Alkalosis, diuretic-induced

In metabolic alkalosis and respiratory acidosis, pH does not usually deviate significantly from normal, but treatment can be required to maintain Pao2 and PaC02 at acceptable levels. Treatment should be aimed at decreasing plasma bicarbonate with sodium and potassium chloride therapy, allowing renal excretion of retained bicarbonate from diuretic-induced metabolic alkalosis. 

Diuretic-induced metabolic alkalosis is another adverse effect that may further compromise cardiac function. This complication can be treated with replacement of K+ and restoration of intravascular volume with saline however, severe heart failure may preclude the use of saline even in patients who have received excessive diuretic therapy. In these cases, adjunctive use of acetazolamide helps to... 

Alkalosis and hypokalaemia (possibly caused by secondary hyperaldosteronism or use of diuretics) shift the dissociation constant towards free, toxic NH3. By contrast, ammonia is considered - in a process resembling a vicious circle - to be a secondary stimulus for aldosterone production. Thiazide diuretics in particular put an overload on the detoxification capacity of the scavenger cells. This is because of an insufficient supply of bicarbonate for carbamoyl phosphate synthetase reaction due to diuretic-induced inhibition of the mitochondrial carboanhydrase. 

In the AN patients who engage in self-induced vomiting or abuse laxatives and diuretics, hypokalemic alkalosis may develop. These patients often have elevated serum bicarbonate, hypochloremia, and hypokalemia. 

Certain foreign compounds may cause the retention or excretion of water. Some compounds, such as the drug furosemide, are used therapeutically as diuretics. Other compounds causing diuresis are ethanol, caffeine, and certain mercury compounds such as mersalyl. Diuresis can be the result of a direct effect on the kidney, as with mercury compounds, which inhibit the reabsorption of chloride, whereas other diuretics such as ethanol influence the production of antidiuretic hormone by the pituitary. Changes in electrolyte balance may occur as a result of excessive excretion of an anion or cation. For example, salicylate-induced alkalosis leads to excretion of Na+, and ethylene glycol causes the depletion of calcium, excreted as calcium oxalate. 

Toxicity Loop diuretics usually induce hypokalemic metabolic alkalosis. Because large amounts of sodium are presented to the collecting tubules, wasting of potassium (which is excreted by the kidney in an effort to conserve sodium) may be severe. Because they are so efficacious, the loop diuretics can cause hypovolemia and cardiovascular complications. Ototoxicity is an important toxic effect of the loop agents. The sulfonamides in this group may cause typical sulfonamide allergy. 

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