The term “aspiration” is used in two different medical senses. In the first sense, it refers to pulmonary aspiration, in which people suck foreign bodies into their tracheas and lungs, or have foreign bodies blown in, as for example by a ventilator. In the second sense, aspiration is a type of medical procedure in which matter is sucked up or out for removal. The meaning intended is usually clear from the context.
Pulmonary aspiration can be very dangerous. One form of pulmonary aspiration can occur when people vomit and part of the vomit enters the lungs. People can also inhale food or drink, or inhale foreign bodies such as dust in the air. Inhaling foreign bodies causes irritation to the delicate tissues in the lungs, and may lead to inflammation and a condition called aspiration pneumonia. Treatment for patients who have aspirated something depends on what it is and other factors.
The risk of aspiration is the key issue behind why people are advised to refrain from eating before general surgery. The concern is that the patient might vomit during surgery or immediately following, and she or he could be at risk of aspirating some of the vomitus. Aspiration is also a concern when people fall unconscious as a result of drug overdose, injury, or alcohol consumption, which is one reason why people should not be left alone in these situations.
Aspiration as a medical procedure can be done in numerous ways. In an aspiration biopsy, for example, a needle is used to access a fluid for sampling and the fluid is sucked into the needle by pulling the plunger. This technique might be used to get a clean urine sample from the bladder, to pull a bone marrow sample, or to retrieve fluid from an abscess. Aspiration may also be used to clear mucus from the nose and mouth, to remove blood from a surgical site, or to clear buildups of fluid in the body.
For some aspiration procedures, the patient may receive anesthesia because it can be painful. In other cases, no anesthetic is required. For example, a doctor using a bulb syringe to clear mucus from the nose of a baby doesn't need to provide analgesia because the procedure should not be painful, while a doctor taking a bone marrow biopsy needs to use anesthetic so that the insertion of the needle is not excruciating for the patient.