Reset Osmostat: A Challenging Case of Hyponatremia

Table 3

Classification of hyponatremia.

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(1) Biochemical severity

 (a) Mild hyponatremia, 130–135 mmol/L

 (b) Moderate hyponatremia, 125–129 mmol/L

 (c) Profound hyponatremia, <125 mmol/L

(2) Time of onset

 (a) Acute hyponatremia <48 hours

 (b) Chronic hyponatremia >48 hours

(3) Symptoms

 (a) Symptomatic hyponatremia

 (b) Asymptomatic hyponatremia

(4) Volume status

 (a) Hypovolaemia

 (b) Normovolaemia

 (c) Hypervolaemia

(5) Serum osmolality

 (a) Hypotonic hyponatremia, <275 mOsm/kg

 (b) Isotonic hyponatremia, 275–295 mOsm/kg

 (c) Hypertonic hyponatremia, >295 mOsm/kg

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