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: The present report describes a case of cardiac arrest and subsequent death as a result of hyperkalaemia following the use of suxamethonium in a 23 - year - old Malawian woman .
### Output Text:
The present report describes a case of cardiac arrest and subsequent death as a result of hyperkalaemia following the use of <span class="chemical">suxamethonium</span> in a 23 - year - old Malawian woman . 