A conceptual approach to the patient with metabolic acidosis. Application to a patient with diabetic ketoacidosis.
We shall illustrate that management of patients with an acid-base disorder could be improved if the acid-base analysis was based on a better understanding of basic concepts of physiology. Three concepts of acid-base physiology and their clinical implications are emphasized in a patient with diabetic ketoacidosis. First, when an acid is produced from neutral precursors in the body, there is a net increase in the number of hydrogen ions (H(+)) and new anions. The corollary is that H(+) will be removed when the accompanying anion is metabolized to a neutral end-product or is excreted in the urine with H(+) or ammonium (NH(4)(+)). Second, buffering of H(+) is beneficial if H(+) are removed by bicarbonate rather than being able to bind to proteins. This latter function depends on having a low tissue PCO(2), due to a combination of hyperventilation plus an adequate blood flow rate to vital organs. Third, the kidneys add new bicarbonate to the body when NH(4)(+) is excreted with chloride ions.
Shafiee
M A
MA
Renal Division, St. Michael's Hospital, University of Toronto, Ont., Canada.
Kamel
K S
KS
Halperin
M L
ML
D000136:Acid-Base Equilibrium; D000838:Anions / Q000378:metabolism; D001774:Blood Chemical Analysis; D001921:Brain / Q000378:metabolism; D002648:Child; D016883:Diabetic Ketoacidosis / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008954:Models, Biological; D011522:Protons; D017693:Sodium Bicarbonate / Q000378:metabolism
D000838:Anions; D007328:Insulin; D011522:Protons; D017693:Sodium Bicarbonate