Insulin Management in Type 2 Diabetes with Cellulitis and Recent Glucocorticoid Administration
Immediate Insulin Dose Adjustments Required
Increase Lantus to 45 units daily (50% increase from baseline 30 units) and maintain current carb ratio and correction scale for now, with plan to reassess and likely intensify prandial coverage within 3 days based on glucose monitoring. 1
Basal Insulin (Lantus) Adjustment
Increase Lantus from 30 units to 45 units once daily due to the combined hyperglycemic effects of cellulitis (acute infection) and recent hydrocortisone administration 1
Glucocorticoids cause significant insulin resistance, with hydrocortisone 100mg IV producing measurable effects on glucose metabolism for 12-24 hours, requiring increased insulin doses 2
For patients on glucocorticoids, adding 0.1-0.3 units/kg/day of basal insulin to the usual regimen is recommended, with doses determined by steroid dose and oral intake 3
The 50% increase (from 30 to 45 units) represents a reasonable starting adjustment given the dual stressors of infection and steroid administration 1
Carbohydrate Ratio Adjustment
Maintain the 1:10 carb ratio initially (1 unit per 10 grams carbohydrate), but monitor closely as this will likely need tightening to 1:8 or 1:7 within 2-3 days 3
The current ratio may be insufficient given the acute illness and steroid effects, but making too many simultaneous changes increases hypoglycemia risk and makes it difficult to identify which adjustment was responsible for any problems 1
Glucocorticoids primarily cause daytime hyperglycemia with peak effects 4-6 hours after administration, disproportionately affecting postprandial glucose control 1
Correction Scale Adjustment
Maintain the 1:15 correction scale initially (1 unit lowers glucose by 15 mg/dL), but plan to reassess within 48-72 hours as insulin resistance from infection and steroids will likely require tightening to 1:12 or 1:10 1, 3
The correction factor (insulin sensitivity factor) should be recalculated using the formula 1500/TDD once the new total daily dose stabilizes 3
Critical Monitoring Requirements
Check fasting and pre-meal glucose daily during this acute illness period, with particular attention to pre-lunch and pre-dinner readings to assess adequacy of prandial coverage 1
Monitor for signs of worsening infection or inadequate glycemic control that would warrant further insulin intensification 1
If fasting glucose remains ≥180 mg/dL after 3 days, increase Lantus by an additional 4 units 3
If fasting glucose is 140-179 mg/dL after 3 days, increase Lantus by 2 units 3
Anticipated Need for Prandial Insulin Intensification
Be prepared to add or increase prandial insulin coverage within 3-5 days if pre-meal and postprandial glucose readings remain elevated despite basal insulin optimization 1, 3
When cellulitis resolves and steroid effects wane (typically 24-48 hours after last dose), insulin requirements will decrease and doses must be reduced by 20-30% to prevent hypoglycemia 1, 3
The current basal dose of 30 units for a patient on 1:10 carb ratio suggests total daily insulin requirements of approximately 50-60 units, which may increase to 75-90 units during acute illness 3
Special Considerations for Cellulitis
Cellulitis requiring hospitalization is associated with undiagnosed or poorly controlled diabetes in 21-37% of cases, indicating this patient may have had suboptimal baseline control 4
Acute infection increases insulin resistance through inflammatory cytokines and counter-regulatory hormones, requiring 30-50% increases in insulin doses 1
As the infection resolves with antibiotic therapy, insulin requirements will decrease, necessitating close monitoring and dose reduction to prevent hypoglycemia 1
Common Pitfalls to Avoid
Do not delay insulin intensification in the setting of acute illness and steroid administration—waiting for "things to settle down" will result in prolonged hyperglycemia and worse outcomes 1
Do not continue escalating basal insulin beyond 0.5 units/kg/day (approximately 60-70 units for most adults) without adding or intensifying prandial coverage, as this leads to overbasalization with increased hypoglycemia risk 3
Do not forget to reduce insulin doses by 20-30% once the infection resolves and steroid effects dissipate (24-48 hours after last dose), as failure to do so will cause severe hypoglycemia 1, 3
Do not rely solely on correction insulin (sliding scale)—scheduled basal-bolus regimens with nutritional and correction components produce better glycemic control and fewer treatment failures than correction insulin alone 1