Continuous monitoring of glucose levels in the hepatic vein and systemic circulation during the Pringle maneuver in beagles

Closed-loop artificial endocrine pancreas from Japan

The development of a closed-loop artificial pancreas (AP) in the Western countries and Japan is different. In Western countries, wearable AP with a closed-loop glycemic control system has been developed as a treatment for patients with type 1 and type 2 diabetes. On the contrary, in Japan, bedside closed-loop AP explored by a Japanese company (Nikkiso, Tokyo, Japan) has developed as perioperative glycemic control device in surgical patients and acute care patients with emergency. In this article, we reviewed the scientific evidence in the past and present and future prospects of perioperative glycemic control using bedside AP with a closed-loop system in Japan. Conventional perioperative strict glycemic controls have three major problems: hyperglycemia, hypoglycemia, and variability in blood glucose concentrations. In Japan, perioperative strict glycemic control using the current bedside AP STG-55 (Nikkiso, Tokyo, Japan) has been developed since 2010. This novel glycemic control method achieved not only stable glycemic control without hyperglycemia, hypoglycemia, and less variability of blood glucose concentrations but also reduced postoperative infectious complications in patients undergoing major surgeries. Among the rapidly increasing number of surgical or emergency patients with diabetes, frailty, and sarcopenia of intrinsic glucose intolerance, more sophisticated and smaller AP available easily in operating rooms and intensive care units will be warranted to promote improved therapeutic outcomes in such critically ill patients.

Artificial endocrine pancreas with a closed-loop system effectively suppresses the accelerated hyperglycemic status after reperfusion during aortic surgery

OBJECTIVES

To control intraoperative hyperglycemia in patients who underwent aortic surgery using STG-55^® artificial endocrine pancreas and clarify the effectiveness of this device.

METHODS

Blood glucose control using the STG-55^® was performed in 18 patients (15 men and 3 women; age, 66 ± 10 years) who required hypothermic circulatory arrest (STG-55^® group). Seventeen patients (10 men and 7 women; age, 71 ± 8 years) whose blood glucose was controlled using the conventional method were included in the control group. Glucose concentration was controlled with the aim of maintaining it at 150 mg/dl.

RESULTS

In both groups, the blood glucose concentrations did not significantly change during the interruption of systemic perfusion; however, a sharp increase was noted immediately after reperfusion. Although the hyperglycemic status persisted after reperfusion in the control group, it was effectively suppressed in the STG-55^® group (STG^® vs. control group at 50 min after reperfusion: 180 ± 35 vs. 212 ± 47 mg/dl, p = 0.026) and blood glucose concentration reached the target value of 150 mg/dl at 100 min after reperfusion (STG^® vs. control group: 153 ± 29 vs. 215 ± 43 mg/dl, p = 0.0008). The total administered insulin dose was 175 ± 81 U and 5 ± 3 U in the STG^® and control groups, respectively (p < 0.0001).

CONCLUSIONS

To treat the accelerated hyperglycemic status in aortic surgery requiring circulatory arrest, strict glycemic control using an artificial endocrine pancreas might be beneficial.

Comparison of subcutaneous and intravenous continuous glucose monitoring accuracy in an operating room and an intensive care unit

Although we have used an intravenous continuous glucose monitor for blood glucose management, a previous study reported that a subcutaneous continuous glucose monitor was also reliable for use in critically ill patients. The aim of this study was to compare the subcutaneous and intravenous continuous glucose monitors. This was an observational trial (UMIN-CTR, ID:000013338). We included patients who were admitted to our intensive care units (ICU) after hepato-biliary pancreatic surgery. Continuous blood glucose measurement was performed from the beginning of the operation to ICU discharge using the intravenous continuous monitor STG-55 (Nikkiso, Tokyo, Japan) and the subcutaneous continuous monitor iPro2 (Medtronic Japan, Tokyo, Japan). The STG-55 measured the glucose level in real time, and the iPro2 measured this every 5 min. We compared glucose levels obtained using the two devices every 5 min using a Bland-Altman plot and a regression analyses. A total of 3592 comparative samples in 15 cases were analyzed. The mean glucose level measured using the STG-55 was 139 ± 21 mg/dl, and that measured using the iPro2 was 144 ± 31 mg/dl. A linear regression line had the equation of the form y = 0.225x + 106. The coefficient of determination was 0.11, and the F-test significance level was set as p < 0.01. The mean of the differences was -5.2 mg/dl, with a 95 % agreement limit of -67 to + 57 mg/dL. The percent error was 44 %. In conclusion, the current study suggests that subcutaneous and intravenous continuous glucose monitoring was not highly correlated during either surgery or ICU stay.

Preoperative oral rehydration therapy with 2.5 % carbohydrate beverage alleviates insulin action in volunteers

Preoperative carbohydrate loading enhances insulin action by approximately 50 %. In some Japanese hospitals, preoperative oral rehydration therapy is performed for preventing dehydration during surgery. We hypothesized that preoperative oral rehydration therapy with a 2.5 % carbohydrate beverage that is widely used in Japan can enhance insulin action. Therefore, we investigated the effect of this 2.5 % carbohydrate beverage on insulin action in volunteers. Six healthy volunteers participated in this crossover randomized study. The participants were segregated into 2 groups: an oral rehydration therapy with 2.5 % carbohydrate beverage group (group A) and a control group (group B). Subjects in group B were allowed to drink only water from 9 pm the day before the test; conversely, group A fasted from 9 pm onward and drank 500 ml of the beverage containing 2.5 % carbohydrate (OS-1; Otsuka Pharmaceutical Factory, Tokushima, Japan) between 9 and 12 pm and again at 6.30 am. At 8.30 am, a hyperinsulinemic normoglycemic clamp was initiated using an artificial pancreas STG-22 (Nikkiso, Tokyo, Japan). Insulin action was evaluated in both groups using the glucose infusion rate. Blood glucose levels at the initiation of the clamp procedure were similar. However, the glucose infusion rate for group A was significantly higher than that of group B (8.6 ± 1.5 vs. 6.8 ± 2.0 mg/kg/min, p = 0.009). In conclusion, the hyperinsulinemic normoglycemic clamp using an artificial pancreas showed that the administration of a 2.5 % carbohydrate oral rehydration solution for preoperative oral rehydration therapy improves insulin action in volunteers.

Effects of intra- and post-operative ischemia on the metabolic profile of clinical liver tissue specimens monitored by NMR

Metabolomic profiles of tissues could greatly contribute to advancements in personalized medicine but are influenced by differences in adopted preanalytical procedures; nonhomogeneous pre- and post-excision ischemia times are potential sources of variability. In this study, we monitored the impact of ischemia on the metabolic profiles, acquired with high-resolution magic-angle-spinning (1)H NMR, of 162 human liver samples collected during and up to 6 h after routine surgery. The profiles changed significantly as a function of intraoperative warm ischemia (WI) and postresection cold ischemia (CI) time, with significant variations in the concentration of the same 16 metabolites. Therefore, a tight control of the preanalytical phase is essential for reliable metabolomic analyses of liver diseases. The NMR profiles provide a reliable "fingerprint" of ischemia and have predictive value: the best-performing predictive models are found to discriminate extreme time points of CI (0' vs 360 ') in the training set with cross-validation accuracy of ~90%; samples in the validation cohort can discriminate short (≤60') from long (≥180') CI with an accuracy of ~80%. For WI, the corresponding figures are 95.6 and 92%, respectively. Therefore, ischemia NMR profiles might become a tool for tissue quality control in biobanks.