The role of bicarbonate in DKA has been debated for decades. Arbitrary initial pH levels to utilize bicarbonate are still currently recommended in many texts. To date, not a single study clearly demonstrates improved clinical outcome using bicarbonate in the treatment of DKA. Acidotic patients routinely recover from DKA without alkali therapy. Routine use of supplemental bicarbonate in the treatment of DKA is not recommended. -IZ l8
Severe metabolic acidosis is associated with numerous cardiovascular (impaired contractility, vasodilation, hypotension) and neurologic (cerebral vasodilation and coma) complications.14 Theoretical advantages of bicarbonate include improved myocardial contractility, elevated ventricular fibrillation threshold, improved catecholamine tissue response and decreased work of breathing.17 These theoretical advantages appear outweighed by the possible disadvantages of bicarbonate administration in DKA of severe and worsening hypokalemia; paradoxical central nervous system acidosis; worsening intracellular acidosis; impaired oxyhemoglobin dissociation; rebound alkalosis; hypertonicity and sodium overload; delayed recovery from ketosis; 18 elevation of lactate levels;17 and possible precipitation of cerebral edema.14 During routine therapy of DKA hydrogen ion production ceases when ketogenesis stops; excessive hydrogen ions are eliminated through the urine and respiratory tract. Ketone body metabolism results in the endogenous production of alkali. Children with initial pH values as low as 6.73 have been shown to promptly recover from DKA without bicarbonate.17
Severe acidosis (pH <7.0) and worsening pH despite aggressive therapy for DKA should prompt the clinician to rule out other causes of metabolic acidosis (i.e., lactate from sepsis or bowel infarction, methanol ingestion, etc.). The potential benefits of bicarbonate in the elderly with cardiovascular instability and DKA must be balanced against the potential disadvantages. 8
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