Management of Severe High‑Anion‑Gap Metabolic Acidosis (DKA)

Diagnostic Priorities

Identify the underlying cause of the high‑anion‑gap acidosis (e.g., DKA, lactic acidosis, toxic ingestions, renal failure) by measuring glucose, serum ketones (β‑hydroxybutyrate), lactate, and osmolal gap. – American Diabetes Association (ADA) guideline 1
Obtain an arterial blood gas immediately to confirm severe acidemia (expected pH < 7.0 when HCO₃⁻ ≈ 11 mmol/L and PCO₂ ≈ 18 mmHg). – British Thoracic Society (BTS) recommendation 7

Start isotonic 0.9 % NaCl at 15–20 mL kg⁻¹ h⁻¹ (≈1–1.5 L in the first hour) to restore intravascular volume and renal perfusion. – ADA strong recommendation 1
Anticipate a total fluid deficit of roughly 6–9 L in severe DKA/acidosis and replace accordingly. – ADA Class II evidence 2
Continue isotonic fluids until the patient is hemodynamically stable, then titrate based on corrected sodium and hydration status. – ADA guideline 1
Add dextrose to the infusion once plasma glucose falls to ~250 mg/dL to avoid hypoglycemia while insulin is continued. – ADA recommendation 1

Do not initiate insulin until serum potassium is >3.3 mmol/L, because insulin drives potassium intracellularly and can precipitate fatal arrhythmias. – ADA strong recommendation 1
Give potassium chloride/potassium phosphate at 20–30 mmol L⁻¹ of IV fluid (≈2 parts KCl : 1 part KPO₄) once urine output is established. – ADA guideline 1
Re‑measure potassium every 2–4 hours during the acute phase. – ADA recommendation 1
Expect a total body potassium deficit of 3–5 mmol kg⁻¹ (≈300–500 mmol) even when initial serum potassium is low. – ADA evidence 2

Start a continuous IV regular insulin infusion at 0.1 U kg⁻¹ h⁻¹ after potassium correction. – ADA Class I recommendation 1
Aim for a plasma glucose decline of 50–75 mg/dL per hour; avoid faster drops to reduce the risk of cerebral edema. – ADA strong recommendation 1

Consider IV sodium bicarbonate only when arterial pH < 6.9, to improve cardiac function and vasopressor responsiveness. – ADA conditional recommendation 1
Do not give bicarbonate if pH > 7.0, as studies show no benefit and a risk of worsening hypokalemia. – ADA recommendation 1
If administered, give 100 mmol NaHCO₃ in 400 mL sterile water with 20 mmol KCl over 2 hours; repeat until pH > 7.0. – ADA guideline 1

Provide supplemental oxygen to keep SpO₂ > 94 % in patients with PO₂ ≈ 70 mmHg. – BTS recommendation 7
Monitor closely for pulmonary edema (including non‑cardiogenic) and for ARDS, especially when aggressive fluids are given or when sepsis/salicylate toxicity is present. – ACEP guidance 6

Evaluate for active bleeding; transfuse packed red cells when hemoglobin < 10 g/dL (≈Hct 30 %) in the setting of severe acidosis and hypoxemia to optimize oxygen delivery. – BMJ guideline 10

Check blood glucose, electrolytes, venous pH, and anion gap every 2–4 hours until metabolic parameters normalize. – ADA recommendation 1
Place the patient on continuous cardiac telemetry because hypokalemia and acidemia predispose to arrhythmias. – ADA guideline 1
Record urine output hourly to guide ongoing fluid replacement. – ADA recommendation 1
Obtain arterial blood gases initially; thereafter venous pH (≈0.03 units lower) is acceptable for trend monitoring. – ADA guidance 1

Plasma glucose < 200 mg/dL, serum bicarbonate ≥ 18 mmol/L, and venous pH > 7.3. – ADA criteria 1
Continue IV insulin until all three targets are met, then transition to subcutaneous insulin with a 1–2 hour overlap. – ADA recommendation 1

Starting insulin before potassium exceeds 3.3 mmol/L (risk of fatal hypokalemia). – ADA strong warning 1
Correcting glucose too rapidly, which increases cerebral edema risk. – ADA caution 1
Relying on nitroprusside ketone tests; β‑hydroxybutyrate is the preferred assay because nitroprusside can give falsely elevated results during treatment. – ADA recommendation 1
Administering excessive bicarbonate, which can worsen hypokalemia and has not demonstrated mortality benefit. – ADA guideline 1
Neglecting to monitor for hyperchloremic metabolic acidosis that may develop from large-volume saline; it is usually transient unless acute renal failure ensues. – ADA observation 9