fluid therapy in icu

2. Fluid compartment & distribution
Fluid compartment of total body weight:
• Neonate: 75-80%
• Infant: 70-75%,
• Adult male: 55-60%
• Adult female 50-55%
• Elderly 45-50%
Fluid distribution

3. Total body water
• Newborn: 70-80% of total body weight
• At 1 year age: 65% of total body weight(remains so
throughout childhood)
• Adults: Males- 60% TBW
Females- 50% TBW
- Higher fat content in females decreases water content.
- Obesity & advanced age decrease water content.

4. Body Water Compartments
Total body weight
Total body water (60%)
Intracellular(40%) Extracellular (20%)
Interstitial Intravascular
(15%) (5%)

6. ELECTROLYTES(mEq/L) ECF ICF
SODIUM 142 10
POTASSIUM 4.30 150
CHLORIDE 104 2
BICARBONATE 24 6
CALCIUM 5 0.01
MAGNESIUM 3 40
PHOSPHATE & SULPHATE 8 150
ECF & ICF electrolyte concn –
ECF - Na,Cl,bicarbonate rich
ICF - K,Mg,phosphate,sulphate,protein rich

7. Basic concepts of fluids
• Osmosis=movement of water across a semipermeable
membrane
• Osmotic activity=it reflects the no. of solute particles per unit
volume of solvent
• Osmotic pressure= force that drives the movement of water
between fluids with different osmotic activities
• 1Mole=1 gm mol.wt.=6×1023 particles
• Meq= no. of moles × valence
• Molarity =no. of moles of solute per liter of solution
• Molality= no. of moles of solute per kg of solvent
• Osmol= (no.of moles) n
n=no.of ionic species produced
• Tonicity=refers to effect of solution on cell volume, used
interchangeably with osmolarity or osmolality

8. Basics of fluid balance
Water without Na expands the
TBW (enter both ICF & ECF in
proportion to their initial volume)
H2
O
H2
O
H2
O
ICF ECF
Isotonic = NO Water
Exchange
Hypotonic = Water Exchange
Hypertonic = water
exchange
H2
O
H2
O

9. CLASSIFICATION OF I.V. FLUID
1) Maintenance Fluid:- replaces fluid loss from lungs , skin ,
urine , faeces ,these losses are poor in salt so this maintenance
fluid should be hypotonic to plasma sodium . eg – 5 % dextrose
, dextrose with 0.45 % NaCl solution .
2) Replacement Fluid :-it correct body fluid deficit caused by
losses such as gastric drainage , vomiting , diarrhoea , oozing
from wound , infection , burns , intestinal edema . eg – isotonic
saline , DNS , RL, Iso – M P G
3) Special Fluid :-used for special indication such as
hypoglycemia , hypokalemia , metabolic acidosis . eg- 25%
dextrose, KCl , Soda Bicarb

10. Hypovolaemia

11. • Static parameters are not reliable
• Fluid challenge –
• Dynamic assessment of fluid responsiveness
• Bedside provocative test with pre-defined rules
• Unmasks hypovolaemia or relative hypovolaemia

12. Fluid challenge
• Fluid boluses is key element of haemodynamic resuscitation - but
overuse can be harmful.
• Principle – to improve clinical indicators by increasing cardiac output.
• Assess change in cardiac output, either directly or indirectly.

13. How to give a fluid challenge?
• Four predefined elements to a fluid challenge,
• Type of fluid
• Rate of fluid administration
• Objective
• Limits - Safety

14. Fluid Challenge…Type of Fluid
• Dependent on clinical situation
• Type of fluid that has been lost
• Severity of circulatory failure
• Risk of bleeding
• Fluids –
• Crystalloids - avoid excessive chloride administration
• Colloids - avoid HES (starch)
• Albumin - may be useful in sepsis, avoid in traumatic brain injury
• Blood – haemorrhage
• No dextrose containing fluid

15. Fluid Challenge…Rate of fluid administration
• Give 500mL over 30 minutes
• No hard data to support a particular regimen
• 250-500mL Crystalloid
• 500-1000mL or 30mL/kg crystalloid

16. Fluid Challenge…Objectives
• Various options
• Target MAP: 65mmHg, may need to higher for the hypertensive
patient
• Target U/O: 0.5mL/kg/hr
• Resolution of end-organ hypoperfusion:
• Resolution of tachycardia
• Improved LOC
• Falling lactate
• Rising ScvO2
• Echo: IVC diameter, Aortic VTI
• Cardiac output monitoring (CO, SV, SVV, PPV) - a 15% increase in
CO or CI after a fluid challenge over 10–30 min
• CVP is unable to predict fluid responsiveness among a broad
range of patients in various clinical settings.

17. Fluid Challenge… Limits for Safety
• If limit is reached before the objective, the fluid challenge should be
stopped
• For eg – Increment of CVP or PAWP: CVP 2-5 mmHg increase or PCWP
3-7mmHg increase -> stop fluid challenge
• Individualise the stopping rule
• If there’s no associated increment in CO then volume infusion will
not benefit

18. Risks with Fluid challenge
• Repeated boluses in a day
• Caution in patients without simultaneous fluid losses
• Irreversible
Risks
↑ Hydrostatic
Pressures
Benefits
↑CO

19. How to do it?
If the safety endpoint is not reached but the clinical endpoint is achieved
Should we continue to give more fluid?

20. Mini fluid challenge
• Described by the AzuRéa Group, 2011
• Sedated and mechanically ventilated patients with acute
circulatory failure in ICU
• 100 ml colloid infused over 1 min predicts fluid responsiveness
- > 10% increase in VTI
• Correlated with >15% increase in VTI after an additional 400 ml
given over the next 14 min
• Sensitivity - 95%
• Specificity - 78%
• Limitations –
• Requires echocardiography (TTE) to measure subaortic velocity time
index (VTI)
• Only deeply sedated mechanically ventilated patients
Muller L et al Anesthesiology 2011; 115:541–7

21. To Summarise
• Patients who respond with significant increase in SV and
should be given a fluid challenge.
• Not all patients who are fluid responders necessarily
require volume expansion
• Mini-fluid challenge
• CVP is unable to predict fluid responsiveness

22. PHASES OF SEPTIC SHOCK
FLOW PHASE
• Phase after initial stabilization where patient mobilizes
excessive fluid spontaneously.
• Metabolic turnover is increased
• Activated immune system
• Induced hepatic acute phase response
Malbrain ML, Van Regenmortel N, Saugel B, De Tavernier B, Van Gaal PJ, Joannes-Boyau O, Teboul JL, Rice TW, Mythen M, Monnet
X. Principles of fluid management and stewardship in septic shock: it is time to consider the four D’s and the four phases of fluid therapy.
Annals of intensive care. 2018 Dec;8(1):66.

23. PHASES OF SEPTIC SHOCK
GLOBAL INCREASED PERMEABILITY SYNDROME:
• Critically ill patients who did not transgress to Flow phase
will remain in continuous state of global increased
permeability and ongoing fluid accumulation.
• Fluid overload with new onset organ failure
Malbrain ML, Van Regenmortel N, Saugel B, De Tavernier B, Van Gaal PJ, Joannes-Boyau O, Teboul JL, Rice TW, Mythen M, Monnet X.
Principles of fluid management and stewardship in septic shock: it is time to consider the four D’s and the four phases of fluid therapy. Annals of
intensive care. 2018 Dec;8(1):66.

24. RISK OF FLUID OVERLOAD
• Inevitable fluid overload
• Fluid boluses and maintenance, drug diluents, artificial
nutrition.
capillary leak
central
hypovolemia
fluid
resuscitation
interstitial
edema
Malbrain ML, Van Regenmortel N, Saugel B, De Tavernier B, Van Gaal PJ, Joannes-Boyau O, Teboul JL, Rice TW, Mythen M, Monnet X.
Principles of fluid management and stewardship in septic shock: it is time to consider the four D’s and the four phases of fluid therapy. Annals
of intensive care. 2018 Dec;8(1):66.

25. Malbrain ML, Van Regenmortel N, Saugel B, De Tavernier B, Van Gaal PJ, Joannes-Boyau O, Teboul JL, Rice TW,
Mythen M, Monnet X. Principles of fluid management and stewardship in septic shock: it is time to consider the four D’s
and the four phases of fluid therapy. Annals of intensive care. 2018 Dec;8(1):66.

26. FLUID OVERLOAD
Malbrain ML, Van Regenmortel N, Saugel B, De Tavernier B, Van Gaal PJ, Joannes-Boyau O, Teboul JL, Rice
TW, Mythen M, Monnet X. Principles of fluid management and stewardship in septic shock: it is time to consider
the four D’s and the four phases of fluid therapy. Annals of intensive care. 2018 Dec;8(1):66.