Aspiration pneumonia is caused by bacteria from the mouth or stomach entering the lungs. It can develop hours to days after aspiration occurs. The most common pathogens have changed from anaerobic bacteria to aerobic bacteria. Diagnosis is based on clinical history, risk factors, and chest x-ray. Treatment depends on whether it is community-acquired or hospital-acquired pneumonia. Antibiotics are used but duration depends on severity and response. Preventive measures focus on oral hygiene and early mobilization of high-risk patients like stroke patients.

1. ASPIRATION PNEUMONIA
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019
DR ANKIT GAJJAR

2. INTRODUCTION
• Aspiration pneumonia is an infection caused
by specific microorganisms
• Chemical pneumonitis – an inflamatory
reaction to irritative gastric contents
• Aspiration pneumonia – 5-15% of CAP
• Large volume aspiration of Colonized
oropharyngeal & Upper GI contents is must
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

3. Microbiologic & Pathogenic concept
• Role of lung microbiome
• Concept of Immigration & elimination
• Any illness lead to change in lung microbiota
(dysbiosis)
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

4. Microbiologic & Pathogenic concept
• Previously, anaerobes were more common
than aerobes
• But nowadays, aerobes are more common in
both CAP & HAP, anaerobes are recovered less
frequently
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

6. CLINICAL FEATURES
ASPIRATION PNEUMONIA CHEMICAL PNEUMONIA
ONSET Hours to days Minutes to hours
SYMPTOMS Fever, Cough, Shock Dyspnea, hypoxia,
tachycardia, diffuse
wheeze… Abn CXR, ARDS
GASTRIC CONTENT Micro / Macroaspiration Ph<2.5, >0.3 ml/kg
(Macroaspiration)
Treatment Antibiotic Supportive
Antibiotic may be for
secondary pneumonia
Steroids No role No role
Outcome poor Good
- Effects of PPI on Aspiration Pneumonia Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

7. DIAGNOSIS
• Clinical history, risk factors & CXR
• CXR is must
• CT Scan may be required
• PCT not helpful
• ET C/S should be sent in all patients

9. TREATMENT
• Change in pathogens from anaerobes to
aerobes
• Anaerobes are common in lung abscess,
necrotizing pneumonia & severe periodontal
disease
• For anaerobes, clindamycin is better than
metronidazole
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

10. TREATMENT
• Antibiotic selection depends on CAP, HAP or pt
in long term care facility
• CAP – Ampicilin-sulbactem or
- Carbapenem (ertapenem) or
- FQ’s – Levo or Moxi
• Clinda if risk of anaerobic infection
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

11. TREATMENT
• HAP – Piperacillin-tazobactam
- Cefepime
- Carbapenem (except Ertapenem)
• If risk of MDR is high
- Aminogycoside/colistin ±
vancomycin/linezolid

12. TREATMENT
• DURATION
- 5-7 days if good clinical response
- 10-14 days if lung abscess, necrotizing
pneumonia or empyema
• No role of steroids
• Treatment can be modified or discontinued
after culture reports
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

13. TREATMENT
CHEMICAL PNEUMONITIS
• Initial ABC management
• No role of steroids or antibiotics
• Indication of Antibiotics
- If pt is taking Acid suppressing medicines
- If pt has small bowel obstruction
- If pt is very serious
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

14. Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

15. PREVENTION
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

16. PREVENTION
• Antibiotics in emergency intubation
- only 2 studies
- ceftriaxone/cefuroxime 2 doses
- does not affect late onset pneumonia
• Role of ACE inhibitors & Cilostazol
• Role of oral care with chlorhexidine
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

17. PREVENTION
• Stroke patients
- Early mobilisation & swallowing exercise
- Trial of soft diet
- RTF in semirecumbent position
- Post pyloric RT & monitoring of RT
aspiration of gastric residual not effective
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

18. CONCLUSIONS
• Preventive measures in high risk patients
• Difficult to differentiate with CAP / HAP
• Diagnostic approach should be based on
clinical findings, risk factors & radio imaging
• Treatment should be based on risk factors
• No role of steroids
Lionel A Mandell, Michael Niederman
NEJM 380;7 FEB 14, 2019

19. THANK YOU