Harold F. Chase

Simple methods for humidifying nonrebreathing anesthesia gas systems.

REATHING THROUGH a tracheostomy B or endotracheal tube exposes the trachea, bronchi, and alveoli to gases and dust particles which normally would be conditioned and filtered respectively by either the nose or pharynx. It is well known that breathing room air, which is relatively dry (4 to 10 mg. per liter) through a tracheostomy tube for a sufficient length of time causes crust formations in t h e respiratory t r a c t and that bronchoscopy is needed to remove them. Attempts are now being made to humidify the inspired air of tracheotomized patients to p reven t complications;l# but as yet little attention has been given to humidification of the inspired gases in anesthesia systems where endotracheal tubes are used and the nose and pharynx bypassed.

Effect of Certain Yohimbine Derivatives upon Arterial Strips

Summary 1. The hydrochloride salts of yohimbine derivatives (ethyl, allyl-amine, allyl, butyl, phenyl and diethylaminoethyl) in the dosage used, 1-500,000 to 1-50,000, do not seem to directly affect the arterial muscle strip whether it is in a contracted or relaxed state. 2. A predetermined, consistently constricting dose of epinephrine HC1, 1-1,000,000, or ephedrine, 1-25,000, administered after yohimbine derivatives is inhibited in its action. 3. This inhibitory action of the yohimbine radicle on epinephrine can be obviated by previously sensitizing the arterial strip to epinephrine by addition of cocaine. 4. Musculo-tropic agents such as histamine, 1-1,000,000, barium chloride, 1-1,000, and sodium nitrite, 1-1,000, are not modified in their actions by yohimbine derivatives. 5. These new yohimbine derivatives are antisympatheticomimetic agents.

TIME, DEHYDRATION, TEMPERATURE and ATROPINE: on respiratory water loss

NONREBREATHING ANESTHESIA SYSA tem in which dry gases are delivered through dry delivery tubes to a nonrebreathing valve and thence to the trachea via a n endotracheal tube results in maximal respiratory water loss when compared with total or partial rebreathing systems.l The nonrebreathing system has been studied for periods of from 1 to 11,

RESPIRATORY WATER LOSS VIA ANESTHESIA SYSTEMSMASK BREATHING

hours in well-hydrated normothermic subjects breathing by mask. Suggestions have been made for a simple method of humidifying nonrebreathing anesthesia systems.2