Summary
Highlights
The video introduces the critical role of fluid and electrolytes in maintaining life, with water making up 70% of the body. It highlights six main electrolytes: potassium, sodium, chloride, calcium, phosphate, and magnesium, explaining their function in muscle contraction, nerve impulses, bone formation, fluid balance, and acid-base balance.
Sodium is discussed as a key extracellular electrolyte regulating water, muscle contraction, and nerve impulses. Normal levels are 135-145 mEq/L. Hyponatremia (below 135) causes cell swelling, and is linked to diuretics, GI loss, Addison's disease, and SIADH. Symptoms include seizures, lethargy, and abdominal cramping. Hypernatremia (above 145) causes cell shrinkage, and is associated with Cushing's syndrome, Conns syndrome, hypertonic solutions, dehydration, and increased sodium intake. Symptoms include fatigue, restlessness, extreme thirst, and decreased urinary output.
Chloride, closely related to sodium, is vital for acid-base balance and digestion. Normal levels are 95-105 mEq/L. Hypochloremia (low levels) is caused by GI losses (vomiting, suction, ileostomy), diuretics, burns, cystic fibrosis, fluid overload, and metabolic alkalosis. Symptoms overlap with hyponatremia. Hyperchloremia (high levels) results from excessive sodium intake, dehydration, decreased bicarbonate, Conns syndrome, corticosteroids, and metabolic acidosis. Symptoms are similar to hypernatremia and acidosis.
Potassium, an intracellular electrolyte, is crucial for muscle contraction and nerve impulses, and has an inverse relationship with sodium. Normal levels range from 3.5-5 mEq/L. Hypokalemia (below 3.5) is caused by loop diuretics, corticosteroids, excess insulin, Cushing's syndrome, starvation, and GI losses. Symptoms include lethargy, shallow respirations, dysrhythmias (ST depression), frequent urination, leg cramps, and low blood pressure. Hyperkalemia (above 5) results from severe burns, tissue damage (rhabdomyolysis), Addison's disease, renal failure, potassium-sparing diuretics, ACE inhibitors, and NSAIDs. Symptoms include muscle weakness (leading to respiratory failure), little/no urinary output, decreased cardiac contractility (weak pulse), muscle twitches, and characteristic tall peaked T waves on EKG.
Calcium is essential for bones, teeth, muscle/nerve conduction, and clotting. Its balance is regulated by vitamin D, parathyroid hormone, and calcitonin. Normal levels are 8.5-10.5 mg/dL. Hypocalcemia (low levels) is caused by decreased parathyroid hormone (e.g., after thyroidectomy), decreased calcium intake, low vitamin D, chronic kidney disease, bisphosphonates, aminoglycosides, and anticonvulsants. Symptoms include convulsions, hyperactive reflexes (Trousseau's and Chvostek's signs), arrhythmias (prolonged QT interval), muscle spasms, and tingling. Hypercalcemia (high levels) is caused by overactive parathyroid, increased vitamin D, supplements, cancer spreading to bones, thiazide diuretics, and lithium. Symptoms include muscle weakness, EKG changes (shortened QT interval), absent reflexes, altered mental status, abdominal distension, and kidney stone formation.
Magnesium, an intracellular electrolyte, functions in nerve and muscle, blood pressure regulation, and muscle contraction/relaxation, interacting closely with calcium and potassium. Normal levels are 1.5-2.5 mg/dL. Hypomagnesemia (low levels) is caused by insufficient intake, other electrolyte imbalances (low calcium, potassium), malabsorption, PPIs, and alcoholism. Symptoms ('TWITCH') include Trousseau's/Chvostek's signs, weakness, increased DTRs, Torsades de pointes, tetany, low calcium/potassium, and hypertension. Hypermagnesemia (high levels) is relatively rare, often due to overcorrection of low magnesium or magnesium sulfate administration (e.g., in preeclampsia), and renal dysfunction. Symptoms ('LETHARGIC') include lethargy, EKG changes (prolonged PR/QT, wide QRS), absent DTRs, hypotension, arrhythmias (bradycardia, heart blocks), red/hot face, GI issues, impaired breathing, and confusion.
Phosphate builds teeth and bones, is stored in bones, absorbed in the gut, and excreted by kidneys, regulated by the parathyroid gland and vitamin D. Normal levels are 2.5-4.5 mg/dL. Hypophosphatemia (low levels) is caused by overuse of aluminum-based antacids, starvation, refeeding syndrome, overactive parathyroid, and low vitamin D. Symptoms ('BONE') include bone pain/fractures, osteomalacia, neurostatus changes, and erythrocyte destruction (hemolytic anemia). Hyperphosphatemia (high levels) is caused by overuse of phosphate-containing laxatives (e.g., Fleet's enema), renal failure, too much vitamin D, rhabdomyolysis, and hypoparathyroidism. Symptoms are similar to hypocalcemia, including convulsions, hyperactive reflexes, arrhythmias, muscle spasms, itching, and Trousseau's/Chvostek's signs.