Strategies to Prevent Aspiration
Strategies to Prevent Aspiration
The patient with full stomach presents a substantial anesthetic risk. Unless strategies to prevent aspiration are successfully employed the patient may suffer the consequences of aspiration, including death (Table 7:1). Serious morbidity in the form of aspiration pneumonitis and pulmonary complications can ensue. Hypoxia can result from mechanical obstruction of food in the trachea and bronchi, leading to death decisions are required when weighing the need to proceed with surgery immediately versus the desire to minimize a patient's anesthetic risk by delaying surgery until patient no longer full stomach. In some instances, the patient's status dictates that the operation be performed immediately. In other cases the surgical operation is more urgent. Ideally, the anesthetist and surgeon should coordinate efforts in deciding when to delay or proceed with surgery.
Table 1.1 Methods to Reduce the Risk of Regurgitation and Pulmonary Aspiration
- Minimize intake
- Adequate preoperative fasting
- Clear liquids only if necessary
- Increase gastric emptying
- e.g., metoclopramide
- Reduce gastric volume and acidity
- Nasogastric tube
- Nonparticulate antacid (e.g., sodium citrate)
- H2-receptor antagonists (e.g., Ranitidine)
- Airway management and protection
- Cricoid pressure
- Cuffed endotracheal intubation
Two common miss conceptions concerning the risk of aspiration on induction of general anesthesia need to be confronted. The first misconception is that the surgical procedure is simple and quick, and therefore the anesthesia risk is slight. The presumption of a simple, quick procedure may or may not be accurate in a given case, but the risk of aspiration during general anesthesia is unrelated to the length or complexity of the surgery. The second misconception is that stomach contents can be emptied via a nasogastric tube. Unfortunately this procedure can never aspirate food particles, and one never is certain that all of the secretions are aspirated.