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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.
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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.
INTAKE Food Drink Metabolic OUTPUT Urine Stool Sweat Respiration NORMAL ROUTES
Intravenous Nasogastric aspiration Enterostomy Colostomy PATHOLOGICAL ROUTES
RENAL LOSS FILTERATION REABSORPTION
WATER 180L/24h 125mls/min 7.5/hr 4xBW =15xECF =60xPV SODIUM 30000mmol/24hr 18125Ueq/min FILTERATION
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 REABSORPTION
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
PHYSIOLOGIC CONTROL OF SODIUM • Aldosterone (2nd factor) • Non aldosterone (factors) • GFR (1st factor) • Renal blood flow. • Oncotic pressure in tubular blood. • Third factor
LIVER 2 GLOBULIN RENIN FROM KIDNEY & ELSEWHERE ANGIOTENSINOGEN ANGIOTENSIN I ANGIOTENSIN II ANGIOTENSIN III DECAPEPTIDE CONVERTING ENZYME IN LUNG OCTAPEPTIDE INACTIVE METABOLITES INACTIVE METABOLITES AMINOPEPTIDE HEPTAPEPTIDE
RENIN ANGIOTENSIN SYSTEM • Indomethacin • B. Blocker • Peptostatin • Captopril • Saralasin
PHYSIOLOGIC CONTROL OF WATER • Intake. • Thirst. • Loss. • ADH • Non ADH factors. • Mannitol. • Urea. • Glucose.
ADH Water A Renal Blood flow Hypothalmic Cellular arosmolality Renin B Angiotensin Na+ Concentration (Osmolality) Aldosterone
CONTROL OF WATER IN COMPARTMENTS INTRAVASCULAR/INTERSTITIAL • Proteins – colloid osmotic pressure. • Hydrostatic pressure. INTERSITITAL/INTRACELULAR • Osmolality – predominantly – Na+
HP THE KINETICS OF PVE INTRACELLULAR INTERSTITIAL VASCULAR CAPILLARY EG CELL OSMILALITY Na+ COP
BLOOD VOLUME RENIN ALDOSTE 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.
I Predominant H2O depletion. With homeostasis Without homeostatis II Predominant Na+ depletion. With homeostasis Without homeostatis DISTURBANCE OF Na+ & H2O METABOLISMH2O & Na+ Deficiency
III Predominant H2O excess. With homeostasis Without homeostatis IV Predominant Na+ excess. Without homeostatis DISTURBANCE OF Na+ & H2O METABOLISMH2O & Na+ Excess
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. PREDOMINANT H2O DEPLETION
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 Water A? Renal Blood flow Hypothalmic Cellular arosmolality Renin B Angiotensin Na+ Concentration (Osmolality) Aldosterone
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. PREDOMINANT Na+ DEPLETION
ADH Water A Renal Blood flow Hypothalmic Cellular arosmolality Renin B? Angiotensin Na+ Concentration (Osmolality) Aldosterone
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 EXCESScommonly associated with failure of homeostasis
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. PREDOMINANT H2O DEPLETION
ADH Water A? Renal Blood flow Hypothalmic Cellular arosmolality Renin B Angiotensin Na+ Concentration (Osmolality) Aldosterone
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 alkalosis + 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.
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 >10% of blood volume. • Adults >15% of blood volume. • HB correction Normal 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
TO Stress – Surgery Stress – Anaesthesia PHYSIOLOGICAL RESPONSE
MANAGEMENT GUIDELINES • Intr-operative • Hartmann’s solution or Ringolact solution • Blood to maintain Hb>10g/dl • Exceptions • Septicaemia. • Lung trauma. • PAWP 15ml/kg/hr