The continuous monitoring of CO2 ductances in pulmonary intensive care.

A cardiorespiratory monitoring system allows the measurement of FAECO2 and FECO2 in the expired air of the patient at the mouth (endtidal CO2) and in a mixing box. From these parameters, combined with the measured PACO2, the alveolo-expired (DuA = PECO2/PAECO2) and alveolar-arterial (Dua = PAECO2/PACO2) ductances which assimilate the respiratory system to a two-stage exchanger have brought about a lot of valuable information 1. DuA improves by 20% in 20 patients after removal of bronchial obstruction (p < 0.

The respiratory response to inhaled carbon dioxide in man after 3 hours exposure to 3% carbon dioxide.

1. The respiratory response to inhaled 3% and 6% CO2 was measured in 10 normal subjects after a 3 h acclimatization period to 3% CO2 in an environmental chamber. Control studies were carried out after a 3 h period of breathing air in the chamber.

[Technical and experimental study of two electronic spirometers (author's transl)].

Two electronic spirometers which use standard pneumotachographs were evaluated for their static and dynamic response, and clinically compared in 20 subjects to a reference flow channel. In the Pneumoscreen the data are digitalized and stored, permitting to play back the flow-volume curves at low or high speed. The instrument provides a direct read-out of forced vital capacity and of five indexes of forced expiration.

[Assessment of an oxygen dilution device with a ventilatory mask (author's transl)].

Oxygen dilution devices (Venturi 3 and 4) with Multi-VentTM mask, using an oxygen flow rate of 6 1/min, are insufficient when subjects' ventilation is increased : inspired oxygen concentration is lower than predicted. This can be detrimental to patients who could benefit by oxygenotherapy during exercise.