BICARBONATE THERAPY IN DIABETIC ACIDOSIS

Bicarbonate in diabetic ketoacidosis - a systematic review

Objective

This study was designed to examine the efficacy and risk of bicarbonate administration in the emergent treatment of severe acidemia in diabetic ketoacidosis (DKA).

Methods

PUBMED database was used to identify potentially relevant articles in the pediatric and adult DKA populations. DKA intervention studies on bicarbonate administration versus no bicarbonate in the emergent therapy, acid-base studies, studies on risk association with cerebral edema, and related case reports, were selected for review. Two reviewers independently conducted data extraction and assessed the citation relevance for inclusion.

Results

From 508 potentially relevant articles, 44 were included in the systematic review, including three adult randomized controlled trials (RCT) on bicarbonate administration versus no bicarbonate in DKA. We observed a marked heterogeneity in pH threshold, concentration, amount, and timing for bicarbonate administration in various studies. Two RCTs demonstrated transient improvement in metabolic acidosis with bicarbonate treatment within the initial 2 hours. There was no evidence of improved glycemic control or clinical efficacy. There was retrospective evidence of increased risk for cerebral edema and prolonged hospitalization in children who received bicarbonate, and weak evidence of transient paradoxical worsening of ketosis, and increased need for potassium supplementation. No studies involved patients with an initial pH < 6.85.

Conclusions

The evidence to date does not justify the administration of bicarbonate for the emergent treatment of DKA, especially in the pediatric population, in view of possible clinical harm and lack of sustained benefits.

Sodium bicarbonate therapy in severe diabetic ketoacidosis

Rates of recovery of plasma glucose and bicarbonate levels, arterial pH, and level of consciousness were determined in a retrospective analysis of 95 episodes of severe diabetic ketoacidosis in patients treated with conventional regimens including low-dose insulin, saline, and potassium administration. No significant differences were found between 73 episodes in 52 patients treated with sodium bicarbonate and 22 episodes in 21 patients not undergoing such treatment. In view of these observations, the potential hazards of sodium bicarbonate replacement therapy, and the fact that sodium bicarbonate is still frequently given, the use of intravenous sodium bicarbonate treatment in patients with severe diabetic ketoacidosis requires reevaluation.

Successful resuscitation in diabetic ketoacidosis: a strong case for the use of bicarbonate

Although severe acidosis is a life-threatening condition owing to its cerebral and cardiac effects, correction of the acidosis with alkali remains a controversial issue in diabetic ketoacidosis. A 22-year-old female patient in diabetic ketoacidosis who was successfully resuscitated after cardiac arrest is presented and a strong case is made for the administration of bicarbonate in severe cases of diabetic ketoacidosis.

Euglycaemic diabetic ketoacidosis

Of a series of 211 episodes of diabetic metabolic decompensation 37 had severe euglycaemic ketoacidosis (a blood sugar level of less than 300 mg/100 ml and a plasma bicarbonate of 10 mEq/1. or less). All were young insulin-dependent diabetics, only one being previously undiagnosed. Vomiting was a common factor, and in all carbohydrate reduction occurred with continued or increased daily insulin dose. Treatment comprised fluid and electrolyte replacement and large doses of insulin covered by adequate carbohydrate, many receiving 10% dextrose. Alkali was either withheld or given sparingly and the therapy was monitored by serial estimations of plasma bicarbonate. All the patients survived.

Acid production in diabetic acidosis; a more rational approach to alkali replacement

The production of organic acids in severe diabetic acidosis was studied to determine the contribution of various acids and to reassess alkali requirements. In 11 patients the mean total concentration of determined organic acids was 16 mEq/l., while the mean estimated base deficit was 24 mEq/l. Acetoacetic and beta-hydroxybutyric acids accounted for 75% of measured organic acid. In 10 patients the mean amount of sodium bicarbonate administered for correction of the acidosis was 185 mEq, while the mean requirement was 394 mEq.These findings imply that the methods commonly used to determine the base deficit and the alkali requirements in patients with diabetic acidosis may be invalid. The prompt administration of alkali should be limited, and we suggest that the blood pH should be restored only to 7.25.