2475
Anesthesia was maintained with fentanyl , nitrous oxide , oxygen , and isoflurane .
 Chemical: fentanyl; Chemical: nitrous oxide; Chemical: oxygen; Chemical: isoflurane
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: fentanyl; Chemical: nitrous oxide; Chemical: oxygen; Chemical: isoflurane