L10 Fluids & transfusion in hypovolaemia Flashcards
osmolarity
Osmolarity is the measure of a solute concentration per unit volume of solvent
The solute is what is dissolved
Solvent what it is dissolved in
solute
is what is dissolved
solvent
what it is dissolved in
osmolality
osmolality is the measure of solute concentration per unit mass of solvent
osmolality is the same in the ICF and in the
ECF
tonicity
tonicity is the measure of osmotic pressure gradient between two solutions
tonicity is only influenced by solutes that cannot cross the semipermeable membranes
normal fluid percentage in body
2/3
ICF - 2/3 of above ECF is 1/3
intravacualr to instal is 3/4 to 1/4 of ICF
using ECF - plasma is 3 litres ( intervascualr ) and 10.5 l is interstitial
hypovolaemia
- A decreased volume of circulating blood in the body- docent suddenly happen
what detects a hypovolaemic state
hypothalamus
and cuase pp to release vasopressin ( vasoconstrictor and retian fluids via aquaproisn)
Symapthic – adrenal medulla adrenalien – vasoconstrictor
Also causes reduction in renal blood flow due to vasoc icnreasng renin. ,angiotension anad aldosterone- fluid retneiona and sodium retention
Antiero pituaitry increase in growth hromoen and ACTH increasing cortisol levels
what controls the endothelial entry of fluids into the interstitial space
glycocalyx
main drug causes of hypovolamia
Loop diuretics – offload to much fluid
Corticosteroids – fluid retention
examples of maintainanc fluid
normal plasma
o.9 NaCl ( saline)
5% dextrose
hartmanns solution
how many stages of hypovolaemic shock
4 - more fluid loss , increased RR and tachycardia, decreased systolic
what is the first sign to change in a deteriorating or shocked patient
RR - increases to compensate for an underlying metabolic acidosis
Crystalloids are what
aqueous solution of electrolytes with no large molecules therefore there will be no oncotic pressure
crystalloids include what
0.9% saline
5% dextrose
hartmanns
benefits of crystalloids
easy to store, not expensive, long shel f life, readily available , low incidence of adverse reactions , variety of formulas and used for maintenance and replacement and there is no religious objection to this
isotonic salien 0.9% NaCl is given into what space
intravascular and then into the interstitial space and the distribution is due to increase hydrostatic pressure between the intravascular compartment and the interstitial compartment
dextrose fluid which is hypotonic will go from intravacualr to interstitial to intracellular and the glucose is rapidly taken up by cells leaving pure water
would you use it in resuscitation
no you wouldn’t use it in resus you would use the isotonic saline ( 0.9 NaCl)
colloids are human albumin solution of 5-20% containing starch , dextran and gelofusin do they just remain int eh intravascular space
yes as the oncotic pressure draws fluid into the intravascular space
colloids have no oxygen carrying capacity as the oncotic effect is weakened. what are the adverse reactions associated with use of these
renal failure , anaphylaxis and coagulopathy
74 year old lady is admitted with a fractured neck of femur awaiting surgical fixation. She is unwell and confused. On examination she has cold peripheries. Her observations are: Pulse 115 bpm Blood pressure is 92/ 55 mmHg RR 22 Temperature 35 degrees A diagnosis of hypovolaemic shock is made. What is your initial resuscitation fluid of choice?
0.9% saline
A 30 year old man presents to the Emergency Department after a traumatic amputation below his right knee. Whilst awaiting intravenous cannulation for resuscitation with fluids, a tourniquet is applied to the right thigh. Unfortunately, there is on-going blood loss which is estimated to be 1.5 litres. This patient is likely to:
Be hypotensive, tachycardia and tachypnoeic grade 3 shock
Unlike crystalloids , red cell transfusion increase oxygen carrying capacity a well as volume
Single unit contains 250-300 ml of conc bloo d
Haematocrit is 0.6 in normal blood this is 0.35
1x packed RBC would expect to increase Hb by 10g/L
at what temp should you store blood
4 degrees
what is a major haemorrhage
loss of more than one blood volume within 24 hours - or 50% of total blood lost in 3 Hours
major haemorrhage protocol
stop the bleeding and ABC activate protocol blood pack - 4 blood, x2 FPP ( 20 mins to defrost) then 2:1 blood to FFP reassess after 4 units