3240
Before nitroprusside infusion , 5 cm H2O CPAP significantly , P less than . 05 , decreased arterial blood pressure , but did not significantly alter heart rate , cardiac output , systemic vascular resistance , or QS / QT .
 nitroprusside, H2O
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 nitroprusside, H2O