Undesirable respiratory symptoms during anesthesia may be said to belong to two classes: those due to the patient's condition and those dependent on the means of administering the anesthetic. The former are often not remediable, the latter may fully be. Time does not permit discussion of the manifold causes which underlie stertor and other unfavorable respiratory signs during etherization, but does require mention of two which may be entirely dependent on the apparatus used, namely, first, added work being done by the lungs and by their auxiliaries, and, second, obstruction to the inflow and outflow of the tidal air.
Both, by virtue of the mass of gauze, of cotton or of sponge through which the patient must force his respiration, are actively inherent in the ether chamber of the average bag-inhaler of which Bennett's, Gwanthmey's, Clover's and Allison's inhalers are familiar types. Both are also caused by the space left
PEDERSEN VC. AN INHALER FOR THE ORDINARY SEQUENCES AND MIXTURES OF ANESTHETICS.ON THE PRINCIPLE OF UNOBSTRUCTED RESPIRATION.. JAMA. 1907;XLIX(12):999-1003. doi:10.1001/jama.1907.25320120021002d