Perioperative hypoglycemia in patients with diabetes: incidence after low normal fasting preoperative blood glucose versus after hyperglycemia treated with insulin.

Perioperatively, insulin to treat hyperglycemia is administered judiciously to minimize the risk of hypoglycemia. In patients with diabetes in whom preoperative blood glucose levels are on the low end of normal, hypoglycemia risk may be underestimated. This retrospective study enrolled subjects with presenting preoperative blood glucose values in these ranges: 70 to 89 mg/dL (low normal group) and above 249 mg/dL (hyperglycemia-treated group). These groups were compared for subsequent perioperative hypoglycemia development. Subjects in the low normal group (n = 308) were older (P < .001), had increased incidence of renal disease (P = .02), and more prevalent beta-blocker use (P = .02) than the hyperglycemia-treated subjects (n = 279). Accounting for differences between groups, the incidence of perioperative blood glucose levels below 70 mg/dL was greater in the low normal group than the hyperglycemia-treated group (17.2% vs 3.6%, P < .001). Of subjects whose blood glucose levels fell below 70 mg/dL, blood glucose levels dropped below 50 mg/dL in 40% of hyperglycemia-treated subjects and 4% of low normal subjects. Perioperative hypoglycemia was likelier to develop in patients with diabetes who presented preoperatively with low normal blood glucose values than in patients treated with insulin for presenting hyperglycemia.

Insulin glargine dosing before next-day surgery: comparing three strategies.

STUDY OBJECTIVE: To evaluate three evening insulin glargine dosing strategies for achievement of target (100-179 mg/dL; 5.5 - 9.8 mmol/L) and widened (80-249 mg/dL; 4.4 - 13.7 mmol/L) preoperative fasting blood glucose (FBG) ranges on the day of surgery. DESIGN: Prospective, randomized, open trial. SETTING: Preoperative units at two sites of a suburban hospital system. PATIENTS: 401 adult, ASA physical status 3 and 4 patients with type 1 and type 2 diabetes, undergoing elective noncardiac surgery. INTERVENTIONS: Patients were divided into two groups according to absence of daily rapid-acting/short-acting insulin (insulin glargine-only group) or presence of daily rapid-acting/short-acting insulin (insulin glargine plus bolus group). Subjects were then randomized to three evening insulin glargine dosing strategies: (a) take 80% of usual dose, (b) call physician for dose, or (c) refer to dosing table, based on self-reported usual FBG and insulin regimen. In the prehospital setting, patients administered the instructed insulin glargine dose on the evening before surgery. MEASUREMENTS: Venous blood glucose values were recorded in the preoperative holding area on the day of surgery. MAIN RESULTS: No significant differences in target preoperative FBG achievement were detected among strategies in the insulin glargine-only group (n = 174) or the insulin glargine plus bolus group (n = 227). In widened preoperative FBG achievement, no significant difference was noted among strategies in the insulin glargine-only group. In the insulin glargine plus bolus group, fewer subjects following the dosing table had FBG > 249 mg/dL (> 13.7 mmol/L; P = 0.031). CONCLUSIONS: Target preoperative FBG achievement was similar among strategies in both insulin glargine groups. An insulin glargine adjustment strategy based on usual glycemic control may better prevent severe preoperative hyperglycemia in patients receiving basal/bolus regimens.

Comparison of insulin pump therapy (continuous subcutaneous insulin infusion) to alternative methods for perioperative glycemic management in patients with planned postoperative admissions.

BACKGROUND: Patients with diabetes who use insulin pumps [continuous subcutaneous insulin infusion (CSII)] undergo surgeries that require postoperative hospital admission. There are no defined guidelines for CSII perioperative use. METHODS: This retrospective single-institution study identified type 1 and type 2 diabetes subjects by electronically searching 2005-2010 anesthesia preoperative assessments for "pump." Surgical cases (n = 92) were grouped according to intraoperative insulin delivery method: (a) CSII continuation of basal rate with/without correctional insulin bolus(es) (n = 53); (b) conversion to intravenous insulin infusion (n = 20); and (c) CSII suspension with/without correctional insulin bolus(es) (n = 19). These groups were compared on mean intraoperative blood glucose (BG) and category of most extreme intraoperative BG. RESULTS: Differences were found on baseline characteristics of diabetes duration (p = .010), anesthesia time (p = .011), proportions receiving general anesthesia (p = .013), and preoperative BG (p = .033). The conversion group had the longest diabetes duration and anesthesia time; it had a higher proportion of general anesthesia recipients and a higher mean preoperative BG than the continuation group. There was no significant difference in mean BG/surgical case between continuation (163.5 ± 58.5 mg/dl), conversion (152.3 ± 28.9 mg/dl), and suspension groups (188.3 ± 44.9 mg/dl; p = .128). The suspension group experienced a greater percentage of cases (84.2%) with one or more intraoperative BG > 179 mg/dl than continuation (45.3%) and conversion (40%) groups Figure 1 groupings (p = .034). CONCLUSIONS: In this limited sample, preliminary findings are consistent with similar intraoperative glycemic control between CSII continuation and CSII conversion to intravenous insulin infusions. Continuous subcutaneous insulin infusion suspension had a greater rate of hyperglycemia. Preoperative differences between insulin delivery groups complicate interpretations of findings.