Acute aspiration

Case history #1

Paramedics are called to the home of a poorly responsive 42-year-old woman with a history of substance misuse. She has a Glasgow Coma Scale (GCS) of 5, is hypoxaemic on room air, and is noted to have fluid around her mouth. After a bolus of intravenous naloxone her GCS improves to 14 but she remains hypoxaemic and becomes tachypnoeic. She is transferred to the accident and emergency department on 15 litres oxygen via a non-rebreather mask. Severe respiratory distress and ongoing hypoxaemia continue, and she requires endotracheal intubation, mechanical ventilation, and admission to the ward. Physical examination reveals bilateral crackles and wheezes.

Case history #2

A 77-year-old woman with a 9-year history of Parkinson's disease is admitted with deteriorating mobility, confusion, malaise, and lethargy. Examination reveals an Abbreviated Mental Test score of 5/10, rigidity and tremor at rest, and right basal crackles. Chest x-ray shows right basal patchy consolidation. Collateral history from her family confirms a history of progressively distressing coughing on eating and drinking. Speech and language therapy assessment confirms moderately impaired swallow function.

Other presentations

Aspiration of gastric contents is commonly seen, particularly in older patients due to associated swallowing dysfunction and comorbidities, or as a consequence of substance misuse.

Aspiration is more common in older patients who have comorbidities, particularly those that affect swallowing function such as stroke. Other presentations include scenarios where the patient has an impaired conscious level (which causes loss of airway protection mechanisms), gastrointestinal disorders, conditions that affect gastric emptying, and oesophageal abnormalities. Additionally, patients undergoing upper airway or endoscopic procedures are at risk, such as during a general anaesthetic or in the intensive care unit, or following gastrointestinal studies with barium. Limited protection is provided by a nasogastric tube, a percutaneous endoscopic gastrostomy, or an endotracheal or tracheostomy tube, and in fact they may increase the risk.[3]Marik PE. Aspiration pneumonitis and aspiration pneumonia. N Engl J Med. 2001 Mar 1;344(9):665-71. http://www.ncbi.nlm.nih.gov/pubmed/11228282?tool=bestpractice.com Patients with acute aspiration can develop aspiration pneumonitis, pneumonia, and acute respiratory distress syndrome.