Endocrine / Renal

DKA vs HHS

Hyperglycemic crises compared

DKA vs HHS
Feature	DKA	HHS
Assessment
Glucose	Glucose >=200 mg/dL is part of the 2024 consensus diagnostic framework, but DKA can occur at lower glucose (euglycemic DKA) when diabetes/history plus ketonemia and acidosis are present	Marked hyperglycemia (classically >=600 mg/dL in current diagnostic criteria)
Ketones	Markedly elevated (serum β-hydroxybutyrate high)	Absent or mild-moderate ketonemia; significant ketonemia/acidosis indicates mixed DKA-HHS
Acidosis	pH <7.3, HCO₃⁻ <18, raised anion gap	pH essentially preserved
Effective osmolality	Variable, often mildly high	Hyperosmolality is required; current criteria use effective osmolality >300 mOsm/kg or total osmolality >320 mOsm/kg
Volume deficit	~5–7 L typical estimate	~8–12 L typical estimate — often larger, develops over days
Management
Potassium physiology	Total-body K⁺ depleted even when serum is normal/high; insulin shifts K⁺ intracellularly — replace to keep ~4–5 mEq/L; HOLD insulin if K⁺ <3.5	Same depletion principle; monitor closely with insulin + fluids
Insulin strategy	IV regular insulin ~0.1 units/kg/h (fixed-rate; pre-bolus not mandatory per current consensus); only after K⁺ secured	Pure HHS without acidosis/significant ketonemia: IV regular insulin 0.05 units/kg/h after initial fluids; mixed DKA-HHS: 0.1 units/kg/h
Fluid priorities	Isotonic crystalloid first hour, then per corrected Na/hemodynamics; add dextrose when glucose <200–250 to continue insulin	Aggressive but monitored repletion; rate tempered in elderly/cardiac/renal disease; correct Na slowly
Traps & pitfalls
Resolution criteria	Beta-hydroxybutyrate <0.6 mmol/L plus pH >=7.3 or bicarbonate >=18 mmol/L (glucose ideally <200 mg/dL); do not use anion-gap closure as the primary endpoint; overlap SC insulin before stopping IV infusion	Resolution features include osmolality <300 mOsm/kg, corrected hyperglycemia, urine output >0.5 mL/kg/h and improved cognition; transition to maintenance insulin with appropriate overlap

Comparing: DKA

Assessment · Glucose

Glucose >=200 mg/dL is part of the 2024 consensus diagnostic framework, but DKA can occur at lower glucose (euglycemic DKA) when diabetes/history plus ketonemia and acidosis are present

Assessment · Ketones

Markedly elevated (serum β-hydroxybutyrate high)

Assessment · Acidosis

pH <7.3, HCO₃⁻ <18, raised anion gap

Assessment · Effective osmolality

Variable, often mildly high

Assessment · Volume deficit

~5–7 L typical estimate

Management · Potassium physiology

Total-body K⁺ depleted even when serum is normal/high; insulin shifts K⁺ intracellularly — replace to keep ~4–5 mEq/L; HOLD insulin if K⁺ <3.5

Management · Insulin strategy

IV regular insulin ~0.1 units/kg/h (fixed-rate; pre-bolus not mandatory per current consensus); only after K⁺ secured

Management · Fluid priorities

Isotonic crystalloid first hour, then per corrected Na/hemodynamics; add dextrose when glucose <200–250 to continue insulin

Traps & pitfalls · Resolution criteria

Beta-hydroxybutyrate <0.6 mmol/L plus pH >=7.3 or bicarbonate >=18 mmol/L (glucose ideally <200 mg/dL); do not use anion-gap closure as the primary endpoint; overlap SC insulin before stopping IV infusion

For healthcare-professional education. Clinical decisions require patient-specific assessment and local protocols.

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