Management of Hyperglycemia in a Hospitalized Patient with Community-Acquired Pneumonia
Scheduled basal insulin and correction insulin is the most appropriate management for this patient.
This 66-year-old woman with confusion, poor oral intake, and stress hyperglycemia (glucose 185–215 mg/dL with HbA1c 5.9%) requires a scheduled insulin regimen that accounts for her inability to eat reliably while preventing dangerous glucose fluctuations.
Why Scheduled Basal Insulin Plus Correction Insulin Is Preferred
Basal insulin with correction doses is the preferred treatment for non-critically ill hospitalized patients with poor oral intake or those who are NPO, according to the American Diabetes Association 1.
The HbA1c of 5.9% indicates this patient does not have pre-existing diabetes; her hyperglycemia is stress-induced from acute illness (pneumonia, confusion, poor intake) 1.
Sliding-scale insulin as monotherapy is strongly discouraged by all major diabetes guidelines because it reacts to hyperglycemia after it occurs rather than preventing it, leading to dangerous glucose fluctuations 1, 2, 3.
For hospitalized patients with poor oral intake, a basal-plus-correction regimen provides continuous background insulin to suppress hepatic glucose production while allowing flexible correction doses when glucose rises 1.
Why the Other Options Are Inappropriate
Empagliflozin and Sliding-Scale Insulin
SGLT2 inhibitors (empagliflozin) are contraindicated in acutely ill hospitalized patients because they increase the risk of euglycemic diabetic ketoacidosis, especially in patients with poor oral intake, infection, or dehydration 1.
This patient has community-acquired pneumonia with confusion and poor intake—precisely the clinical scenario where SGLT2 inhibitors pose maximum danger 1.
Sliding-scale insulin alone provides inadequate glycemic control, with only 38% of patients achieving mean glucose <140 mg/dL compared to 68% with scheduled basal-bolus regimens 1, 2, 3.
Metformin and Sliding-Scale Insulin
Metformin should be withheld in hospitalized patients with acute infection because the combination of hypoperfusion, potential renal impairment, and tissue hypoxia markedly raises the risk of lactic acidosis 1.
This patient has pneumonia (acute infection) with confusion (potential hypoperfusion) and poor oral intake—all contraindications to metformin in the hospital setting 1.
Metformin's delayed onset of action (days to weeks) makes it insufficient for managing acute stress hyperglycemia in the 185–215 mg/dL range 1.
Again, sliding-scale insulin as the sole insulin regimen is condemned by guidelines 1.
Sliding-Scale Insulin Only
Using only sliding-scale insulin in the inpatient setting is strongly discouraged by the American Diabetes Association 1.
Sliding-scale monotherapy results in treatment failure (>2 consecutive glucose readings >240 mg/dL) in approximately 19% of patients versus 0–2% with basal-bolus therapy 2.
Without basal insulin, this patient will experience wide glucose swings and inadequate overnight coverage, increasing the risk of both hyperglycemia and rebound hypoglycemia 1, 2, 3.
Practical Implementation
Initial Dosing
For a hospitalized patient with stress hyperglycemia and poor oral intake, start with basal insulin at 0.1–0.15 units/kg/day (lower dose given her lack of pre-existing diabetes and high-risk features: age 66, confusion, poor intake) 1.
Administer basal insulin (glargine or detemir) once daily at bedtime to provide continuous background coverage 1.
Correction Insulin Protocol
Add correction doses of rapid-acting insulin: 2 units for glucose >250 mg/dL and 4 units for glucose >350 mg/dL, administered in addition to basal insulin 1.
Check glucose every 4–6 hours in patients with poor oral intake or NPO status 1.
Titration
Increase basal insulin by 2 units every 3 days if fasting glucose remains 140–179 mg/dL, or by 4 units every 3 days if fasting glucose ≥180 mg/dL 1.
Target fasting glucose 80–130 mg/dL and random glucose 140–180 mg/dL for most non-critically ill hospitalized patients 1, 2.
Hypoglycemia Management
If glucose falls <70 mg/dL, treat immediately with 15 g fast-acting carbohydrate (or IV dextrose if NPO) and reduce basal insulin by 10–20% 1.
In this elderly patient with confusion and poor intake, vigilance for hypoglycemia is critical 1.
Common Pitfalls to Avoid
Never use sliding-scale insulin as the sole regimen in hospitalized patients requiring insulin therapy—this approach is ineffective and unsafe 1, 2, 3.
Do not start SGLT2 inhibitors in acutely ill hospitalized patients with infection, poor intake, or dehydration 1.
Do not use metformin in hospitalized patients with acute infection (pneumonia) due to lactic acidosis risk 1.
Do not withhold basal insulin entirely in patients who are NPO or have poor intake—basal insulin suppresses hepatic glucose production independent of food intake and prevents dangerous hyperglycemia 1.
Do not delay insulin dose adjustments—75% of hospitalized patients who experience hypoglycemia receive no insulin dose adjustment before the next administration, highlighting a critical management gap 1.
Transition Planning
Once the patient's oral intake improves and pneumonia resolves, reassess the need for continued insulin therapy 1.
Given her normal HbA1c (5.9%), this patient likely will not require insulin after discharge once the acute stressor (pneumonia) resolves 1.
Obtain an HbA1c at discharge to confirm the absence of underlying diabetes and guide outpatient management 1.