Search

Background Treatment options for chronic SIADH include water restriction (WR) and urea. The usefulness of urine osmolality to guide the choice of the treatment option is not clearly defined. We hypothesized that urine osmolality can indicate whether treatment with mild water restriction alone could be successful. Methods Retrospective Review of clinical and biochemical (blood and urine) data of patients with chronic SIADH treated for at least one year with mild WR (1.5–2 l/day) either with or without urea. Results Twenty nine patients were included. Nine patients were treated by mild WR. Mean serum sodium (SNa) and mean Uosm were 129 ± 2 mEq/l and 274 ± 78 mOsm/kgH2O respectively before WR, and increased to 138.5 ± 3 mEq/l and 505 ± 87 mOsm/kgH 2 O ( P 2 O respectively and increased to 136.5 ± 1 mEq/l and 490 ± 151 mOsm/kgH 2 O ( P 2 O and increased to 136.5 ± 2 mEq/l and 698 ± 157 mOsm/kgH 2 O ( P Conclusions About 30% of patients could be treated by moderate WR alone. All these patients presented an initial urine osmolality lower than 400 mOsm/kgH 2 O.