Flashcards in Fluid Management Deck (20):
What is maintenance fluid?
Fluid which replaces insensible losses
Allows excretion of excess solute load in urine
What is resuscitation fluid?
Fluid which replaces deficit and ongoing losses (blood, vomit, sweat)
In what types of fluid loss is K lost most?
What is the major difference in cation between intra and extracellular fluids?
What is tonicity?
The total concentration of solutes that exert an osmotic force across a membrane
What is the normal value for [Na]?
What is the normal value for [K]?
3.5 - 5
What is the normal value for osmolality?
Which cation maintains plasma tonicity and ECF volume?
What is natriuresis? What mediates it?
Urination of Na and water
Stretch on the atria and release of atrial natriuretic peptide
Why are children at risk of hyponatraemia?
Large brain : intra-cranial volume ratio
What is the Na threshold at which seizures occur?
cf to 111mmol/l in adults
What is the 4/2/1 rule?
• 4 ml/kg/hr for 0-10 kg
• 2 ml/kg/hr for 10-20 kg
• 1 ml/kg/hr for 20+ kg
• Max 100ml/hr
How much energy does 1L of 5% dextrose have in it?
What was the PIMS study?
RCT at RCH comparing plasma-lyte and 5% D with 0.45% in 5% dextrose
- Showed less hyponatraemic in isotonic plasma-lyte
What must you consider in prescription of maintenance?
ADH response continues post-op/hospital
4/2/1 rule based on healthy children
Hydration status of children is difficult to assess
Age, nutritional status
Kids eat and drink early
How does maintenance change in sick children? Why?
Reduce 4/2/1 rule by 75-50%
Stress response causes retention
Which groups are high risk for fluid overload?
Craniofacial/neurosurg patients, major surgery
Children requiring full maintenance fluids
Why do we add dextrose?
Prevent hypoglycaemia and ketosis
Prevent hypotonia induced haemolysis - less of an issue now that we're using isotonic solutions