This Fortnight in Medicine (Episode III)

No association between preprocedural fasting and witnessed pulmonary aspiration: A systematic review and meta-analysis

Here are a couple of other older articles to give you the history of preprocedural fasting.

Reducing the Risk of Acid Aspirations During Cesarean Section

Fasting from midnight — the history behind the dogma

CT Angiography, Healthy Lifestyle Behaviors, and Preventive Therapy