Crystalloids
Types
 Saline e.g. 0.9% saline, Hartmann’s solution 0.18% saline in 4%
glucose.
 Glucose : e.g. 5% glucose, 10% glucose, 20% glucose.
 Postassium chloride
 Sodium bicarbonate : e.g. 1.26%, 8.4%.
Uses
 Crystlloid fluids are used to provide the daily requirements of watr
and electrolytes. They should be given to critically ill patients as a
continuous background infusion to supplement fluids given during
feeding or to carry drugs
 Higher concentration glucose infusions are used to prevent
hypoglycaemia.
 Potassium chloride is used to supplement crystalloid fluids.
 Correction of metabolic acidosis (sodium bacarbonate)
Routes
 IV
1
Notes



Plasma volume should be maintained or replaced with
colloid solutions since crystalloids are rapidly lost from
the plasma. It should be noted that plasma substitutes
are carried in 0.9% saline. So that the majority of
critcally ill patients only require 0.9% saline infusions for
excess loss.
Sodium content of 0.9% saline is equivalent to that of
extra cellular fluid. A daily requirement of 70-80mmol
sodium is normal although there may be excess loss in
sweat and from the gastrointestinal tract.
Hartmann’s solution has no practical advantage over
0.9% saline for fluid maintenance. It may, however, be
useful if large volumes of crystalloid are exchanged (e.g.
during continuous haemofiltration) to maintain acid –
balance.
2


5% glucose is used to supply intravenous water
requirements, the 50g/L glucose being present to ensure
an isotonic solution. Normal requirement is 1.5-2.0L/day.
Water loss in excess of electrolytes is uncommon but
occurs in excess sweating, fever, hyperthyroidism
diabetes insipidus and hypercalcaemia.
Potassium chlorid must be given slowly since rapid
injection may cause fatal arrhythmias. No more than
40mmol/h may be given although 20mmol/h is more
usual. Frequency of infusions are predicted by plasma
potassium measurements.
3
Ion content of crystalloids (mmol/L)
Na+
0.9% saline
Hartmann’s
0.18% saline in
4% glucose
150
131
30
K+
5
HCO3
C1
Ca2
29
150
111
30
2
Ion content of gastrointestinal fluids (mmol/L)
Gastric
Biliary
Pancreatic
Small bowel
Large bowel
H+
40-60
Na+
20-80
120-140
120-140
120-140
100-120
5-15
5-15
5-15
5-15
K+
5-20
30-50
70-110
20-40
20-40
HCO3
C1
150
100-150
80-120
40-80
90-130
90-130
4
Sodium Bicarbonate
Type
 Isotonic sodium bicarbonate 1.26%
 Hypertonic sodium bicarbonate (1mmol/ml) 8.4%
Uses
 Correction of metabolic acidosis
 Alkalinisation of urine
Routes
 IV
5
Notes



Sodium bacarbonate may be given as an isotonic
(1.26%) solution to correct acidosis associated with
renal failure or to induce a forced alkaline diuresis. The
hypertonic (8.4%) solution is rearely required in
intensive care practice to raise the pH to >7.0 in the
serve metabolic fusion or necrosis is present
Administration may be indicated as either specific
therapy (e.g. alkaline diuresis for salicylate overdose), or
if the patient is symptomatic (usually dyspnoeic) in the
absence to tissue hypoperfusion (e.g. renal failure).
The PaCO2 may rise in minute volume is not increased.
Bicarbonate anot cross the cell membrane without
dissociation so the increase in PaCO2 may result in
intracellular acidosis and depression of myocardial cell
function.
6
Convincing human evidence that bicarbonate improves
myocardial contractility or increases responsiveness to
circulating catecholamines in severe acidosis is lacking
though anecdotal success has been reported. Acidosis
relating to myocardial depression is related to
intracellular changes which are not accurately reflected
by arterial blood chemistry.
 Excessive administration may cause hyperosmolality,
hypernatraemia hypokalaemia and sodium overload.
 Bicarbonate may decrease tissue oxygen availability by a
left shift of the oxyhaemoglobin dissociation curve.
 Soidum bacarbonate does have a place in the
management of acid retention or alkali loss, e.g. chronic
renal failure, renal tubular acidosis, fistulae, diarrhoea,
Fluid and potassium deficit should be corrected first.

7
Ion content of sodium bacarbonate (mmol/L)
1.26% sodium
Bacarbonate
8.4% sodium
bacarbonate
Na+
150
1000
K+
HCO3
150
C1
Ca2
1000
8
Colloids
Types
 Albumin: e.g. 4.5-5%, 20-25% human albumin solution
 Dextran: e.g. 6% Dextran 70
 Gelatin: e.g. 3.5% polygeline (Haemaccel), 4% succinylated gelatin
(Gelofusion)
 Hydroxyethyl starch: e.g. 6% hetastarch (Elo-HAES, Hespan), 6 & 10
pentastarch (Pentaspain, HAES-steril)
Uses
Used for maintenance of plasma volume and acute replacement of plasma
volume deficit.
 Short term volume expansion (gelatin, dextran)
 Medium term volume expansion (albumin, pentastarch)
 Long term volume expansion (hetastarch)
Routes
 IV
Side effects
 Dilution coagulopathy
 Anaphylaxis
 Interference with blood cross matching (Dextran 70)
9
Notes


Smaller volumes of colloid are required for resuscitation
with less contribution to oedema. Maintenance of plasma
colloid osmotic pressure (COP) is a useful effect not seen
with crystalloids but they contain no clotting factors or
other plasma enzyme systems.
Albumin is the main provider of COP in the Plasma and
has a number of other functions. However, there is no
evidence that maintenance of plasma albumin levels, as
opposed to maintenance of plasma COP with artificial
plasma substitutes, is advantageous.
10




Albumin 20-25% and Pentaspan 10% are hyperonocotic
and used to provide colloid where salt restriction is
necessary. This use is rearely necessary in intensive care
where it has been shown that plasma volume expansion
is related to the weight of colloid infused rather than the
concentration.
Artificial colloids used with ultrafiltration or diuresis are
just as effective in oedema states.
Polygeline is a 3.5% solution and contains calcium (6.25
mmol/L) The calcium contents prevents the use of the
same administration set for blood transfusion.
Succinylated gelatin is a 4.5% solution with a larger
molecular weight range than polygeline giving a slightl
longer effect. This and the lack of calcium in solution
make this more useful solution than polygeline for short
term plasma volume expansion.
11






In patients with capillary leak there is onsiderable leak of
albumin and smaller molecular weight colloids to the
interstitum.
In these caes it is probably better to use larger
molecular weight colloids such as hydroxyethyl starch.
Hetastarch is usually a 6% solution with a high degree
of protection from metabolism.
The molecular weight ranges vary but molecular sizes
are large enough to ensure a prolonged effect.
These are the most useful colloids in capillary leak.
Pentastarch has a lower degree of protection from
metabolism and therefore a shorter effect.
12
Unique features of albumin
 Transport of various molecules
 Free radical scavenging
 Binding of toxins
 Inhibition of platelet aggregation
Relative persistence of colloid effect
 Albumin
+++
 Dextran 70
++
 Gelofusin
+
 Haemaccel
+
 Hespan
++++
 Pentaspan
++
 Elo-HAES
++++
 HAES-Steril
++
 Presistence is dependent on molecular size and protection from
metabolism.
 All artificial colloids are polydisperse (i.e. there is a range of
molecular sizes).
13