TY - CHAP M1 - Book, Section TI - Fluid & Electrolyte Abnormalities A1 - Wong, Mariko Koya A1 - Campbell, Kellie Hunter A2 - Williams, Brie A. A2 - Chang, Anna A2 - Ahalt, Cyrus A2 - Chen, Helen A2 - Conant, Rebecca A2 - Landefeld, C. Seth A2 - Ritchie, Christine A2 - Yukawa, Michi PY - 2014 T2 - Current Diagnosis & Treatment: Geriatrics, 2e AB - Hyponatremia is commonly defined as a serum sodium concentration less than 135 mEq/L (or 135 mmol/L).Hypernatremia is commonly defined as a serum sodium greater than 148 mEq/L (or 148 mmol/L).Hypokalemia is typically defined as a serum potassium concentration of less than 3.5 mEq/L.Hyperkalemia is typically defined as a serum potassium concentration greater than 5.0 mEq/L.Nocturnal polyuria is present when urine production during 8 hours of sleep is >33% of 24-hour urine production, nighttime urine production rate is >0.9 mL/min or 7 PM to 7 AM urine volume is >50% of total 24-hour volume. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessmedicine.mhmedical.com/content.aspx?aid=1100067698 ER -