Classification and causes of hyponatremia mnemonics + notes

Hi!

Classification and causes of hyponatremia mnemonics + notes:

1. Hyponatremia with low osmolality :

     (i) reduced effective blood volume

              (A) increased ECF volume -

                               - Edematous kidney (nephrotic syndrome)

                               - Cirrhosis of liver

                               - Failure of heart

              (B) REduced ECF volume -

                                - Renal loss of Na ( Diuretics, Ketonuria, Addison's disease)

                                - Extrarenal loss of Na ( sweating, diarrhea, vomiting, peritonitis, pancreatitis)

    (ii) Normal/ increased EBV

                - Inadequate ADH syndrome

                - Constant thirst

                - Renal failure (chronic)

2. Hyponatremia with raised osmolality :

( H & M)

- Hyperglycemia 

- Mannitol administration 

Note -

- Hyponatremia per se does not produce any significant clinical features. The low osmolality that it causes is responsible for various features.

- Slow correction of hypotonicity produces gradual rise in osmolality without any significant risk. But rapid correction of hyponatremia produces loss of brain water resulting in brain damage!

- The rate of correction should be around 0.6 mEq/L/hr. In severely symptomatic patients, total correction in a day should not exceed 8-10 mEq/L/hr.

That's all

Hope it helps

- Jaskunwar Singh