What are the potential complications and management strategies for an adult patient with a known history of diabetes presenting with Diabetic Ketoacidosis (DKA)?

Complications of Diabetic Ketoacidosis

The most common complications of DKA include hypoglycemia from excessive insulin, hypokalemia from insulin and bicarbonate therapy, and hyperglycemia from premature discontinuation of IV insulin without subcutaneous coverage. 1

Treatment-Related Metabolic Complications

Hypoglycemia

• Occurs from overzealous insulin administration, particularly when insulin infusion rates are not adjusted as glucose falls 1
• Add dextrose-containing fluids when glucose reaches 250 mg/dL to prevent hypoglycemia while continuing insulin to clear ketosis 2
• Monitor blood glucose every 1-2 hours during active treatment 2, 3

Hypokalemia

• Total body potassium is severely depleted (3-5 mEq/kg in DKA) despite initially normal or elevated serum levels due to acidosis-driven extracellular shift 1
• Begin potassium replacement when serum levels fall below 5.5 mEq/L, assuming adequate urine output 1
• Add 20-40 mEq/L potassium to infusion fluids (2/3 KCl and 1/3 KPO4) to maintain levels between 4-5 mEq/L 2
• If initial potassium is <3.3 mEq/L, delay insulin therapy until potassium is restored to prevent life-threatening arrhythmias, cardiac arrest, and respiratory muscle weakness 2, 3

Hyperchloremic Metabolic Acidosis

• Develops from excessive normal saline administration as chloride replaces ketoanions lost during osmotic diuresis 1
• This is transient and not clinically significant except in acute renal failure or extreme oliguria 1
• Consider balanced electrolyte solutions rather than 0.9% saline to minimize this complication 2

Rebound Hyperglycemia and Recurrent Ketoacidosis

• Occurs when IV insulin is discontinued without prior administration of subcutaneous basal insulin 1, 2
• Administer basal insulin (glargine or detemir) 2-4 hours BEFORE stopping IV insulin infusion to prevent DKA recurrence 2, 4, 3

Cerebral Edema

Cerebral edema is rare (0.7-1.0% in children) but carries >70% mortality when symptomatic, with only 7-14% recovering without permanent neurological damage. 1

Clinical Presentation

• Initial signs include deteriorating level of consciousness, lethargy, and decreased arousal 1
• Progression includes headache, seizures, incontinence, pupillary changes, bradycardia, and respiratory arrest 1
• Neurological deterioration can be so rapid that papilledema is not found 1

Prevention Strategies

• Limit osmolality reduction to maximum 3 mOsm/kg/h during fluid resuscitation 1
• Add dextrose to hydrating solution once blood glucose reaches 250 mg/dL 1
• In hyperosmolar states, maintain gradual replacement of sodium and water deficits 1
• Avoid excessive fluid administration rates, particularly in pediatric patients (initial reexpansion should not exceed 50 mL/kg over first 4 hours) 1

Pulmonary Complications

Hypoxemia and Noncardiogenic Pulmonary Edema

• Hypoxemia results from reduced colloid osmotic pressure causing increased lung water content and decreased lung compliance 1
• Patients with widened alveolo-arteriolar oxygen gradient on initial blood gas or pulmonary rales on examination are at higher risk 1
• Monitor closely in patients with cardiac compromise or renal disease during aggressive fluid resuscitation 1

Cardiac Complications

Arrhythmias

• Result primarily from electrolyte imbalances, particularly hypokalemia and hypophosphatemia 2
• Continuous cardiac monitoring is crucial in severe DKA to detect arrhythmias early 2, 3
• Hypokalemia-induced arrhythmias can be fatal if potassium replacement is inadequate 2, 3

Hypophosphatemia

• Serum phosphate typically falls during insulin therapy despite total body depletion (5-7 mmol/kg) 1
• Routine phosphate replacement has not shown beneficial effects on clinical outcomes 1, 2
• Consider phosphate replacement (20-30 mEq/L potassium phosphate) only in patients with cardiac dysfunction, anemia, respiratory depression, or serum phosphate <1.0 mg/dL 1, 2
• Overzealous phosphate therapy can cause severe hypocalcemia 1

Prevention of Complications

Monitoring Requirements

• Draw blood every 2-4 hours for serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 2, 3
• Use continuous flow-sheet documentation to organize recovery parameters and treatment interventions 1
• Monitor fluid input/output and hemodynamic parameters continuously 1, 2

Critical Pitfalls to Avoid

• Never discontinue IV insulin before administering subcutaneous basal insulin 2, 4, 3
• Never delay potassium replacement when levels fall below 5.5 mEq/L 1
• Never give insulin if initial potassium is <3.3 mEq/L 2, 3
• Avoid rapid correction of osmolality (>3 mOsm/kg/h) 1
• Do not use bicarbonate therapy routinely, as studies show no benefit in resolution of acidosis or time to discharge 2, 3