The use of bicarbonate in patients with diabetic ketoacidosis (DKA) is controversial (1), especially in patients with severe DKA (pH <7.0). Previous studies have shown that the use of bicarbonate in patients with moderate DKA (pH >7.0) is not associated with better outcomes, when compared with saline-treated control subjects (25), and can generate lactate (3). The use of bicarbonate therapy in patients with severe DKA has not been addressed adequately, due to a lack of data on benefit or harm of bicarbonate therapy in severe DKA, but dogmatic use of bicarbonate still continues in such cases. In our initial randomized study, 5 of 11 patients had pH <7.0 (none below 6.9), but the outcome was no different from the group of patients who did not receive bicarbonate (4).

To examine this issue we evaluated records of 41 patients with DKA who were admitted to the medical intensive care unit at the Regional Medical Center, The University of Tennessee, between July 1999 and December 2000. We identified 5 DKA patients (group 1) with pH <7.0 (mean pH 6.85 ± 0.09) and compared their responses to treatment with 36 case subjects (group 2) with pH >7.0 (7.15 ± 0.11). The admission glucose and biochemical parameters were not significantly different between the two groups. All patients were treated with a low-dose insulin infusion protocol (1). Four of the five patients with severe DKA received a small initial dose of intravenous bicarbonate (50 mmol), whereas none of the patients with pH >7.0 received bicarbonate therapy. One patient with severe DKA died during the hospital stay. She was admitted with pneumonia, sepsis, and multi-organ failure and received bicarbonate therapy for her acidosis. Of the remaining four cases who survived, three received 50 mmol bicarbonate each and one did not. The administration of bicarbonate therapy did not appear to have an impact on the time for resolution of DKA or hospital length of stay in the four patients when compared with the patients who did not get bicarbonate. However, the number of subjects was too few to draw any meaningful conclusion on the utility of bicarbonate. There was no mortality in group 2.

Our review of present cases showed that 12% of patients admitted to the hospital with DKA had pH <7.0. This clearly indicates that the number of patients with severe DKA is large enough to merit a comprehensive study on the efficacy of bicarbonate therapy. Furthermore, the cardiac and, especially, the left ventricular status of such patients is not known (6). This controversial subject could only be settled by evidence-based studies under a prospective randomized protocol, which at this time is not available.

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Morris LR, Murphy MB, Kitabchi AE: Bicarbonate theapy in severe diabetic ketoacidosis.
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Address correspondence to Abbas Kitachi, Division of Endocrinology, Department of Medicine, The University of Tennessee Health Science Center, Memphis, TN. E-mail: akitabchi@utmem.edu.