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Pneumonia, Aspiration: Differential Diagnoses & Workup
Updated: May 5, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
- Multimedia
Differential Diagnoses
Other Problems to Be Considered
Hypersensitivity pneumonitis
Workup
Laboratory Studies
The lab studies obtained should be guided by the clinical presentation. Patients with signs or symptoms of sepsis or septic shock require further lab testing than those with uncomplicated aspiration syndromes. The following lab tests are useful in both aspiration pneumonia and pneumonitis.
- Complete blood count with differential
- Determine white count as marker of possible infection.
- Determine band count; a left shift further supports the diagnosis of bacterial pneumonia.
- Determine baseline hemoglobin/hematocrit and platelets for further management.
- Basic metabolic panel
- Serum electrolytes, BUN, and creatinine levels can be used to assess fluid status and the need for intravenous hydration. This is especially important in patients who present with fever, vomiting, or diarrhea who may have significant fluid loss.
- Serum BUN and creatinine levels can also be used to assess renal function in order to appropriately dose antibiotics. In addition, these values can be used to assess end-organ damage in patients who present with sepsis or septic shock.
- Arterial blood gas analysis
- Arterial blood gas analysis is used to assess oxygenation and adds information to guiding oxygen supplementation.
- Assess the patient's pH status.
- Lactate level (often included with blood gases) can be used as an early marker of severe sepsis or septic shock.
- Mixed venous gas measurement
- This should be obtained in any patient in whom septic shock is suspected.
- Decreased mixed venous oxygen saturation is a marker for septic shock.
- Blood cultures
- Baseline screening for bacteremia
- In uncomplicated pneumonia (no signs of sepsis or septic shock), blood cultures have a low yield and are not necessary for initial management and treatment.
- Sputum culture and Gram stain - These are generally not helpful in initial diagnosis or treatment.
Imaging Studies
- Chest radiograph - Posteroanterior (PA) and lateral
- Location of infiltrate4
- The right middle and lower lung lobes are the most common sites of infiltrate formation due to the larger caliber and more vertical orientation of the right mainstem bronchus.
- Patients who aspirate while standing can have bilateral lower lung lobe infiltrates.
- Patients lying in the left lateral decubitus position are more likely to have left-sided infiltrates.
- The right upper lobe is a common area of consolidation in alcoholics who aspirate in the prone position.
- Presence of pleural effusion may indicate the need to perform thoracentesis to rule out empyema.
- Location of infiltrate4
Chest radiograph of a patient with aspiration pneumonia of the left lung after a benzodiazepine overdose. The patient was probably positioned to the left at the moment of aspiration.
- Chest CT scan
- This is not usually necessary on an emergent basis.
- In the presence of pleural effusion or empyema, CT may aid in further characterization of the infiltrate.
Procedures
- Bronchoscopy with protected brush or protected bronchial sample
- Bronchoscopy may be helpful in nosocomial aspiration pneumonia for guiding antibiotic therapy.
- This is not useful in the treatment of community-acquired aspiration pneumonia.
- Thoracentesis
- Chest tube placement (for drainage of large empyema)
More on Pneumonia, Aspiration |
| Overview: Pneumonia, Aspiration |
 Differential Diagnoses & Workup: Pneumonia, Aspiration |
| Treatment & Medication: Pneumonia, Aspiration |
| Follow-up: Pneumonia, Aspiration |
| Multimedia: Pneumonia, Aspiration |
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References
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Marik PE. Aspiration pneumonitis and aspiration pneumonia. N Engl J Med. Mar 1 2001;344(9):665-71. [Medline].
Akritidis N, Gousis C, Dimos G, Paparounas K. Fever, cough, and bilateral lung infiltrates. Achalasia associated with aspiration pneumonia. Chest. Feb 2003;123(2):608-12. [Medline].
Marom EM, McAdams HP, Erasmus JJ. The many faces of pulmonary aspiration. AJR Am J Roentgenol. Jan 1999;172(1):121-8. [Medline].
Drakulovic MB, Torres A, Bauer TT, et al. Supine body position as a risk factor for nosocomial pneumonia in mechanically ventilated patients: a randomised trial. Lancet. Nov 27 1999;354(9193):1851-8. [Medline].
Lumpkin JR, Westfall MD. Aspiration pneumonia. In: Emergency Medicine: Concepts and Clinical Practice. 1992:1112-20.
Marik PE, Careau P. The role of anaerobes in patients with ventilator-associated pneumonia and aspiration pneumonia: a prospective study. Chest. Jan 1999;115(1):178-83. [Medline].
Mier L, Dreyfuss D, Darchy B. Is penicillin G an adequate initial treatment for aspiration pneumonia? A prospective evaluation using a protected specimen brush and quantitative cultures. Intensive Care Med. 1993;19(5):279-84. [Medline].
Moll J, Kerns W 2nd, Tomaszewski C. Incidence of aspiration pneumonia in intubated patients receiving activated charcoal. J Emerg Med. Mar-Apr 1999;17(2):279-83. [Medline].
Pennza PT. Aspiration pneumonia, necrotizing pneumonia, and lung abscess. Emerg Med Clin North Am. May 1989;7(2):279-307. [Medline].
Preston AJ, Gosney MA, Noon S. Oral flora of elderly patients following acute medical admission. Gerontology. Jan-Feb 1999;45(1):49-52. [Medline].
Sasaki H, Sekizawa K, Yanai M. New strategies for aspiration pneumonia. Intern Med. Dec 1997;36(12):851-5. [Medline].
Vadeboncoeur TF, Davis DP, Ochs M. The ability of paramedics to predict aspiration in patients undergoing prehospital rapid sequence intubation. J Emerg Med. Feb 2006;30(2):131-6. [Medline].
Further Reading
Keywords
aspiration pneumonia, aspiration pneumonitis, aspiration pneumonia treatment, Mendelson syndrome, pneumonitis, altered level of consciousness, abnormal swallowing reflexes, acute respiratory distress syndrome, acute respiratory failure, bacterial pneumonitis, chemical pneumonitis, community-acquired aspiration pneumonia, Staphylococcus aureus, nosocomial infection, empyema, stress dyspnea, rest dyspnea, cyanosis, putrid expectoration, tachypnea, tachycardia, bradycardia, crackles, bronchial rales, pleural effusion, egophony, cerebrovascular accident, intracranial mass lesions, sepsis, meningitis
