Patients with respiratory decompensation shortly after aspiration of gastric/oropharyngeal contents are considered to have aspiration pneumonitis (inflammation of the lung without true infection). Most of these patients will improve with supportive care alone over 24-48 hours (https://pubmed.ncbi.nlm.nih.gov/22392230/), though some can have a very severe course including ARDS.
Patients with aspiration pneumonitis can have a leukocytosis, fevers, opacity on chest X-ray, and worsening respiratory status, and these are not useful for distinguishing aspiration pneumonitis from a true bacterial pneumonia. The onset of symptoms is often very abrupt and, in conjunction with a known or strongly suspected aspiration event, can be suggestive of a chemical pneumonitis due to aspiration, rather than bacterial pneumonia. Some scenarios where this can occur include a seizure event, code blue, intubation, etc.
A subset of patients with a macro-aspiration will go on to develop bacterial pneumonia during their recovery from their chemical pneumonitis. If a true bacterial pneumonia develops, it is typically 48-72 hours after the aspiration event. Note, however, most patients will recover spontaneously from aspiration pneumonitis with supportive care.
“Prophylactic” antibiotics after aspiration events do not seem to be effective in preventing the development of bacterial pneumonia. (https://pubmed.ncbi.nlm.nih.gov/29438467/). In inpatient scenarios, the entire clinical picture should be considered in deciding whether to pursue treatment for aspiration pneumonia or with broader coverage hospital acquired/ventilator associated pneumonia.
Exclusion: Hematologic malignancy or bone marrow transplantation, cystic fibrosis, patients cared for under the Advanced Lung Diseases service, and other severe immunosuppression or immunocompromise
| Diagnosis | Common Pathogens | Drug(s) of First Choice | Alternative Drug(s) | Comments | Expected Duration |
|---|---|---|---|---|---|
|
Acute Aspiration of Gastric Contents "Aspiration Pneumonitis" |
Mixed enteric flora | Antibiotics not indicated | N/A |
Patients who acutely aspirate gastric contents are considered to have aspiration pneumonitis. Many of these patients will have resolution of symptoms within 24-48 hours with only supportive care Prophylactic antimicrobial therapy for acute aspiration pnuemonitis does not improve patient outcomes and may increase antimicrobial resistance |
Antibiotics not indicated |
| Bacterial Pneumonia after Community Aspiration Event | Mixed enteric flora, oral flora, and CAP organisms | Ceftriaxone | Levofloxacin | Anaerobes are not a common cause of bacterial pneumonia after aspiration. If present, ceftriaxone provides adequate coverage of oral anaerobes | 5 days |
| Bacterial Pneumonia After In-Hospital Aspiration | Refer to Hospital Acquired Pneumonia Guidelines | Refer to Hospital Acquired Pneumonia Guidelines | Refer to Hospital Acquired Pneumonia Guidelines | Refer to Hospital Acquired Pneumonia Guidelines | N/A |
| Lung Abscess or Empyema | Oral anaerobes, Strep sp., Staph aureus |
Consider MRSA coverage in patients with history of MRSA infection or colonization |
Clindamycin | Often characterized by insidious onset of cough/fever, purulent sputum, and evidence of cavitation/effusion in patients at risk for chronic aspiration |
ID consult recommended |
Asai N, Suematsu H, Ohashi W, Shibata Y, Sakanashi D, Kato H, Shiota A, Watanabe H, Hagihara M, Koizumi Y, Yamagishi Y, Mikamo H. Ceftriaxone versus tazobactam/piperacillin and carbapenems in the treatment of aspiration pneumonia: A propensity score matching analysis. J Infect Chemother. 2021 Oct;27(10):1465-1470. doi: 10.1016/j.jiac.2021.06.011. Epub 2021 Jun 20. PMID: 34158237
Bai, A. D., Srivastava, S., Digby, G. C., Girard, V., Razak, F., & Verma, A. A. (2024). Anaerobic Antibiotic Coverage in Aspiration Pneumonia and the Associated Benefits and Harms: A Retrospective Cohort Study. Chest, 166(1), 39–48. https://doi.org/10.1016/j.chest.2024.02.025
Dragan V, Wei Y, Elligsen M, Kiss A, Walker SAN, Leis JA. Prophylactic Antimicrobial Therapy for Acute Aspiration Pneumonitis. Clin Infect Dis. 2018 Aug 1;67(4):513-518. doi: 10.1093/cid/ciy120. PMID: 29438467.
Jaoude P, Badlam J, Anandam A, El-Solh AA. A comparison between time to clinical stability in community-acquired aspiration pneumonia and community-acquired pneumonia. Intern Emerg Med. 2014 Mar;9(2):143-50. doi: 10.1007/s11739-012-0764-2. Epub 2012 Mar 6. PMID: 22392230.