Counterproductive effects of sodium bicarbonate in diabetic ketoacidosis.

Abstract

Although a growing body of evidence supports that alkali therapy in diabetic ketoacidosis (DKA) might be counterproductive, our knowledge about the consequences of this treatment on ketone metabolism is limited. Consequently, we performed clinical and animal studies to further examine this topic. The clinical studies assessed seven patients with DKA treated with continuous insulin infusion at a low dosage. Three of them also received sodium bicarbonate (NaHCO3), whereas the remaining four acted as controls. The group receiving NaHCO3 showed a 6-h delay in the improvement of ketosis as compared with controls. In addition, there was an increase in acetoacetate (AcAc) levels during alkali administration, followed by an increase in 3-hydroxybutyrate (3-OHB) level after its completion. Significant differences were not found between groups in the response of plasma glucose to the overall therapy. The animal study examined the effects of a NaHCO3-rich perfusate on the hepatic production of ketones with the in situ rat-liver preparation. Alkali loading resulted in an immediate increase in the AcAc level followed by increases in both the 3-OHB level and the 3-OHB/AcAc ratio after its completion. Hepatic ketogenesis increased even further, to about twice the basal level, after termination of the NaHCO3 loading. This investigation confirms that alkali administration augments ketone production and unravels an effect of bicarbonate infusion that promotes a selective build up of AcAc in body fluids. The data support that alkali therapy in DKA has nonsaltuary effects in the metabolism and plasma levels of ketones.

Arterial Blood Gas Results Rarely Influence Emergency Physician Management of Patients with Suspected Diabetic Ketoacidosis

“…In some cases, administration of sodium bicarbonate may produce deleterious effects, which include increased ketone body formation, decreased ketone body metabolism, and cerebral edema. [5][6][7][8][9] Our study also attempted to determine the correlation and precision between venous pH and arterial pH values. Previous studies have shown an excellent correlation of arterial and venous pH values in the laboratory and various clinical settings.…”

“…1 Sodium bicarbonate therapy has not been proven to be beneficial to DKA patients with a pH equal to or greater than 6.9. [5][6][7][8][9] An increased anion gap is a predictor of the presence of metabolic acidosis, and the related degree of acidosis can be estimated by the size of the anion gap. The acidemia of DKA can be attenuated by the respiratory alkalosis commonly associated with DKA, IV fluid administration, and insulin administration to the patient.…”

Uso de bicarbonato de sódio na acidose metabólica do paciente gravemente enfermo

“…Quanto maior o acúmulo de ácidos orgânicos, maior a queda no bicarbonato sérico e, consequentemente, mais elevado é o AG. [10][11][12][13][14] [d] Portanto, a magnitude da elevação do AG reflete a magnitude do acúmulo de ácidos orgãnicos. Com o tratamento da doença de base e a reversão das condições metabólicas responsáveis pela produção excessiva destes ácidos orgânicos, o acetato e o lactato são rapidamente convertidos em bicarbonato (sendo, por isso, considerados precursores de bicarbonato ou "bicarbonato em potencial").…”

Cetoacidose diabética canina

“…Para a reposição de bicarbonato, o ideal é a monitoração pela hemogasometria, calculada pela fórmula [Bicarbonato (mEq) = Peso(kg)x0,4x(24 -bicarbonato paciente) x 0,5], em que o fator 0,5 indica metade da dose a ser infundida lentamente pela via intravenosa no período de seis horas (BRUYETTE, 1997). Estudos em humanos com CAD demonstraram que a administração de bicarbonato não traz benefícios em pacientes com pH sanguíneo entre 6,9 e 7,1 (VIALLON et al, 1999), além de levar ao aumento da cetogênese hepática (OKUDA et al, 1996). De acordo com BARONE et al (2007), existem evidências de que a terapia com bicarbonato pode aumentar a síntese de corpos cetônicos, contrapondo-se, assim, aos efeitos da insulina.…”