Etiology and Management of Acute Metabolic Acidosis: An Update

Abstract

Background: The etiology of acute metabolic acidosis (aMA) is heterogeneous, and the consequences are potentially life-threatening. The aim of this article was to summarize the causes and management of aMA from a clinician's perspective. Summary: We performed a systematic search on PubMed, applying the following search terms: "acute metabolic acidosis," "lactic acidosis," "metformin" AND "acidosis," "unbalanced solutions" AND "acidosis," "bicarbonate" AND "acidosis" AND "outcome," "acute metabolic acidosis" AND "management," and "acute metabolic acidosis" AND "renal replacement therapy (RRT)/dialysis." The literature search did not consider diabetic ketoacidosis at all. Lactic acidosis evolves from various conditions, either with or without systemic hypoxia. The incidence of metformin-associated aMA is actually quite low. Unbalanced electrolyte preparations can induce hyperchloremic aMA. The latter potentially worsens kidney-related outcome parameters. Nevertheless, prospective and controlled data are missing at the moment. Recently, bicarbonate has been shown to improve clinically relevant endpoints in the critically ill, even if higher pH values (> 7.3) are targeted. New therapeutics for aMA control are under development, since bicarbonate treatment can induce serious side effects. Key Messages: aMA is a frequent and potentially life-threatening complication of various conditions. Lactic acidosis might occur even in the absence of systemic hypoxia. The incidence of metformin-associated aMA is comparably low. Unbalanced electrolyte solutions induce hyperchloremic aMA, which most likely worsens the renal prognosis of critically ill patients. Bicarbonate, although potentially deleterious due to increased carbon dioxide production with subsequent intracellular acidosis, improves kidneyrelated endpoints in the critically ill.

Severe acidosis due to 5-oxoprolinase inhibition by flucloxacillin in a patient with shoulder prosthesis joint infection

“…Buffering, e.g. with sodium bicarbonate, should be performed if the symptoms are clinically relevant (Matyukhin et al, 2020;Adeva-Andany et al, 2014). In the case of refractory acidosis, the administration of N-acetylcysteine can be considered (Hundemer and Fenves, 2017;Tummers et al, 2020).…”

Emergent Hemodialysis Followed by Continuous Renal Replacement Therapy: A Management Challenge in a Patient With Life-Threatening Metabolic Acidosis of Multifactorial Etiology

“…The exact definition of acute metabolic acidosis is controversial; however, the development of acidosis within hours to days after the causative factor insult is considered acute. Among the commonly described causes, the accumulation of organic acids is commonly encountered in clinical settings, and lactic acid is one of the most commonly accumulated organic acids in the pathogenesis of metabolic acidosis [ 3 ]. Accumulation of these organic acids leads to a high anion gap metabolic acidosis (HAGMA).…”

“…Accumulation of these organic acids leads to a high anion gap metabolic acidosis (HAGMA). If the acidosis is secondary to underproduction or overexcretion of bicarbonate, it leads to a state termed normal or non-anion gap metabolic acidosis [ 3 ].…”

Clinical outcomes of sodium bicarbonate therapy in critically ill pediatric patients with metabolic acidosis are associated with chloride

“…Whether SB treatment to correct metabolic acidosis actually improves clinical outcomes is controversial [7,8]. In adults with severe metabolic acidemia, SB treatment has no effect on mortality or the SOFA score [9].…”