294 INOKGANIC AGENTS 



3. Motor spinal area (loss of motion and partial loss 

 of reflex action). 



4. Sensory medullary centres. 



5. Motor medullary centres (failure of respiration). 

 Ether does not affect the nerves or muscles when inhaled 



or ingested. Ether depresses the action of the nerves, how- 

 ever, when applied locally. 



Respiration. — The respiratory centre is stimulated by 

 inhalation or ingestion of therapeutic quantities of ether. 

 Paralysis of the respiratory centre occurs in the last stage 

 of ether poisoning. Ether vapor is irritant to the respira- 

 tory mucpiis membrane, and causes coughing and choking 

 during inhalation. It is not an appropriate ansesthetic, there- 

 fore, in inflammatory conditions of the respiratory tract, be- 

 cause its vapor is given in greater concentration than in 

 chloroform. In giving ether by the drop method undue irri- 

 tation of the lungs is avoided and such conditions as 

 bronchitis, pulmonary edema and pneumonia. Ether vapor 

 excites the peripheral ends of the trifacial nerve in the face,, 

 and the vagus nerve in the lungs, so that temporary arrest 

 of respiration often occurs when a fresh supply of ether- 

 is added during inhalation. 



Temperature. — The temperature of the body may be- 

 raised during the stage of excitement and struggling, but 

 prolonged etherization leads to loss of heat, owing to evapo- 

 ration of ether from the lungs, and general depression of the 

 nervous system. 



Elimination. — Ether is eliminated principally from the 

 liTngs. Recent experiments indicate that ether causes con- 

 traction of the renal arteries, with diminution in the size 

 of the kidneys, suppression of urine and albuminuria. Ether 

 damages the kidneys, however, less than chloroform, which 

 sometimes leads to fatty degeneration. 



Acetone has been found in the urine of 90% of patients 

 in human practice within 18 hours of etherization (through 

 a closed cone). Death may sometimes occur in coma, follow- 

 ing ether ansesthesia, with rapid pulse and breathing and the 

 odor of acetone in the breath. This occurs less often than 

 with chloroform (which see, under Metabolism). 



Uses. — Apart from its value as an anajsthetic, ether 

 is mainly of service for two purposes. Eirst: in collapse, 



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