[Investigation of the hypoosmolal syndrome in carcinomas of the lung (author's transl)]. / Investigación del síndrome hipoosmolal en el carcinoma de pulmón.

A study was performed on 30 patients diagnosed antomopathologically for malignant neoplasia of the lung (epidermoid carcinomas, adenocarcinomas, oat-cell carcinomas, and neoplasias which could not be definitely classified). The following parameters for blood and urine were determined: osmolality, sodium, potassium, urea, and creatinine. Osmotic free water, creatinine, sodium, and potassium clearances were also calculated, as well as the plasma osmolality/urinary osmolality ratio. The basic aim of our study was to investigate for the presence of disturbances in the metabolism of water and alterations in plasmatic and urinary osmolality in this type of tumor. These could appear as complete inadequate ADH secretion syndromes as discovered by Bartter and Schwartz or as incomplete syndromes (hypoosmolality and/or hyponatremia). Among the more significant results was the tendency toward oliguira seen in 44% of the patients and the high incidence of plasmatic hypoosmolality (31%). In three patients plasmatic hypoosmolality and hyponatremia were concommitant in repeated observations. A complete inadequate ADH secretion syndrome was discovered in another patient with an oat-cell carcinoma. He presented plasmatic hypoosmolality, hyponatremia, relative urinary hypertonia, and oliguria but not renal, suprarenal, or hepatic pathology.