Lecture on Fluids and Electrolytes: Potassium
Importance of Potassium
- Electrolyte Role: Potassium is a critical electrolyte within our cells.
- Osmolarity Contribution: It significantly contributes to the osmolarity or concentration of the cell cytoplasm.
- Body Processes: Potassium is essential for:
- Muscle cell function
- Metabolism
- Protein synthesis
Regulation of Potassium
- Link with Sodium: Potassium and sodium regulation in the body are closely linked.
- Role of Aldosterone:
- Secreted by the adrenal glands.
- Targets the kidneys, particularly the distal convoluted tubules and collecting ducts in the nephron.
- It is released due to increased plasma potassium concentration and Angiotensin II (from renin-angiotensin system activation).
- Effect: Increases sodium reabsorption and potassium secretion, thus lowering plasma potassium levels.
Disorders of Potassium Concentration
Hyperkalemia
- Definition: High plasma potassium (>5.5 mEq/L).
- Causes:
- Kidney disease
- Addison's disease
- Tissue damage
- Potassium supplements
- Certain blood pressure medications (e.g., ACE Inhibitors)
- Symptoms:
- Fatigue
- Weakness
- Numbness, tingling
- Nausea, vomiting
- Breathing and cardiovascular issues
Hypokalemia
- Definition: Low plasma potassium (<3.5 mEq/L).
- Causes:
- Kidney disease
- Diabetes ketoacidosis
- Vomiting and diarrhea
- Extreme alcohol use
- Some diuretics
- Symptoms:
- Constipation
- Fatigue
- Weakness or muscle spasms
- Dysrhythmias (abnormal heart rhythms)
- Paralysis
Conclusion
- Understanding the role and regulation of potassium is crucial in maintaining overall health.
- Potassium disorders can have significant health impacts and need careful management.
Note: Always consult healthcare providers for management of electrolyte imbalances.