Clinical Overview
Hyperglycemia-corrected sodium is a structured clinical decision-support tool. It estimates the sodium concentration expected after accounting for glucose-related transcellular water shift. It standardizes calculation and communication, but its output remains an estimate that must be interpreted with the complete history, examination, laboratory method, imaging, serial trend, and institutional protocol. Enter contemporaneous data and verify units before relying on the result.
The displayed category reflects cohorts and conventional thresholds rather than a diagnosis or mandatory treatment instruction. Document inputs with the result, reassess when the patient changes, and prioritize time-critical stabilization over score completion. Discordance between the calculated estimate and clinical concern should prompt review of measurements, assumptions, competing diagnoses, and specialist advice.
When to Use
- Hyperglycemia with measured sodium requiring tonicity interpretation
- DKA or hyperosmolar-state assessment alongside effective osmolality
Limitations & Safety
The correction factor is approximate and may vary at extreme glucose levels; treatment decisions require serial measured values and tonicity. Performance varies with population, prevalence, disease stage, treatment era, and local laboratory reference intervals. Avoid extrapolation to groups excluded from validation, and do not use a low score to dismiss concerning symptoms or a high score to prove a diagnosis.
Clinical decisions should incorporate contraindications, comorbidities, patient preferences, and current regional guidance. Pregnancy, childhood, older age, critical illness, altered physiology, and organ failure often require population-specific interpretation. Clinipocket stores no entered patient values; record clinically relevant results in the approved medical record.
- Not a replacement for measured serial electrolytes
- Rapid glucose and water shifts require repeated clinical and biochemical reassessment
Formula / Scoring Criteria
Katz corrected Na = measured Na + 1.6 × [(glucose−100)/100]. Hillier corrected Na = measured Na + 2.4 × [(glucose−100)/100], glucose in mg/dL
Interpretation
- <135 mmol/L — Corrected hyponatremia: Water excess may persist beyond glucose shift. Assess tonicity, volume, renal function, and cause.
- 135–145 — Reference range: Measured low sodium may largely reflect hyperglycemia. Continue protocol and serial monitoring.
- >145 — Corrected hypernatremia: Free-water deficit may be substantial. Plan fluids and correction rate carefully.
Evidence & References
- Katz MA. Hyperglycemia-induced hyponatremia.
- Hillier TA, et al. Hyponatremia: evaluating the correction factor.
Clinical FAQs
Why are two results shown?
Katz uses 1.6 and Hillier 2.4 mmol/L per 100 mg/dL glucose above 100; both are approximations.
Can I use mmol/L glucose?
This version expects mg/dL; multiply glucose in mmol/L by 18.
Does corrected sodium replace effective osmolality?
No. Calculate and trend tonicity separately.