RT Book, Section A1 Malkina, Anna A1 Hadley, Lesca A2 Walter, Louise C. A2 Chang, Anna A2 Chen, Pei A2 Harper, G. Michael A2 Rivera, Josette A2 Conant, Rebecca A2 Lo, Daphne A2 Yukawa, Michi SR Print(0) ID 1180017290 T1 Fluid & Electrolyte Abnormalities T2 Current Diagnosis & Treatment Geriatrics, 3e YR 2021 FD 2021 PB McGraw-Hill Education PP New York, NY SN 9781260457087 LK accessmedicine.mhmedical.com/content.aspx?aid=1180017290 RD 2024/04/19 AB ESSENTIALS OF DIAGNOSISHyponatremia is commonly defined as a serum sodium concentration 145 mEq/L (145 mmol/L).Hypokalemia is typically defined as a serum potassium concentration of 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.