An Evaluation of Respiratory Depression by Alveolar Gas Changes During Pentothal Sodium Anesthesia.

Pulmonary Ventilation and Carbon Dioxide Levels During Anaesthesia

“…As might be expected, depression is maximal initially; after this early period respiratory volumes appeared adequate to ordinary clinical observation, but it is noteworthy that by physiological standards respiration was inadequate throughout in all patients. Records of respiratory depression and recovery during thiopenpentone anaesthesia in animals have been reported (Ament et al, 1949). Cyclopropane is reputedly the most powerful respiratory depressant of inhalation anaesthetics.…”

A New Method of Spirometry Applicable to Routine Anaesthesia

“…He found, using a graduated rebreather with a demand apparatus (1922), that there were very great variations in ventilation, including considerable under-ventilation, during ether anaesthesia (1928). There was little further work involving measurement of respiratory volumes until Ament, Suskind, and Rahn (1949) described the measurement of minute volume by expiring through unidirectional valves into a gasmeter, during thiopentone anaesthesia. Ridley and Faulconer (1952) and later Zinberg and Jensen (1954) have described the use of gasmeters in a modified circle system.…”