1 Disturbances in water management Osmolality © Department of Biochemistry (V.P.), Faculty of Medicine, MU Brno 2009 2 Disturbances in water management: 1/ ECF is hyperosmolar 2/ ECF is isoosmolar 3/ ECF is hypoosmolar 3 Arrange of next Schemas : 1/ inicial situation advanced situation (disturbance) 2/ the name of disturbances is according to changes in ECF: ( „hyper-/iso-/hypo-TONIC + over-/de-HYDRATATION" ) 3/ ECF ICF extracellular intracellular 4 fluid fluid ECF is hyperosmolar : 1/ retention / supply Na+ 2/ loss of „pure" water 5 Retention / supply Na+ : ECF is hyperosmolar t[Na+] • I ■ ■ ■ • HO • water to the ecf ® expansion of ecf • edema - danger of pulmonary edema ! • deficit of water in i c f —> disturbances of CNS 6 Retention / SUPPlv Na+ : - hypertonic overhydration causes: excessive administration of salt overactivity of adrenal cortex (Conn, Cushing) administration of steroids cerebral „salt retention syndrome" drinking of see-water (after shipwreck) symptoms: vomiting diarrhoae labile blood pressure changes in central venous pressure pulmonary oedema restlessness 7 Loss of „pure" water ECF is hyperosmolar H2O H2O ( normal hematocrite ) water to the E CF deficit of water mainly in IC F ® disturbances of CNS 8 Loss of „pure" water : = hypertonic dehydration causes: inadequate water intake (failing feeling of thirst in old persons) increased water losses due to sweating osmotic diuretics hyperventilation chronic nephropathy polyuric phase of akute renal failure diabetes insipidus symptoms: thirst fever dryness restlessness delirium, coma 9 ECF is isoosmolar: 1/ loss of isotonic fluid ( ® blood circulation disturbances ) 2/ isoosmotic expansion of ECF ( ® edema ) because of the same osmolality, no transfers of water between ECF and ICF, the changes are in the volume of ECF only. 10 Isotonic fluid losses : = isotonic dehydration causes: vomiting diarrhoea fistulae symptoms: diuretics thirst drainage of ascites tiredness/faiting burns weakness sedative and CO intoxication rapid puls sunstroke hypotonia collapse vomiting muscle cramps 11 Isoosmotic expansion of ECF • • — isotonic overhydration causes: excessive administration of isotonic infuson solutions in oliguric and anuric states cardiac failure nephrotic syndrome chronic uraemia acute glomerulonephritis cirrhosis of liver symptoms: protein-losing enteropathy oedema effusions dyspnoea 12 ECF is hypoosmolar: 1/ loss of „pure" Na+ 2/ water intoxication 13 Loss of „pure" Na+ : ECF is hvpoosmolar ■ • ■ I ■ • ■ • ■ I ■ • ■ • h2o • leakage of water into ICF ® T intracranial pressure • hvpovolemia of e C F ® blood circulation disturabces 14 Loss of „pure" Na+ : = hypotonic dehydration causes: iadequate sodium intake after its losses through vomiting, diarrhoea and sweating increased sodium losses due to adrenal failure chronic diuretic therapy diarrrhoea symptoms: fistula losses tiredness/faiting weakness hypotonia rapid puls collapse vomiting fever muscle cramps depressed conscinous level 15 Water intoxication ECT je hypoosmolar + h2o • leak of water into IC F ® t intracranial pressure 16 Water intoxication : = hypotonic overhydration causes: excessive administration of salt-free solutions gastric lavage with water increased ADH activity příznaky: weakness nausea vomiting dyspnoea confusion loss of consciousness 17 HO x CH2 CH OH oH CH CH-NH „extáze" / „ecstasy" CH3 Intoxikace vodou Water intoxication (= hypotonická hyperhydratace po požití „extáze") CH2 NH adrenalin / epinephrine CH x x 1) <1 ® „hyperaldosteronismus" (accidental sample of urine is sufficient for determination, we cannot know the volume) 32 osmolalita osmolality 33 Ca = Cb Osmotic pressure and osmotic equilibrium: t' a b Vychozi slav |3 Ca>Cb + e o Ca =Cb 34 osmotic pressure: II = i • c • R • T (mmol / kg) osmotic concentration: = i • c (mmol / L) c = molarity i = ionization 35 212 F pure water 32 F 100 °C cista voda 0 °C elevace (zvýšení) bodu varu roztok osmoticky aktivních částic deprese (snížení) bodu tání boiling-point elevation a solution of osmotic active particles freezing-point depression 36 Osmometry - cryoscopic principle i 0 1 2 3 minuta 37 The osmolality of blood plasma : ~ 300 mmol . kg -1 mosimik^g-1 man 290 ± 10 mmol . kg 1 woman 285 ± 10 mmol . kg 1 38 The blood plasma osmolality: ~ 300 mmol . kg -i 350 mmol . kg 1 the critical value (life threatening) The urine osmolality: 50 -1.400 mmol . kg 1 39 The correction formula for compensation of water in hypernatraemia : . [Na+] - 140 TOW H2O (litres) =---- • TBW 2 140 60 % of bodv weight 40 The blood plasma osmolality: Na+, K+, HCO3-, glucose, urea P-osmolality (mmol . kg -1) @ @ 2[Na+] + [glucose] + [urea] ( 2 * 140 + 5 + 5 = 290 ) 41 U-osm / S-osm : @ 2 - -> normal kidney function (child and adult) @ 1 - -> isostenuria: 1/ effective diuretics 2/ renal insufficiency *) 3/ norm in the newborn @ 0,5 - -> water intoxication @ 0,2 - -> diabetes insipidus *) insufficiency: renal < 1,2 < extrarenal 42 The urine osmolality: ~ 1.200 mmol . kg 1 ~ 500 —> urea, Na+, K+, NH4+ no calculation possible ! 43 Osmometr Osmometer Osmometer (cryoscopic measurement) (scheme) The sample cannot be measured repeatedly - freezing and unfreezing change properties of protein ! + 1 mol . kg-1 ® -1,86 oC + 1 mmol . kg-1 ® -0,001.86 oC !! The calibration: 9,485 g NaCl / kg water = 9,485 / 58,443 = 0,161.953 mol NaCl / kg water = = 161,95 mmol NaCl / kg water (161,95 * 2 = 323,905 mmol / kg - at completely dissociation 161,95 * 1,86 = 301,227 mmol / kg @ 300 mmol / kg water 45 Onkometr Oncometer 46 Oncotic pressure - principle of measurement : The oncotic pressure is a part of the osmotic pressure of plasma maintained by macromoleculs. the sample of blood serum / plasma pressure sensor semipermeable membrane (permeability to M, = 20.000) The permeability of saline solution into sample through the membrane is given by osmosis. The sensor measures the pressure decrease of saline solution (due to decrease its volume „under" membrane) The oncotic pressure = colloid osmotic pressure = „COP" COP = 2,66 - 3,33 kPa (approximately 3 kPa) COP = 1,33 -2,66 kPa ® danger of edema pulmonum COP < 1,4 kPa ® no survive without i.v. administration of albumin (80 % COP of plasma ensures albumin) 48 pressure Capillary - the movement of fluid between plasma and ISF : arterial end of capillary oncotic pressure hydrostatic pressure length of blood capillary venous end of capillary hydrostatic pressure exceeds oncotic pressure ® filtration of fluid into ISF oncotic pressure exceeds hydrostatic pressure ® reabsorption of ISF back to the capillary 49 The oncotic pressure - normal concentrations of blood proteins : P-albumin = 35 - 50 g . l-1 P-total protein = 62 - 82 g . l-1 Compare: grave swelling and ascites in serious hypoproteinemias of the kwashiorkor type ! 50 51