What is the immediate management for an adult patient with type 1 diabetes (T1D) presenting with diabetic ketoacidosis (DKA)?

Immediate Management of Adult DKA in Type 1 Diabetes

Begin with aggressive isotonic saline resuscitation 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 potassium is ≥3.3 mEq/L, while monitoring and replacing electrolytes every 2-4 hours until resolution criteria are met (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L). 1

Initial Assessment and Diagnostic Workup

• Confirm DKA diagnosis with: blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria 1
• Obtain immediate laboratory evaluation: plasma glucose, BUN/creatinine, serum ketones (β-hydroxybutyrate preferred), electrolytes with calculated anion gap, osmolality, arterial blood gases, complete blood count, and ECG 1
• Identify precipitating factors: infection (obtain bacterial cultures from urine, blood, throat if suspected), myocardial infarction, stroke, pancreatitis, trauma, insulin omission, or SGLT2 inhibitor use 1
• Administer appropriate antibiotics immediately if infection is suspected 1

Fluid Resuscitation Protocol

• First hour: Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (1-1.5 L for average adult) 1
• Subsequent hours: Continue fluid replacement based on hydration status, serum electrolytes, and urine output to correct estimated deficits within 24 hours 1
• When glucose reaches 250 mg/dL: Switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy 1

Insulin Therapy

Critical Pre-Insulin Check

• DO NOT start insulin if potassium <3.3 mEq/L - aggressively replace potassium first to prevent life-threatening cardiac arrhythmias and respiratory muscle weakness 1
• Delay insulin therapy until potassium ≥3.3 mEq/L is achieved 1

Standard IV Insulin Protocol

• Start continuous IV regular insulin infusion at 0.1 units/kg/hour (preferred method for moderate to severe DKA) 1
• Target glucose decline of 50-75 mg/dL per hour 1
• If glucose does not fall by 50 mg/dL in the first hour, check hydration status; if acceptable, double the insulin infusion rate hourly until steady decline achieved 1
• Continue insulin infusion until resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels 1

Alternative for Mild-Moderate Uncomplicated DKA

• For hemodynamically stable, alert patients with mild-moderate DKA: subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin 1
• This approach is NOT appropriate for critically ill or mentally obtunded patients, who require continuous IV insulin 1

Electrolyte Management

Potassium Replacement (Critical)

• If K+ <3.3 mEq/L: Hold insulin, aggressively replace potassium until ≥3.3 mEq/L 1
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO₄) to IV fluids once adequate urine output confirmed 1
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy 1
• Target serum potassium 4-5 mEq/L throughout treatment 1
• Total body potassium depletion averages 3-5 mEq/kg body weight in DKA; insulin therapy will unmask this by driving potassium intracellularly 1

Bicarbonate Administration

• Bicarbonate is NOT recommended for pH >6.9-7.0 - multiple studies show no difference in resolution of acidosis or time to discharge 1
• Bicarbonate may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1

Monitoring Protocol

• Draw blood every 2-4 hours for: serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 1
• Monitor potassium levels closely every 2-4 hours during active treatment 1
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor acidosis resolution 1
• Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA resolution 1

Resolution Criteria

• DKA is resolved when ALL of the following are met: 1
  • Glucose <200 mg/dL
  • Serum bicarbonate ≥18 mEq/L
  • Venous pH >7.3
  • Anion gap ≤12 mEq/L
• Target glucose between 150-200 mg/dL until DKA resolution parameters are met 1

Transition to Subcutaneous Insulin

• Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia 1
• Once DKA is resolved and patient can eat, start multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin 1
• If patient remains NPO after DKA resolution, continue IV insulin and fluid replacement, supplementing with subcutaneous regular insulin as needed 1
• Adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 1

Critical Pitfalls to Avoid

• Premature insulin initiation with K+ <3.3 mEq/L leads to life-threatening arrhythmias 1
• Stopping IV insulin when glucose falls below 250 mg/dL is a common cause of persistent or worsening ketoacidosis - continue insulin and add dextrose instead 1
• Stopping IV insulin without prior basal subcutaneous insulin causes rebound hyperglycemia and ketoacidosis 1
• Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 1
• Overly rapid correction of osmolality increases cerebral edema risk, particularly in younger patients 1
• Inadequate fluid resuscitation worsens both DKA and any concurrent conditions like pancreatitis 2

Special Considerations

• SGLT2 inhibitors: Discontinue immediately and do not restart until 3-4 days after metabolic stability is achieved 1
• Thromboprophylaxis: Consider enoxaparin as part of standard hospital thromboprophylaxis protocols after initial fluid resuscitation, as DKA creates a hypercoagulable state 3
• ICU admission indicated for: cardiovascular instability, inability to protect airway, obtundation, acute abdominal signs, or inadequate floor capacity for frequent monitoring 4