Transcript FLUID & ELECTROLYTE BALANCE

FLUID & ELECTROLYTE
BALANCE
Prof. M. H. Mumtaz
BALANCE
 Water
Balance
 Elecrolyte
 Acidbase
Balance
Balance
 Nutritional
Balance
FLUID & ELECTROLYTE
BALANCE
 Intke
& loss routes.
 Distribution of water and electrolytes.
 Physiological control of water and
sodium.
 Assessment of balance.
 Physiological response to pathological
conditions.
 Practical approach to therapy.
NORMAL ROUTES
INTAKE
Food
 Drink
 Metabolic

OUTPUT
Urine
 Stool
 Sweat
 Respiration

PATHOLOGICAL ROUTES

Intravenous
Nasogastric
aspiration
 Enterostomy
 Colostomy

RENAL LOSS
FILTERATION
REABSORPTION
FILTERATION
WATER
 180L/24h
 125mls/min
 7.5/hr
 4xBW =15xECF
=60xPV
SODIUM
 30000mmol/24hr
 18125Ueq/min
REABSORPTION
WATER
 75%PT
 5%L
 15%DT
 4-4.86%CT
 Urine 1ml/kg/hr

SODIUM
 CI 14585Ueq
 HCO3 3375Ueq
 PO4 NH3 50Ueq
 K+ 50Ueq
 Total – 18060Ueq

24-HRS RENAL DEALING
Mmol
Filtered
Reabsorbed
Na+
26000
25850
K+
900
900
Cl-
18000
17850
HCO3
4900
4900
Urea
870
460
Creatinin
12
1
1
12
Uric acid
50
49
4
5
Glucose
800
800
51532
50810
Total
Secreted
100
Excreted
Location
150
PLDC
100
PD
150
PLDC
PD
410
PLDC
P
P
105
827
PLDC
SECRETION IN GUT

SALIVARY
– Quantitiy 1500/24 hrs.

GASTRIC
– Quantitiy 3000/24 hrs.

BILIARY
– Quantitiy 500/24 hrs.

PANCREATIC
– Quantitiy 2000/24 hrs.

TOTAL
– Quantitiy 7000mls.
FEACAL LOSS
Na+ & H2O secretion
 Na+ & H2O absorption

– Epithelial cells
– Duration of contact
H2O secreted > 7000ml
 Loss = 100-150mls
 Na+ secreted.

– 1500mmols/24hrs
– Loss 15mmol/24hrs
LOSS IN SWEAT & EXPIRED
AIR
900mls water
 30mmols Na
 Sweat loss.

– Temp.
– ADH.
– Aldosterone

Respiratory loss.
– Respiratory rate.
– Hamidification.
DISTRIBUTION OF WATER &
ELECTROLYTE
water distribution
 Total
body water 60% of body wt in male
 Total body water 52% of body wt in female
2/3rd IC
1/3rd EC
66% extravascular
33% intravascular
ELECTROLYTE
DISTRIBUTION mmol/L
Subtance
Plasma
Interstitial F IC
Na+
141.00
144.00
10.00
K+
3.70
3.80
156.00
Cl-
102.00
115.00
3.00
HCO-3
25.00
28.00
10.00
Ca++
2.5
0.00
0.00
Mg++
0.80
0.00
11.00
PO4--
1.10
0.00
31.00
Sodium
Potassium
Magnessium
Phosphates
chlorids
IC
EC
Low
100 time
30 time more
Less
Predominantly
Less
more
Predominantly
Less
more
less
Predominantly
PHYSIOLOGIC CONTROL OF
SODIUM
(2nd factor)
 Non aldosterone (factors)
 Aldosterone
–
–
–
–
GFR (1st factor)
Renal blood flow.
Oncotic pressure in tubular blood.
Third factor
LIVER
ANGIOTENSINOGEN
RENIN
FROM KIDNEY & ELSEWHERE
ANGIOTENSIN I
CONVERTING
ENZYME
DECAPEPTIDE
IN LUNG
ANGIOTENSIN II
AMINOPEPTIDE
2 GLOBULIN
OCTAPEPTIDE
INACTIVE METABOLITES
ANGIOTENSIN III
HEPTAPEPTIDE
RENIN ANGIOTENSIN
SYSTEM
 Indomethacin
 B.
Blocker
 Peptostatin
 Captopril
 Saralasin
PHYSIOLOGIC CONTROL OF
WATER
 Intake.
– Thirst.
 Loss.
– ADH
– Non ADH factors.
 Mannitol.
 Urea.
 Glucose.
Water
ADH
A
Renal Blood flow
Hypothalmic
Renin
Cellular arosmolality
B
Na+ Concentration
(Osmolality)
Angiotensin
Aldosterone
CONTROL OF WATER IN
COMPARTMENTS
INTRAVASCULAR/INTERSTITIAL
 Proteins – colloid osmotic pressure.
 Hydrostatic pressure.
INTERSITITAL/INTRACELULAR
 Osmolality – predominantly – Na+
CONTRIBUTION OF PLASMA CONSTITUENTS TO PLASMA
OSMOLARITY
Electrolyte
Concentration
Osmolality
Na+ anion
135
135
270
K+ anion
3.5
3.5
7
Ca++ anion
2.5
2.5
5
Mg++ anion
1
1
2
Urea
5
5
Gencose
5
5
Protein
70G/L
1
Total
295
THE KINETICS OF PVE
INTRACELLULAR
INTERSTITIAL
VASCULAR
CAPILLARY
EG
CELL
OSMILALITY
Na+
COP
HP
BLOOD VOLUME
RENIN
ALDOSTE
Na+
Na+
ADH
Osmolality
H2O
ASSESSMENT OF BALANCE
assessment of state of hydration
 History.
 Clinical
Helping Tools
state.
– Blood pressure.
S,D,M,
– Heart rate.
– Temperature.
– Skin texture.
1,CVP
2,T.E.D.
3,LIDCO/any?
ASSESSMENT OF BALANCE
assessment of state of hydration
 Lab
evidence.
– Haemoconcentration.
 Proteins.
 Hb.
 Haematocrit.
– Hemodilution.
 Protein.
 Hb.
 HCT
ASSESSMENT OF IMBALANCE

Hypo-osmolality (hyponatraemia)
–
–
–
–
–

Cellular overhydration.
Headache.
Confusion.
Fits.
Coma.
Hyper-osmolality (hypernatraemia)
–
–
–
–
–
Cellular dehydration.
Thirst.
Confusion.
Coma.
No fits.
HYPOVOLEMIA (ISOMOLOL)
 Hypotension.
 Collapse.
 Haemoconcentration .
 Low GFR uremia.
HYPERVOLEMIA (ISOMOLOL)
 Blood pressure.
 Oedema.
 Cardiac failure.
 Haemodilution.
 Urea.
CLINICAL PRESENTATIONS
Sodium 125
Mmol/L
141
155
120
Proteins 65
L/L
45
65
45
DISTURBANCE OF Na+ & H2O
METABOLISM
H2O & Na+ Deficiency
I
 Predominant H2O
depletion.
II
 Predominant Na+
depletion.

With homeostasis

With homeostasis

Without homeostatis

Without homeostatis
DISTURBANCE OF Na+ & H2O
METABOLISM
H2O & Na+ Excess
III
 Predominant H2O
excess.

With homeostasis

Without homeostatis
IV
 Predominant Na+
excess.

Without homeostatis
PREDOMINANT H2O DEPLETION
WITH HOMEOSTASIS

Excess fluid loss.
–
–
–
–
–

Sweat.
Gastric juice.
Stool.
On respirator.
Extensive burns.
Deficient intake.
– Inadequate water supply
– Mechanical obstruction to
intake.
WITHOUT HOMEOSTASIS




Comatosed patient
response to thirst.
Diabetes inspidus.
Osmotic diresis.
Nephrogenic diabetes
inspidus.
PREDOMINANT H2O DEPLETION

HOMEOSTASIS?
Clinical signs.
– Hypernatraemia.
– Dehydration.
– Oligurea.

Lab. Findings
– Hypernatremia & haemacrit.
– Mild uraemia

Urine.
–
–
–
–
volume
osmolality.
SG
Urea increase




CLINICAL FINDINGS
Polyrea.
Urine of low osmolality.
Low SG.
Low urea concentration.
UNCONSCIOUS PATIENT
water depletion Na+
CAUSES

Over breathing.
– Pneumonia.
– Acidosis.
– Brain stem injury.
Inadequate humidification.
 Hypertonic infusions.
 Diabetes inspidus.
 No response to thirst.
 Infants with gastroenteritis.
 Infats with bronchopneumonia.

Water
ADH
A?
Renal Blood flow
Hypothalmic
Renin
Cellular arosmolality
B
Na+ Concentration
(Osmolality)
Angiotensin
Aldosterone
PREDOMINANT Na+ DEPLETION
WITH
HOMEOSTASIS
Vomiting
 Diarrhoea.
 Fistula
 Sweating
Replacement low Na+
homeostasis?

WITHOUT
HOMEOSTASIS
Addison disease.
 Psaudo-addison disease.
 Renal tubular failure.

PREDOMINANT Na+ DEPLETION
WITH
HOMEOSTASIS
 Clinical signs.
WITHOUT
HOMEOSTASIS
 Clinical signs.
– Hypernatraemia.
– Fluid depletion
– Hypo-osmolality.

Lab. Findings
–
–
–
–
–
Hypernatremia
 vol. of urine
Haemodilution
plasone urea.
Urinary Na+ excretion.
Lab. Finding
 Haemo-concentration
 Renal circulatory
insufficiency uraemia.

Water
ADH
A
Renal Blood flow
Hypothalmic
Renin
Cellular arosmolality
B?
Na+ Concentration
(Osmolality)
Angiotensin
Aldosterone
PREDOMINANT H2O EXCESS
commonly associated with failure of homeostasis
WITH
HOMEOSTASIS
Fluid with low Na+
 Homeostasis?
 Clinical signs.

– Hypo-osmolality.

Lab. Findings.
– Haemodilution.
– Hyponatraemia.
FAILURE OF
HOMEOSTASIS
Renal failure.
 Anappropriate ADH
secretion.
 Oxytocin drip in 5%
glucose.

PREDOMINANT H2O DEPLETION

Clinical signs.

– Hypernatraemia.

– Fluid depletion
– Hypo-osmolality.
Lab. Findings
–
–
–
–
–
Hypernatremia
 vol. of urine
Haemodilution
plasone urea.
Urinary Na+ excretion.
Clinical signs.
Lab. Finding
 Haemo-concentration
 Renal circulatory
insufficiency uraemia.

Water
ADH
A?
Renal Blood flow
Hypothalmic
Renin
Cellular arosmolality
B
Na+ Concentration
(Osmolality)
Angiotensin
Aldosterone
PREDOMINANT Na+ EXCESS
ALWAYS FAILURE OF HOMEOSTASIS
 Primary
aldosteronism (conn’s
syndrome).
– Cushings syndrome.
– Secondary aldosteronism.
 Clinical
finding (conn’s syndrome)
– Volume excess.
– Hypertension rarely oedema.
– Those of hypokalaemia.
PREDOMINANT Na+ EXCESS
ALWAYS FAILURE OF HOMEOSTASIS
 Lab.
–
–
–
–
Findings.
Hypokaelemia.
HCO3.
Na+.
Urinary Na+ (Hypokalaemia a
lkalosis + BP

– Aldo + Renin.
PREDOMINANT Na+ EXCESS
ALWAYS FAILURE OF HOMEOSTASIS
 2ndary
aldosteronism.
 Clinical finding (conn’s syndrome)
– As in primary.
 Lab.
–
–
–
–
–
Findings.
Normal Na+
Urinary Na+.
Findings of primary abnormality.
Hypokalaemia
Uraemia.
THERAPY
Water
Neonate – 1 month
1st wk
110mls/kg/24hrs.
2nd 3rd wk
120-130mls/kg/24hrs.
1month – 1yr
100mls/kg/24hrs
1yr – 3yrs
90mls/kg/24hrs
3yrs – 7yrs
80mls/kg/24hrs
7yrs – 13yrs
70mls/kg/24hrs
13yrs onwards like adulsts 40-60mls/kg/24hrs
Calculate/hour then/min then drops/min
ELECTROLYTE
 Na+
1.5 - 2mmol/kg/24hrs
 K+
1 - 1.52mmol/kg/24hrs
 Ca++
as requried
 Mg
0.5mmol/GN2 loss
 PO4
0.5mmol/kg/24hrs
 Na+
1.5 - 2mmol/kg/24hrs
DAILY CALCULATIONS
1st day – Per kg wt
Subsequent days = weighting
= previous Out P+500mls
THERAPY DURING OPERATION
Daily fluid requirement.
 Hb correction.
 Blood loss.

– Newborn
– Adults

>10% of blood volume.
>15% of blood volume.
HB correction
Normal Hb of that age – Hb of patient x blood volume.

Blood volume
– Premature
– Newborn
– Adults
85-90mls/kg.
80-85mls/kg.
75-80mls/kg.
THERAPY DURING
OPERATION
CONTROVERSIAL?
Benefit  No renal failure.
Drawback Blood coaguability
PHYSIOLOGICAL RESPONSE
TO
Stress – Surgery
Stress – Anaesthesia
ADH
Aldosterone
Renin
Retention of
H2O + Na+
Loss of K+
2 – 4 days
MANAGEMENT GUIDELINES
 Intr-operative
– Hartmann’s solution
or
15ml/kg/hr
Ringolact solution
– Blood to maintain Hb>10g/dl
 Exceptions
– Septicaemia.
– Lung trauma.
– PAWP
POSTOPERATIVE PERIOD
 24
– 48 HRS.
dextrose/ saline = 30ml/kg/day
+
30mmol K+/L
– Replace specific losses.
– Maintain urine output>0.5ml/kg/hr.
POSTOPERATIVE PERIOD
 AFTER
48 HRS
– Add Na+
– 4% D/W 0.18% saline 30ml/kg/day.
or
5% D/W 7ml/kg/day
+
Normal aline 23ml/kg/day.
– Assess serum K+ level.
– Consider parentral nutrition.
CHOICE OF FLUIDS
COLLOIDS
Blood in different
forms.
 Plasma.
 Plasma substitutes.

CRYSTALLOIDS
Na+ containing
fluids.
 Na+ free fluids.
 Hyper-osmolar
solution.

PLASMA
 Dried
plasma.
 FFP.
 Plasma
protein fraction.
 Albumin.
 Drid
fibrinogen.
 Cryoprecipitate.
PLASMA SUBSTITUTES
 Dextran.
 Gelatin
preparations
 Polyvinyl
 HES
pyrolidone
MONITORING
 CVS.
 Respiratory
 Renal
System.
 CNS.
 Lab
System.
Results.
Helping tools for assessment

1, CVP

2, TED

3, LIDCO
HYPERNATRAEMIA
MANAGEMENT
Definition
 Na
> 145 mmol/L
 Clinical
presentation
Na 158—160 mmol/L
Acute /chronic onset
CAUSES

1,Associated with hypovolaemia
 2,Associated
with hypervolaemia
 3,Associated
with euvolaemia
CAUSES
 Associated
with hypovolaemia &
dehydration
1,Dermal loss
2,GI loss
3,Urine loss,diuretics
4,Post obstriction
5,Hyperosmolar- non ketotic coma
CAUSES
 Associated
with hypervolaemia
Iatrogenic
Hyperaldosteronism
Excess salt ingesation
CAUSES
 Associated
with euvolaemia
Diabetes inspidus
Hypodipsia
Fever
Hyperventilation
Mechanical ventilation
Clinical presentation
 Hyper-osmolarity
leads to;
Confusion
Somnolence
Coma
Death
MANAGEMENT
 AIMS
Diagnose & treat underlying cause
Correct Hyper-tonicity
MANAGEMENT
 INITIAL
assessment &investigation
1,Hydration status
2,Consider causes
3,Cause unclear, measure
Urine osmolality
Urine Na concentration
Correction of
Hypernatraemia
 1,
If rapid development in hours ,rapid
correction ie reduce 1 mmol/L/ hour
2,If slow development ie in days, slow
correction, target 10 mmol/L/day
3,Only hypotonic fluids used
4.Correct shock with 0.9% saline
5,Where hypertonic Na gain with
overload ,use diuretics +5% Dext.
CORRECTION
6,Determine,
Fluid requirement-water deficit
Required Na fall
Appropriate infusate
Rate of infusion
7,Recheck electrolytes frequently
WATER DEFICIT
 Water
deficit=
total body water *(1-(140/serumNa) )
Effect of 1L of infusate on serum Na =
;Change in serum Na mmol/L =
(infusate Na-Serum Na/ TBW)
How to drop Na 1 mmol/L/H
 Total
body water= Body Wt.*60/100
= 70Kg * 60/100= 42 L
ECF = 1/3 rd of 42L = 14 L
EC Na Excess = 14 L (Na excess/L)
= 14 L ( 160-140)
= 14*20 = 280 mmol
How to drop Na 1mmol/L/H
Total Na Excess in ECF=160-140=20*14=280
 Total amount of fluid
required to lower Na =280/140=2L
Rate 1mmol/L/H=14mmol/H in ECF
Time required to lower 280 mmol=280/14
=20 hours
Rate of fluids to lower 280 mmol Na in
20 hours at the rate of 1mmol/h =2L/20 h
=100 mls/hour
Type of fluid=5% dextrose in water
