In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: After interviewing the attending nurses and reviewing the written documentation , it is clear that every administration of metoclopramide was immediately ( within s ) followed by asystole .
### Output Text:
After interviewing the attending nurses and reviewing the written documentation , it is clear that every administration of <span class="chemical">metoclopramide</span> was immediately ( within s ) followed by asystole . 