CHAPTER 7
Endocrine, Metabolic,
Fluid, and Electrolyte
Disorders
Kenny V. Banh, MD
Fluid and Hydration 385
BASICDEFINITIONS 385
TOTALBODYWATER ANDDISTRIBUTION 385
PHYSIOLOGY 385
FLUIDBALANCE 386
Electrolyte Pump Physiology 387
Sodium 387
HYPONATREMIA(Na+<135 mEq/L) 388
HYPERNATREMIA(Na+>145 mEq/L) 390
Potassium 391
HYPOKALEMIA(K+<3.5 mEq/L) 391
HYPERKALEMIA(K+>4.5 mEq/L) 393
Calcium 394
HYPOCALCEMIA(Ca2+<8.5 mg/dL) 395
HYPERCALCEMIA(Ca2+>10.5 mg/dL) 395
Magnesium 396
HYPOMAGNESEMIA(Mg2+<1.4 mEq/L) 397
HYPERMAGNESEMIA(Mg2+>2.2 mEq/L) 397
Chloride 398
HYPOCHLOREMIA(Cl–<100 mEq/L) 398
HYPERCHLOREMIA(Cl–>110 mEq/L) 398
Acid-Base Disorders 399
INTERPRETINGBLOODGASES 399
METABOLICACIDOSIS(↓pH + ↓HCO 3 – ) 400
METABOLICALKALOSIS(↑pH + ↑HCO 3 – )4 01
RESPIRATORYACIDOSIS(↓pH + ↓HCO 3 – )4 01
RESPIRATORYALKALOSIS(↓pH + ↓HCO 3 – ) 402
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