Relationship between blood glucose level and outcome in acutely ill severe patients with glucose intolerance evaluated by means of a bedside-type artificial pancreas

Objective

To verify the significance of strict blood glucose (BG) control and to clarify the beneficial BG level in acutely ill severe patients with glucose intolerance.

Materials and methods

Ninety patients were retrospectively investigated in whom BG control was performed by means of the bed-side type artificial pancreas (AP), STG22 (NIKKISO Corp., Japan). The patients were evaluated at two phases, that is, early phase or just after admission (E phase) and late phase (L phase: about 1 week after the E phase). Based on the daily mean BG level (BGm), patients were classified into two groups (i.e. high group and low group), which were compared with the three selected BGm values, or 150, 175, and 200 mg/dl. The patients with BGm below 150 mg/dl was group 150b and those above 150 mg/dl was group 150a, as well as those below 175 mg/dl being group 175b and those above 175 mg/dl being group 175a, and those below 200 mg/dl being group 200b and those above 200 mg/dl being group 200a. Parameters studied were as follows: sex, age, underlying diseases including diabetes mellitus, the amount of administered glucose (G [kcal/kg/day]), the amount of administered insulin (I [U/kg/day]) from the AP, the rate of septic patients, the severity (SOFA score), and the mortality (%). Nutritional support for all the patients was performed with total parenteral nutrition.

Results

(1) E phase (1.2 ± 0.8 days [mean ± SD] after the operation of AP, n = 84): group 200b (BGm: 173 ± 19, n = 68) had lower G (23.4 ± 6.8 vs 27.4 ± 8.3, P < 0.05), I (1.11 ± 0.73 vs 2.47 ± 1.34, P < 0.001), and lower mortality (29 vs 56, P < 0.05) as compared with group 200a (BGm: 224 ± 22, n = 16). Other parameters were not significantly different between group 200b and group 200a. However, regarding the mortality, there was no statistical difference between groups 175b and 175a, and between groups 150b and 150a. (2) L phase (7.6 ± 1.4 days after the operation of AP, n = 88): group 175b (BGm: 155 ± 18, n = 58) had lower I (0.76 ± 0.58 vs 2.30 ± 1.19, P < 0.001) and lower mortality (28 vs 50, P < 0.05) as compared with group 175a (BGm: 197 ± 17, n = 30). Other parameters were not significantly different between group 175b and group 175a. In this phase the mortality was not statistically different both between groups 200b and 200a, and between groups 150b and 150a.

Interpretation

BG control has recently been widely accepted as one of the most important therapies that improve outcome, which was reconfirmed by our strict BG control using the AP. However, the optimal BG goal remains to be elucidated. Our clinical trial suggested that we should change the goal chronologically.

Conclusion

BG control aiming at a BG level lower than 200 mg/dl at the early stage and lower than 175 mg/dl at about 1 week later may link to the improvement of outcome of the acutely ill severe patients. The AP would be effective and essential for improving the outcome as well as for the evaluation of BG control and glucose tolerance through the strict BG control.