Understanding fluid requirements Flashcards
how much fluid is lost in urine per day?
24-48ml/kg/day
how much fluid is lost in faeces per day?
10-20ml/kg/day
how much fluid is lost in respiration and sweat per day?
20ml/kg/day
how much of an adult animal’s body is water?
60% water
how much of a young animal’s body is water?
70-80% water
how much of an older animal’s body is water?
50-55% water
what is the main solvent in the body?
water
what is <7 pH?
acidic
what is >7 pH?
alkaline
what is 7 pH?
neutral
what should the pH be in the body?
7.35-7.45
what are some ways that the body controls its acid-base balance?
- respiration
- kidneys
- buffers
what is homeostasis?
no movement of blood plasma
what are the two effects of fluid loss from plasma water?
- osmoregulators stimulate the release of antidiuretic hormone making the animal thirsty
- the kidney detects a reduction in plasma water as a reduction in renal blood flow which stimulates the release of Renin which generates angiotensin
what does RAAS stand for?
renin-angiotensin-aldosterone system
What is osmotic pressure?
The pressure which draws the water across the membrane
What are the four methods to assess dehydration?
- clinical history
- clinical examination
- laboratory analysis
- clinical measurements
What are some clinical signs of dehydration?
- gum moistness
- skin tenting
- sunken eyes
- urine output
- PCV
How do you correct fluid loss?
5 R’s
- resuscitation (correcting shock)
- routine maintenance
- replacement
- redistribution
- reassessment (regular monitoring)
What are the maintenance rates of fluid for cats and dogs?
50ml/kg/day
What are the maintenance rates of fluid for rabbits?
100ml/kg/day
What is a standard giving set drip factor?
20 drops/ml
What is a paediatric giving set drip factor?
60 drops/ml
What are the steps to working out drops per second?
1- work out maintenance requirements (BW X 50/100)
2- work out ml per hour (divide by 24)
3- work out drops per hour (multiply by drip factor)
4- work out drops per minute (divide by 60)
5- work out frequency of drops per second (divide by 60)
What is the dehydration/fluid deficit calculation?
Body weight x dehydration % x 10ml = fluid deficit
How much should you account for every episode of v+/d+ in fluid losses?
4ml/kg/episode
How much should you increase the fluid deficit by for 1% PCV increase?
Add 10ml/kg for every 1% increase in PCV
How many litres should you add to your fluid deficit if there is weight loss involved?
1kg = 1L
what is a buffer?
- a substance that maintains or stabilises the pH in the presence of high or low levels or hydrogen ions
what is diffusion?
a passive process where electrolytes pass from a solution of high electrolyte concentration to a solution of low electrolyte concentration
what is osmosis?
the passive movement of water molecules from a solution of low electrolyte concentration to a solution of high electrolyte concentration across a semi-permeable membrane
what is active transport?
the movement of electrolytes against an osmotic gradient
what do isotonic solutions achieve?
increases the extracellular fluid volume
what does hypotonic solutions achieve?
used when the cell is dehydrated and fluids need to be put back intracellularly
