Fluid and Electrolyte Emergencies

Fluid and electrolyte emergencies become dangerous when a concentration change disrupts the organ that depends on it most. Potassium abnormalities can alter skeletal-muscle strength and cardiac conduction; sodium abnormalities change extracellular osmolality and can injure the brain; abnormal volume can impair perfusion or gas exchange. This lesson emphasizes hyperkalemia, acute symptomatic hyponatremia, and the volume findings that change urgency. The safest approach is to connect the laboratory value with the patient’s rhythm, neurologic status, respiratory effort, kidney function, urine output, and recent medications rather than treating a number in isolation.