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: Clinical evaluations suggested an initial diagnosis of severe thrombocytopenia and haemolysis .
### Output Text:
Clinical evaluations suggested an initial diagnosis of severe thrombocytopenia and haemolysis . 