Fluid balance and therapy in critically ill
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Transcript of Fluid balance and therapy in critically ill
Dr Anand.M.TiwariF.N.B critical care medicine
Intensivist
Revision of the known facts
What is the water content of human body?
Male female
50 to 60% of body weight
Higher in neonates and children
Lower in elderly
Lower in women
40% is intracellular.
20% extracellular
15% is interstitial 5% is intravascular
28 L
14L
3.5 L
Diffusion Facilitated diffusion Active transport Osmosis Osmolality Calculation 2na+glu/18+ bun/2.8 Freezing point
depression method
Hypotonic (cell swells) 200mosm/litre
Hypertonic cell shrink –360 mosm/l
Isotonic nochange 280mosm/l
IntracellularInterstitial
Intravascular
2/3 1/3
3/4 1/4
IntracellularInterstitial
Intravascular
2/3 1/3
3/4 1/4
ECF osmolality = ICF osmolality
K, ATPCreatinine PO4phospholipids
Na, ClHCO3
Intravascular
Interstitial
3/4 1/4
Capillary membrane
Plasma proteins
IntracellularInterstitial
Intravascular
2/3 1/3
3/4 1/4
Na
K
Plasma Na 153
IC K 150
Intracellular Interstitial
Intravascular
2/3 1/3
3/4 1/4
Intracellular
Interstitial Intravascular
2/3 1/3
3/4 1/4
IntracellularInterstitial
Intravascular
2/3 1/3
666ml 250ml 84ml
IntracellularInterstitial
Intravascular
2/3 1/3
750ml 250ml
IntracellularInterstitial
Intravascular2/3 1/3
1000ml
IntracellularInterstitial
Intravascular2/3 1/3
1000ml
Intake and output must be balanced.Intake---N fluid ingested—2100 +from metabolism(200)=2300mloutput—urine-1400+feces(100) -sweat-100 - insensible loses—skin-350+lungs350ml
Subject to variation environmental condition and disease states
Weight Water requirement 0-10 kg 4mL/kg/hr10-20 kg 40mL/hr +2ml/kg/hr for each kg>10kg>20kg 60ml/hr +1ml/kg/hr for each
kg>20kg
for 60kg man this = 100ml/hr or 2400 ml/24 hrsfor normal people!!
Solutions Volumes Na+ K+ Ca2+ Mg2+ Cl- HCO3- Dextrose mOsm/L
ECF 142 4 5 103 27 280-310
Lactated Ringer’s
130 4 3 109 28 273
0.9% NaCl 154 154 308
0.45% NaCl 77 77 154
D5W 50 250
D5/0.45% NaCl 77 77 50 406
3% NaCl 513 513 1026
6% Hetastarch
500 154 154 310
5% Albumin 250,500
130-160
<2.5 130-160 330
25% Albumin 20,50,100
130-160
<2.5 130-160 330
Crystalloidsrelatively large volume for resus
Ideal for repleshing third space loss
Less fear of allergic reaction
Used as diluent for ionotropic adminstration
Colloids Lesser volume
better expander more duration
Allergic reaction seen as well interfearance with blood crossmatch
R.L hartmen “solution, balanced salt solution
Isotonic -isobaric- iso-osmolar- crystalloid solution.
Concentrations of ions—Na-131mEq/l calcium-2mEq/l
bicarbonate-29mEQ/L AS LACTATE
K+ 5MeQ/L, CL- 110mEq/lPh-6.5,osmolarity-279
mosm/L
Normal saline Isotonic isobaric 0.9% w/vsolution
Na+/cl- =154mEq/l Ph-5.0 0smolarity -308mosm/L
--common maintainence fluid till other are made available
---in treatment of diabetic ketoacidosis—2 litres
--upper intestinal obstruction and hypochloremia
RL-Solutions provides electrolytes with lactate.
Lactate is rapidly metabolized in liver to bicarbonate helps in correction of acidosis
Mild to moderate hypovolemia due to any cause
As a maintainence fluid Preloading before spinal
anaesthesia Risk—Lactic acidosis hyperkalemia
NS-Only fluid compatible with blood.
Flushing of dialysis set with saline Surgeons use for –washing crush injuries peritoneal lavageunder water seal bottle
Can be used as diluent for medication
NS-RISK-Hyperchloraemic metabolic acidosis more likely with renal insufficiency
FULFILLS INDICATIONS OF BOTH 5% DEX AND .9% SALINE
Useful particularly in pediatric patient Safely be used as maintainence fluid. Avoid for surgical procedures as dex best
media for bacterial growth Can be used along with blood
It provides calories –each gm of glucose 4 kcal.
--used to correct water deficit --used to correct hypoglycemia --used as carrier for giving drugs
dopamine, aminophylline,noradrenaline,insulin,SNP
Higher concentration is irritant to vien. Avoid extravasation Water intoxication,odema states Should not be given along with blood
transfusion Avoid in known hyperglycemic as
maintainence fluid
Hemaccel 3.5% poly gelatin Na 145/cl 145 k-5.1, ca++-6.25mEq/l
Mol wt 30,000 pH 7.3 Half life 4-6hr Use in mod to severe shock. Priming solution
Citrated blood should not be mixed. Produces histamine release/anaphylactic Dose should not increase 1000ml in 24 hrs. Careful in digitalized patient Avoid in hepatic renal and CCF However unlike other colloids does not
cause agglutination and Rolex formation
6% SOLUTION mol wt-2,00,000da Dose 20ml/kg in 24 h These are hyperoncotic and cause
intravascular volume expansion Duration 12-24 hrs The incidence of anphylactoid reaction is
low
IT interferes PL Aggregation and coagulation.
Thermo osmalarity-308mosm/l Ability to with draw fluid from interstital
space in to intravascular compartment It should be cautiously used in presence of
renal failure
Dextran 40/ rheomacrodex --IT decreases viscosity of blood. --it improves micro circulation. --plasma half life 6-12hrs --dose 20 cc/kg/24hrs --it does not interfere with blood gp and
crossmatch
Accumulation and tissue storage
Effects on renal function
Coagulopathy and bleeding risk
Increase in amylase levels
Anaphylactic potentials
Cost factors
New generation colloids-0.4 Molar substitution==degradation factor
hydroxyl ethyl group No risk of accumulation even with dosages
increased from 20ml/kg---50ml/kg No effects on renal and coagulopathy Quest for the new colloid--
Balanced colloid solution like volulyte will end the debate
HES therapy was associatedwith higher
HES therapy was associated with higher rates of acute renal failure and renal-replacement therapy than wasRinger’s lactate.
N Engl J Med 2008;358:125-39.Copyright © 2008 Massachusetts Medical Society
What is the first sign of shock? a. Tachycardia b. hypotension c. narrow pulse pressure d. low urine output
parameter
class1 clqss2 class3 class4
%blood vol/cns
<15%
anxious
15-30%
agitated
30-40%
confuse
>40%
lethargic
Pulse rate
<100 >100 >120 >140
Supine b.p
n n decrease decreas
Urine output
>30ml/hr .20-30ml 5-15ml <5ml
Fluid resuscitation in uncontrolled bleeding is deleterious
Delayed resuscitation is valid in trauma systems with short response times (<20 minutes to hospital from injury)
Attempts to control bleed should be given greater importance
Fluids (pre-op) 2.4 L 0.4 L (p<0.001)Survival 62% 70% (p=0.04)ARDS/ renal failure 30% 23% (p=0.08)Sepsis/ infectionHospital days 14+24 11+19 (p=0.006)
N Engl J Med 1994; 331:1105-1109.
598 patients; penetrating torso injuryField systolic BP <90 mm Hg (58+35)
309 289
Immediate fluids Delayed until induction
Trauma
Haemorrhage
Coagulation Hypotension
Fluid Resuscitation
Haemorrhage Haemorrhage
Fluid Resuscitation
Raises BP
Dilutesfactors
Restores volume +o2 carrying capacity Indicated in severe hemorrhagic shock eg
pelvic trauma ,variceal bleed Pre-operative measure Blood products for replenishing
coagulation/factors eg FFP, PL Conc,
Pyrexial reaction,allergy Transmission of disease-syphilis ,viral
hepatitis,HIV,malaria Hemolytic reactions Citrate intoxication Hyperkalemia ,hypothermia Volume overload TRIM,TRALI
PERIPHERIAL INTRACATH 16G Same gauze central line Hagen poiseuille equation rate @{radius}
4th power inversely proportional to length :;; infusion through central catheter will be
as much as 75% less than infusion rate through peripheral cathter of equal diameter
Fluid resuscitation may consist of natural or artificial colloids or crystalloids
No evidenced-based support for one type of fluid over another
•Crystalloids have a much larger volume of distribution compared to colloids•Crystalloid resuscitation requires more fluid to achieve the same endpoints as colloid•Crystalloids result in more edema
Choi PTL. Crit Care Med 1999;27:200-210.
Cook D. Ann Intern Med 2001;135:205-208.
Schierhout G. BMJ 1998;316:961-964.
Fluid Therapy: Choice of FluidFluid Therapy: Choice of Fluid
Grade C
Dellinger, et. al. Crit Care Med 2004, 32: 858-873.
Fluid challenge in patients with suspected hypovolemia may be given
500 - 1000 mL of crystalloids over 30 mins300 - 500 mL of colloids over 30 minsRepeat based on response and toleranceInput is typically greater than output due to venodilation and capillary leakMost patients require continuing aggressive fluid resuscitation during the first 24 hours of management
Fluid Therapy: Fluid ChallengeFluid Therapy: Fluid Challenge
Grade E
Dellinger, et. al. Crit Care Med 2004, 32: 858-873.
Central venous pressure (CVP) 8–12 mmHg
– Mean arterial pressure (MAP) 65 mmHg – Urine output 0.5 ml/kg h1 – Central venous (superior vena cava) or
mixed venous oxygen saturation 70%.
Rationale. Early goal-directed therapy (EGDT)
IntracellularInterstitial
Intravascular
2/3 1/3
3/4 1/4
Na
Blood Pressure—not a sensitive marker until blood loss >30%
NIBP-spuriously low measurement in patient with hypovolemia (vasoconstrictor response)
Direct IAP better ? Cardiac filling pressures CVP—limitation—Indirect measure
Change in CVP measured before and 5 mins after bolus of fluid◦0-3 mmHg: underfilled◦3-5 mmHg: adequately filled◦5-7 mmHg: overfilled
1 a wave is due to atrial contraction
2.c wave due to buldging of tricuspid valve in rt atrium
3 x descent depicts atrial relaxation
4 v due to rise in atrial pressure before the tricuspid valve opens
5 y decent is due to atrial emptying as blood enters ventricles
Watch out forSystolic pressure variation