Urine pH – an overview

Urinary pH Manipulation

urinary ph manipulation can efficaciously decrease tubular resorption of watery nonionic acids and bases. manipulation of the urine ph can enhance the body waste of acidic or basic chemicals through a mechanism known as ion trapping.23 The membranes of the nephron are by and large more permeable to nonionized and nonionic molecules. Compounds are filtered and secreted in the nonionized form of weak acids or bases by nonionized dispersion across cell membranes. With handling of urinary ph, the change in the intraluminal ph promotes the formation of a higher intratubular divide of the ionize drug, effectively trapping the ionized moiety in the urinary distance since the ionized form can no longer cross the cell membrane.23 For weak acids, alkaline urine increases the fraction that is ionized. acidic urine does the lapp for weak bases. In each case, an increase in the ionize form of the drug decreases resorption, enhancing nephritic elimination.24 Urine alkalinization can be used to enhance the elimination of salicylates and phenobarbital.25 There is besides some tell for its efficacy in methotrexate toxicity and poisoning with the chlorophenoxy herbicides.23 Urinary acidification can be used to enhance the elimination of chloroquine, amphetamine, quinine, and phencyclidine.26 Alkalinization of the urine can be achieved by adding 150 milliequivalent sodium bicarbonate to 1 L of dextrose 5 % in water ( D5W ) to run at 100 to 250 cc/hr. The goal is to achieve a urinary ph of greater than 7, which normally requires 0.25 to 0.5 mEq/kg/hr ( mesa 51-1 ) .27 This can lone be achieved if the patient has integral nephritic function, and urinary alkalinization should be avoided in patients with severe acuate kidney injury ( AKI ). Risks of urinary alkalinization include volume overload, alkalemia, hypernatremia, and hypokalemia.23 It is important to treat the hypokalemia, because it will prevent the alkalinization of the urine by promoting distal hydrogen secretion in position of potassium secretion. Hypokalemia can be avoided by adding 20 to 40 mEq potassium chloride to each liter of D5W with sodium bicarbonate.19 Acetazolamide will enhance urinary alkalinization but should be avoided because of the risk of worsening systemic acidemia, which can enhance perniciousness of certain poisonings, most notably salicylates.28

urinary acidification is rarely practice because of the electric potential to worsen nephritic injury in many poisonings. Arginine hydrochloride or ammonium chloride have been shown to be effective urinary acidification agents. Although urinary acidification may enhance elimination of faint bases, it can not be recommended as a treatment for toxicity from these compounds. Complications of urinary acidification include myoglobinuria, acute nephritic failure, and hyperkalemia.26

informant : https://nutritionline.net
Category : Healthy