Functional Residual Capacity in Patients with Pulmonary Emphysema

doi:10.1059/0003-4819-57-1-18

Functional Residual Capacity in Patients with Pulmonary Emphysema

A Comparative Study Using Gas Dilution and Plethysmographic Techniques for Measurement

Requests for reprints should be addressed to Joseph C. Ross, M.D., Department of Medicine, Indiana University Medical Center,
1100 West Michigan Street, Indianapolis 7, Indiana
.

Excerpt

Many methods have been used to measure the functional residual capacity of the lung (FRC), some simple, others complicated and elaborate. Nevertheless, an accurate measurement of functional residual capacity in patients with pulmonary emphysema has been more difficult than expected and, as time has passed, it has become apparent that the functional residual capacity in patients with emphysema is larger than previously thought.

In 1940, Darling, Cournand, and Richards (1) described the open circuit nitrogen (7-minute washout) method, now widely used, for estimating functional residual capacity, but pointed out that imperfect gas mixing in the lung could impair the accuracy

Summario in Interlingua

Le residue capacitate functional del pulmon (RCF) esseva determinate in 4 subjectos normal e in 9 patientes con emphysema pulmonar per medio del technicas eluitori de nitrogeno e de helium a circuito aperte, de plethysmographia de corpore total, e del methodo classic de Darling de nitrogeno a circuito aperte con elution de 7 minutas. Le studio esseva interprendite pro determinar le relative e le absolute fidelitate del technicas de elution prolongate de gas e del technica conventional de elution de nitrogeno de 7 minutas in le estimation del RCF de patientes con emphysema in comparation con le methodo plethysmographic. In subjectos normal, le valores pro RCF obtenite secundo le varie methodos esseva multo congruente. Tamen, in le patientes con emphysema, le elution de helium e de nitrogeno e le plethysmographia a corpore total produceva constantemente valores plus alte pro RCF que le methodo conventional a 7 minutas secundo Darling. Le valores medie esseva: technica de nitrogeno de 7 minutas, 4,93 litros; technica de nitrogeno de 15 minutas, 5,47 litros; technica de helium a circuito aperte, 5,51 litros; e technica plethysmographic, 6,33 litros. Duo del patientes habeva grande cystes. Quando illes esseva excludite, le valores medie pro le remanente 7 patientes esseva technica de nitrogeno de 7 minutas, 5,11 litros; technica de nitrogeno de 15 minutas, 5,45 litros; technica de helium a circuito aperte, 5,68 litros; e technica plethysmographic, 5,86 litros. Iste resultatos indica que in patientes con sever emphysema le methodo conventional de Darling produce valores que es troppo micre, sed methodos a eluition mesura apparentemente omne areas con le exception de illos que es totalmente non-ventilate. Le volumine de tal non-ventilate areas (cystes, etc.) pote esser determinate per calcular le differentia inter le productos del methodo plethysmographic que mesura omne le aere in le cavitate thoracic e illos del methodo plethysmographic que mesura omne le areas que es ventilate, mesmo si solo lentemente.

Article and Author Information

From the Department of Medicine, Indiana University Medical Center, Indianapolis, Indiana.
This work was supported in part by research grant H-4080 and in part by research grant H-6228, and with facilities provided by Cardiovascular Clinical Research Center Grant H-6308, all from the National Heart Institute, National Institutes of Health.
- Received January 8, 1962.
- Accepted February 8, 1962.