Has she been having any vomiting or diarrhea lately?Any history or renal disease,Congestive cardiac failure,hypothyroidism or liver disease?Since when has she been having the hyponatraemia?Whether restriction of fluids is adequate will depend on whether the hyponatraemia is hypovolemic,euvolemic or hypervolemic.Cause of dilutional hyponatremia would include Syndrome of Inappropriate AntiDiuretic Hormone(SIADH) and would present with euvolemia and no oedema.The urinary concentration of sodium will be over 20mEq/L and there will be absence of any disease process which may cause sodium loss.Depletional hyponatremia amy occur with decreased intake of salt,vomiting or/and other causes of sodium loss.Restriction of water and fluid intake will help in SIADH and euvolemic hyponatremia in mild to moderate cases where the level is not below 125mEq/L.The correction of sodium is done gradually with not more than 10% replacement being done in a day.SSRI drugs,antipsychotic /psychiatric drugs,diuretic,certain antibiotics and other drugs which may contribute to loss of sodium may need to be stopped.The decision whether sodium replacement is required would be based on the cause ,level of sodium loss and the volumic state,also the presence of any disease responsible for the hyponatremia .
She has had mild vomiting and diarrhea over the past 5 days but the low sodium was detected before the onset of these symptoms. She has Atrial Fibrillation but not yet detected cardiac failure, though she has had ankle swelling, predominantly in her left ankle, over the past 2 weeks. Her doctor told me yesterday that she does have blood markers for cancer and she will have scans today and tomorrow. She also had high ALP blood test results.