Use of Helium for Determination of Pulmonary Capacity

A preliminary report is made at this time of a new method employing helium, because it has all the advantages and none of the dangers of the hydrogen method.

Abstract

Hydrogen has been used for the determination of the pulmonary capacity by VanSlyke and Binger,1 who pointed out the danger of explosion and of poisoning with arsine. This procedure was replaced by oxygen dilution methods, particularly the Christie method,3 which has been in use in this laboratory for the last 10 years. A recent report2 has resulted in new interest in hydrogen, because of the ease and rapidity of analysis for this gas by thermal conductivity. A preliminary report is made at this time of a new method employing helium, because it has all the advantages and none of the dangers of the hydrogen method.A closed spirometer system with a blower is used. Carbon dioxide is absorbed by soda-lime. An important precaution is the addition of a water bottle to replace water vapor lost in the soda-lime. Dead space is measured by the oxygen dilution method. Part of the mixture circulating in the respiratory system is shunted through a thermal conductivity cell∗ with precautions to assure complete saturatio...