Management of Hyperglycemia
Initial Assessment and Risk Stratification
The immediate management of hyperglycemia depends critically on the clinical context, severity of hyperglycemia, and presence of acute complications—with different approaches required for newly diagnosed diabetes, acute illness settings, and specific precipitants like corticosteroid use or immune checkpoint inhibitor therapy.
Determine the Clinical Context
Screen systematically for the underlying cause using fasting blood glucose, random blood glucose, and HbA1c to distinguish between new-onset diabetes, stress hyperglycemia, medication-induced hyperglycemia, or diabetic emergencies 1
Rule out hyperglycemic emergencies first: Check for diabetic ketoacidosis (DKA) with ketone measurement (blood ketones >3.0 mmol/L or urine ketones) and assess for hyperosmolar hyperglycemic state (HHS) by calculating osmolality ≥320 mOsm/kg using [(2×Na+) + glucose + urea] 1, 2
Identify precipitating factors including corticosteroid use, acute coronary syndrome, stroke, critical illness, immune checkpoint inhibitor therapy, or infections that require specific management approaches 1, 3
Severity-Based Treatment Algorithm
Severe Hyperglycemia (HbA1c >9% or Random Glucose >200 mg/dL with Symptoms)
For newly diagnosed type 2 diabetes with HbA1c >9%, the American Diabetes Association recommends immediate dual therapy with metformin plus basal insulin rather than attempting lifestyle modification alone, as delays perpetuate beta-cell dysfunction and increase complication risk 4, 5
Initiate basal insulin at 0.1-0.2 units/kg/day administered at bedtime, titrating by 2-4 units every 3 days based on fasting glucose readings, targeting fasting glucose <130 mg/dL 4
Start metformin simultaneously (unless contraindicated by renal or hepatic dysfunction) to reduce hepatic glucose production, prevent weight gain, and provide cardiovascular benefits that persist long-term 1, 5
Implement aggressive lifestyle intervention with at least 16 sessions over 6 months focusing on 500-750 kcal/day energy deficit, 150 minutes weekly of moderate-intensity aerobic activity plus resistance training, and diabetes self-management education 4, 6
Monitor HbA1c every 3 months until target <7% is achieved, then at least twice yearly, with daily fasting blood glucose monitoring to guide insulin titration 4, 5
Moderate Hyperglycemia in Acute Illness Settings
In hospitalized patients and those with acute coronary syndrome or stroke, insulin remains the most appropriate agent, with target blood glucose 140-180 mg/dL to balance glycemic control against hypoglycemia risk 7, 3
For critically ill patients: Use continuous intravenous insulin infusion with concomitant glucose solution under strict monitoring, targeting blood glucose 140-180 mg/dL 7, 3
For non-critically ill inpatients: Transition to scheduled subcutaneous basal-bolus insulin regimens (long-acting basal analogs like glargine or detemir, plus rapid-acting analogs like aspart, lispro, or glulisine for prandial coverage) supplemented with correction doses 7
In acute stroke: Initiate treatment when blood glucose >200 mg/dL, as persistent hyperglycemia (>200 mg/dL) during the first 24 hours independently predicts expansion of infarct volume and poor neurological outcomes 1
In acute coronary syndrome: Treatment is recommended for any patient with hyperglycemia >180 mg/dL or postprandial glucose >140 mg/dL, using intravenous insulin in the intensive care phase, then transitioning to subcutaneous regimens in consultation with endocrinology 3
Corticosteroid-Induced Hyperglycemia
For patients on immune checkpoint inhibitors or other cancer therapies requiring corticosteroids, the pattern of hyperglycemia follows the pharmacokinetics of the steroid, with prednisone causing peak hyperglycemia 8 hours post-dose (late morning/afternoon) and dexamethasone peaking at 7-9 hours 1
Diagnose with two abnormal tests (random glucose ≥11.1 mmol/L on different occasions and/or HbA1c ≥6.5%) in the context of corticosteroid use 1
Educate patients about glucose monitoring, symptoms of severe hyperglycemia, hypoglycemia management, and the critical need to adjust diabetes medications when steroid doses change 1
Consider sulfonylureas or metformin for isolated daytime hyperglycemia patterns, though metformin requires preserved renal and hepatic function 1
For patients on SGLT2 inhibitors: Provide re-education about diabetic ketoacidosis risk, particularly euglycemic DKA, ensure capability to measure ketones, and consider discontinuing SGLT2 inhibitors if ketone monitoring is not feasible 1
Critical Pitfalls to Avoid
Never attempt lifestyle modification alone for 3-6 months when HbA1c >9%, as this represents clinical inertia that prolongs exposure to severe hyperglycemia and increases complication risk 4, 5
Never use sliding-scale insulin (SSI) regimens as monotherapy, as they exclude basal insulin and are ineffective for glycemic control 7
Never discontinue metformin when adding insulin in type 2 diabetes, as metformin should continue indefinitely to reduce insulin requirements and provide cardiovascular benefits 5
Never ignore the risk of hypoglycemia when intensifying therapy—patients should always carry fast-acting sugar (hard candy or glucose tablets), recognize their hypoglycemia symptoms, and monitor blood glucose frequently before activities like driving 8
Never focus solely on glucose control without addressing cardiovascular risk factors (lipids, blood pressure) and screening for complications, as this leaves major mortality risks unmanaged 6
Transition and Long-Term Management
Once glycemic control stabilizes on metformin plus insulin, consider adding or transitioning to GLP-1 receptor agonists or SGLT2 inhibitors, as these agents provide additional HbA1c reduction of 0.5-1.5%, promote weight loss, and offer cardiovascular and renal protection that may allow insulin reduction or discontinuation 4, 6
Target HbA1c <7% for most adults to reduce microvascular complications (retinopathy, nephropathy, neuropathy), as demonstrated by the UKPDS showing persistent cardiovascular benefits emerging over 10-year follow-up despite initial convergence of HbA1c levels 1, 6
Refer to endocrinology for all patients requiring insulin therapy, and to diabetes educators and registered dietitians for structured education on medication administration, glucose monitoring, hypoglycemia management, and medical nutrition therapy 1, 4
Screen for diabetes distress and depression at every visit, as psychological factors directly impair self-management and treatment adherence 4, 6