1. Case123456 P[Na + ] 120120120120120120 Glu1001001350100100100 Urea1515151512515 C Osm 250250320250290250 M Osm 250290320325290290 Osm gap 040075040 Effective Osm 245285315320245245 Cerebral edema ↑- ↑ ↓ ↓↑↑ Diagnosis?????? Case 2: Different Causes of Hyponatremia

2. Dilutional hyponatremia PseudohypoNa Iso-osmotic True hyponatremia

3. Case123456 P[Na + ] 120120120120120120 Glu1001001350100100100 Urea1515151512515 C Osm 250250320250290250 M Osm 250290320325290290 Osm gap 040075040 Effective Osm 245285315320245245 Cerebral edema ↑- ↑ ↓ ↓↑↑ DiagnosisTrueHyponatremia Pseudohyponatre mia Protein/ lipid Dilutional HypoNa (hyperglycemia) MannitolTrueHyponatremia Renal insufficiency MethanolEthanol Case 2: Different Causes of Hyponatremia

4. Hyponatremia 1. Calculated osmolality = 2 x Na + GLU/18 + BUN/2.8 2. measured osmolality 3. Osmolar gap = measure osm – calculated osm Increased osmolar gap >10 Ethanol, methanol, ethylene glycol, mannitol Ethanol, methanol, ethylene glycol, mannitol Pseudohyponatremia ( hyperproteinemia, hyperlipidemia )Pseudohyponatremia ( hyperproteinemia, hyperlipidemia )

5. Case 1 Case 1 True and acute hyponatremia with brain edema, not a chronic, 注意治療要快一點 True and acute hyponatremia with brain edema, not a chronic, 注意治療要快一點 Case 2Case 2 Iso-osmotic or pseudohyponatremia due to hyperproteinemia, hyperlipidemiaIso-osmotic or pseudohyponatremia due to hyperproteinemia, hyperlipidemia Nonsense osmolar gap, 間接性的關係 Nonsense osmolar gap, 間接性的關係 不用治療 不用治療

6. Case 3.Case 3. Hyperosmotic hyponatremia due to hyperglycemiaHyperosmotic hyponatremia due to hyperglycemia 先算 Na decrease 1.6 meq/L for each increase glucose100mg/dl 先算 Na decrease 1.6 meq/L for each increase glucose100mg/dl mOsm increases in parellel with cosm, osm gap is zeromOsm increases in parellel with cosm, osm gap is zero Effective osm is abnormally increased, 要先 r/o risk of brain edemaEffective osm is abnormally increased, 要先 r/o risk of brain edema Treat hyperglycemiaTreat hyperglycemia Case 4Case 4 Hyperosmotic hyponatremia due to mannitolHyperosmotic hyponatremia due to mannitol Mannitol is non sodium particleMannitol is non sodium particle Cosm 裏面 mannitol 沒有算進去, abnormal low value of CosmCosm 裏面 mannitol 沒有算進去, abnormal low value of Cosm and increased osm gap and increased osm gap 有無 brain edema 要看 effective osm, not sodium 有無 brain edema 要看 effective osm, not sodium cerebral edema 用 mannitol 治療後 Brain cell volumecerebral edema 用 mannitol 治療後 Brain cell volume 變 relatively 小 變 relatively 小

7. Case 5 True hyponatremia due to elevated BUN, renal insufficiencyTrue hyponatremia due to elevated BUN, renal insufficiency Mosm and Cosm 裏面 BUN 算進去. The OG is Zero Mosm and Cosm 裏面 BUN 算進去. The OG is Zero Urea is ineffective osmoleUrea is ineffective osmole Effective osm is low, hyponatremia 是有意義的, 有 risk of cerebral edema,Effective osm is low, hyponatremia 是有意義的, 有 risk of cerebral edema, Treatment 快 or 慢 depend on conditionTreatment 快 or 慢 depend on condition Case 6 True hyponatremia, due to use of glycine in TURP or bladder irrigation, methanol, ethanol ingestion,  retained particle,True hyponatremia, due to use of glycine in TURP or bladder irrigation, methanol, ethanol ingestion,  retained particle, 有 osm gap 有 osm gap Low effective osmolality is increased risk of cerebral edemaLow effective osmolality is increased risk of cerebral edema Treatment is urgentTreatment is urgent