Fluid and Nutrition Management Flashcards
what are the three common reasons for fluids to be prescribed?
resuscitation
maintenance
replacement
what is the distribution of fluid between extracellular and intracellular?
extracellular - 1/3
intracellular - 2/3
what is the distribution of fluid between the extracellular vascular and interstitial compartments?
vascular - 1/4
interstitial - 3/4
what is the absolute distribution of fluid in the vascular compartment?
1/12th or about 8%
why is it important that fluid remain in the intravascular compartment?
in order to increase intravascular volume and increase tissue perfusion rate
why is it important to give and monitor fluids in a NBM patient?
because majority of our fluid intake is oral and this needs to be replaced
what are the signs and symptoms of a dehydrated patient?
- dry mucous membranes
- reduced skin turgor
- low urine output
- hypotension
- tachycardia
- increased capillary refill time
what are the signs and symptoms of a fluid overloaded patient?
- raised JVP
- peripheral or sacral oedema
- pulmonary oedema
what is the recommended daily water requirement?
25 ml/kg/day
what is the recommended daily sodium requirement?
1.0 mmol/kg/day
what is the recommended daily potassium requirement?
1.0 mmol/kg/day
what is the recommended daily glucose requirement?
50 g/day
what are the two kinds of intravenous fluids?
crystalloids and colloids
how do colloid fluids work?
they have large proteins in the fluid, increasing the oncotic pressure keeping the fluid in the vascular compartment
what are the three common crystalloid fluids?
- 0.9% saline (normal saline)
- 5% dextrose
- Hartmann’s solution
what are the contents of normal saline?
water, sodium, and chloride
true or false: normal saline is isotonic
true
which compartments does normal saline distribute into?
it is isotonic so stays in the extracellular compartment
what percentage of normal saline stays in the intravascular space?
25%
true or false: normal saline can be used in resuscitation
true
it can be used in both maintenance and resuscitation
what is hyperchloraemic acidosis?
when too much saline is given in fluid maintenance leading to an excess of chloride ions in the plasma
what are the contents of 5% dextrose solution?
water and dextrose
is 5% dextrose solution hypotonic or hypertonic?
hypotonic
what happens to the dextrose in 5% dextrose solution?
it is immediately taken up by the cells, leaving the water behind
how does the water distribute itself in 5% dextrose solution and how much remains in the vascular space?
it distributes itself evenly across all compartments, leaving only 8% in the vascular space
when can 5% dextrose solution be used?
it can only be used in fluid maintenance as it maintains hydration without giving an excess of electrolytes
why is it useful to give a NBM patient 5% dextrose solution?
as they have no other intake of glucose and need some form of energy
what are the contents of Hartmann’s solution?
water, sodium, chloride, potassium, lactate, calcium
true or false: Hartmann’s solution is isotonic
true
what compartments does Hartmann’s solution distribute into?
it stays in the extravascular compartment, with 25% remaining intravascularly
when is Hartmann’s solution given?
it can be used for maintenance and resuscitation
why would someone use Hartmann’s over 0.9% saline?
because Hartmann’s is considered more physiologically accurate due to the other electrolytes present
what measurement is considered a reduced urine output?
< 0.5ml/kg/hour
how is a patient with reduced urine output managed?
- measure urine output
- check if they are in retention or if they have a blocked catheter
- be given a fluid challenge
what is a fluid challenge?
250-500mls given over 15-30 minutes to prevent hypovolaemia
true or false: malnourished patients make bad surgical candidates
true
they are at increased risk of surgical complications such as reduced wound healing and infection
what does surgery do to the body’s metabolism?
the physiological stress results in a hyper metabolic state with a catabolic response
what is the indication for giving oral nutritional supplements (ONS)?
if the patient is unable to eat sufficient calories
what is the indication for giving a nasogastric tube (NGT)?
if the patient is unable to take sufficient calories orally or has a dysfunctional swallow
what is the indication for gastrostomy feeding (PEG/RIG)?
if the patient’s oesophagus is blocked or dysfunctional
what is the indication for jejunal feeding (jejunostomy)?
if the patient’s stomach is inaccessible or if there is an outflow obstruction
what is the indication for parenteral nutrition?
if the patient’s jejunum is inaccessible or if they have intestinal failure
when would treating malnutrition not be considered a reason to delay surgery?
if the underlying cause for malnutrition is being treated in the surgery (e.g. someone with active Crohn’s disease)
true or false: patient should wait post-op before eating again
false
early post-operative feeding has been shown to reduce post-operative complications
what is the recommended daily intake of sodium?
1-2mmol/kg/day
what is the recommended daily intake of potassium?
1mmol/kg/day
what is the recommended daily intake of glucose?
50g/day
what is the recommended daily intake of water?
25-30ml/kg/day
