Certified Ambulatory Perianesthesia Nurse (CAPA) Practice Exam

What effect does ingesting clear liquids shortly before anesthesia induction typically have?

1. Decrease peristalsis of the intestines

2. Create an alkaline pH

3. Have no effect on gastric acidity

4. Reduce the residual gastric volume

The correct answer is: Reduce the residual gastric volume

Ingesting clear liquids shortly before anesthesia induction helps to reduce the residual gastric volume. This is an important consideration for patients undergoing procedures requiring anesthesia, as a lower gastric volume decreases the risk of aspiration during intubation and anesthesia administration. Clear liquids are less dense and move quickly through the gastrointestinal tract, leading to a more rapid gastric emptying. Guidelines have evolved to allow for clear liquid intake up to a couple of hours before surgery, recognizing that this practice does not significantly increase the risk of aspiration and can improve patient comfort by minimizing thirst and promoting hydration. Other options, such as reducing peristalsis or affecting gastric acidity, are not directly related to the immediate effects of consuming clear liquids. In fact, the consumption of clear liquids does not typically create a significant change in gastric pH within the short time frame before surgery, nor does it inherently alter peristaltic activity in a manner relevant to anesthesia protocols. Thus, the focus on reducing residual gastric volume stands as the primary rationale for allowing clear liquids shortly before anesthetic induction.