Basic Fluid Therapy for Veterinary Nurses Flashcards
Why are fluids so important in the body?
- Act as form of transport
- Act as solvent for electrolytes, non electrolytes, glucose and lipids
- pain relief can be added, slow release, small amount
What are electrolytes?
- Responsible for maintaining normal cellular function
- Concentrations are normally controlled by body’s homeostatic mechanisms
- extracellular fluids (intravascular and intestitial) contains large amounts of Na and Cl ions
- main intercellular ion is K
- Ca is very important for maintenance of normal cellular function especially nerve, muscle and heart
How much of our body is fluid?
60% of body weight is fluid
Younger animal 70-80%
Older animals less
What does ICF stand for?
Intercellular fluid
What is water balance?
Water input = water output
What is water input?
Drinking
Food
Metabolism
What is water output?
Divided into sensible loss and insensible loss
What is sensible loss?
Can be regulated by body
Urine
Lactation
Faeces
What is insensible loss?
Cannot be regulated by body - depends on ambient temp and body systems
Respiration
Skin
What is the daily average water loss in cats and dogs?
Dogs: 40-60 ml/kg/day
Cats: 60 ml/kg/day
Why might we give an animal fluid therapy?
To rehydrate Restore electrolyte balance Shock Maintenance Replace ongoing losses To give medication During surgery to maintain BP
Define fluid therapy
The administration of fluid to treat and maintain the hydration, blood volume, electrolyte and acid base status of the animal
Define electrolytes
A compound that conduct an electric current when in solution
Define dehydration
Water depletion
No single sign can indicate dehydration, which is not detectable until 5% or more of body water is lost
Define olguria
A low production of urine
Define polyguria
A high production of urine
What percentage fluid deficit with what clinic signs are there?
0-5% - no clear signs, may be thirst, depression, urine concentration
5-7% - skin elasticity lowered, sunken eyes, dry MM, pulse rapid, low CRT, oliguria, low BP
7-10% - Anuria, cold
extremities, weak pulse, skin permanently tented
10-12% - collapse, progressive shock
How do we assess/monitor dehydration?
- History
- Physical exam - body cond, tenting, coat, MM, CRT, weight
- Clinical signs - central venous pressure, body weight, urine output
- clinical pathology
- resp rate
- pulse rate
- depression
- thirst
What clinical signs are there?
Central venous pressure - cup will fall when sever dehydration ensues
Body weight - helpful indicator of you have good nursing practice and records, weight increases with hydration / decreases with dehydration
Urine output - measures via active collection (catheter) or passive collection (weighing bedding, normal = 1-2 ml/kg/day
0.5 ml/kg/day = oliguria
How can we assess dehydration using clinical pathology?
PCV - for every 1% increase in PCV animal had lost 10ml/kg, guide for assessment of clinical improvement
Bloods - haemoglobin and total serum proteins both rise in dehydration
Urine specific gravity - elevated
Six questions should be asked before starting fluid therapy…
Is fluid therapy indicated? What type of fluid? What route of admin? How rapid? How much? When should be discontinued?
What are two most indications of fluid therapy?
- Replacement of fluid deficits in dehydration
- correction or perfusion deficits in hypovolaemia (decreased blood volume)
What is shock?
A condition where effective capillary perfusion has been severe impaired, resulting in deterioration of cell function. Blood flow has become insufficient to provide tissues with O2 and nutrients and to remove wastes which build to toxic levels
What are the 3 types of shock?
- Hypovolaemic shock
- Vasculogenic shock
- Cardiogenic shock
What is Hypovolaemic shock?
Low level of circulating blood volume due to:
- haemorrhage (internal/external)
- plasma loss (burns, exudate)
- water and electrolyte loss (decreased intake/loss vomiting or diarrhoea)
- combination of the above
Exudate: a mass of cells or fluid that has seeped out of blood vessels or an organ.
What is vasculogenic shock?
Results from loss of vascular tone
Includes;
- septic and endotoxic shock (release of gram positive organisms
- Anaphylactic reactions - allergic reactions to vaccine or drug such as poisonous plants
- CNS depression
What is cardio genie shock?
Mainly due to cardiac output failure
Cardiac output: beat/min of how much is being pushed around the body
What are the clinical signs of shock?
Tachycardia Tachypnoea Weak pulse Pale MM Prolonged CRT Cold extremities Muscle weakness Depression/lethargy
What are the two fluid classifications?
Crystalloids
Colloids
What are crystalloid fluids?
Similar to fluids on the body
Contains electrolytes and non electrolytes
Capable of entering all body fluid compartments
Larger amounts must be given compared to colloids because is distributed to other sites
Examples of crystalloid fluids…
- Hartmans
- NaCl, sodium lactate, KCl, CaCl (dihydrate) water for injection
- 0.9% NaCl
What is colloid therapy?
Contain large-molecule weight particles that stay in the intravascular space until they are excreted or downgraded
Have a slightly negative charge, attracts sodium particles which in turn attract water particles
Can hold water within the IV compartment and produce an octonic pressure thus drawing fluid from outside the vessel
What are colloids?
Protein is the natural colloid in plasma
During shock resuscitation it is recommended to use crystalloids as well as colloids as the use of colloids alone may cause a fluid shift from the interstitial space to the intravascular space
What are the 2 classifications of colloids?
Natural (plasma)
Synthetic - allergic reactions are more common with blood products and Helton colloid infusions than with dextran and hetastarch infusions
What are the routes of administration?
Enteral
- oral
Parenteral
- IV
- SQ
- intraperitoneal - abdomen
- intraosseous - bone
About oral admin for fluid therapy…
Suitable for very mild dehydration only
Slower absorption
Can’t use with gastro intestinal problems
Also possibility of inhalation
About IV admin for fluid therapy…
Preferred route of admin
Only route for hypertonic solutions to treat acid base
Surgical prep of incision site
Constant monitoring required
Important to look after vein - possible infection
Catheter should be changed every 48-72 hours
About SQ admin for fluid therapy…
Slower absorption
Cheaper
Quick and easy
Good for maintenance in smalls animals
Title value in shock or dehydrated animals
Fluid no irritant and isotonic
Total volume should be administered over different sites (shoulders, back, hindquarters)
About intraperitoneal admin for fluid therapy…
Has large surface for absorption
Careful about asepsis
Care not to injure bowel
For small mammals and young animals
About intraosseous admin for fluid therapy…
Usually restricted to patients who do not have accessible veins and in very small or young animals
Into femur through trochanteric fossil
Be careful about asepsis
What veins are used for fluid administration?
Cephalic
Saphenous
Femoral
Jugular
What equipment is required for IV administered fluid therapy?
IV catheter
Administration set
Fluid
Transfusion pump
