https://idwiki.org/index.php?action=history&feed=atom&title=Hypernatremia 2026-04-29T10:02:41Z Revision history for this page on the wiki MediaWiki 1.43.8 https://idwiki.org/index.php?title=Hypernatremia&diff=4267&oldid=prev 2020-07-04T01:17:39Z

<p>Imported from text file</p> <p><b>New page</b></p><div>== Definition ==<br /> <br /> * A serum sodium above 145mmol/L, usually indicative of a free-water deficit<br /> <br /> == Free Water Deficit ==<br /> <br /> $$ FWD = \text{free water deficit} \ TBW = \text{total body water} $$<br /> <br /> $$ TBW_{man} = 0.6 \times weight \ TBW_{woman} 0.5 \times weight $$<br /> <br /> $$ FWD_total = \frac{Na_{current} - 140}{140} \times TBW \ FWD_{24h} = \frac{10}{Na_{current} - 10} \times TBW $$<br /> <br /> == Differential Diagnosis ==<br /> <br /> * Hypervolemic (increased salt intake)<br /> ** Hypertonic saline or bicarb<br /> ** Salt-water drowning<br /> * Eu- or hypovolemic (increased free water loss)<br /> ** Appropriate urinary concentration, with osmolality &amp;gt;600-800 mOsm/L<br /> *** Insensible losses (fever, exercise, heat, burns)<br /> *** Gastrointestinal water loss (diarrhea)<br /> *** Remote renal water loss<br /> ** Inappropriate urinary dilution, with osmolality &amp;lt;300-600 mOsm/L<br /> *** Urine osmoles &amp;gt; 750 mOsm/d<br /> **** Osmotic diuresis (e.g. mannitol)<br /> *** Urine osmoles ≤ 750 mOsm/d: diabetes insipidus<br /> **** ddAVP increases urine osmolality<br /> ***** Central diabetes insipidus<br /> **** ddAVP does not increase urine osmolality<br /> ***** Nephrogenic diabetes insipidus<br /> <br /> == Investigations ==<br /> <br /> * Electrolytes &amp;amp; creatinine<br /> * Urine lytes, osmolality, to rule out diabetes insipidus<br /> * Follow serum and urine lytes and osmolality daily or more frequently<br /> <br /> == Management ==<br /> <br /> * Treat underlying cause, and correct free water deficit<br /> * Correction rate<br /> ** No more than 10 mmol daily, in general<br /> ** Usually corresponds to 1-2x maintenance fluids of 1/2 NS<br /> ** If acute &amp;lt;48h, can correct by up to 1mmol/h (24mmol daily)<br /> * Monitor urine and sodium lytes, urine osmolality, and urine output while correcting<br /> ** If correcting too quickly, switch fludis<br /> * In cases of diabetes insipidus<br /> ** For central DI: ddAVP<br /> ** For nephrogenic DI from lithium: amiloride 2.5-10mg/d<br /> <br /> [[Category:Nephrology]]</div>

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