Diabetic Ketoacidosis

In this episode of AudioBoards, we break down the step-by-step management of diabetic ketoacidosis (DKA), one of the most critical  emergencies in clinical practice. By the end of this episode, you’ll have a clear, algorithmic framework for managing DKA confidently—from initial presentation through resolution of ketosis and safe transition to subcutaneous insulin.

Transcript

Welcome back to AudioBoards. Today we're covering one of the most important emergencies you'll encounter in medicine: diabetic ketoacidosis, or DKA. The good news is that DKA is highly treatable. The challenge is recognizing it early, managing it systematically, and avoiding common pitfalls that can lead to serious complications. Our focus today is practical bedside management—how to diagnose DKA, resuscitate patients effectively, manage insulin and electrolytes safely, and know when the crisis has truly been resolved.

Let's start with the basics. DKA is a state of severe insulin deficiency combined with excess counterregulatory hormones such as glucagon, cortisol, catecholamines, and growth hormone. The result is uncontrolled hepatic glucose production, lipolysis, ketone formation, metabolic acidosis, dehydration, and significant electrolyte abnormalities. The hallmark features are hyperglycemia, ketosis, and metabolic acidosis.

So what should make us suspect DKA clinically?

Patients typically present with polyuria, polydipsia, nausea, vomiting, abdominal pain, weakness, fatigue, weight loss, and signs of dehydration. As the acidosis worsens, they may develop tachycardia, hypotension, Kussmaul respirations, fruity-smelling breath, altered mental status, or even coma.

Just as important as recognizing DKA is identifying what caused it. Common precipitating factors include infection, myocardial infarction, stroke, pancreatitis, trauma, surgery, missed insulin doses, insulin pump failure, new-onset diabetes, corticosteroid use, and SGLT2 inhibitors. Every patient with DKA should undergo a careful search for the underlying trigger.

Diagnosis requires three components: hyperglycemia, ketosis, and metabolic acidosis.

Most patients have a glucose level above 200 mg/dL, although glucose may be normal or only mildly elevated in euglycemic DKA. Ketosis is ideally confirmed with serum beta-hydroxybutyrate, which is the predominant ketone body in DKA. Metabolic acidosis is demonstrated by a low pH, low serum bicarbonate, or both.

Severity is generally categorized as mild, moderate, or severe based on the degree of acidosis, ketone elevation, and mental status changes. Patients with severe DKA, hemodynamic instability, or altered mental status typically require ICU-level care.

Once we've made the diagnosis, what's the first step?

Think about DKA management as four parallel processes: fluid resuscitation, insulin therapy, electrolyte management, and treatment of the precipitating cause.

The first priority is restoring intravascular volume. Most patients are profoundly dehydrated because of osmotic diuresis caused by hyperglycemia. Initial therapy consists of isotonic crystalloid fluids. Typical rates are 500 to 1,000 mL per hour during the first several hours, although rates should be individualized based on blood pressure, volume status, cardiac function, renal function, and age.

As resuscitation continues, fluid selection and infusion rates are adjusted according to hemodynamics, serum sodium, urine output, and ongoing losses.

When should insulin be started?

After initial fluid resuscitation has begun and after confirming potassium is at a safe level.

Insulin is the definitive treatment because it suppresses lipolysis, halts ketone production, reduces hepatic glucose output, and allows glucose utilization by peripheral tissues. Continuous intravenous regular insulin is the standard therapy for most patients with moderate or severe DKA.

One of the most important concepts in DKA management is that insulin is being used primarily to stop ketogenesis. Lowering glucose is important, but resolving ketosis is the true therapeutic goal.

Why is potassium such a major focus during treatment?

Because potassium abnormalities can be life-threatening.

Despite frequently presenting with normal or elevated serum potassium levels, patients with DKA have substantial total body potassium deficits due to urinary losses. Once insulin therapy begins and acidosis improves, potassium rapidly shifts back into cells, causing serum potassium to fall.

If the potassium level is below 3.5 mEq/L, insulin should be held temporarily while potassium is replaced. Starting insulin in a profoundly hypokalemic patient can precipitate dangerous arrhythmias and cardiac arrest.

If potassium is between 3.5 and 5.0 mEq/L, potassium replacement is generally started along with insulin therapy. If potassium is initially elevated, replacement can be delayed, but levels must be monitored closely because they often decline rapidly during treatment.

So frequent monitoring is essential throughout therapy?

Glucose is typically monitored every one to two hours. Electrolytes, renal function, bicarbonate, venous pH, and ketone levels are reassessed regularly. Effective management requires constant reassessment of volume status, electrolyte balance, and the rate of ketoacid clearance.

What happens when glucose starts to normalize?

This is where many mistakes occur.

As glucose falls to approximately 250 mg/dL, dextrose-containing fluids should be added while insulin therapy continues. Many trainees mistakenly believe that insulin can be stopped once glucose reaches a normal range. That's incorrect.

Remember, the metabolic crisis is not over simply because the glucose is normal. Ketosis and acidosis often persist after glucose has improved. Adding dextrose allows continued insulin administration while preventing hypoglycemia.

What about bicarbonate?

Routine bicarbonate administration is not recommended in DKA. Most patients will correct their acidosis with fluids and insulin alone. Bicarbonate therapy is generally reserved for patients with severe acidemia, particularly when the pH is below 7.0.

Similarly, phosphate replacement is not routinely required. It should be considered in patients with severe hypophosphatemia or when complications such as respiratory muscle weakness, cardiac dysfunction, or severe muscle weakness are present.

What complications should we watch for during treatment?

Hypoglycemia and hypokalemia are the most common treatment-related complications. That's why close monitoring is so important.

Patients may also develop hyperchloremic metabolic acidosis during recovery, which generally resolves on its own. Cerebral edema is rare in adults but remains a potentially devastating complication. Clinicians should also monitor for fluid overload, particularly in older adults and patients with heart failure or kidney disease.

How do we know when DKA has resolved?

Resolution is based on correction of ketoacidosis, not glucose normalization alone.

The patient should demonstrate clearance of ketones, normalization of acid-base status, improvement in bicarbonate levels, and overall clinical recovery. Once DKA has resolved and the patient can eat reliably, the transition to subcutaneous insulin can begin.

The transition phase is extremely important.

Intravenous insulin should never be stopped abruptly without providing basal insulin coverage. Long-acting basal insulin should be administered before discontinuing the insulin infusion to ensure adequate overlap and prevent recurrence of ketoacidosis. Failure to provide this overlap is a common cause of rebound hyperglycemia and recurrent DKA.

What are the biggest mistakes clinicians make?

Several mistakes come up repeatedly.

First, focusing exclusively on glucose rather than ketone clearance.

Second, stopping insulin too early.

Third, inadequate potassium monitoring and replacement.

Fourth, failing to identify and treat the precipitating cause.

Fifth, insufficient overlap between intravenous and subcutaneous insulin.

And sixth, failing to recognize euglycemic DKA, particularly in patients taking SGLT2 inhibitors.

Let’s finish with a simple, practical bedside framework you can run on every DKA patient.

When you see DKA, think:

First, fluids. Start isotonic crystalloid—usually normal saline or a balanced crystalloid—at 500 to 1,000 mL per hour for the first 2 to 4 hours, then adjust based on hemodynamics, urine output, sodium, and overall volume status. The goal is restoration of perfusion and correction of the free water deficit.

Second, assess and correct potassium before insulin.
If potassium is < 3.3 mEq/L, hold insulin and give potassium until it rises above 3.3.
If potassium is 3.3 to 5.2 mEq/L, start insulin and add potassium to fluids (typically 20–30 mEq per liter) to maintain serum potassium around 4–5.
If potassium is > 5.2 mEq/L, you can start insulin but do not replace potassium initially—monitor closely because it will fall quickly once insulin is started.

Third, start insulin safely.
Begin a continuous IV regular insulin infusion at 0.1 units/kg/hour.
Your goal is a glucose decline of about 50–75 mg/dL per hour, but more importantly, you are targeting closure of the anion gap and resolution of ketosis, not just glucose correction.

Fourth, add dextrose at the right time.
When glucose falls to approximately 200–250 mg/dL, switch fluids to include dextrose (commonly D5 with 0.45% or 0.9% saline depending on sodium and volume status).
At this point, you do not stop insulin—you reduce or continue it to keep clearing ketones while preventing hypoglycemia.

Fifth, continue insulin until ketosis resolves.
Keep the insulin infusion running until all of the following are improving:

• Closed or near-closed anion gap
• Bicarbonate ≥ 15–18 mEq/L
• Venous pH > 7.3
• Beta-hydroxybutyrate is normalizing
  Glucose alone is never the endpoint.

Sixth, treat the precipitating cause.
Infection, missed insulin, myocardial infarction, pancreatitis, medications—every case has a driver. If you don’t fix it, DKA will recur.

Seventh, transition carefully to subcutaneous insulin.
Give long-acting basal insulin 2 to 4 hours before stopping the insulin infusion. This overlap prevents rebound hyperglycemia and recurrent ketoacidosis.

So the key takeaway is that DKA isn’t simply a hyperglycemia problem. It’s a metabolic emergency involving insulin deficiency, ketosis, dehydration, and electrolyte derangements.

Exactly. The glucose number gets your attention, but the real target is closing the anion gap and stopping ketone production. Once you think in those terms, DKA management becomes systematic and much safer.

Thanks for listening to AudioBoards. Stay tuned for more educational content in our next episode! The views and opinions expressed on the AudioBoards Podcast do not necessarily reflect those of our employers. This podcast is for educational purposes only and should not be used to diagnose or treat any medical conditions. It is not a substitute for professional medical advice. Always consult a qualified, board-certified healthcare provider for any medical concern.