Na+

Electrolyte Navigator — Sodium

CDMtools · admission gate first, then work-up · not for direct patient use
Draft · verify locally

Hyponatraemia

Na<135 mmol/L — admission decision first, then cause work-up

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Hypernatraemia

Na>145 mmol/L — admission decision first, then rehydration plan

↑

Patient values

Normal range 135–145 mmol/L
Corrects sodium for hyperglycaemia-driven dilution
Severe symptoms (any one → emergency)
Reduced consciousness (GCS ≤8) / coma
Seizures
Cardiorespiratory distress / arrest
Vomiting
Moderately severe symptoms
Confusion
Headache
Nausea without vomiting
Admission risk flags
Known/likely fall >10 mmol/L in <48h
Possible adrenal insufficiency
Recent intercurrent illness (chest infection / UTI / GI upset)

Pathway

Click any step on the pathway above for bedside and lab assessment cues.

Interpretation

Enter a sodium value to begin routing.

Patient values

Normal range 135–145 mmol/L
Admission risk flags
Known/suspected rapid rise
Oral/NG rehydration is practical
Access to water
Impaired access/intake (reduced consciousness, frail/elderly, sedated, care-dependent)
Likely mechanism
Unreplaced water losses (fever, diarrhoea, osmotic diuresis, diabetes insipidus)
Sodium gain (hypertonic feeds/saline, high-sodium antibiotics, mineralocorticoid excess)
Context
On lithium therapy

Pathway

Click any step on the pathway above for bedside and lab assessment cues.

Interpretation

Enter a sodium value to begin routing.

CDMtools — Electrolyte Navigator (pilot). Draft thresholds — verify locally against current guidance before clinical use. Local protocols vary (e.g. mild-hyponatraemia banding differs slightly between NICE CKS and the North Bristol admission protocol used here for the admission gate). Click any underlined term for its definition and source.