Fluid and Electrolyte Imbalance Lee, Chin-Chan Chang Gung Memorial Hospital, Keelung 1 Outline Salt and Water Control Hyponatremia Hypernatremia Case Demonstration 60% 20% 15% 40% 5% 60% 20% 15% 40% 5% 60% (TBW) 40% (ECF) 20% (ICF) 15% 5% Not really correct, but useful Urine osmolality Na, Cl, Urea, Glu,.. ADH ADH secretion Urine sodium Volume status Renin-angiotensin-aldosterone Low UNa means low effective Low effective circulating volume circulating volume High plasma osmolality Take Home Message Osmoregulation and volume regulation Definition of Hyponatremia Importance of Sodium level and Osmolality (both Urine and Blood ) Take Home Message Hyponatremia always accompanied with high Uosm (except..), that means High ADH Causes of persistent High ADH, e.g. Low effective circulating volume (the UNa will be low) If no evident causes found, then, SIADH possibility high, (the UNa will be high) Some exception: renal failure…. (both Urine and Blood ) Thank You 30