ELECTROLYTE IMBALANCES EXAM REVIEW QUESTIONS AND ANSWERS (GRADED A+)

ELECTROLYTE IMBALANCES EXAM REVIEW QUESTIONS AND ANSWERS (GRADED A+) Hypercalcemia (treatment) - Answer-Treat underlying cause. Hydration, increasing salt intake, and forced diuresis (careful to prevent potassium or magnesium depletion), bisphosphonates and calcitonin Hypocalcemia (causes) - Answer-Hypoparathyroidism is a common cause of hypocalcemia Eating disorders, Prolonged vomiting, excessive diarrhea, excessive dietary magnesium (as with supplementation) excessive dietary zinc (as with supplementation), prolonged use of medications/laxatives containing magnesium, osteoporosis treatment or preventive agents (such as Bisphosphonates and Denosumab) agents for the treatment of hypercalcemia (such as Calcitonin), Chronic renal failure, Absent active vitamin D (from decreased dietary intake, decreased sun exposure) Anticonvulsant therapy, Vitamin-D dependent rickets, pseudohypoparathyroidism, severe acute hyperphosphataemia, Tumour lysis syndrome, acute renal failure Rhabdomyolysis (initial stage), exposure to hydrofluoric acid, pancreatitis, Alkalosis, often caused by hyperventilation, multiple blood transfusions Hypocalcemia (S/S) - Answer-Petechiae, purpura (bleeding abnormalities) Oral, perioral and acral paresthesias (often first sign) Carpopedal and generalized tetany Trousseau sign Chvostek's sign Tendon reflexes are hyperactive Laryngospasm, bronchospasm and laryngeal stridor increased heart rate Intermittent QT prolongation - high risk of torsades de pointes labored, shallow breathing generalized tonic clonic seizures Hypocalcemia (treatment) - Answer-Intravenous calcium gluconate 10% can be administered, or if the hypocalcaemia is severe, calcium chloride is given instead. This is only appropriate if the hypocalcemia is acute and has occurred over a relatively short time frame. Do not put calcium chloride in NS (it increases GFR and calcium excretion) Maintenance doses of both calcium and vitamin-D are often necessary. Phases of renal failure - Answer-1. Initial - decreased GFR 2. Oliguric - no GFR 3. Diuretic 4. Recovery Renal Failure ( causes) - Answer-hypovolemia, mechanical ventilation, surgery, myoglobinuria Loop diuretics - Answer-Lasix, bumex, edecrin Act on the thick ascending limb of the loop of Henle to inhibit sodium and chloride reabsorption and dilates the renal arteries Thiazides - Answer-used for HTN and edema Zaroxolyn, Diuril, HCT Potassium sparing diuretics - Answer-Used as adjunctive therapy with other drugs to treat HTN or CHF Aldactone, dyrenium Metabolic Acidosis (causes) - Answer-excessive potassium (potassium leaves the cell, hydrogen enters the cell) Severe diarrhea renal failure ketoacidosis shock salicylate poisoning hypoxia - results in anaerobic metabolism which increases lactic acid Metabolic Acidosis (s/s) - Answer-H/A, confusion, lethargy, coma, reduced myocardial contractility, chest pain, palpitations, anxiety, N/V, muscle weakness, bone pain, hypotension, ventricular dysrhythmias, Kussmaul repirations Metabolic Acidosis (treatment) - Answer-Bicarbonate IV Metabolic alkalosis (causes) - Answer-vomiting, diuretic uses, Hyperaldosteronism, Exogenous alkali administration (Sodium bicarbonate therapy in the presence of renal failure, metabolism of lactic acid or ketoacids), Milk-alkali syndrome, Hypercalcemia, Intravenous penicillin, massive blood transfusion. Metabolic alkalosis (S/S) - Answer-Symptoms of metabolic alkalosis are not specific. Because hypokalemia is usually present, the patient may experience weakness, myalgia, polyuria, and cardiac arrhythmias Metabolic alkalosis (treatment) - Answer-The management of metabolic alkalosis depends primarily on the underlying etiology and on the patient's volume status. In the case of vomiting, administer antiemetics, if possible. If continuous gastric suction is necessary, gastric acid secretion can be reduced with H2-blockers or more efficiently with proton-pump inhibitors. In patients who are on thiazide or loop diuretics, the dose can be reduced or the drug can be stopped if appropriate. Alternatively, potassium-sparing diuretics or acetazolamide can be added Respiratory acidosis (causes) - Answer-Acute respiratory acidosis occurs when an abrupt failure of ventilation occurs ( myasthenia gravis, amyotrophic lateral sclerosis, Guillain-Barré syndrome, muscular dystrophy, or airway obstruction related to asthma or chronic obstructive pulmonary disease (COPD) exacerbation. Chronic respiratory acidosis may be secondary to many disorders, including COPD, scoliosis, and obesity Respiratory acidosis (S/S) - Answer-Confusion, easy fatigue, lethargy, shortness of breath, sleepiness Respiratory acidosis (treatment) - Answer-Treatment is aimed at the underlying disease, and may include: •Bronchodilator drugs to reverse some types of airway obstruction •Noninvasive positive-pressure ventilation (sometimes called CPAP or BiPAP) or a breathing machine, if needed •Oxygen if the blood oxygen level is low Respiratory alkalosis (causes) - Answer-Respiratory alkalosis may be produced as a result of medical treatment (iatrogenically) during excessive mechanical ventilation. Other causes include: * psychiatric causes: anxiety, hysteria and stress * CNS causes: stroke, subarachnoid haemorrhage, meningitis * drug use: doxapram, aspirin, caffeine and coffee abuse * moving into high altitude areas, where the low atmospheric pressure of oxygen stimulates increased ventilation * lung disease such as pneumonia, where a hypoxic drive governs breathing more than CO2 levels (the normal determinant) * fever, which stimulates the respiratory center in the brainstem * pregnancy * high levels of NH4+ leading to brain swelling and decreased blood flow to the brain Respiratory alkalosis (S/S) - Answer-Symptoms of respiratory alkalosis are related to the decreased blood carbon dioxide levels, and include peripheral paraesthesiae. In addition, the alkalosis may disrupt calcium ion balance, and cause the symptoms of hypocalcaemia (such as tetany and fainting) with no fall in total serum calcium levels. However, chronic respiratory alkalosis leads to hyperphosphatemia and hypocalcemia, by inducing renal PTH-resistance Hyperkalemia (causes) - Answer-Acute kidney failure, drugs (NSAIDS, Lisinopril (and other ACE inhibitors), ARBs, antibiotics (PCN and trimethoprim), Azole antifungals, K sparing diuretics (triamterene, amiloride, aldactone)), chronic kidney disease, Addison's disease (adrenal failure), Alcoholism or heavy drug use that causes rhabdomyolyis (breakdown of muscle releases potassium into the blood stream), destruction of red blood cells due to severe injury or burn, excessive use of potassium supplements (salt substitutes), increased sodium intake, decreased phosphorus, Vit D deficiency, DM