What is the management plan for a patient presenting with Diabetic Ketoacidosis (DKA), particularly in the elderly or those with severe forms or complicating medical conditions?

Management of Diabetic Ketoacidosis (DKA)

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in the first hour), followed by continuous IV regular insulin at 0.1 units/kg/hour once serum potassium is ≥3.3 mEq/L, while simultaneously identifying and treating precipitating factors. 1, 2

Initial Assessment and Diagnostic Criteria

Diagnostic criteria for DKA:

• Blood glucose >250 mg/dL 1
• Arterial pH <7.3 1
• Serum bicarbonate <15 mEq/L 1
• Presence of ketonemia or ketonuria 1

Essential laboratory workup immediately upon presentation:

• Plasma glucose, serum ketones (β-hydroxybutyrate preferred), electrolytes with calculated anion gap 1, 2
• Arterial or venous blood gas (venous pH typically 0.03 units lower than arterial) 1
• Blood urea nitrogen, creatinine, serum osmolality 1, 2
• Complete blood count with differential 1, 2
• Urinalysis with urine ketones 1, 2
• Electrocardiogram 1, 2
• Bacterial cultures (blood, urine, throat) if infection suspected 1

Identify precipitating factors concurrently:

• Infection (most common precipitant), myocardial infarction, stroke, pancreatitis, trauma 1, 2
• Insulin omission or inadequacy 1
• SGLT2 inhibitor use (can cause euglycemic DKA) 1, 2
• Alcohol abuse, cerebrovascular accident, new diagnosis of diabetes 1

Fluid Resuscitation Protocol

Initial fluid therapy:

• Start with 0.9% normal saline at 15-20 mL/kg/hour for the first hour 1, 2
• This aggressive initial fluid replacement is critical to restore intravascular volume, improve tissue perfusion, and enhance insulin sensitivity 3, 1

Subsequent fluid management:

• Fluid choice depends on hydration status, serum electrolyte levels, and urine output 1, 2
• When serum glucose falls to 200-250 mg/dL, switch to 5% dextrose with 0.45-0.75% saline while continuing insulin infusion 3, 1, 2
• This prevents hypoglycemia and ensures complete resolution of ketoacidosis 1, 2
• Total fluid replacement should aim to correct estimated deficits within 24 hours 1

Critical caveat for elderly and those with comorbidities:

• In patients with congestive heart failure or renal disease, fluid administration must be more cautious with close monitoring for volume overload 4, 5
• In hypertensive emergency concurrent with DKA, balance aggressive fluid resuscitation against risk of worsening hypertension 3
• Continuous cardiac monitoring is essential in elderly patients and those with hypertensive emergency to detect arrhythmias early 3

Critical Potassium Management

This is a life-threatening consideration that must be addressed before insulin therapy:

If serum K+ <3.3 mEq/L:

• DO NOT start insulin therapy 1, 2
• Continue isotonic saline but hold insulin 2
• Confirm adequate urine output, then aggressively replace potassium with 20-40 mEq/L in IV fluids 2
• Starting insulin with hypokalemia can cause life-threatening cardiac arrhythmias, respiratory muscle weakness, and death 1, 2

If serum K+ 3.3-5.5 mEq/L:

• Add 20-30 mEq potassium per liter of IV fluid (use 2/3 KCl and 1/3 KPO₄) once adequate urine output is confirmed 1
• Target serum potassium of 4-5 mEq/L throughout treatment 1

If serum K+ >5.5 mEq/L:

• Withhold potassium initially but monitor closely 1
• Levels will drop rapidly with insulin therapy as potassium is driven intracellularly 1

Critical understanding:

• Total body potassium depletion in DKA averages 3-5 mEq/kg body weight, and this depletion is universal despite initial serum levels 1
• Insulin therapy will unmask this depletion by driving potassium intracellularly, requiring massive potassium repletion during treatment 1
• Check potassium levels every 2-4 hours during active treatment 1
• Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 1

Insulin Therapy Protocol

For moderate-to-severe DKA or critically ill/mentally obtunded patients:

• Once K+ ≥3.3 mEq/L, give IV bolus of 0.1 units/kg regular insulin 3, 1, 2
• Start continuous infusion at 0.1 units/kg/hour regular insulin 3, 1, 2
• Target glucose decline of 50-75 mg/dL per hour 1, 2

If plasma glucose does not fall by 50 mg/dL in the first hour:

• Check hydration status 1
• If acceptable, double the insulin infusion rate every hour until steady glucose decline achieved 1

Continue insulin infusion until complete resolution of ketoacidosis:

• pH >7.3, serum bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L 3, 1, 2
• Continue insulin regardless of glucose levels 1
• Target glucose between 150-200 mg/dL until DKA resolution parameters are met 1

Critical pitfall to avoid:

• Premature termination of insulin therapy before complete resolution of ketosis leads to recurrence of DKA 3, 1
• Interruption of insulin infusion when glucose levels fall is a common cause of persistent or worsening ketoacidosis 1

Alternative approach for mild-to-moderate uncomplicated DKA in hemodynamically stable, alert patients:

• Subcutaneous rapid-acting insulin analogs at 0.15 units/kg every 2-3 hours combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin 1
• This requires adequate fluid replacement, frequent point-of-care glucose monitoring, and treatment of concurrent infections 1
• Continuous IV insulin remains the standard of care for critically ill and mentally obtunded patients 1

Bicarbonate Administration

Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0 3, 1, 2

Rationale:

• Multiple studies show no difference in resolution of acidosis or time to discharge with bicarbonate use 3, 1
• Bicarbonate may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1

Exception:

• Consider IV sodium bicarbonate only if serum pH falls below 6.9, or when pH <7.2 and/or bicarbonate <10 mEq/L pre- and post-intubation to prevent hemodynamic collapse 6

Monitoring During Treatment

Laboratory monitoring every 2-4 hours:

• Blood glucose, serum electrolytes (especially potassium), blood urea nitrogen, creatinine 1, 2
• Serum osmolality, venous pH, anion gap 1, 2
• Follow venous pH and anion gap to monitor resolution of acidosis 1

Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA:

• The nitroprusside method only measures acetoacetic acid and acetone, not the predominant ketone body 1

Clinical monitoring:

• Continuous cardiac monitoring in elderly patients and those with hypertensive emergency 3
• Monitor for signs of cerebral edema (more common in children but can occur in adults): altered mental status, headache, neurological deterioration 1
• Overly rapid correction of osmolality increases risk of cerebral edema 1

DKA Resolution Criteria

DKA is resolved when ALL of the following are met:

• Glucose <200 mg/dL 3, 1, 2
• Serum bicarbonate ≥18 mEq/L 3, 1, 2
• Venous pH >7.3 3, 1, 2
• Anion gap ≤12 mEq/L 3, 1, 2

Transition to Subcutaneous Insulin

Critical timing to prevent rebound hyperglycemia and recurrent DKA:

Administer basal insulin (glargine, detemir, or intermediate-acting) 2-4 hours BEFORE stopping IV insulin infusion 3, 1, 2

• This overlap period is essential to prevent recurrence of ketoacidosis and rebound hyperglycemia 3, 1
• Stopping IV insulin without prior administration of basal subcutaneous insulin causes rebound hyperglycemia and ketoacidosis 1

Recent evidence suggests:

• Adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 1

Insulin dosing after resolution:

• If patient is NPO (nothing by mouth), continue IV insulin and fluid replacement, supplement with subcutaneous regular insulin as needed 1
• When patient can eat, start multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin 1
• Estimate total daily insulin requirement at 0.3-0.4 units/kg/day, with half as basal and half as prandial coverage 2

Special Considerations for Elderly and Severe DKA

Elderly patients:

• More cautious fluid administration if congestive heart failure or renal disease present 4, 5
• Higher risk of vascular complications from undertreatment 7
• Continuous cardiac monitoring essential 3

Severe DKA with hypertensive emergency:

• Balance aggressive fluid resuscitation against risk of worsening hypertension 3
• Avoid overly aggressive blood pressure reduction which can lead to organ hypoperfusion 3
• Adjust antihypertensive regimen based on blood pressure control and renal function 3

Chronic kidney disease:

• More cautious potassium repletion 5
• If anuric or oliguric, potassium repletion must be more cautious with nephrology consultation 1
• Fluid management requires careful monitoring for volume overload 5

SGLT2 inhibitor-associated DKA:

• Discontinue SGLT2 inhibitors immediately 1, 2
• Do not restart until 3-4 days after metabolic stability achieved 1, 2
• SGLT2 inhibitors must be discontinued 3-4 days before any planned surgery to prevent DKA 3, 1
• Can present as euglycemic DKA (glucose may be <250 mg/dL) 1, 8

Pregnancy:

• DKA in pregnancy requires specialized management with lower thresholds for intervention 5
• Higher risk of fetal complications 5

Treatment of Precipitating Factors

Concurrent treatment of underlying cause is crucial:

• Administer appropriate antibiotics if infection confirmed (obtain chest X-ray, bacterial cultures) 1, 2
• Manage myocardial infarction or stroke if present 3, 1
• Treat pancreatitis, trauma, or other precipitating conditions 1
• Failure to identify and treat underlying cause leads to treatment failure 3

Discharge Planning and Prevention of Recurrence

Before discharge:

• Identify outpatient diabetes care providers 1
• Educate patients and families on glucose monitoring, insulin administration, recognition and treatment of hyperglycemia/hypoglycemia 1
• Ensure appropriate insulin regimen prescribed with attention to medication access and affordability 1
• Review all medications to ensure no chronic medications were stopped and safety of new prescriptions 3
• Schedule follow-up appointments prior to discharge 1
• Medication reconciliation with attention to access and scheduled follow-up visits 3

Patient education to prevent recurrence:

• Recognition, prevention, and management of DKA 1
• Understanding of diabetes diagnosis, home glucose goals, when to call healthcare professional 1
• Self-care guidelines during illness 8
• Adherence to insulin therapy 8

Common Pitfalls to Avoid

• Starting insulin before correcting severe hypokalemia (K+ <3.3 mEq/L) - can cause fatal arrhythmias 1, 2
• Premature termination of insulin therapy before complete resolution of ketosis - leads to recurrent DKA 3, 1
• Stopping IV insulin without prior basal subcutaneous insulin - causes rebound hyperglycemia 1
• Failure to add dextrose when glucose falls below 250 mg/dL - leads to hypoglycemia and premature insulin discontinuation 1
• Inadequate fluid resuscitation - worsens DKA 3
• Overly aggressive blood pressure reduction in hypertensive emergency - causes organ hypoperfusion 3
• Inadequate potassium monitoring and replacement - leading cause of mortality 1
• Using bicarbonate in patients with pH >7.0 - worsens outcomes 3, 1
• Failure to identify and treat precipitating cause - leads to treatment failure 3, 1