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Updated: Jul 13, 2026
Lavage-induced Surfactant Depletion in Pigs As a Model of the Acute Respiratory Distress Syndrome (ARDS)
Published on: September 7, 2016
Experimental severe Pseudomonas aeruginosa pneumonia and antibiotic therapy in piglets receiving mechanical
Carlos M Luna1, Sebastián Baquero, Sebastián Gando
1Acevedo 1070, Banfield (1828), Buenos Aires, Argentina. cymluna@advancedsl.com.ar
Background:
Little is known about the general and local consequences of severe pneumonia under mechanical ventilation (SPMV) and how these are resolved with antibiotic therapy (ABT).
Objectives:
To investigate the physiologic, biological, microbiological, and pathologic changes produced by experimental SPMV in a porcine model, and to evaluate the effect of ABT.
Methods:
Pseudomonas aeruginosa was inoculated in 12 large white-Landrace piglets receiving mechanical that were killed after 72 h if death did not occur before. Vital signs, serum and BAL cytokines, serum C-reactive protein (CRP), and graded postmortem lung pathology and cultures (blood and quantitative BAL and lung) were evaluated. Six piglets received inappropriate ABT (no ABT or ceftriaxone), and six piglets received appropriate ABT (ciprofloxacin).
Measurements And Main Results:
Pathologic and microbiological evidence of infection were present in all the animals in both groups. SPMV produced significant oxygenation and lung compliance worsening, increased serum CRP, and reduced BAL fluid tumor necrosis factor (TNF)-alpha. Arterial thrombosis in lung pathology was associated with higher temperature, hypoxemia and low lung compliance, higher initial serum CRP and TNF-alpha concentrations, and increased serum interleukin (IL)-6 and BAL IL-6 and TNF-alpha. Reduced ABT reduced body temperature and culture positivity.
Conclusions:
This model resembles VAP and has been used for studying pulmonary infection and inflammation related to mechanical ventilation. ABT reduced fever and bacterial burden in SPMV but had no effect on cytokine or CRP concentrations, oxygenation, or lung mechanics. Pulmonary artery thrombosis was associated with worse response to infection.
Insights
Severe pneumonia under mechanical ventilation (SPMV) causes lung damage and inflammation. Antibiotic therapy (ABT) reduced fever and bacterial load but did not improve lung function or inflammation markers in this porcine model.
Area of Science:
- Pulmonary Medicine
- Infectious Diseases
- Critical Care Medicine
Background:
- Severe pneumonia under mechanical ventilation (SPMV) consequences remain poorly understood.
- The resolution of SPMV with antibiotic therapy (ABT) requires further investigation.
Purpose of the Study:
- To investigate physiologic, biologic, microbiologic, and pathologic changes in experimental SPMV.
- To evaluate the efficacy of ABT in resolving SPMV in a porcine model.
Main Methods:
- Pseudomonas aeruginosa inoculation in mechanically ventilated piglets.
- Assessment of vital signs, serum/BAL cytokines, CRP, and postmortem lung pathology/cultures.
- Comparison of inappropriate (no ABT/ceftriaxone) versus appropriate (ciprofloxacin) ABT groups.
Main Results:
- SPMV induced significant worsening of oxygenation and lung compliance, increased CRP, and reduced BAL TNF-alpha.
- Pulmonary artery thrombosis correlated with higher temperature, hypoxemia, low lung compliance, and elevated inflammatory markers (CRP, TNF-alpha, IL-6).
- ABT reduced fever and bacterial burden but did not impact cytokine/CRP levels, oxygenation, or lung mechanics.
Conclusions:
- The porcine model effectively simulates ventilator-associated pneumonia (VAP) for studying infection and inflammation.
- ABT in SPMV mitigates fever and bacterial load but does not resolve systemic inflammation or improve respiratory mechanics.
- Pulmonary artery thrombosis is linked to a poorer response to infection in SPMV.
