Aspiration Pneumonitis (Chemical Pneumonitis)
In aspiration pneumonitis, antibiotic therapy is not necessary. However, since it is difficult to distinguish between pneumonitis and pneumonia, it is common practice to use antibiotics with the potential for aspiration pneumonia in mind - Young Gon Son
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Chief Corner: Aspiration Pneumonitis vs. Aspiration Pneumonia
Due to the volume of aspiration needed to cause a pneumonitis, aspiration pneumonitis typically occurs after a witnessed aspiration event. In addition, aspiration pneumonitis is a hyperacute process resulting in immediate acute respiratory distress and hypoxia typically within hours of aspiration. This is due to direct caustic effects of the acidic gastric contents followed by neutrophil infiltration into the alveoli. Symptoms often resolve within 48 hours. Aspiration pneumonia on the other hand is more likely with unwitnessed aspiration events and symptoms may not occur for up to 48 hours after the event. Like all other pneumonias, aspiration pneumonia is a clinical diagnosis with suggestive…
Articles of Interest
Aspiration Pneumonitis/Pneumonia
Aspiration pneumonitis is an abrupt chemical injury caused by inhalation of sterile gastric contents.
Aspiration Pneumonitis – Diagnosis & Treatment
Antibiotics not recommended in mild and moderate cases. Multiple studies showing no difference in outcomes.
Chemical Pneumonitis from Hydrocarbon Aspiration
While hydrocarbons have been reported to be toxic to various organ systems, the most frequent adverse effect is aspiration, which can cause a chemical pneumonitis from direct injury to the lung parenchyma.
Mendelson's Syndrome
In 1946 Curtis Lester Mendelson wrote an article entitled "The aspiration of stomach contents into the lungs during obstetric anaesthesia", in the American Journal of Obstetrics and Gynaecology.
Pneumonitis and pneumonia after aspiration
Aspiration pneumonitis and aspiration pneumonia are clinically difficult to distinguish. Although there is some degree of overlap, the two aspiration syndromes are separate disease entities with distinguishable pathophysiology... If aspiration as a preceding event is not obvious, the patient is more likely to have aspiration pneumonia. A large volume of stomach contents is needed to induce chemical pneumonitis, resulting in a more evident aspiration events in cases of aspiration pneumonitis. Furthermore, the clinical course of aspiration pneumonitis is more rapidly progressing; hyper-acute hypoxemia occurs, and devastating lung injury can occur and be resolved within 48 hours. These patients are likely to exhibit symptoms such as bronchospasm, frothy sputum, and bilateral patchy infiltrates, even in nondependent lung fields.
Resources
Life in the Fastlane
Aspiration pneumonitis, or Mendelson syndrome, is chemically induce inflammation of the lungs as a result of aspiration of gastric contents. Aspiration pneumonia is infection of the lungs following aspiration by micro-organisms colonising the GI tract.
Life in the Fastlane
First line antibiotics: -> benzylpenicillin + metronidazole-> or clindamycin.
Radiopaedia
Features can be variable and range from a pulmonary edema pattern to areas of consolidation. CT is superior to plain films in demonstrating mild aspiration and distal airway involvement.
