Fluids Flashcards
Hydrostatic Pressure
the pressure of the blood against the wall
Capillary hydrostatic pressure is greatest at?
Arterial end
proteins cross capillary membranes easily
no- most cant cross capillary membrane
What is the main contributor to osmotic pressure
Albumin
What does COP stand for?
colloid osmotic pressure
Which has higher COP
Capillary or ISF
capillary
Are cations negatively or positively charged
(+ve)
Are Anions negatively or positively charged
(-ive)
Extracellular Fluid Cations
Sodium (Na)
Calcium (Ca)
Extracellular fluid Anions
Chloride (Cl)
Bicarbonate (HCO3)
Intracellular Fluid Cations
Potassium (K)
Magnesium (Mg)
Intracellular Fluid Anions
Phosphate (PO4)
Insensible/ Inevitable loss calculation
20ml/kg/24 hrs
Urinary loss calculation
24-48ml/kg/24 hrs
Faecal loss calculations
10-20ml/kg/24 hrs
Calculations of fluids for obese patients
estimate normal body weight
Renin angiotensin system
- Release of Renin=
- Angiotensin= vasoconstriction
- Aldosterone= increased Na retention = increased water
reabsorption
Part of the brain that controls thirst
hypothalamus
What effects do Osmoreceptors have when release ADH
Stimulates the reabsorption of water
Primary Water Loss causes
- Lack of water available
- Excessive panting
- Prolonged inability to drink
- Fever
- DI
Mixed Water Depletion causes
- Haemorrhage
- Vomiting
- Diarrhoea
Electrolyte Imbalance conditions
Hypa/Hyponatraemia
Hypa/Hypokalaemia
Hypa/Hypocalcaemia
Hypa/Hypoglycaemia
pH
acidic =
Alkaline=
acidic = 0
Alkaline=14
What is the ‘normal’ pH?
7.35-7.45
What are the 3 principle means of balancing pH:
Buffers
Respiration
Renal system
How do buffers help maintain the body’s acid base balance
Buffers – bicarbonate are used to ‘soak up’ the hydrogen ions, preventing acidosis
How does respiration help maintain the body’s acid base balance
Respiration – chemoreceptors monitor hydrogen ions and alter respiration
accordingly, increasing ventilation increases the carbon dioxide expired, and reduces acidosis
How do the kidneys help maintain the body’s acid base balance
hydrogen ions are excreted into the urine, reducing acidosis
clinical presentation of
* <5%
* Mild deficit (5-6%)
* Moderate (6-8%)
* Severe (10-12%)
<5% = Not detectable
5-6% = Subtle loss of skin elasticity
6-8% = Marked loss of skin elasticity
prolonged CRT
Slightly sunken eyes
Dry MM
10-12%=Tented skin
CRT (>2 secs)
protruded 3rd eyelid
Dry MM
Shock
Type of fluids for hypovolaemic shock
Isotonic crystalloids
Hypovolaemic shock fluid doses
- 60-90ml/kg in dogs
- 40-60ml/kg in cats
How long should shock fluid doses be given over
30 min
how often to flush a catheter
6 hours
