Fluid Prescribing Flashcards
5 Rs of fluid prescribing
- resuscitation
- replacement
- routine maintenance
- redsitribution
- reassessment
name 2 crystalloids
sodium chloride 0.9% and Hartmanns solution
what are the benefits of crystalloids
cheap and widely available
what does Hartmanns contain
crystalloid with added electrolytes eg Potassium
define routine maintenance
provide daily maintenance requirements
define replacement
- Provides daily maintenance requirements and replacement of any ongoing abnormal losses
define resuscitation
- Re-establishes haemodynamic stability through restoring intravascular volume
name a colloid
Gelofusin
colloids
should theoretically maintain onctoic pressure, however in practice they are not very good
what are the negative sides of colloids
risk of anaphylaxis
expensive
what solution is recommended for resuscitation
- crystalloid solution
- balanced crystalloid is good as excessive sodium chloride 0.9% can cause hypercholermic metabolic acidosis
what is hypercholermic metabolic acidosis
an acidosis with a normal anion gap, caused by increased chloride and decreased bicarbonate
when is Hartmanns solution avoided
in cases of eg rhabdomyolysis and AKI/CKD, when sodium chloride 0.9% is preferred due to the risk of hyperkalaemia (cells die and release phosphate and potassium ions)
what is recommended for replacement therapy
balanced/crystalloid
what is the normal daily requirement for water
25-30ml/kg/day
what is the normal daily requirement for sodium, potasiuma and chloride
1mmol/kg/day
what is the normal daily requirement for glucose
50-100g/day
what fluids are recommended for routine maintenance
- 0.18% Sodium chloride/4% dextrose
- 0.45% Sodium chloride
- 5% dextrose
what is the max fluid volume given in a day roughly
2.4l
which fluids redistribute most into the PV
balanced/crystalloids

when should albumin be used
- severe sepsis
- hepatorenal syndrome
- large volume paracentesis
- therapeutic plasma exchange
blood as a colloid
it is the most physiological colloid, it increases oxygen carrying capacity
there is a risk of a type II hypersensitivity ABO reaction - overwhelming systemic inflammatory response that can occur with 1ml of blood
PRC
packed RBCs - indicated when paient has lost a lot of blood or has anaemia
FFP and cryoprecipitate
- FFP used when there are low clotting factors or other blood proteins
- cryoprecipitate is a concentrated subset of FFP components
management of hyponatraemia if the patient is dry
0.9% saline
management of hyponatraemia if the patient is euvolaemic
- consider SIADH - do a paired urine and serum osmolality and urinary electrolytes
- the RAAS system is still intact, maintaining volumes
treatment of SIADH
water restriction to ≤1l a day and treat underlying cause
management of hyponatraemia if the patient is overloaded
water restriction
consider diuretics if there is significant or symptomatic volume overload (eg ascites or pitting oedema)
what is the goal of initial therapy in correction of hyponatraemia
- raise the serum sodium concentation by 4-6mg in a 24 hour period
- in emergency, in a 6 hours period or less
- maintain sodium constant thereafter
what must sodium rise be restricted to in 24 hours
- 9mg/L
- rapid correction risks osmotic demyelination - widespread demyelination of pontine area
which patients are at risk of osmotic demyelination
- those with Sodium serum concentrations ≤105mg/L, and those with hypokalemia, alcoholism, malnutrition and liver disease
what is severe hyponatraemia defined as
Na <120 mmol/L
what is emergency treatment
100ml 3% saline over 10-15 minutes
which patients are indicated for aggressive therapy to raise sodium ASAP
- severe symptoms due to hyponatraemia eg seizures, obtundation
- acute hyponatraemia with symptoms
- hyperacute hypnatramie due to self induced water intoxication, even if there are no symptoms. serum Na may worsen spontaeously due to delayed ingestion of water
- symptomatic patients with acute post op hyponatraemia or hyponatraemia associated with intracranial pathology
what is there a risk of with acute onset hyponatraemia
- cerebral oedema due to osmotically driven water flow across BBB
- manifest as impaired consciousness, seizures, raised ICP
- potentially death due to brain herniation