Clinical Utility of β-Hydroxybutyrate vs Anion Gap to Define Resolution of Diabetic Ketoacidosis

Updated guidelines for managing diabetic ketoacidosis (DKA) preferentially recommend using β-hydroxybutyrate instead of anion gap for determining DKA resolution. Although physiological reasons suggest benefits of β-hydroxybutyrate over anion gap, clinical data supporting this idea are limited.

To compare time to DKA resolution (time from initial intravenous insulin to first dose of long-acting subcutaneous insulin) between patients managed with β-hydroxybutyrate and patients managed with anion gap.

This retrospective study evaluated patients with DKA who were managed with the same continuous intravenous insulin protocol at 2 participating sites, one that used β-hydroxybutyrate and the other that used anion gap to assess resolution. The primary outcome was time to first dose of long-acting insulin, with secondary outcomes including incidence of DKA recurrence after transition to subcutaneous insulin.

A total of 178 patients were included, with 89 in the β-hydroxybutyrate-managed arm. Baseline characteristics, including DKA severity, were similar in the 2 groups. Conversion to a long-acting insulin regimen occurred at a median (IQR) of 23.5 (17.9-31.0) hours in the β-hydroxybutyrate group and 13.3 (10.0-18.2) hours in the anion gap group (P < .01) with no difference in rates of DKA recurrence.

Monitoring anion gap rather than β-hydroxybutyrate for DKA resolution led to shorter time on an insulin infusion with no increase in DKA recurrence. Prospective studies evaluating β-hydroxybutyrate thresholds or how to best use β-hydroxybutyrate in practice are warranted.