PART III. PHARMACODYNAMICS. 



ANAESTHESIA. 



ETHER, CHLOROFORM, NITROUS OXIDE, ETHYL CHLORIDE. 



1. Take 3 frogs of equal size, weight, and condition. Count respirations, and 

 note general reflex excitability. Place No. i in a flask fitted with stopper and thistle 

 tube. Noting time, introduce 5 mils Ether. Observe and record symptoms. 



Compare symptoms and times with effects produced with frog No. 2 when 5 mils 

 Chloroform are used. 



Compare symptoms and times on frog No. 3 when briefly subjected to the fumes 

 of Ethyl Chloride. 



2. Etherize lightly a large frog. Open its thorax just enough to connect heart 

 with writing lever. Secure continuous tracings while frog is gradually killed with 

 definite increments of ether per second. Note amount of Ether used, time required to 

 produce a fatal effect, and graphic phenomena obtained. Tabulate your results. 



3. Repeat Experiment No. 2, using Chloroform instead of Ether, having selected 

 a frog of equal weight and condition. Tabulate your findings. 



4. Secure a mammal (cat, dog, or rabbit). Gently soothe the animal, and observe 

 its "normal" rate of pulse and respiration. Under the instructor's guidance, etherize 

 the animal, carefully noting all phenomena educed. Let a student assistant fasten the 

 animal to the operating board, and make suitable connections for registering pulse and 

 respiration. Obtain graphs of the ether norms, and compare with the pre-ether find- 

 ings of the same systems. 



Proceed to bring about the death of the animal by definite increments of Ether 

 per second. Carefully note all phenomena, both graphic and general, especially danger 

 signals. What system weakens first under the influence of Ether? 



As soon as death seems to have occurred, attempt resuscitation by: (a) dilating 

 sharply the anal sphincter, using forceps; (b) compressing the thorax at the rate of 

 60 times a minute; (c) injecting adrenin solution (i to 1000) into the jugular vein, the 

 carotid artery, or through the thorax into the heart. 



5. Repeat Experiment No. 4, using Chloroform instead of Ether. 



6. Under the direct guidance of the instructor, carefully etherize a volunteer 

 fellow-student.* Pay strict attention to your task, while other members of your sec- 

 tion take careful notes of their findings as to pulse-rate, blood-pressure, respiration, 

 and such other general phenomena as may be elicited. 



Let the subject later describe his sensations, both while going under the influence 

 of ether, and while coming out. 



7. As assignments permit, make careful studies of respiration, pulse, blood-pres- 

 sure, and other symptomatic phenomena, on various subjects undergoing anesthetiza- 

 tion in the operating room. 



* Note : The student acting as anaesthetist should first have read very carefully the discussion on Anaes- 

 thesia in "Cushny's Pharmacology," pp. 211 to 218 inclusive. 



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