Bedside Monitoring of Blood β -Hydroxybutyrate Levels in the Management of Diabetic Ketoacidosis in Children

Abstract

Introduction:

Diabetic ketoacidosis (DKA) affects many children with type 1 diabetes. Insulin treatment of DKA is traditionally guided by changes in the blood glucose levels and blood gases, whereas β-hydroxybutyrate (β-OHB)—the main ketoacid causing acidosis—is rarely measured. The purpose of this study was to evaluate if bedside monitoring of blood β-OHB levels can simplify management of DKA through elimination of superfluous laboratory monitoring.

Methods:

Our emergency department treated 68 children with DKA using a standard protocol with monitoring of venous pH, partial pressure of CO₂ (pCO₂), bicarbonate, glucose, blood urea nitrogen, and electrolytes (two to 10 time points per patient). Venous β-OHB levels were measured using the Precision Xtra^™ meter (MediSense/Abbott Diabetes Care, Abbott Park, IL) and, on duplicate batched serum samples, using a reference laboratory method (Cobas Mira Plus; Roche Diagnostics, Indianapolis, IN). Correlations between bedside meter β-OHB and other parameters were evaluated in a series of general linear models with a time series covariance structure fit using spatial power law.

Results:

The bedside meter β-OHB levels were significantly correlated with pH (r = –0.63; P <0.0001), bicarbonate (r = –0.74; P <0.0001), and pCO₂ (r = –0.55; P <0.0001) at all points of measurement during the treatment (unadjusted Pearson correlations). The pH, bicarbonate, and pCO₂ were entered into separate time series analysis models with treatment duration as a measure of time. The results confirmed that bedside levels of β-OHB correlated very closely with time-dependent levels of venous pH, bicarbonate, and pCO₂. Good agreement between the two methods of β-OHB measurement (r = 0.92; P <0.0001) was confirmed using the Bland-Altman plot analysis.

Conclusions:

The Precision Xtra accurately measures blood β-OHB levels, particularly at lower levels. While the initial measurement of pH and/or bicarbonates is warranted, real-time β-OHB levels may replace repeat laboratory measurement of these parameters in the management of DKA. Future studies should evaluate safety and cost-effectiveness of such simplified DKA treatment protocol.