1、.,1,老年低鈉血癥,北大醫(yī)院 周國(guó)鵬,.,2,流行病學(xué),發(fā)病率約 1% 外科病房發(fā)病率約4.4% 重癥病人發(fā)病率 30%,.,3,70歲老年病人,7%門診病人合并低鈉血癥 入院時(shí)：1120%合并低鈉血癥 73%為醫(yī)源性（輸液、利尿） 住院病死率 8%，同齡病人2倍 住院時(shí)間延長(zhǎng),Luckey, A.E. classically urine osmolality is 300 or greater, but the urine osm of 220 in the setting of a serum na of 121 is inappropriately elevated (over 100

2、 really is inappropriate),.,62,Case.,3. What other laboratory data would be needed? TSH Cortisol level (although not orthostatic) probably neuroimaging given underlying dementia and risk for CVA, subdural, etc consider uric acid to help differentiate hypovolemia from SIADH (hypouricemia in SIADH, el

3、evated/normal uric acid if dehydrated),.,63,Case.,4. How might her diet be contributing to her hyponatremia? Poor solute intake could result in dilute urine and hyponatremia as discussed previously,.,64,Case.,5. How is the urine Na helpful in differentiating SIADH from hypovolemia? What in this case

4、 would limit its usefulness? Urine Na should be normal/elevated with SIADH and should be low with hypovolemia thiazide diuretic use may elevated urine na temporarily,.,65,Case.,6. How does water intake or hypotonic fluid intake worsen the hyponatremia with SIADH? Example: patient with SIADH, urine o

5、smolality of 616 mosmol/kg; 1 liter of NS has 308 mosmol of NaCl, 1000 cc H2O; Isotonic Saline NaCl H2O In 308 1000 ml Out 308 500 ml (conc 616) Net 0 +500 of free H2O!,.,66,Case.,7. How would you manage this patient? Water restriction? Need to address amount of intake she has had Avoid rapid correc

6、tion (osmotic demylination) Discontinuation of Thiazide Would probably not give IVF initially as most may be due to thiazide, SIADH, poor diet, although may be complicating element of hypovolemia; if n/v persisted after holding thiazide, consider small amount of normal saline (relatively hypertonic with urine osm of 220),.,67,小結(jié),低鈉血癥病因復(fù)雜 治療基于癥狀嚴(yán)重程度 嚴(yán)