6. Fluid therapy SDLs Flashcards
You attend a Farm to assess a calf with severe diarrhoea, the calf is still bright but has a prolonged skin tent and tacky membranes. The patients heart rate and pulses are normal. The Farmer is not happy to let you remove the calf from the farm for treatment and doesn’t want anything ‘complicated’. You agree to provide an oral fluid plan to the farmer. Which fluid type would be most appropriate?
isotonic
Isotonic is the most appropriate method for oral rehydration, there are no deleterious effects on the GI tract itself and importantly you are unlikely to negatively affect the patients electrolyte levels - particularly when leaving an owner in charge or administration where they may give it quicker than you advise for convenience.
You are treating a horse for uncomplicated dehydration via an intravenous route. The patient has a mild metabolic acidosis on blood gas analysis. Which of the following solutions would be most appropriate.
isotonic hartmanns
The patient is stable so we don’t need to be aggressive by using hypertonic saline. Hartmanns is a balanced solution and appropriate for the mild acidosis, whereas saline may make the acidosis worse. Dextrose 5% saline is too hypotonic and may alter electrolytes.
During a bitch spay major haemorrhage occurred and the patients blood pressure dropped significantly to dangerous levels. There is no blood available in the practice to administer and the patients blood was suctioned into a non-sterile container so auto-transfusion is not possible. The haemorrhage has been controlled. Which of the following fluid types could be used to restore circulating volume rapidly?
hypertonic saline
Hypertonic saline would be an appropriate choice in this patient because it is not dehydrated and only hypovolaemic, rapid intravascular expansion should therefore be possible and it should be followed with an isotonic solution.
A collapsed Labrador Retriever presents to you, the owner reports it has had profuse watery diarrhoea for 24 hours and has started vomiting. Your initial triage reveals a prolonged skin tent, dry mucous membranes, weak pulses and a marked tachycardia. Which of the following fluid types would be the most appropriate to start at this point?
isotonic hartmanns
This patient is both dehydrated and hypovolaemic, therefore, hypertonic saline would be contraindicated. The most likely outcome of hypovolaemia and dehydration will be a metabolic acidosis secondary to poor perfusion and anaerobic respiration, so isotonic hartmanns would be the best choice at an aggressive rate.
A beagle presents to you having been kicked in the head by a horse. The patient’s mentation is subdued and the owner reports it had a short seizure in the car on the way to you. Which of the following fluid types would be beneficial to this patient.
hypertonic saline
This presentation is classical for a raised intracranial pressure following head trauma, as such hypertonic saline would be the treatment of choice to osmotically remove fluid from the cerbral space and relieve the pressure build up.
through which ways does the body lose fluid
- urine (most significant)
- feces/diarrhea (also Na, K, Cl and HCO3 in diarrhea)
- vomit
- blood loss
- third space loss
- inflammatory exudate
- insensible losses (sweat)
- redistribution
what is meant by fluid loss through third space loss
- the third space means body cavities (thorax/abdo)
- fluid can be transudate, modified transudate or exudate depending on disease causing it
- the loss of fluid +/- protein are the major concerns, both will reduce the blood volume -> poor oxygen supply to tissues -> anaerobic respiration -> lactic acid formation -> acidosis
what is transudate
low protein, low cell count fluid
a thin, watery fluid with low protein and cell content that passes through membranes or squeezes into tissue
what is modified transudate
high protein low cell count
what is exudate
high protein, high cell count (esp albumin)
what is meant by fluid loss through inflammatory exudate
- this is loss of fluid due to inflammation (burns are good example)
- burns lead to marked fluid and protein loss from the site
- depending on the extent of the burn that fluid and protein loss can be significant
what is meant by insensible fluid losses
- losses that are almost impossible to quantify so have to be guessed to a certain extent
- examples are sweating and breathing, through both fluid is lost but usually only to a small degree. can be significant in some cases (sweating horses)
what is meant by fluid loss through redistribution
- no loss of volume per se
- increase in blood vessels to fill
- rekates to hypovolaemia and distributive shock
- in distributive disease (sepsis) blood vessels dilate around the body
- blood volume hasnt changed but there are more pipes to fill up now so whilst you havent lost any fluid you need more fluid to fill those blood vessels back up
- peripheral vasodilation causes a relative hypovolemia due to change in capacitance
where is fluid stored
- intracellular
- extracellular divided into:
- interstitium
- intravascular space
where is most of the blood stored in the body
intracellular and interstitial compartments
< 10% body weight in intravascular component
define dehydration
loss of fluid from the intracellular and interstitial compartments
list transfuison products and indications for their use
whole blood - haemorrhage (when we need to replace blood volume)
packed RBCs = anaemia (have to use whole blood in cats and Large animals)
fresh frozen plasma = when we have loss of clotting factors (rat poison or liver disease)
albumin = loss of albumin (protein losing enteropathy)
how do you calculate fluid rates for dehydration
