Accuracy of Continuous Glucose Monitoring in Patients After Total Pancreatectomy with Islet Autotransplantation

Abstract

Background: Among postsurgical and critically ill patients, malglycemia is associated with increased complications. Continuous glucose monitoring (CGM) in the inpatient population may enhance glycemic control. CGM reliability may be compromised by postsurgical complications such as edema or vascular changes. We utilized Clarke Error Grid (CEG) and Surveillance Error Grid (SEG) analysis to evaluate CGM performance after total pancreatectomy with islet autotransplantation. Materials and Methods: This subanalysis evaluated Medtronic Enlite 2 CGM values against YSI serum glucose in seven post-transplant patients (86% female; 38.6 -9.4 years) on artificial pancreas for 72 h at transition from intravenous to subcutaneous insulin. Sensor recalibration occurred for absolute relative difference (ARD) ‡20% x2, ‡30% x1, or by investigator discretion based on trend. Results: Sensor analysis showed mean absolute relative difference (MARD) of 11.0% -11.5%. The sensors were recalibrated 8.3 times/day; active sensor was switched 1.4 times/day. Calibration factor was 7.692 -3.786 mg/nA$dL (target = 1.5-20 mg/nA$dL). CEG analysis showed 86.1% of pairs in Zone A (clinically accurate zone) and 99.4% of pairs in Zones A + B (low risk of error). SEG analysis of hypoglycemia/hyperglycemia risk showed 92.22% of pairs in the ''no risk'' zone, 5.96% of pairs in the ''slight lower'' risk zone, 1.01% of pairs in the ''slight higher'' risk zone, and only 0.81% of pairs in the ''moderate lower'' risk zone. Conclusions: Overall performance of the Medtronic Enlite 2 CGM in the post-transplant population was reasonably good with ''no risk'' or ''slight lower'' risk by SEG analysis and high CGM-YSI agreement by CEG analysis; however, frequent recalibrations were required in this intensive care population.

Continuous glucose monitoring following pancreatectomy with islet autotransplantation in children

“…The investigators found that CGM values had a clinically acceptable correlation with blood glucose values . Forlenza et al . have demonstrated the value of CGM in the total pancreatectomy with IAT adult patient population, using a closed loop system during the transition from insulin infusion to subcutaneous insulin.…”

“…Unlike intermittent monitoring, CGM can provide useful data about the direction of change, the magnitude of change, and warnings to predict hypoglycemia and hyperglycemia occurrences before and after a threshold is reached. There have been several favorable adult reports of CGM use in the ICU setting and one report of its use following IAT in adults . There are limited reports in critically ill children that support CGM usage, and the utility of CGM in the pediatric IAT population in the immediate postoperative setting has not been defined.…”

Optimizing Hybrid Closed-Loop Therapy in Adolescents and Emerging Adults Using the MiniMed 670G System

“…All other parameters are system determined based on the previous days of total daily insulin and fasting glycemic control. This system has been studied in inpatient, hotel, camp, and outpatient settings with favorable glycemic outcomes (10)(11)(12)(13)(14). The pivotal study of the 670G system involved 124 participants with type 1 diabetes aged 14-75 years wearing the system for 3 months in an outpatient setting.…”

Continuous Glucose Monitor Use and Accuracy in Hospitalized Patients

“…4,5 More recently, other populations such as those with total pancreatectomy with islet autotransplantation (TPIAT) are being studied as reported in this issue of the Journal. 6 Patients with chronic pancreatitis undergoing TPIAT or total pancreatectomy without islet autotransplantation (TP) represent a growing cohort worldwide. Patients enrolled for TPIAT may be euglycemic or have various stages of hyperglycemia from impaired glucose tolerance to diabetes mellitus.…”

“…15 Forlenza et al report measures of CEG and SEG in their report. 6 They compare CGM data 10 min after YSI measurement with YSI data obtained every 30 min. 16 The seven subjects in their study provide about 21 days of data.…”