Prolonging Glycemic Control in Hospitalized Diabetics

During his “Inpatient Diabetes Management” presentation at the 14^th Annual Southern Hospital Medicine Conference, held November 7-9, 2013, in New Orleans, LA, endocrinologist Pavan Chava, DO, noted that the direct costs of diabetes are estimated at $176 billion, and about 50% of the total cost stems from inpatient acute care.

According to Chava, 1 in 4 patients admitted to a hospital has a diagnosis of diabetes, making it the 4^th leading comorbid condition among hospital discharges. In diabetics, mortality risk isn’t increased until mean glucose reaches >146 mg/dl, which is defined as hyperglycemia.

Patients with hyperglycemia or known diabetes should get an A1c test during the hospitalization if their A1c levels haven’t been checked in the previous 2 to 3 months, Chava said. A1c 6.5% or greater can be diagnosed as diabetes, while A1c 5.7-6.4% can be diagnosed as pre-diabetes, or at risk for diabetes.

In contrast, hypoglycemia is defined as blood glucose (BG) <70 mg/dL, where levels below 50 mg/dL can cause cognitive impairment. Hypoglycemia is associated with an increased risk of mortality and prolonged hospital stay. To minimize a patient’s risk of hypoglycemia, Chava said sulfonylureas should be avoided, glucose levels should be monitored frequently at specific intervals, insulin regimen should be modified when BG is <100 mg/dL, total daily dose (TDD) should be increased by 20% when BG is <70 mg/dL, and patients should be given instructions for adjustment in nutrition or IVF with dextrose.

The basal forms of injectable insulin are Lantus and Levemir, while prandial forms include Apidra, Humalog, and NovoLog. Basic insulin regimens comprise of:

• 0.2-0.3 units/kg for TDD: Age >70 or glomerular filtration rate (GFR) <60
• 0.4 U/kg for TDD: BG 140-200 mg/dL
• 0.5 U/kg for TDD: BG 201-400

According to Chava, 50% of TDD is administered as basal insulin and 50% as prandial insulin, though the dosing may need to be adjusted based on nutritional status, hypoglycemia at home, and impaired renal function. Still, basal/prandial regimens are preferred over subcutaneous ones, and oral diabetes medications should rarely be used in a hospital setting, as they are too difficult to titrate and have many side effects.

If type 1 or type 2 diabetes patients are infused, Chava said they should be transitioned to basal 1-2 hours prior to the discontinuation of infusion. If the patient is stable Chava advised using the last 6 to 8 hours of infusion rates to calculate the 24-hour requirements, then using 60-80% of the infusion amount as the TDD, giving 50% as the basal dose and 50% as the prandial dose, and adjusting based on nutritional status. Glucose targets are 140-200 mg/dL for the critically ill, <140 mg/dL pre-meal, and <180 mg/dL random.

Chava said sliding scale therapy, which involves progressively increasing pre-meal insulin doses, should not be used for prolonged glycemic control in the hospital, as it does not provide adequate glycemic control and should never be used as the sole treatment of type 1 diabetes. According to Chava, rapid-acting insulin should be given every 4-6 hours, though type 1 diabetics should also receive basal insulin.