Fluid therapy Flashcards
What is the approximate % fluid deficit in an animal with tacky mucous membranes?
5-6%
What is the approximate % fluid deficit in an animal with skin tenting and dry mucous membranes?
6-8%
What is the approximate % fluid deficit in an animal with increased pulse rate and sunken eyes?
8-10%
What is the approximate % fluid deficit in an animal with weak pulses, dry corneas, dull mentation?
10-12%
What is the approximate % fluid deficit in a collapsed animal?
12-15%
Describe the clinical signs of overhydration
- Wet MM
- Increased skin elasticity
- Shivering
- Nausea
- V++
- Restlessness
- Serous nasal discharge
- Chemosis
- Tachypnoea
- Dyspnoea
- Pulmonary crackes
- Pulmonary oedema
- Pleural effusion
- Ascites
- Diarrhoea
- SC oedema
Discuss the use of central venous catheters in hospitalised patients
- Measure central venous pressure
- Gives indication of intravascular filling
- CVP <0cm = volume depleted
- CVP >10cm H2O = volume overload or CHF
- Pleural effusion falsely elevates CVP
In severe acute uraemia, what occurs in 80% of dogs?
Hypertension
When does lactic acidosis occur?
Dehydration, poor tissue perfusion (may compound acidosis in renal failure)
What may lead to an increased PCV and increased TP?
Dehydration
What may lead to an increased PCV and normal or decreased TP?
Splenic contraction (polycythaemia, hypoproteinaeima)
What may lead to a normal PCV and increased TP?
- Normal hydration with hyperproteinaemia
- Anaemia and dehydration
What may lead to a decreased PCV and increased TP?
- Anaemia with dehydration
- Anaemia with hyperproteinaemia
What may lead to a decreased PCV and normal TP?
Non-haemorrhagic anaemia with normal hydration
What may lead to a normal PCV and normal TP?
- Normal
- Acute haemorrhage
- Dehydration with anaemia and hyporptoeinaemia
What may lead to a decreased PCV and decreased TP?
- Blood loss
- Anaemia and hypoproteinaemia
- Overhydration
List the routes for fluid administration
- Oral (best if possible)
- Rectal
- Subcut (good for small furries)
- Intraosseous
- Intravenous
- Intraperitoneal
When is the use of colloids indicated? Give an approximate rate
Patient suffering from hypoalbuminaemia
20-50ml/kg/day (depending on colloid)
Give an example of fluid rate that may be used in an animal with hypovolaemic shock
60-90ml/kg in dogs, 45-60ml/kg in cats
- Give 1/4 over 5-15 mins then repeat if no improvement
Compare the fluid replacement rates in AKI and CKD
- AKI: fast replacement (6-8 hours)
- CKD slower replacement (12-24hours)
- Slower rates for animals with cardiac insufficiency
Outline your approach to the fluid therapy of a dehydrated animal
- First replace losses + maintenance over 8 hours
- Then the rest of the maintenance fluids over the next 16 hours
- Continual reassessment of ongoing losses and response to fluid therapy, may need to reduce or increase
Outline your approach to the fluid therapy of an oliguric patient
- Oliguria can be pathological or physiological
- To determine which, give fluid push (3-5% BWT over short period of time) and assess urine output: if no urine produced, is pathological (i.e. something wrong with urinary tract)
- Rule out obstruction or leakage before assuming renal damage
- Consider diuretics if pre-renal factor correct but no urine output
Describe the fluid therapy of an anuric patient
Replace insensible losses only i.e. 22ml/kg/day, unless overhydrated in which case withhold insensible losses
What is the normal urine output for small animals and what constitutes oliguria?
Normal: 1-2ml/kg/hour
Oliguria <1-2ml/kg/hour
What features can be monitored to assess fluid therapy?
- Weight
- MM, Hr, RR
- Urine output
- Arterial blood pressure
- PCV, TP
- Electrolytes, urea, creatinine, blood gas values
Outline your approach to taking a patient off fluids and how you know when to do this
- Once animal is drinking and eating and producing urine
- Taper fluids as azotaemia resolves, taper by 25% each day
- Should see appropriate decrease in urine production but must continue
- If urine production not decreasing, kidneys unable to concentrate so taper more slowly
Discuss the use of outpatient fluid therapy
- Can be offered to some owners
- Daily/EOD SC injection
- Devices can be implanted
- Use LRS or 0.9% saline
What cardiac derangements are typical with hyperkalaemia
- Bradycardia
- Tall T waves, short QT interval, wide QRS, small wide or absent P waves
- Sinoventricular rhythm, ventricular fibrillation, ventricular standstill
List drugs that may exacerbate hyperkalaemia in a patient with renal disease
- Beta blockers
- Digoxin
- ACE-I
- NSAIDs
- TPN
- Cyclosporine
- Trimethoprim
