Accuracy and Feasibility of a Novel Glucose/Lactate Continuous Multi-Analyte Sensing Platform in Humans.

BACKGROUND AND AIM: Continuous glucose monitoring systems (CGMs) have been commercially available since 1999. However, automated insulin delivery systems may benefit from real-time inputs in addition to glucose. Continuous multi-analyte sensing platforms will meet this area of potential growth without increasing the burden of additional devices. We aimed to generate pilot data regarding the safety and function of a first-in-human, single-probe glucose/lactate multi-analyte continuous sensor. METHODS: The investigational glucose/lactate continuous multi-analyte sensor (PercuSense Inc, Valencia, California) was inserted to the upper arms of 16 adults with diabetes, and data were available for analysis from 11 of these participants (seven female; mean [SD] = age 43 years [16]; body mass index [BMI] = 27 kg/m2 [5]). A commercially available Guardian 3 CGM (Medtronic, Northridge, California) was also inserted into the abdomen for comparison. All participants underwent a meal-test followed by an exercise challenge on day 1 and day 4 of wear. Performance was benchmarked against venous blood YSI glucose and lactate values. RESULTS: The investigational glucose sensor had an overall mean absolute relative difference (MARD) of 14.5% (median = 11.2%) which improved on day 4 compared with day 1 (13.9% vs 15.2%). The Guardian 3 CGM had an overall MARD of 13.9% (median = 9.4%). The lactate sensor readings within 20/20% and 40/40% of YSI values were 59.7% and 83.1%, respectively. CONCLUSIONS: Our initial data support safety and functionality of a novel glucose/lactate continuous multi-analyte sensor. Further sensor refinement will improve run-in performance and accuracy.

A novel thermal compression device for perioperative warming: a randomized trial for feasibility and efficacy.

BACKGROUND: Inadvertent perioperative hypothermia (IPH) leads to surgical complications and increases length of stay. IPH rates are high with the current standard of care, forced air warming (FAW). Our hypothesis is that a prototype thermal compression device that heats the popliteal fossa and soles of the feet, with lower leg compression, increases perioperative temperatures and reduces IPH compared to the current standard of care. METHODS: Thirty six female breast surgery patients, at a tertiary academic hospital, were randomized to the device or intraoperative FAW (stage I) with a further 18 patients randomized to the device with a single heating area only (stage II, popliteal fossa or sole of the feet). Stage I: 37 patients recruited (final 36). Stage II: 18 patients recruited (final 18). INCLUSION CRITERIA: general anesthesia with esophageal monitoring for over 30 min, legs available and able to fit the device and no contraindications to leg heating or compression. The intervention was: Stage I: Investigational prototype thermal compression device (full device group) or intraoperative FAW. Stage II: Device with only a single heating location. Primary outcomes were perioperative temperatures and incidence of IPH. Secondary outcomes were local skin temperature, general and thermal comfort scores and presence of perioperative complications, including blood loss. RESULTS: Mean temperatures in the full device group were significantly higher than the FAW group in the pre-operative (36.7 vs 36.4 °C, p < 0.001), early intraoperative (36.3 vs 35.9 °C, p < 0.001), intraoperative (36.6 vs 36.2 °C, p < 0.001) and postoperative periods (36.8 vs 36.5 °C, p < 0.001). The incidence of IPH in the device group was also significantly lower (16.7% vs 72.0%, p = 0.001). Thermal comfort scores were significantly higher in the full device group and hypothermia associated wound complications were higher in the FAW group. CONCLUSIONS: The thermal compression device is feasible and has efficacy over the FAW. Further studies are recommended to investigate clinically significant outcomes. TRIAL REGISTRATION: clinicaltrials.gov ( NCT02155400 ).

Usage and effectiveness of the low glucose suspend feature of the Medtronic Paradigm Veo insulin pump.

BACKGROUND: Sensor-augmented insulin pumps may be programmed to suspend insulin delivery in response to hypoglycemia. The Medtronic Paradigm® Veo™ pump with automatic low glucose suspend (LGS) was released in 2009. Data from 7 months of real-world use of the system were analyzed to assess usage patterns and effectiveness of LGS. METHOD: Data from 935 patients totaling 49,867 patient days were collected; the LGS feature was on for 82% of these days. A subset of 278 subjects who used the pump for ≥3 months was analyzed separately; these subjects provided 28,401 patient days of data, with LGS used for 92% of the time. RESULTS: The LGS threshold was most commonly set between 50 and 60 mg/dl. A total of 27,216 LGS events occurred, and 60% began in the afternoon or evening. The median duration of LGS events was 9.87 min, 45% lasted for <5 min, and 11% lasted for >115 min (equivalent to the full extent of the LGS event between 115 and 120 min). Among the episodes lasting for >115 min, the mean sensor glucose (SG) was 58.8 ± 12.4 mg/dl at LGS activation (time 0), rose to 102.2 ± 52.8 mg/dl by the end of the LGS episode (when insulin delivery was automatically resumed), and was 150.1 ± 68.6 mg/dl at 240 min. In the 278-subject subgroup, LGS usage significantly reduced the number of SG readings <50 mg/dl (p = 0.001) and >300 mg/dl (p = 0.001). CONCLUSIONS: The LGS feature was on for most of the patient days in the study. Most LGS episodes lasted for <10 min. Use of the LGS feature significantly reduced exposure to hypoglycemia. Profound hyperglycemia resulting from LGS episodes lasting >115 min was not observed.

Insights from a large observational database of continuous glucose monitoring adoption, insulin pump usage and glycemic control: the CareLink™ database.

OBJECTIVE: The CareLink™ (Medtronic, Inc., Northridge, CA) database houses data from continuous glucose monitoring (CGM), insulin pumps, and blood glucose (BG) meters. This study examined CGM usage and its relationship to insulin delivery and glycemia in CareLink users with type 1 diabetes mellitus (T1DM). METHODS: Users whose CareLink accounts contained =120 days of pump and glucose readings within a 180-day interval were further selected and stratified based on the frequency of CGM use and adequacy of glycemic control; correlations between these variables were sought. RESULTS: The proportion of subjects with pre-specified favorable glycemic parameters rose with increasing sensor use (p<0.001). These subjects administered more and smaller boluses, gave a higher proportion of their total daily dose (TDD) of insulin as boluses, and maintained lower TDDs than those with pre-specified less-favorable glycemic parameters (all p<0.001). CONCLUSIONS: A favorable dose effect of CGM use was evident. CGM data facilitates smaller and more frequent bolus dosing, allowing for improved glycemic control.