Evaluation of sensor sites for continuous glucose monitoring in cats with diabetes mellitus

Abstract

The continuous glucose monitoring system allows generation of detailed glucose curves via measurement of glucose concentration in interstitial fluid. The conventional site for sensor placement in diabetic cats is the subcutaneous tissue of the lateral chest wall. The aim of this study was to investigate the feasibility and accuracy of sensors placed in the lateral chest wall and in two alternative sites -the dorsal neck and lateral knee fold -of diabetic cats. Initialisation was successful in 15/20 lateral chest wall sensors, 9/10 neck sensors and 3/10 knee fold sensors. Compared with the reference portable blood glucose meter, 0.8% of measurements from lateral chest wall sensors, 0.7% from knee fold sensors and 0% from neck sensors would have resulted in erroneous treatment. This preliminary study suggests that dorsal neck placement may be superior to lateral chest wall and lateral knee fold; however, further investigation with a larger number of cases would be required to confirm this finding.

Feline Diabetes Mellitus

“…Additionally, initial calibration is more often successful when the neck is used. Technical problems include failure to successfully calibrate after the initialization period, discontinuation of recordings at some time during the long-term measurement (usually due to calibration errors) and loss of proper placement of the sensor underneath the skin (Hafner et al, 2013).…”

Update on insulin treatment of dogs and cats with non-complicated diabetes mellitus

“…There are commercially available CGMSs that differ in their SC tissue glucose concentration working range (20-600 mg dl -1 , depending on the device), duration of the initialization period between insertion of the sensor and the first display (0.5-2h), timing of the initial and subsequent calibrations, cable or wireless connection between the sensor and the monitor, and their ability for real-time display of the recordings or not (Rios and Ward, 2008;Wiedmeyer and DeClue, 2008;Affenzeller et al, 2010;Moretti et al, 2010;Dietiker-Moretti et al, 2011;Fleeman, 2011;Hafner et al, 2013;Surman and Fleeman, 2013). Continuous research efforts aim to optimize the site of the body where the sensor is inserted into the SC tissue and to validate different CGMSs for dogs and cats (Rios and Ward, 2008;Affenzeller et al, 2010;Moretti et al, 2010;Dietiker-Moretti et al, 2011;Hoenig et al, 2012;Hafner et al, 2013;Mori et al, 2013;Surman and Fleeman, 2013).…”

“…These systems use a small, flexible and disposable sensor that is inserted into SC tissue to constantly measure glucose concentration in the interstitial fluid with the glucose oxidase reaction; since blood and interstitial fluid glucose concentrations equilibrate relatively fast (5-12 min) and CGMSs are calibrated based on the former, they have the ability to accurately measure glucose concentration every 1-10sec, average and display the results every 3-5min and work constantly for up to 48-144h (Wiedmeyer and DeClue, 2008;Affenzeller et al, 2010;Moretti et al, 2010;Affenzeller et al, 2011;Dietiker-Moretti et al, 2011;Fleeman, 2011;Hafner et al, 2013;Mori et al, 2013;Surman and Fleeman, 2013).…”

“…Continuous research efforts aim to optimize the site of the body where the sensor is inserted into the SC tissue and to validate different CGMSs for dogs and cats (Rios and Ward, 2008;Affenzeller et al, 2010;Moretti et al, 2010;Dietiker-Moretti et al, 2011;Hoenig et al, 2012;Hafner et al, 2013;Mori et al, 2013;Surman and Fleeman, 2013).…”

“…Insulin glargine or detemir is administered initially at 0.25 or 0.5 U kg -1 BID if blood glucose concentration is <360 mg dl -1 or >360 2010; Affenzeller et al, 2011;Dietiker-Moretti et al, 2011;Fleeman, 2011;Hoenig et al, 2012;Hafner et al, 2013;Mori et al, 2013;Surman and Fleeman, 2013). Besides the cost of the device, disadvantages of CGMs include the possibility of sensor disconnection or fouling, their dependence on accurate calibration based on blood glucose concentrations, the possible delay of measurement because, depending on the device, calibration is impossible when blood glucose concentration is very low (<20-40 mg dl -1 ) or high (>400-600 mg dl -1 ) and the inaccuracy of the results when used in animals with dehydration or under general anesthesia (Rios and Ward, 2008;Wiedmeyer and DeClue, 2008;Affenzeller et al, 2010;Moretti et al, 2010;Affenzeller et al, 2011;Dietiker-Moretti et al, 2011;Hoenig et al, 2012;Surman and Fleeman, 2013).…”