1. Diabetic Ketoacidosis (DKA)

Quick Recap

Endocrine & Metabolic System, Protocol 1/9. Closely paired with HHS (next protocol) — shared resuscitation framework, distinct diagnostic/management nuances.

1. Definition & Diagnostic Criteria

DKA = hyperglycemia (typically BG 250-800 mg/dL) + anion gap metabolic acidosis (arterial pH <=7.3) + ketosis (positive urine/plasma ketones) + dehydration and variable electrolyte abnormalities.

Severity grading:

Ketone assay caveat: standard nitroprusside assays measure ACETOACETATE and acetone, but NOT beta-hydroxybutyrate, which requires a separate assay — in early/severe DKA where beta-hydroxybutyrate predominates, the standard urine/serum ketone test can UNDERESTIMATE true ketone burden; a low standard ketone reading does not fully exclude significant ketosis if the clinical picture is compelling.

Mixed acid-base disorder consideration: a concurrent severe contraction metabolic alkalosis (from vomiting/volume loss) can ELEVATE the measured bicarbonate, MASKING the underlying metabolic acidosis — apply the delta gap framework (see Severe Metabolic Acidosis protocol) when the numbers don't add up cleanly.

Euglycemic DKA: a recognized entity, particularly with SGLT2 inhibitor use (canagliflozin, empagliflozin, dapagliflozin) — continuous renal glucose elimination in a ketotic state can produce a NORMAL or near-normal glucose despite significant ketoacidosis. Actively ask about SGLT2 inhibitor use in any unexplained anion gap acidosis, since the absence of marked hyperglycemia does not exclude DKA in this context.

2. Pathophysiology

Absolute insulin deficiency -> rise in counterregulatory hormones (cortisol, growth hormone, catecholamines, glucagon) -> impaired peripheral glucose utilization + increased gluconeogenesis + accelerated glycogenolysis -> hyperglycemia. Insulin deficiency + counterregulatory hormones -> lipolysis -> free fatty acid release -> hepatic conversion to ketones -> metabolic acidosis. Ketones and hyperglycemia both drive osmotic diuresis -> sodium and potassium loss. Initial labs often show apparent hyperkalemia (potassium efflux from cells in the acidotic environment), but TOTAL BODY potassium is actually DEPLETED — this distinction is central to safe potassium management (Section 6).

3. Immediate Stabilization (ABCDE)

Airway/Breathing: Kussmaul respirations (deep, labored breathing) reflect respiratory compensation for the metabolic acidosis — do not suppress this compensatory mechanism (e.g., with sedation) without addressing the underlying acidosis.

Circulation:

• Two wide-bore peripheral IVs for volume resuscitation
• Central line indicated for: severe hypotension, lack of peripheral access, need for multiple infusions, severe acidosis, impaired cardiorespiratory/renal status
• Fluid deficits in DKA can exceed 6L (average 8-10L when considering DKA/HHS together, per some sources)
• Infuse 1L 0.9% NS over 1 hour as initial resuscitation
• CRITICAL SEQUENCING: serum potassium must be >3 mEq/L BEFORE starting insulin therapy — insulin drives potassium intracellularly and can precipitate dangerous hypokalemia if given to an already-hypokalemic patient; correct potassium first or concurrently, never insulin-first in a hypokalemic patient

Checklist:

4. Fluid Management

Sequence:

1. Initial resuscitation: 15-20 mL/kg/h (or ~1L/h) 0.9% NS for the first 1-2 hours to restore circulating volume
2. After initial bolus: reduce to 4-14 mL/kg/h; fluid TYPE then determined by corrected sodium: 0.9% NS continues if corrected sodium is LOW; switch to 0.45% (half-NS) if corrected sodium is NORMAL or ELEVATED
3. Once BG falls below 250 mg/dL: add 5% dextrose-containing fluids, continuing until the anion gap NORMALIZES (not just until glucose normalizes) and the patient tolerates oral intake — the anion gap closure, not glucose control, is the true endpoint signaling resolved ketoacidosis
4. Special caution in renal/cardiac dysfunction patients to avoid fluid overload during this large-volume resuscitation

Corrected sodium calculation: add 1.6 mEq/L to measured sodium for every 100 mg/dL glucose elevation above 100 mg/dL — hyperglycemia causes a dilutional pseudohyponatremia that must be corrected for before interpreting true sodium status and choosing fluid type.

Rapid correction of sodium/osmolality risks cerebral edema (more common in pediatric DKA, extremely rare in adults but still a consideration) — avoid overly aggressive free water replacement once volume-repleted.

5. Precipitating Cause Investigation — Do Not Delay

Prompt DKA management is essential, but finding/treating the PRECIPITATING CAUSE should not be delayed or neglected — blood/urine/sputum cultures, CXR, ECG, and empiric treatment based on clinical suspicion should occur IN PARALLEL with metabolic correction, not after.

If abdominal pain does not resolve with correction of dehydration/acidosis, evaluate further — DKA-associated abdominal pain typically resolves with treatment; persistence suggests a separate intra-abdominal process (or the precipitating cause itself, e.g., pancreatitis, appendicitis) requiring independent workup.

Common precipitants: infection, insulin omission/noncompliance, new-onset diabetes (DKA may be the FIRST presentation, especially in young patients), cardiovascular events, CVA, pancreatitis, drug/alcohol use, pulmonary embolism, trauma, pregnancy. Medications contributing: corticosteroids, pentamidine, thiazides, sympathomimetics, and (as above) SGLT2 inhibitors.

DKA occurs predominantly in type 1 DM but in up to 1/3 of cases involves type 2 DM — do not exclude DKA based on a type 2 diabetes label alone.

6. Insulin Therapy

IV bolus followed by continuous infusion (in the ICU/severe setting).

Hyperglycemia resolves FASTER than acidosis — supraphysiologic insulin doses are needed initially to overcome hyperglycemia-induced insulin resistance; but insulin must CONTINUE after euglycemia is reached to drive peripheral ketone utilization and close the anion gap.

Target BG 150-200 mg/dL with concurrent 5% dextrose infusion UNTIL the anion gap closes — do not stop insulin once glucose normalizes; the dextrose-plus-insulin combination allows continued acidosis correction without hypoglycemia.

Rate of glucose decline: 50-100 mg/dL/hour target. Decline >75-100 mg/dL/h risks osmotic cerebral edema (0.3-1% in pediatric DKA, extremely rare in adults) — note glucose lowering IS naturally more rapid in the first 2 hours from initial volume expansion alone, which is expected and not itself concerning.

Transition off IV insulin: give intermediate- or long-acting SUBCUTANEOUS insulin 1-2 HOURS BEFORE discontinuing the insulin drip — failure to overlap properly causes rebound hyperglycemia/DKA recurrence, a common and entirely preventable error. Stop dextrose-containing IV fluids once the patient tolerates oral intake.

Mild-moderate DKA (non-ICU alternative): subcutaneous rapid-acting insulin (lispro/aspart) q1-2h can substitute for IV insulin, but is LESS RELIABLE for achieving needed insulin levels in seriously ill patients. Severe DKA, hypotension, or reduced SC absorption (e.g., anasarca) mandates IV insulin and ICU admission.

Priming dose: evidence suggests a priming/loading dose of insulin is UNNECESSARY in a low-dose insulin protocol if an adequate maintenance dose of regular insulin is given — worth knowing given this remains inconsistently practiced.

7. Potassium Management (Detailed)

Total body potassium is depleted at presentation REGARDLESS of the measured serum level (which is often falsely elevated by the acidotic transcellular shift) — caution in concurrent CKD, where true hyperkalemia is more plausible and standard potassium repletion protocols need modification.

Repletion protocol:

• Serum K+ <3.5 mEq/L: give potassium 20-40 mEq/h as a controlled infusion, through a CENTRAL line with continuous cardiac monitoring; do NOT start insulin until potassium repletion has begun
• Serum K+ 3.5-5.0 mEq/L: give potassium ~20 mEq/h
• Serum K+ >5.0 mEq/L or anuric: no potassium supplementation needed yet
• Target maintenance range: 4-5 mEq/L
• Ensure adequate urine output before IV potassium repletion
• Add potassium to 0.45% saline rather than 0.9% saline to avoid creating a hypertonic infused fluid

Insulin/fluid correction causes an intracellular potassium shift — this is WHY early, proactive (not reactive) potassium repletion is essential; waiting for a low potassium result before beginning repletion risks dangerous hypokalemia developing faster than it can be corrected.

8. Other Electrolyte Considerations

Magnesium: hypomagnesemia occurs EARLY in DKA and requires correction; monitor serum magnesium levels.

Phosphate: depletion is common; replace only if severely depressed (<1 mg/dL) or in patients with respiratory failure, cardiac failure, or hemolytic anemia — routine phosphate repletion is NOT indicated for mild-moderate hypophosphatemia given limited evidence of benefit and risk of iatrogenic hypocalcemia from over-repletion.

9. Bicarbonate Therapy — Limited, Controversial Role

Metabolic acidosis typically improves with volume/perfusion restoration and insulin therapy alone — bicarbonate has NOT been shown to improve outcomes in DKA and carries real risks: paradoxical worsening of intracellular/CSF acidosis, increased CO2 production, adverse tissue oxygenation effects, post-resuscitation metabolic alkalosis.

Consider bicarbonate ONLY if pH remains persistently <7.0 after 2-3 hours of standard treatment — a narrow, late-rescue indication, not a routine intervention. (Consistent with the broader Severe Metabolic Acidosis protocol's cautious bicarbonate stance.)

10. Investigations

Complete metabolic panel with magnesium/phosphate, BUN/creatinine (can be spuriously elevated by ketone interference with the chemical assay), ABG with anion gap, CBC with differential, urinalysis + urine ketones, serum ketones (understanding the beta-hydroxybutyrate assay limitation, Section 1), ECG, CXR, infectious workup per precipitant screening.

11. Organ Support

Aggressive fluid resuscitation; IV insulin infusion; potassium/magnesium/phosphate repletion per protocol; standard ICU supportive care; treat the precipitating cause in parallel.

12. Consultation Matrix

13. Monitoring Framework

Hourly glucose during active insulin infusion, electrolytes (especially K+) every 2-4 hours initially, anion gap trend as the primary resolution marker (not just glucose), frequent neuro checks (esp. in younger patients, cerebral edema vigilance), fluid balance tracking.

14. Complications

Hypokalemia (from insulin-driven intracellular shift if repletion inadequate/mistimed), cerebral edema (rare in adults, more common pediatric, from rapid osmolality shifts), rebound DKA (inadequate SC-IV insulin transition overlap), volume overload in cardiac/renal-impaired patients, hypoglycemia (overly aggressive insulin without adequate dextrose once glucose falls). Prevention: potassium-before-insulin sequencing, careful glucose decline rate monitoring, proper SC-IV insulin transition overlap, individualized fluid rate in comorbid patients. Rescue: standard hypokalemia/hypoglycemia management, mannitol/hypertonic saline for suspected cerebral edema (rare).

15. Escalation & De-escalation

Escalate: severe DKA criteria, hypotension, reduced SC absorption -> IV insulin + ICU admission.

De-escalate: anion gap closed, tolerating oral intake, hemodynamically stable -> transition to SC insulin (with proper overlap), discontinue dextrose IV fluids, transition to floor-level care with endocrinology follow-up.

16. ICU Discharge Criteria

Anion gap normalized (not just glucose), tolerating oral intake, transitioned successfully to SC insulin with appropriate overlap, precipitating cause identified/treated, electrolytes stable, patient/family diabetes education initiated (especially for new-onset diabetes or clear insulin-omission precipitant).

17. Documentation & Medicolegal Checklist

18. Key Guidelines

Dhatariya KK, Vellanki P. Treatment of DKA/HHS: novel advances in the management of hyperglycemic crises (UK versus USA). Curr Diab Rep. 2017;17(5):33.

19. Landmark Evidence

Kitabchi AE, Murphy MB, Spencer J, Matteri R, Karas J. Is a priming dose of insulin necessary in a low-dose insulin protocol for the treatment of DKA? Diabetes Care. 2008;31(11):2081-2085 — established priming dose as unnecessary with adequate maintenance dosing. Viallon A, Zeni F. Does bicarbonate therapy improve the management of severe DKA? Crit Care Med. 1999;27(12):2690 — argues against routine bicarbonate use even at pH 6.90-7.1.

20. Controversies

The precise bicarbonate threshold (pH <7.0 vs a range) for consideration remains debated, with some evidence arguing against its use even at pH as low as 6.90. Optimal phosphate repletion threshold and clinical benefit remain incompletely established. Euglycemic DKA recognition and workup protocols are still evolving as SGLT2 inhibitor use becomes more widespread, and standard DKA severity criteria (anchored on glucose thresholds) may need adaptation for this population.

21. References

1. Diabetic Ketoacidosis and Hyperosmolar Hyperglycemic State chapter. Washington Manual of Critical Care, 4th ed, 2025 (Ch. 31).
2. Talekar S, Shukla U. Diabetic Emergencies. ICU Protocols: A Step-wise Approach, 2nd ed. Springer; 2020 (Ch. 5).
3. Dhatariya KK, Vellanki P. Treatment of DKA/HHS: UK versus USA. Curr Diab Rep. 2017;17(5):33.
4. Kitabchi AE, Murphy MB, Spencer J, Matteri R, Karas J. Is a priming dose of insulin necessary in a low-dose insulin protocol for DKA? Diabetes Care. 2008;31(11):2081-2085.
5. Modi A, Agrawal A, Morgan F. Euglycemic diabetic ketoacidosis: a review. Curr Diabetes Rev. 2017;13(3):315-321.
6. Viallon A, Zeni F. Does bicarbonate therapy improve the management of severe diabetic ketoacidosis? Crit Care Med. 1999;27(12):2690.

See also: Hyperosmolar Hyperglycemic State (Endocrine & Metabolic System) for the closely related, shared-framework companion protocol.