Acute aspiration

Acute aspiration is the inhalation of foreign material into the airways beyond the vocal cords.

Usually occurs in patients with risk factors such as swallowing dysfunction, impaired conscious level, or substance misuse.

Patients with risk factors for acute aspiration should undergo a bedside clinical examination before feeding.

Patients undergoing a general anaesthetic are also at risk of acute aspiration. Anaesthesia-related aspiration can be prevented by identifying patients susceptible to vomiting and reflux, minimising gastric contents before surgery, minimising emetic stimuli, and avoiding complete loss of protective reflexes from over-sedation.

Antibiotics are not indicated early after aspiration, but they should be considered if the pneumonitis does not resolve after 48 hours.

Patients with neurological deficits, infants (not covered in the topic), older patients (aged >70 years), and debilitated patients with dysphagia may also aspirate barium sulfate during radiological procedures, which can result in severe pneumonitis.

Screening for dysphagia is recommended for patients at risk of, or following, aspiration due to suspected dysphagia (including all patients following an acute stroke), which should involve a swallowing assessment initially, and input from the multidisciplinary team.

Aspiration is the inhalation of liquid or solid particles, particularly gastric contents or food and drink, into the airways below the vocal cords.[1]Raghavendran K, Nemzek J, Napolitano LM, et al. Aspiration-induced lung injury. Crit Care Med. 2011 Apr;39(4):818-26. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3102154 http://www.ncbi.nlm.nih.gov/pubmed/21263315?tool=bestpractice.com It can lead to aspiration pneumonitis (chemical injury) or aspiration pneumonia (infection), both of which can lead to acute respiratory distress syndrome (ARDS). See Aspiration pneumonia and Acute respiratory distress syndrome (ARDS). Not all episodes of aspiration lead to an infection. 

This topic covers acute aspiration in adults. It does not discuss the inhalation of foreign bodies - see Foreign body aspiration.

Awareness is increasing for silent or more subclinical chronic micro-aspiration, which has been implicated as a potential aggravating mechanism across a variety of disorders such as interstitial lung disease, asthma, chronic obstructive pulmonary disease (COPD), and chronic cough. Chronic micro-aspiration is not covered in this topic.[2]Lee AS, Lee JS, He Z, et al. Reflux-aspiration in chronic lung disease. Ann Am Thorac Soc. 2020 Feb;17(2):155-64. https://www.atsjournals.org/doi/10.1513/AnnalsATS.201906-427CME http://www.ncbi.nlm.nih.gov/pubmed/31697575?tool=bestpractice.com