Accession Number : ADA193073

Title :   Interaction between Lung Mechanics and Gas Exchange by Low Volume High Frequency Pulmonary Ventilation in Patients with Respiratory Failure.

Descriptive Note : Annual summary rept. 1 Oct 83-30 Sep 84,

Corporate Author : BRIGHAM AND WOMEN'S HOSPITAL BOSTON MA

Personal Author(s) : Drazen, Jeffrey M ; Drinker, Phillip ; Rossing, Thomas ; Solway, Julian ; Kamm, Roger D

PDF Url : ADA193073

Report Date : 21 Nov 1984

Pagination or Media Count : 45

Abstract : The factors influencing both dynamic hyperinflation and gas transport under the condition of low volume high frequency pulmonary ventilation (HFV) were examined. In the former area we measured gas transport and dynamic lung volumes in tracheostomized human subjects simultaneously in order to help determine the mechanism(s) responsible for gas trapping. We found that application of a fixed tidal volume (about 50-100 ml) over a range of frequencies from 0.5-20 Hz resulted in increased gas transport efficiency until a critical frequency was reached; above this frequency no further increase in alveolar ventilation was achieved. In contrast, mean lung volume (dynamic functional residual capacity) increased only above a critical frequency. These findings were compared using a variety of electrical analog models including one which incorporated airflow limitation; our findings suggest that airflow limitation mediates dynamic hyper-inflation. We also made measurements of gas transport during oscillatory flow in a hardware model which incorporated branching airways.

Descriptors :   *GAS EXCHANGE(BIOLOGY), *ARTIFICIAL RESPIRATION, *PULMONARY FUNCTION, AIR FLOW, ALVEOLI, ANALOG SIMULATION, BIOMECHANICS, DYNAMICS, EFFICIENCY, FLOW, HUMANS, LIMITATIONS, LUNG, MEAN, MODELS, OSCILLATION, RESIDUALS, TRACHEOTOMY, VENTILATION, VOLUME, RESPIRATORY DISEASES, RESPIRATORS, HIGH FREQUENCY

Subject Categories : Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE