Fluid Management Flashcards
Describe a standard post op fluid regimen
2l 5% dextrose
1l 0.9% saline
Plus 20mmol potassium per bag
Over 24 hours
What is a normal post operative fluid requirement in adults?
2-3 litres over 24 hours
This is enough to cover urinary faecal and insensible losses but may need to be increased depending on operative losses and ongoing losses e,g, from surgical drains
What are some common iatrogenic causes of hyponatremia?
Diuretics
Inappropriate IV fluids eg. Too much dextrose compared to NaCl
Fluid overload (dilutional hyponatremia)
Give some clinical signs of severe hyponatremia
Confusion
Seizures
Coma
Due to osmosis of water into brain cells in response to decreased osmolality
Give some signs and symptoms of moderate hyponatremia
Headaches, nausea, muscle weakness, lethargy
Give some signs of fluid overload
Raised JVP
peripheral oedema
Pulmonary oedema (creps)
Give some signs of dehydration
Tachycardia Decreased BP compared to baseline Postural hypotension Decreased skin turgor Dry mucus membranes Increased urea on U&E
Give some causes of hyponatremia
Renal loss - addisons, diuretics
Diarrhoea
Vomiting
Burns
What condition may some patients develop post operatively that can cause hyponatremia?
Transient SIADH
What are the biochemical findings in SIADH?
Hyponatremia
Lows plasma osmolality
High urine osmolality
Concentrated urinary sodium
What are the normal adult daily requirements for sodium?
80-160 mmol
Let’s just say 120mmol
What are the normal daily adult requirements for potassium?
40-80mmol
i.e. 60mmol
What is the maximum safe rate of potassium infusion? How would you monitor for adverse effects?
5mmol/hour
Monitor ECG
What is a potential adverse effect of saline?
Hperchloraemic acidosis
How much sodium is in a litre of 0.9% saline?
154mmol
