In order to ensure safety for elective anesthesia, standard practice requires pre-operative fasting to ensure that the stomach is empty prior to induction. The question of timing of pre-operative consumption of oral fluids remains vexed, and challenges anesthesiologists on a frequent basis. In the past few years, a new controversy in pre-operative fasting has arisen: clear drinks with increased content of protein and carbohydrate have been introduced to the market. Families and professionals alike are confused whether to regard these products as clear liquids (2 hours fasting) or as solids (at least 6 hours).
Ultrasound is now considered an accepted tool in the anesthesia literature as a surrogate for aspiration risk with different materials and in different disease states.
