15. Hillier Study on Pseudohyponatremia Na = 140 - 0.016 Glucose Na = 140 - 0.024 Glucose Na = 141 - 0.016 Glucose Na = 151 - 0.04 Glucose
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23. Free water clearance 0.5 liter free water Solute component (plasma osmolality 284 mOsm/kg) Use clearance to calculate the osmolar clearance 1 liter 142 mOsm/Kg 0.5 liter 284 mOsm/Kg
24. Free water clearance Solute component (Solute Clearance) ? 0.5 liter Zero mOsm/Kg Free water component (Free water Clearance) The free water component equals urine volume minus the solute component 1 liter 142 mOsm/Kg 0.5 liter 284 mOsm/Kg
42. ADH is normally used to regulate osmolality We start with an increase in the plasma osmolality This is detected by the brain The brain releases ADH ADH acts on the kidney The kidney reacts by retaining water and producing a small amount of concentrated urine. The retained water goes here not here
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47. The response to hyponatremia Low sodium concentration causes water to move into the cells. In the brain this causes an increase in ICP. Compensated chronic hyponatremia is essentially asymptomatic.
48. The problem with compensation The starting point is after compensation has reduced the amount of intracellular solute and the ICP Now, an over-eager intern sees the low sodium and starts an infusion of 3% NaCl to raise the sodium to normal. Sodium 108 The sodium draws water from the inside of the cells causing the brain to shrivel. The problem with interns Sodium 134