158 



Scientific Proceedings (127) 



72 (2032) 



Studies on lung volume. VI. The absolute and relative size of 

 the different lung volumes. 



By CHRISTEN LUNDSGAARD and KNUD SCHIERBECK. 



[From the Medical Clinic of the University of Copenhagen, Ben- 

 mark.} 



In 27 normal adults, 19 men, 8 women, age 19 to 36 years, to- 

 tal capacity, vital capacity, residual, complementary and reserve 

 air were determined. Vital capacity was determined by expira- 

 tion into a Krogh spirometer. The highest value of five deter- 

 minations was chosen. Reserve and complementary air and mid- 

 dle capacity were determined by rebreathing air plus oxygen from 

 a Krogh spirometer. Total capacity was determined by the 

 dilution method (rebreathing oxygen). That complete mixture 

 took place was proved by construction of mixture curves. 

 Residual air was determined directly by the dilution method and 

 indirectly as the difference between the total capacity and the 

 vital capacity. The highest and lowest values are recorded in 

 Table I. The values in this and the following 3 papers are given 

 at observed tension and room temperature. 



If the total lung volume is given a value of 100, we obtain 

 an average value for the other volumes as shown in Table II, 

 where we have included the corresponding values calculated from 

 previous investigator's publications. We have determined the 

 mean error of each determination by means of the usual formula 



for the mean error in percentage of the mean are given in 

 Table III. 



In order to find out whether or not any systematic error was 

 responsible for the deviations from the mean, we compared the 

 observed and calculated number of errors in the different groups. 

 The agreement was satisfactory. In Table IV are given the 

 relative size of the lung volumes. If we know the normal value 

 of one of the lung volumes, the normal values for the other may 

 be calculated by means of the figures in Table IV. We do not 



(n— 1) 



• % The values for the mean, for the mean error and 



