fluid & electrolyte balance prof. m. h. mumtaz balance f water balance f elecrolyte balance f...
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FLUID & ELECTROLYTE BALANCE
Prof. M. H. Mumtaz
BALANCE
Water Balance
Elecrolyte Balance
Acidbase 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 Secreted Excreted Location
Na+ 26000 25850 150 PLDC
K+ 900 900 100 100 PD
Cl- 18000 17850 150 PLDC
HCO3 4900 4900 PD
Urea 870 460 410 PLDC
Creatinin 12 1 1 12
Uric acid 50 49 4 5 P
Glucose 800 800 P
Total 51532 50810 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 & ELECTROLYTEwater 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
IC EC
Sodium Low 100 time
Potassium 30 time more Less
Magnessium Predominantly more
Less
Phosphates Predominantly more
Less
chlorids less Predominantly
PHYSIOLOGIC CONTROL OF SODIUM
Aldosterone (2nd factor) Non aldosterone (factors)– GFR (1st factor)– Renal blood flow.– Oncotic pressure in tubular blood.– Third factor
ANGIOTENSINOGEN
ANGIOTENSIN I
ANGIOTENSIN II
ANGIOTENSIN III
LIVER 2 GLOBULIN
FROM KIDNEY & ELSEWHERE
DECAPEPTIDE
IN LUNG
OCTAPEPTIDE
INACTIVE METABOLITESINACTIVE METABOLITES
HEPTAPEPTIDE
AMINOPEPTIDE
CONVERTING ENZYME
RENIN
RENIN ANGIOTENSIN SYSTEM
Indomethacin
B. Blocker
Peptostatin
Captopril
Saralasin
PHYSIOLOGIC CONTROL OF WATER
Intake.– Thirst.
Loss.– ADH– Non ADH factors.
Mannitol. Urea. Glucose.
ADH
Hypothalmic
Cellular arosmolality
Na+ Concentration (Osmolality)
Water
Renal Blood flow
Aldosterone
Angiotensin
Renin
A
B
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
HP
CAPILLARY
CELL
EG
OSMILALITY
Na+
COP
BLOOD VOLUME
RENINALDOSTE
Na+
Na+
ADH Osmolality
H2O
ASSESSMENT OF BALANCEassessment of state of hydration
History. Helping Tools
Clinical state. 1,CVP
– Blood pressure. 2,T.E.D.
S,D,M, 3,LIDCO/any?
– Heart rate.
– Temperature.
– Skin texture.
ASSESSMENT OF BALANCEassessment 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
Mmol/L
125 141 155 120
Proteins L/L
65 45 65 45
DISTURBANCE OF Na+ & H2O METABOLISM
H2O & Na+ Deficiency
I Predominant H2O
depletion.
With homeostasis
Without homeostatis
II Predominant Na+
depletion.
With homeostasis
Without homeostatis
DISTURBANCE OF Na+ & H2O METABOLISMH2O & 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.
ADH
Hypothalmic
Cellular arosmolality
Na+ Concentration (Osmolality)
Water
Renal Blood flow
Aldosterone
Angiotensin
Renin
A?
B
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.– Hypernatraemia.
Lab. Findings– Hypernatremia vol. of urine
– Haemodilution plasone urea.
– Urinary Na+ excretion.
WITHOUT HOMEOSTASIS
Clinical signs.– Fluid depletion
– Hypo-osmolality.
Lab. Finding Haemo-concentration Renal circulatory
insufficiency uraemia.
ADH
Hypothalmic
Cellular arosmolality
Na+ Concentration (Osmolality)
Water
Renal Blood flow
Aldosterone
Angiotensin
Renin
A
B?
PREDOMINANT H2O EXCESScommonly 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.
Lab. Findings– Hypernatremia vol. of urine
– Haemodilution plasone urea.
– Urinary Na+ excretion.
Clinical signs.– Fluid depletion
– Hypo-osmolality.
Lab. Finding Haemo-concentration Renal circulatory
insufficiency uraemia.
ADH
Hypothalmic
Cellular arosmolality
Na+ Concentration (Osmolality)
Water
Renal Blood flow
Aldosterone
Angiotensin
Renin
A?
B
PREDOMINANT Na+ EXCESSALWAYS 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+ EXCESSALWAYS FAILURE OF HOMEOSTASIS
Lab. Findings.– Hypokaelemia. HCO3. Na+. Urinary Na+ (Hypokalaemia a
lkalosis + BP
Aldo + Renin.
PREDOMINANT Na+ EXCESSALWAYS 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.
THERAPYWaterNeonate – 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/24hrsDAILY CALCULATIONS1st day – Per kg wtSubsequent days = weighting
= previous Out P+500mls
THERAPY DURING OPERATION Daily fluid requirement. Hb correction. Blood loss.– Newborn >10% of blood volume.
– Adults >15% of blood volume.
HB correctionNormal Hb of that age – Hb of patient x blood volume.
Blood volume– Premature 85-90mls/kg.
– Newborn 80-85mls/kg.
– Adults 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
Ringolact solution– Blood to maintain Hb>10g/dl
Exceptions– Septicaemia.– Lung trauma. PAWP
15ml/kg/hr
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 pyrolidone
HES
MONITORING
CVS.
Respiratory System.
Renal System.
CNS.
Lab 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