How to manage hyperglycemia in a patient with impaired renal function and recent steroid use after metformin was held?

Managing Hyperglycemia in a Post-Surgical Patient with Impaired Renal Function and Recent Steroid Use

For this 63-year-old male with a BMI of 40, impaired renal function (GFR 40), and steroid-induced hyperglycemia (blood glucose 216 mg/dL), insulin therapy should be initiated immediately while metformin remains held due to renal impairment.

Initial Assessment and Management

• The patient has multiple risk factors contributing to hyperglycemia:

  • Type 2 diabetes with suboptimal control (A1C 8.3%) 1
  • Recent dexamethasone administration (4 mg, 40 hours ago) 1
  • Impaired renal function (GFR 40 ml/min/1.73m²) 1
  • Post-surgical state (ileal urinary diversion) 1
  • Full liquid diet 1

• Metformin should remain held due to:

  • eGFR of 40 ml/min/1.73m² (below threshold for full-dose therapy) 1, 2
  • Recent surgical procedure with potential for volume depletion 2
  • Risk of lactic acidosis in the post-surgical setting 1, 2

Immediate Management Plan

1. Initiate basal-bolus insulin regimen:

   • Start with 0.3-0.5 units/kg/day total insulin 1
   • Split as 50% basal insulin (glargine/detemir) and 50% prandial insulin 1
   • For this 125 kg patient, approximately 18-20 units basal insulin once daily and 6-7 units rapid-acting insulin with each meal 1

2. Blood glucose monitoring:

   • Check capillary blood glucose before meals and at bedtime 1
   • Target blood glucose range: 140-180 mg/dL while in hospital 1
   • Monitor for hypoglycemia, especially given renal impairment 1

3. Adjust insulin doses:

   • Increase basal insulin by 10-20% every 1-2 days if fasting glucose remains >180 mg/dL 1
   • Adjust prandial insulin based on pre-meal glucose values and carbohydrate intake 1
   • Consider higher insulin requirements due to steroid effect (typically peaks 7-9 hours after administration) 1

Discharge Planning

• Metformin considerations:

  • May restart at reduced dose (maximum 1000 mg/day) when patient is stable, eating normally, and kidney function is stable 1
  • Monitor renal function closely (every 3-6 months) 1

• Consider adding GLP-1 receptor agonist:

  • Once patient is eating normally, consider adding dulaglutide or liraglutide 1
  • These agents can be used with eGFR >15 ml/min/1.73m² 1
  • Benefits include weight loss and lower hypoglycemia risk 1

• SGLT2 inhibitor consideration:

  • May be added once patient is stable for renoprotection 3
  • Use only if eGFR remains >30 ml/min/1.73m² 1, 3

Important Considerations and Pitfalls

• Avoid sulfonylureas due to increased risk of hypoglycemia in renal impairment 1
• Monitor for vitamin B12 deficiency if metformin is restarted (especially with long-term use) 1, 2
• Adjust insulin doses when steroid doses are tapered to avoid hypoglycemia 1
• Be aware that metformin clearance is reduced in renal impairment, increasing risk of lactic acidosis 2, 4
• Consider extended-release metformin when restarting, which may have better tolerability 5
• Educate patient on hypoglycemia recognition and management 1

Follow-up Recommendations

• Reassess renal function in 48-72 hours 2
• Monitor electrolytes and acid-base status 2
• Adjust diabetes regimen based on diet advancement and medication tolerance 1
• Consider endocrinology consultation if glycemic control remains suboptimal 1