What is the treatment for a 50-year-old diabetic patient with sudden onset of headache, blurred vision, hyperglycemia (Fasting Blood Sugar (FBS) 280), and significant ketonuria (urine ketones greater than 160)?

Diabetic Ketoacidosis (DKA) - Immediate Treatment Required

This patient meets diagnostic criteria for diabetic ketoacidosis and requires immediate hospitalization with aggressive intravenous fluid resuscitation, continuous IV insulin therapy, and electrolyte replacement. 1, 2

Diagnostic Confirmation

This patient's presentation is consistent with DKA based on:

• Hyperglycemia: Blood glucose 280 mg/dL (>250 mg/dL threshold) 1, 2
• Significant ketonuria: Urine ketones >160 mg/dL (moderate to large) 1, 2
• Clinical symptoms: Headache and blurred vision suggest metabolic derangement 3

Critical next step: Obtain immediate laboratory workup including venous blood gas, complete metabolic panel, serum ketones (preferably β-hydroxybutyrate), and calculate anion gap to confirm acidosis (pH <7.3, bicarbonate <15 mEq/L required for DKA diagnosis). 1, 4

Immediate Management Protocol

1. Fluid Resuscitation (First Priority)

Begin aggressive IV fluid replacement with 0.9% normal saline at 15-20 mL/kg/hour (approximately 1-1.5 L in the first hour for a 70 kg patient) to restore circulating volume and tissue perfusion. 1

• Subsequent fluid choice depends on corrected serum sodium, hydration status, and urine output 1
• Correct serum sodium for hyperglycemia: add 1.6 mEq/L for every 100 mg/dL glucose above 100 5, 1
• Total fluid deficit should be corrected within 24 hours 4

2. Insulin Therapy

After confirming serum potassium is ≥3.3 mEq/L, start continuous IV regular insulin infusion at 0.1 units/kg/hour (approximately 5-7 units/hour for average adult) without an initial bolus. 5, 4

• If glucose does not fall by 50 mg/dL in the first hour, double the insulin infusion rate hourly until steady decline of 50-75 mg/dL per hour is achieved 5
• Critical pitfall to avoid: Never stop insulin infusion when glucose normalizes—ketoacidosis takes longer to resolve than hyperglycemia 1, 4

3. Glucose Management During Treatment

When blood glucose falls to 250 mg/dL, add dextrose 5% to IV fluids while continuing insulin infusion to prevent hypoglycemia and allow continued ketone clearance. 1, 4

• Target glucose 150-200 mg/dL until DKA resolves 4
• Continue insulin infusion until ALL resolution criteria are met (see below) 1, 4

4. Potassium Replacement (Critical)

Despite possible initial hyperkalemia, total body potassium is severely depleted in DKA. 5

Once serum potassium falls below 5.5 mEq/L and adequate urine output is confirmed, add 20-30 mEq potassium per liter of IV fluid (2/3 KCl and 1/3 KPO4) to maintain serum potassium 4-5 mEq/L. 5, 1

• If initial potassium is <3.3 mEq/L: Delay insulin therapy and aggressively replace potassium first to prevent fatal cardiac arrhythmias 5
• Monitor potassium every 2-4 hours 1, 4

5. Monitoring Protocol

Draw blood every 2-4 hours for glucose, electrolytes, BUN, creatinine, venous pH, and calculate anion gap. 1, 4

• Venous pH is sufficient for monitoring (typically 0.03 units lower than arterial pH)—repeat arterial blood gases are unnecessary 1, 4
• Measure serum β-hydroxybutyrate (not urine ketones) to monitor ketone clearance 1, 4
• Common pitfall: Nitroprusside-based urine ketone tests only measure acetoacetate and can falsely appear to worsen during treatment as β-hydroxybutyrate converts to acetoacetate 1, 4

DKA Resolution Criteria

DKA is resolved only when ALL of the following are met: 1, 4

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3
• Anion gap ≤12 mEq/L

Transition to Subcutaneous Insulin

Once DKA is resolved and patient can eat, initiate subcutaneous basal-bolus insulin regimen and continue IV insulin for 1-2 hours after first subcutaneous dose to ensure adequate plasma insulin levels and prevent rebound ketoacidosis. 4

Identify and Treat Precipitating Cause

The most common triggers for DKA include: 6, 3

• Infection (most common—obtain cultures if suspected) 1
• Insulin omission or nonadherence
• New diagnosis of diabetes
• Acute illness or physiologic stress

Obtain bacterial cultures (blood, urine, throat) if infection is suspected, as this is the most common precipitating factor. 1

Special Considerations for This Patient

The sudden onset headache and blurred vision warrant additional evaluation:

• These symptoms may represent DKA-related metabolic derangement 3
• However, rule out other acute intracranial pathology if symptoms persist after metabolic correction
• Monitor closely for cerebral edema during treatment (rare in adults but can occur with overly aggressive fluid resuscitation) 5

Critical Pitfalls to Avoid

• Never discontinue insulin when glucose normalizes—continue until ketoacidosis resolves (pH >7.3, bicarbonate ≥18) 1, 4
• Never delay potassium replacement once levels fall below 5.5 mEq/L—hypokalemia can cause fatal arrhythmias 5
• Never rely on urine ketones to monitor treatment response—use serum β-hydroxybutyrate 1, 4
• Never give insulin if potassium <3.3 mEq/L—correct potassium first 5