Papers ox medicine and public health 121 



what limited, but in which, under favorable circum- 

 stances, there is little evidence of decompensation. 



Group Three consists of patients whose vital capacity 

 to 70% of the normal. The characteristic feature 

 of this group is the much less favorable clinical condition 

 than those with a higher vital capacity. Dyspnea on mod- 

 erate exertion was always complained of, and usually 

 was the most prominent symptom. All patients whose 

 vital capacity was 40 to 45 per cent of the normal were 

 in bed. Some of them were slightly dyspneic when com- 

 pletely at rest, and others upon the least exertion. With 

 the vital capacity of from 40 to 60 per cent of the nor- 

 mal, patients were rarely dyspneic while in bed, and 

 most of them could walk slowly without becoming short 

 of breath. "When the vital capacity was between 60 and 

 70 per cent, the patients usually could walk fairly com- 

 fortably, and could even ascend the stairs without dis- 

 tress. Of the 67 patients comprising this group, 7 per 

 cent could do light work, 33 per cent were up and about, 

 and 34 per cent were in bed at the time of the examina- 

 tion. 



Group four consists of patients whose vital capacity is 

 40 per cent of the normal or less. The patients of this 

 group were compelled to remain in bed, and practically 

 all showed signs of decompensation. Many were dyspneic 

 when absolutely quiet, and others on the slightest exer- 

 tion. In 8 patients whose vital capacity was below 30 

 per cent, extreme dyspnea and orthopnea were noted. 

 The lowest vital capacity found was 17 per cent. There 

 was a close relation between the clinical condition and 

 the vital capacity, and as these patients improved, there 

 was a corresponding rise in the vital capacity. Patients 

 whose maximum respiratory exchange falls within this 

 class during their first period of decompensation may 

 improve so that they are able to return to a fairly normal 

 life, but the occurrence of such a low vital capacity in the 

 later attacks makes the prognosis unfavorable. Few pa- 

 tients who have at any time fallen into this group have 

 shown great clinical improvement, and the mortality is 

 more than 50 per cent. 



