T8: Administering Medication and Fluids Flashcards
General clinical equipment is used for consultation and diagnosis.
It includes:
- Thermometer (mercury, digital; rectal or aural): used to measure the animal’s temperature
- Otoscope or Auroscope: used to visually examine the ear canal, nostril, vagina etc.
- Ophthalmoscope: to examine the structures of the eye (e.g. retina, optic disc, blood vessels)
- Stethoscope: used to listen to the heart, lungs and gut sounds
- Laryngoscope: for examination of the back of the throat, larynx and pharynx.
Medical equipment used in the standard administration of drugs and fluids includes
- Syringes of medication and solutions, and needles
- Catheters: stylet or butterfly
- Giving sets
- Fluid bags or bottles
- Infusion pumps
- Paediatric administration sets
Should you use the smallest or largest syringe tgat will comfortably hold volume you wish to inject?
smallest
Always use the smallest and finest needle that will perform the task, except for when using a ….?
catheter; use largest
Things to consider when choosing a needle size are:
- The size of the animal
- Thickness of the skin
- Viscosity or “thickness” of the injected material
- How fast you want to give the injectionThe volume of the drug to be administered
- Veterinary preference: some vets will use one gauge or type of needles for each particular job
Describe a winged needle catheter
Needles have plastic wings on the shaft to facilitate placement.
The needle size ranges from 25 to 19 gauges. Plastic tubing of various lengths extends behind the needle, which allows the operator to connect the syringe to the catheter without disturbing the needle.
These catheters are easy to place but difficult to maintain. They are used for smaller animals, and are best reserved for short term. They are the least stable type of catheter.
Describe a over the needle catheter
Most common type of catheter used in veterinary practice.
They are a form of stylet catheters, and their main use is peripheral vein catheterisation.
These are generally presented as a soft Teflon outer tube reinforced by a steel needle on the inside to penetrate initially the skin and vein wall
Describe a through the needle catheter
Used primarily in the jugular vein. The catheters are protected by a plastic sleeve to prevent contamination.
Once catheter is placed, and the needle withdrawn. most through the needle catheters require a needle guard. The needle guard protects the catheter from sticking the animal and shearing the catheter.
Why give medication?
- Treat disease
- Control disease
- Prevent disease
- Minimise pain
- Restraint
List the 4 basic routes of admin
- Topical (skin, eyes, ears)
- inhalation
- enteric (oral, rectal)
- parenteral injection
Choice of injection route depends on:
- nature of drug
- nature of disease
- size of animal/ability to handle
- V of drug req
- req time of onset of action
- req length of action
- speed of absorption
Describe the two methods for holding a syringe
- Between your thumb on one side of the barrel and the middle three fingers on the other. The little finger is used to press the plunger.
- Place the barrel between the index and middle finger. Use the thumb to press the plunger.
What are the two broad effects a drug has on the body?
- LOCAL EFFECT - where the drug acts directly at the local area where it is administered eg skin creams, local anaesthesia
SYSTEMIC EFFECT - where the drug circulates via the blood stream to affect the body as a whole, including oral, parenteral and rectal routes of administration.
Describe how a drug is absorbed into the blood stream
The drug is absorbed into blood stream.
→ It is then dispersed throughout the blood stream, and reaches a certain concentration evenly through the circulation
→ It is then carried around the body until it reaches the target site, where it leaves the blood stream and enters the target cells
→ At the target cells the drug affects the target cells only if it is at the sufficient concentration
→ There is only continuous action by the drug if the concentration of the drug in the blood stream remains high enough
Drugs are continuously removed from circulation by which methods?
- Inactivation by liver
- Excretion by kidneys
- Volatile drugs breathed out by lungs (e.g. anaesthetics)
- Storage in fatty tissue (This means for some animals, the degree of fat of animal can effect the concentration and duration of activity of some drugs)
- As drug is lost, concentration lowers; the effect of the drug on the cells is lowered.
Describe oral admin and the A/D?
- Drugs administered per os can act locally in GIT or systemically by absorption into BS. Forms of per os medication include tablets, capsules, powder, syrup, solution, suspension and paste.
Advantages
- Least painful
- Usually easily administered by pet owner
- Strict sterility is not necessary
- Disadvantages
- Cannot give to vomiting/diarrhoeic patient
- Inhalation – possibility of choking, pneumonia
- Variable rate of absorption (gut contents)
- Animal resents administration
- Animal may spit or vomit it out
- Irritation of gut – possibility of vomiting, ulceration
- Difficult to alter doses
Describe ID injection and its A/D?
- Fine needle is injected into skin –forms bleb. Commonly used for ID allergy testing.
- *Advantages**
- Absorption into blood results in good local effect
- Tiny amounts
- Disadvantages
- Technically difficult – easy to go through skin (subcutaneous)
- Can be painful and irritating
Describe SC injection and its A/D?
- Under the skin. Commonly used for vaccinations, sedation, antibiotics and conditions such as vomiting.
- *Advantages**
- Simple procedure
- Least painful
- Relatively large volumes may be administered due to loose attachment of the skin to underlying tissue
- Can administer emulsions and suspensions safely (provided oil can be metabolised) without risk of embolism
- Disadvantages
- Slow speed of action – taking at least 15 minutes for therapeutic effect
- Absorption can vary with location of site, solubility of drug and environmental temperature
- Can get tissue reactions
- Not effective in shocked/dehydrated patients
- Irritant/acidic/alkaline substances will cause pain, inflammation and necrosis
Describe IM injection and its A/D?
- Injected deep into muscle tissue, ensure you draw back to check for blood in hub of needle before injecting.
Advantages
- Faster absorption than SC
- Higher drug concentrations in blood than SC
- Prolonged duration of effect compared with intravenous route due to the slower absorption
- Can use with products unsuitable for intravenous administration – e.g. oil-based drugs
- Good for situations where restraint of animal for intravenous administration is not possible or appropriate – e.g. injured, fractious
- Disadvantages
- Must avoid nerves and bones
- Small volumes only
- Risk of abscess or tissue reaction
- More painful
- Product must be relatively non-irritant, or tissue damage will occur; causing the animal pain and the clinic the embarrassment of a lesion
Describe IV injection and its A/D?
Aka venepuncture, administration of drugs directly into the vein. Used for rapid drug administration, IV fluid admin, blood transfusion and the collection of blood samples. Site depends on the method of animal restraint, but it is vital to find an accessible vein of sufficient size. Equipment used includes hypodermic needles, angiocaths, or butterfly needles.
Advantages
- Rapid rise of drug concentration with rapid systemic effect
- No delay in absorption compared to other routes of administration
- Best method to ensure an accurate dose
- Large quantities can be given over a long period of time (in drip)
- Allows administration of irritant drugs that would damage tissues if given via SC or IM. Care must still be taken to avoid leakage around the vein; catheterisation safeguards against this. If perivascular leakage does occur the areas must be diluted with sterile 0.9% saline solution
- Useful in shocked patient as would not get absorption via other routes
Disadvantages
- Risk of embolism – must not contain any particles (e.g. most penicillins) or oils; must not have air bubbles
- Requires more technical skill and precision to avoid damaging veins – veins are quite delicate and easily damaged and this damage can cause “blown” veins, bruising or the development of a haematoma
- Asepsis vital to prevent infection being carried around the body (septicaemia)
- Must be given slowly
Describe the technique for admin of IV injection
- Safe restraint of animal with correct positioning
- Shave site
- Swab with antiseptic/alcohol
- Remove all air from syringe
- Raise vein – compress it proximally
- can use heat in lab animals
- Insert needle with bevel up
- Draw back for flash of blood to double check you are in the vein
- Release proximal compression
- Inject slowly
- When finished, withdraw needle quickly, apply pressure to site for 1 minute
- Check that no haemorrhage occurs
DEscribe technique for IV catheter placement
- Prepare all equipment prior to procedure
- Safe restraint of animal with correct positioning
- Shave site
- Swab with antiseptic/alcohol
- Raise vein – compress it proximally
- Insert catheter into the skin over the vein at an angle of approx 30 degrees, with stylet bevel up
- Look for flash of blood
- Change angle to be more level with the angle of the vein
- Advance catheter over the stylet along the direction of the vein, while proximal compression is released
- Remove stylet
- Look for flash of blood to double check you are still in the vein
- Place catheter plug (injection port)
- Tape catheter into position
How long can an IV catheter stay in place before removing it?
72 hours
What is phlebitis?
inflammation of the vessel wall as a result of damage to the endothelial lining of the vein. Phlebitis is characterised by swelling, tenderness upon palpation, and erythema of the skin over the vessel

