What are the key considerations for the diagnosis and management of diabetic ketoacidosis (DKA) in a patient with a history of diabetes, possibly type 1 diabetes mellitus (T1DM), presenting with hyperglycemia, metabolic acidosis, and ketosis?

Diabetic Ketoacidosis Case Presentation: Anticipated Questions and Answers

What are the diagnostic criteria for DKA?

DKA is diagnosed when blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria. 1, 2

• Obtain arterial blood gases, complete blood count with differential, urinalysis, plasma glucose, blood urea nitrogen, electrolytes with calculated anion gap, chemistry profile, creatinine, serum osmolality, and electrocardiogram immediately 1, 2
• Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring ketosis, as the nitroprusside method only measures acetoacetic acid and acetone, not β-hydroxybutyrate (the predominant ketone body in DKA) 1, 2
• Mental status can vary from full alertness to profound lethargy or coma 1
• Physical findings include poor skin turgor, Kussmaul respirations, tachycardia, hypotension, and dehydration 1

What are the most common precipitating factors?

Infection is the most common precipitating factor, occurring in 30-50% of cases, with urinary tract infection and pneumonia being the most frequent. 1, 3

• Other precipitating factors include new-onset type 1 diabetes, discontinuation or inadequate insulin therapy, cerebrovascular accident, myocardial infarction, pancreatitis, trauma, and certain drugs 1, 2
• SGLT2 inhibitors can cause euglycemic DKA and must be discontinued 3-4 days before any planned surgery 1, 2
• Obtain bacterial cultures (urine, blood, throat) if infection is suspected and administer appropriate antibiotics 2

What is the initial fluid resuscitation protocol?

Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in the average adult) during the first hour. 1, 2

• Subsequent fluid choice depends on hydration status, serum electrolyte levels, and urine output 1, 2
• When serum glucose reaches 250 mg/dL, change fluid to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy until ketoacidosis resolves 1, 2
• Total fluid replacement should aim to correct estimated deficits within 24 hours 2
• Aggressive initial fluid replacement is critical to restore tissue perfusion and improve insulin sensitivity 2

What is the insulin therapy protocol?

Start continuous intravenous regular insulin infusion at 0.1 units/kg/hour without an initial bolus in pediatric patients; adults may receive an initial bolus of 0.15 units/kg followed by 0.1 units/kg/hour. 1, 2

• Target glucose decline of 50-75 mg/dL per hour 1, 2
• If plasma glucose does not fall by 50 mg/dL from initial value in the first hour, check hydration status; if acceptable, double the insulin infusion rate every hour until steady glucose decline is achieved 1, 2
• Continue insulin infusion until resolution of ketoacidosis (pH >7.3, serum bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels 2, 4
• For mild DKA in hemodynamically stable, alert patients, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin 1, 2

How do you manage potassium replacement?

If serum potassium <3.3 mEq/L, delay insulin therapy and aggressively replace potassium until levels reach ≥3.3 mEq/L to prevent life-threatening arrhythmias and respiratory muscle weakness. 2

• Total body potassium depletion averages 3-5 mEq/kg body weight in DKA, and insulin therapy will unmask this depletion by driving potassium intracellularly 2
• If potassium 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, 2
• If potassium >5.5 mEq/L, withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy 2
• Target serum potassium of 4-5 mEq/L throughout treatment 2
• Check potassium levels every 2-4 hours during active treatment 2

Should bicarbonate be administered?

Bicarbonate administration is NOT recommended for DKA patients with pH >6.9-7.0, as multiple studies show no difference in resolution of acidosis or time to discharge. 1, 2

• Bicarbonate may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1, 2
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor resolution of acidosis 1, 2

What are the criteria for resolution of DKA?

DKA is resolved when glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L. 2

• Target glucose between 150-200 mg/dL until DKA resolution parameters are met 2
• Draw blood every 2-4 hours to determine serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 2
• Generally, repeat arterial blood gases are unnecessary 1

How do you transition from IV to subcutaneous insulin?

Administer basal insulin (intermediate or long-acting such as glargine or detemir) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia. 1, 2, 4

• Once the patient is able to eat, start a multiple-dose schedule using a combination of short/rapid-acting and intermediate/long-acting insulin 1, 2
• If the patient remains NPO after DKA resolution, continue IV insulin and fluid replacement, supplementing with subcutaneous regular insulin as needed 1, 2
• Adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 2

What are the most common complications during DKA treatment?

Cerebral edema is one of the most dire complications, occurring more commonly in children and adolescents than adults. 2

• Monitor closely for signs of altered mental status, headache, or neurological deterioration 2
• Overly rapid correction of osmolality increases the risk of cerebral edema 2
• Hypokalemia from inadequate monitoring and replacement is a leading cause of mortality in DKA 2
• Hypoglycemia from overzealous insulin treatment without glucose supplementation 2
• Persistent or worsening ketoacidosis from premature termination of insulin therapy or failure to add dextrose when glucose falls below 250 mg/dL 2

What monitoring is required during treatment?

Draw blood every 2-4 hours for serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH. 1, 2

• Monitor blood glucose at least every 2-4 hours 5
• Continuous monitoring of glucose during transition from IV to subcutaneous insulin is essential 4
• Direct measurement of β-hydroxybutyrate is preferred over nitroprusside method for monitoring ketone resolution 1, 2

What patient education should be provided at discharge?

Identify outpatient diabetes care providers before discharge, educate patients on glucose monitoring, insulin administration, recognition and treatment of hyperglycemia/hypoglycemia, and schedule follow-up appointments prior to discharge. 2

• Provide education on sick day management and signs of DKA recurrence 4
• Ensure the patient understands their diabetes diagnosis, home glucose goals, and when to call healthcare professionals 2
• Schedule outpatient follow-up within 1-2 weeks if glycemic control is not optimal at discharge 4
• Future episodes of DKA can be reduced through patient education programs focusing on adherence to insulin and self-care guidelines during illness 6

What are the key pitfalls to avoid in DKA management?

Stopping IV insulin without prior administration of basal subcutaneous insulin causes rebound hyperglycemia and ketoacidosis. 2

• Premature termination of insulin therapy before complete resolution of ketosis leads to DKA recurrence 2, 7
• Interruption of insulin infusion when glucose levels fall is a common cause of persistent or worsening ketoacidosis 2
• Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy 2
• Inadequate potassium monitoring and replacement can lead to life-threatening hypokalemia 2
• Starting insulin therapy when potassium <3.3 mEq/L without correction first 2