Quantitative assessment of water content of human lung: a study on open lung biopsy specimen.

Quantitative assessments of human lung water are necessary to evaluate lung water changes, but little knowledge is available about a human "normal" lung. To determine a "normal" lung water content, pieces of lung tissue were obtained from lungs which should be resected for solitary nodular lung diseases, and the water content was assessed in terms of the ratio of extravascular lung water to blood free dry lung weight (Qw1), using the gravimetric methods. Among 152 patients who underwent open thorax surgeries for their solitary nodular lung diseases, 35 lung specimens were obtained from lungs which were free from any abnormal lesions. Since the postoperative histological examination did not reveal any pathological findings except for the solitary nodules in the resected lobes of 35 patients, the 35 pieces were also considered to be "normal". The value of Qw1 was 3.66 +/- 0.29 (mean +/- S.D.) g/g blood free dry lung. This value would serve as a reference of Qw1 in human "normal" lung.