are rare low volumes and injection rates → SYSTEMIC CIRCULATION Part of the circulatory system that delivers oxygenated blood to the body and returns deoxygenated blood to the heart → → LV arteries arterioles venules veins RA Possible complications: Phlebitis - Inflammation of the vein Causes: mechanical irritation (cannula movement), chemical irritation (drugs/contrast), infection S/sx: redness, warmth, pain along the vein, vein feels hard (cord-like) Infection – microbial contamination at insertion site or bloodstream Causes: poor aseptic technique, prolonged cannula use Hematoma – collection of blood outside the vessel Causes: vein punctured during insertion, poor technique or multiple attempts Air embolism – air enters the bloodstream and blocks circulation Causes: improper IV setup, loose connections s/sx: sudden shortness of breath, chest pain, cyanosis → → → capillaries → PHARMACOLOGY AND VENIPUNCTURE 💉 SYSTEMIC CIRCULATION MATERIALS NEEDED FOR VENIPUNCTURE Gloves – 1 pair Torniquet Alcohol swabs or cotton balls and alcohol Leukoplast tape / first aid paper tape 20 gauge IV cannula Tissues 1L empty bottle