Fluid, Electrolyte And Acid-Base Homeostasis
Sample Solution
1. Ms. Brown's Water and Electrolyte Imbalance:
Based on her laboratory values, Ms. Brown likely has a mixed water and electrolyte imbalance with elements of:
- Hyponatremia (low sodium): Serum Na+ of 156 mEq/L is below the normal range of 135-145 mEq/L.
- Dehydration: Inability to eat or drink for 2 days suggests hypovolemia, a decrease in total body fluid volume. This can contribute to her low sodium and other imbalances.
- Hyperkalemia (high potassium): Serum K+ of 5.6 mEq/L is above the normal range of 3.5-5.0 mEq/L.
2. Water Imbalance and Potassium Level Manifestations:
Full Answer Section
Types of Water Imbalance:- Hyponatremia: Can cause confusion, nausea, muscle weakness, lethargy, and seizures in severe cases.
- Hypernatremia: Less common in this case, but can cause thirst, drowsiness, muscle cramps, and coma in severe cases.
- Hypotonic dehydration: Caused by fluid loss exceeding electrolyte loss, leading to swelling of cells. Symptoms include fatigue, muscle cramps, nausea, and dizziness.
- Hypertonic dehydration: Caused by electrolyte loss exceeding fluid loss, leading to cell shrinkage. Symptoms include thirst, confusion, and rapid heartbeat.
- Muscle weakness: This is the most common symptom and can range from mild fatigue to paralysis.
- Cardiac arrhythmias: High potassium can disrupt heart rhythm, potentially leading to serious complications.
- Tingling/numbness: Potassium imbalances can affect nerve function, causing tingling or numbness in extremities.
- Weakness and fatigue
- Nausea and vomiting
- Muscle cramps
- Dizziness or lightheadedness
- Confusion or delirium
- Irregular heartbeat
- Treatment for Ms. Brown:
- Fluid resuscitation: Intravenous fluids with appropriate electrolytes, considering her hyponatremia and hypovolemia.
- Potassium monitoring: Closely monitoring her K+ levels and potentially administering insulin or glucose to drive potassium back into cells.
- Addressing the underlying cause: Treating the cough and any other contributing factors, such as infection or metabolic issues.
- Acid-Base Imbalance on ABGs:
- Mild metabolic acidosis: pH of 7.30 is slightly below the normal range of 7.35-7.45.
- Normal respiratory status: PaCO2 of 32 mmHg and PaO2 of 70 mmHg are within normal ranges.
- Compensatory metabolic response: HCO3– of 20 mEq/L is slightly elevated, indicating her body is trying to buffer the acidosis.
- Anion Gap:
- Definition: The anion gap is the difference between the measured cations (Na+ and K+) and the main measured anions (Cl– and HCO3–). It normally ranges from 8-16 mEq/L.
- Clinical significance: A widened anion gap (>16 mEq/L) indicates the presence of unmeasured negatively charged molecules (anions) in the blood. This can be due to various conditions, including diabetic ketoacidosis, lactic acidosis, and renal failure.