An 8-year old boy is brought to the emergency department because he has been lethargic and has had several episodes of nausea and vomiting for the past day. He has also had increased thirst over the past two months. He has lost 5.4 kg (11.9 lbs) during this time. He is otherwise healthy and has no history of serious illness. His temperature is 37.5 °C (99.5 °F), blood pressure is 95/68 mm Hg, pulse is 110/min, and respirations are 30/min. He is somnolent and slightly confused. His mucous membranes are dry. Laboratory studies show: Hemoglobin 16.2 g/dL Leukocyte count 9,500/mm3 Platelet count 380,000/mm3 Serum Na+ 130 mEq/L K+ 5.5 mEq/L Cl- 99 mEq/L HCO3- 16 mEq/L Creatinine 1.2 mg/dL Glucose 570 mg/dL Ketones positive Blood gases, arterial pH 7.25 pCO2 21 mm Hg Which of the following is the most appropriate next step in management?

Intravenous hydration with 0.9% normal saline and insulin

Intravenous hydration with 0.45% normal saline and insulin

Intravenous hydration with 5% dextrose solution and 0.45% normal saline

Intravenous hydration with 0.9% normal saline and potassium chloride

A previously healthy 14-year-old girl is brought to the emergency department by her mother because of abdominal pain, nausea, and vomiting for 6 hours. Over the past 6 weeks, she has also had increased frequency of urination, and she has been drinking more water than usual. She has lost 6 kg (13 lb) over the same time period despite having a good appetite. Her temperature is 37.1°C (98.8°F), pulse is 125/min, respirations are 32/min, and blood pressure is 94/58 mm Hg. She appears lethargic. Physical examination shows deep and labored breathing and dry mucous membranes. The abdomen is soft, and there is diffuse tenderness to palpation with no guarding or rebound. Urine dipstick is positive for ketones and glucose. Further evaluation is most likely to show which of the following findings?

Serum glucose concentration > 800 mg/dL

A 48-year-old man presents with DKA. Initial treatment is initiated with fluids and insulin infusion. Labs show glucose 460 mg/dL, pH 7.18, bicarbonate 10 mEq/L, potassium 4.5 mEq/L, and creatinine 2.8 mg/dL (baseline 1.0). After 4 hours, glucose decreases to 380 mg/dL but pH worsens to 7.12, bicarbonate drops to 8 mEq/L, and lactate is 5.2 mmol/L (initially 1.8). Blood pressure is 85/50 mmHg. Evaluate the clinical situation and necessary intervention.

Evaluate for sepsis or other concurrent illness causing lactic acidosis

Administer additional fluid bolus for persistent hypotension

Increase insulin infusion rate to accelerate ketone clearance

Add bicarbonate therapy for worsening acidosis

Continue current management as DKA takes time to resolve

A 25-year-old woman with type 1 diabetes presents with DKA. She admits to intentionally withholding insulin to lose weight. This is her fifth DKA admission in 8 months. Current pH is 7.14, glucose 520 mg/dL, bicarbonate 11 mEq/L. Medical costs exceed $150,000 for recurrent admissions. The team is frustrated. Evaluate the comprehensive management approach beyond acute DKA treatment.

Multidisciplinary approach including psychiatry, eating disorder specialist, diabetes educator, and close outpatient follow-up

Referral to ethics committee for discussion of resource allocation

Involuntary psychiatric commitment for non-compliance

Insulin pump placement to prevent future manipulation

Standard DKA treatment with discharge to outpatient endocrinology

A 55-year-old man with type 2 diabetes and end-stage renal disease on hemodialysis presents with DKA. Initial glucose is 580 mg/dL, pH 7.12, bicarbonate 10 mEq/L, and potassium 6.2 mEq/L. He is fluid overloaded with bilateral crackles and peripheral edema. His last dialysis was 3 days ago. Evaluate the optimal management strategy addressing both DKA and renal failure.

Insulin infusion with limited fluids and urgent hemodialysis

Standard DKA protocol with furosemide for fluid management

Bicarbonate therapy to correct acidosis without fluids

Subcutaneous insulin with no IV fluids due to volume overload

Standard DKA protocol with aggressive fluid resuscitation

A 38-year-old pregnant woman at 28 weeks gestation with type 1 diabetes presents with nausea and vomiting. Labs show glucose 310 mg/dL, pH 7.27, bicarbonate 15 mEq/L, and positive urine ketones. Fetal monitoring shows reactive non-stress test. She has been taking her insulin but unable to eat for 24 hours due to hyperemesis. Analyze the optimal management approach considering maternal and fetal risks.

Aggressive DKA treatment with lower glucose targets (100-150 mg/dL) and close fetal monitoring

Standard DKA protocol with standard glucose targets (200-250 mg/dL)

Immediate cesarean delivery followed by DKA treatment

Conservative management with oral intake and subcutaneous insulin

Standard DKA protocol with delivery planning after stabilization

A 42-year-old man with type 1 diabetes on insulin pump presents with DKA after pump malfunction. He is admitted and started on IV insulin infusion. After 14 hours of treatment, his glucose is 210 mg/dL on D5-0.45% saline, pH 7.36, bicarbonate 19 mEq/L, and anion gap 12. He is alert, eating, and requesting to go home. Evaluate the appropriate transition strategy.

Give subcutaneous insulin, overlap for 1-2 hours, then stop IV insulin and observe

Switch to subcutaneous insulin and discharge immediately

Stop IV insulin immediately and restart insulin pump at home

Continue IV insulin for another 6 hours to ensure stability

Discontinue IV insulin, discharge with oral medications

A 52-year-old woman with type 2 diabetes is admitted for DKA. Initial pH is 7.08, bicarbonate 8 mEq/L, and anion gap 28. She is started on standard DKA protocol. After 10 hours of treatment, her glucose is 180 mg/dL, pH is 7.28, bicarbonate is 14 mEq/L, but anion gap remains elevated at 22. Chloride is 115 mEq/L (elevated). Analyze the acid-base status.

Mixed anion gap and non-anion gap acidosis

Renal tubular acidosis unmasked by treatment

Persistent DKA requiring increased insulin rate

Non-anion gap metabolic acidosis from excessive saline administration

Resolving DKA with appropriate response to treatment

A 35-year-old man with type 1 diabetes presents with DKA. Initial labs show pH 6.95, bicarbonate 6 mEq/L, glucose 610 mg/dL, and potassium 5.8 mEq/L. After starting standard DKA protocol with fluids and insulin, he develops altered mental status and seizures 3 hours into treatment. CT head is unremarkable. Analyze the most likely complication.

Cerebral edema from overly rapid correction

Meningitis as precipitating factor for DKA

Hyperkalemia from potassium supplementation

Hyponatremia from excessive free water

Hypoglycemia from excessive insulin

Special populations (pregnancy, elderly) for USMLE Step 2 CK: High-Yield Management Lessons

DKA in Pregnancy - Bundle of Trouble

Pathophysiology & Presentation:
- Physiologic insulin resistance (↑ human placental lactogen, cortisol) + compensated respiratory alkalosis → lower buffering capacity.
- Lower threshold for DKA; often presents as euglycemic DKA (BG <200 mg/dL).
- Triggers: Infections (UTIs), corticosteroids for fetal lung maturity, tocolytics (e.g., terbutaline), and insulin pump failure.
Maternal-Fetal Risks:
- Maternal: Treatment-related hypoglycemia/hypokalemia, pulmonary edema, preterm labor.
- Fetal: Maternal acidosis → ↓ uteroplacental perfusion → fetal hypoxia, arrhythmias, and high risk of intrauterine demise.
Management Priorities:
- 📌 MOM's I-V: Monitor (Maternal vitals, Fetal HR), Oxygen, Meds, Insulin, Volume (Fluids).
- Positioning: Left lateral decubitus to prevent aortocaval compression.
- Volume First: Aggressive IV hydration with isotonic saline (1-2 L in the first 1-2 hours).
- Insulin: IV regular insulin infusion (0.1 U/kg/hr). Avoid insulin bolus to prevent rapid osmotic shifts.
- Potassium: Add K+ to IVFs once serum K+ is <5.2 mEq/L and urine output is confirmed.
- Glucose: Add dextrose (D5) to fluids when serum glucose approaches 200 mg/dL to prevent iatrogenic hypoglycemia.

⭐ Euglycemic DKA is a major diagnostic pitfall. In pregnancy, DKA can develop with blood glucose levels only slightly elevated (e.g., 220 mg/dL) due to hormonal changes and increased glomerular filtration rate.

DKA in the Elderly - Golden Years, Glucose Fears

Atypical Presentation is Key: Classic symptoms (polyuria, polydipsia) are often absent. Suspect DKA in any elderly diabetic patient with unexplained altered mental status, dehydration, or weakness.
- Common Signs: Confusion, delirium, lethargy, falls, incontinence.
- Abdominal pain is less frequent than in younger adults.
Diagnostic & Management Nuances:
- Higher Osmotic Threshold: May tolerate extreme hyperglycemia (e.g., >600 mg/dL) before symptoms appear, leading to diagnostic delays and overlap with Hyperosmolar Hyperglycemic State (HHS).
- Renal Function: Pre-existing chronic kidney disease can blunt the anion gap and affect ketone clearance.
- ⚠️ Cautious Fluid Resuscitation: Risk of fluid overload is high. Start with 0.9% NaCl at a slower rate (e.g., 250-500 mL/hr), guided by close monitoring of cardiac and respiratory status.
- Insulin Sensitivity: May be more sensitive to insulin; consider lower initial infusion rates. Prone to hypoglycemia.
- Potassium Deficits: Can be profound. Monitor K+ levels very closely, especially with underlying renal disease or diuretic use.

⭐ Mortality in elderly DKA can exceed 20%, often precipitated by a severe underlying illness like MI, stroke, or sepsis, which may itself be masked by the altered metabolic state.

In pregnancy, DKA can occur at lower glucose levels (euglycemic DKA), posing a high risk of fetal demise.

Elderly patients have higher mortality due to comorbidities like renal and cardiac disease, complicating fluid and electrolyte management.

Altered mental status may be the primary presentation in older adults, delaying diagnosis.

Management in the elderly requires cautious fluid resuscitation to prevent volume overload.

Pregnant patients have physiologic insulin resistance and may require earlier bicarbonate therapy.

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