PRESENTATION: We report two patients. The first is a 68-year-old woman who presented with a 2-day history of vomiting. She was hypernatraemic and her elevated serum sodium concentration did not improve initially, despite adequate fluid replacement. She subsequently developed polyuria and polydipsia. The second patient, a 77-year-old woman, presented with delirium and severe hypernatraemia after being treated for a chest infection 1 week earlier. Both patients were on long-term lithium treatment. INVESTIGATION: In both the cases, a supervised water-deprivation test done after normalization of the blood biochemistry showed partial nephrogenic diabetes insipidus. OUTCOME: Lithium was discontinued. CONCLUSION: Older people on lithium-especially those requiring supportive care-are at risk of severe hypernatraemia after an acute illness or if their fluid intake is restricted.
PRESENTATION: We report two patients. The first is a 68-year-old woman who presented with a 2-day history of vomiting. She was hypernatraemic and her elevated serum sodium concentration did not improve initially, despite adequate fluid replacement. She subsequently developed polyuria and polydipsia. The second patient, a 77-year-old woman, presented with delirium and severe hypernatraemia after being treated for a chest infection 1 week earlier. Both patients were on long-term lithium treatment. INVESTIGATION: In both the cases, a supervised water-deprivation test done after normalization of the blood biochemistry showed partial nephrogenic diabetes insipidus. OUTCOME: Lithium was discontinued. CONCLUSION: Older people on lithium-especially those requiring supportive care-are at risk of severe hypernatraemia after an acute illness or if their fluid intake is restricted.
Authors: Soham Rej; Marilyn Segal; Nancy C P Low; Istvan Mucsi; Christina Holcroft; Kenneth Shulman; Karl Looper Journal: Can J Psychiatry Date: 2014-06 Impact factor: 4.356