What is the appropriate insulin infusion dosage for an 85-year-old woman with severe hyperglycemia (elevated glucose level)?

From the Guidelines

For an 85-year-old woman with severe hyperglycemia, the appropriate insulin infusion typically starts at 0.05-0.1 units/kg/hour, adjusted based on frequent glucose monitoring, with a target glucose range of 140–180 mg/dL (7.8–10.0 mmol/L) 1. Given the patient's weight of 139.6 lbs (approximately 63.4 kg), this would translate to an initial insulin infusion rate of approximately 3.17-6.34 units per hour. The infusion should be accompanied by intravenous fluids (usually normal saline) to address dehydration, and regular electrolyte monitoring, particularly potassium. Blood glucose should be checked every 1-2 hours initially, with the goal of decreasing glucose by 50-75 mg/dL per hour until reaching 200-250 mg/dL. Once stabilized, transition to subcutaneous insulin should be planned. This conservative approach is necessary because elderly patients have reduced renal function, increased insulin sensitivity, and higher risk of hypoglycemia, as noted in recent guidelines 1. The treatment must also address the underlying cause of hyperglycemia, whether it's infection, medication effect, or other stressors. Close monitoring for hypoglycemia is essential, as elderly patients often have blunted symptoms and greater risk of adverse outcomes from low blood sugar. It's also important to consider that glucose concentrations between 180 mg/dL and 250 mg/dL (10–13.9 mmol/L) may be acceptable in patients with severe comorbidities, as suggested by recent research 1. Clinical judgment combined with ongoing assessment of clinical status should be incorporated into the day-to-day decisions regarding insulin dosing 1.

Some key points to consider in the management of this patient include:

• The importance of frequent glucose monitoring to adjust the insulin infusion rate
• The need for intravenous fluids and electrolyte monitoring to prevent dehydration and electrolyte imbalances
• The goal of decreasing glucose levels by 50-75 mg/dL per hour until reaching a target range
• The importance of addressing the underlying cause of hyperglycemia
• The need for close monitoring for hypoglycemia and its potential consequences in elderly patients. Given the most recent and highest quality study available 1, these considerations should guide the management of the patient's hyperglycemia.

From the FDA Drug Label

The average range of total daily insulin requirement for maintenance therapy in insulin-treated patients without severe insulin resistance lies between 0.5 and 1 unit/kg/day. For intravenous use, Humulin R U-100 should be used at concentrations from 0.1 unit/mL to 1 unit/mL in infusion systems with the infusion fluids 0.9% sodium chloride using polyvinyl chloride infusion bags.

The patient weighs 139.6 lbs, which is approximately 63.4 kg. To calculate the insulin infusion dosage, we need to consider the patient's weight and the severity of hyperglycemia. Given the patient's severe hyperglycemia (elevated glucose level of 28.1 mmol/L), the dosage may need to be adjusted. However, the provided information does not include a specific dosage recommendation for intravenous insulin infusion in this scenario. The average time required to attain near normoglycemia was 161 ± 14 minutes for Humulin R U-100, but the initial dose was 0.5 U/h, adjusted to maintain blood glucose concentrations near normoglycemia (100 to 160 mg/dL) 2. Considering the patient's age (85 years) and weight (63.4 kg), a conservative approach would be to start with a lower dose and adjust as needed. A possible initial dose could be 0.5-1 unit/kg/day, which would be approximately 31.7-63.4 units/day for this patient. For intravenous use, this could be translated to an initial infusion rate of 0.5-1 unit/h, with close monitoring of blood glucose levels and adjustment of the infusion rate as needed to maintain normoglycemia 2. It is essential to closely monitor the patient's blood glucose levels and adjust the insulin infusion dosage accordingly to avoid hypoglycemia.

From the Research

Insulin Infusion Dosage for Severe Hyperglycemia

The appropriate insulin infusion dosage for an 85-year-old woman with severe hyperglycemia (elevated glucose level) can be determined based on several factors, including her current glucose level, weight, and medical history.

• The patient's finger stick glucose level is 28.1 mmol/L, which is significantly higher than the recommended target range of 140 to 180 mg/dL 3, 4.
• The patient's weight is 139.6 lbs, which may be a factor in determining the insulin dosage.
• There is no specific formula provided in the studies for calculating the insulin infusion dosage based on the patient's weight and glucose level.

Recommended Glucose Targets and Insulin Regimens

• The recommended glucose target range for hospitalized patients is 140 to 180 mg/dL 3, 4.
• Insulin remains the most appropriate agent for managing hyperglycemia in hospitalized patients 3.
• The use of electronic glycemic management systems (eGMS) may result in less variable blood glucose control and less hypoglycemia 5.
• The choice of insulin regimen depends on the patient's previous experience with insulin, baseline diabetes control, and renal function 4.

Considerations for Insulin Infusion Dosage

• The insulin infusion dosage should be adjusted based on the patient's glucose level, with the goal of achieving the recommended target range 3, 4.
• The use of sliding-scale insulin regimens is not recommended, as they increase the risk of hypoglycemia and large fluctuations in blood glucose levels 3, 4.
• The patient's renal function and other comorbidities should be considered when determining the insulin infusion dosage 4.

Guidance from Clinical Practice Guidelines

• The Endocrine Society Clinical Practice Guideline recommends the use of insulin regimens for prandial insulin dosing, glucocorticoid, and enteral nutrition-associated hyperglycemia 6.
• The guideline also recommends the use of noninsulin therapies and emerging diabetes technologies, such as continuous glucose monitoring and insulin pump therapy 6.