Evaluation of a bedside blood ketone sensor: the effects of acidosis, hyperglycaemia and acetoacetate on sensor performance.

Abstract

AIMS:

To assess the performance of a handheld bedside ketone sensor in the face of likely metabolic disturbances in diabetic ketoacidosis, namely: pH, glucose and acetoacetate.

METHODS:

The effects of pH (7.44-6.83), glucose (5-50 mmol/l) and acetoacetate (0-5 mmol/l) were examined in venous blood to investigate the accuracy of betahydroxybutyrate measurement (0-5 mmol/l) by a handheld ketone sensor. Sensor results were compared with a reference method. Linear regression models were fitted to the difference between the methods with the concentration of metabolite as the explanatory factor.

RESULTS:

Decreasing pH and increasing glucose had no effect on the accuracy of the handheld ketone sensor; the gradients of the fitted lines were -0.14 and -0.003, respectively. The 95% confidence intervals were -0.7-0.4 and -0.01-0.004, respectively (P = 0.59 and 0.4, respectively). In the acetoacetate study, a positive relationship between the sensor and reference method results was found, the gradient was 0.09. The 95% confidence interval was 0.05-0.14 (P < or = 0.001), indicating that high concentrations of acetoacetate interfere with the sensor performance.

CONCLUSIONS:

Acidosis and hyperglycaemia have minimal effects on the sensor performance. However, high concentrations of acetoacetate result in some overestimation of betahydroxybutyrate. This bedside ketone sensor provides useful data over a broad range of conditions likely to be encountered during moderate to severe diabetic ketoacidosis.

• Authors: A S A Khan, J A Talbot, K L Tieszen, E A Gardener, J M Gibson, J P New
• Journal: Diabetic medicine : a journal of the British Diabetic Association (Diabet Med) Vol. 21 Issue 7 Pg. 782-5 (Jul 2004) ISSN: 0742-3071 [Print] England
• PMID: 15209774 (Publication Type: Evaluation Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Acetoacetates
• Blood Glucose
• Ketone Bodies
• acetoacetic acid

Topics

• Acetoacetates (blood)
• Acidosis (blood)
• Biosensing Techniques (instrumentation)
• Blood Glucose (analysis)
• Blood Glucose Self-Monitoring (instrumentation)
• Diabetic Ketoacidosis (blood, diagnosis)
• Humans
• Hydrogen-Ion Concentration
• Hyperglycemia (blood)
• Ketone Bodies
• Linear Models
• Point-of-Care Systems
• Self Care (instrumentation)