How does one interpret the following lab values in a patient with hyponatremia.
Serum Na : 104 meq/l
Serum K : 3.1 meq/l
GRBS :90 mg/dl
serum osmolality : 236 mosmol/kg
urine osmolality : 117 mosmol/kg
Urine Na : 12 meq/l
Urine K : 9 meq/l
Serum creat : 0.3 mg/dl
BUN : 5 mg/dl
Uric acid : 0.5 mg/dl
TSH and random cortisol : normal
Most of the values would well with SIADH except for urine Na and K which suggest volume depletion. Can they co-exist ? Clinically the patient appears dehydrated but not severely so. Treating with adequate hydration (normal saline) and 3% saline has brought up the Sodium to 120 over 2 days.