2752
Under proper control of respiration , body temperature and end - tidal CO2 , intravenous administration of fentanyl ( 50 or 100 micrograms / kg ) consistently promoted an increase in electromyographic activity recorded from the gastrocnemius and abdominal rectus muscles .
 Chemical: CO2; Chemical: fentanyl
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: CO2; Chemical: fentanyl