Ventilator-Assisted Pneumonia Animal Model
- Duration of study - 1 day
- Lead time - 20 days
- Standard results - Microbiology, Histology
Model Utility:
Healthcare-associated/hospital acquired infections (HAIs) are those infections patients acquire during the course of receiving treatment for other conditions within a healthcare setting. In 2002, the number of HAIs in US hospitals was estimated as 1.7 million resulting in approximately 99,000 deaths during that year (Klevens 2007).
Ventilator-associated pneumonia (VAP) is one of the most commonly occurring HAIs and tremendous efforts are expended each year in researching new ways of combating these outbreaks. The financial incentives for health-care providers are enormous, since a single patient with hospital acquired VAP can cost more than $40,000 per occurrence (Rello 2002; Cocanour 2005).
In combating VAP, Staph aureus, Pseudomonas aeruginosa and Acinetobacter are frequently cited as the most critical pathogens to study, since they account for the majority of infections in this field. (Kollef 2005; Chaix 1999; Engemann 2003; El Solh 2008; Hartzell 2007).
Our pig model of VAP has been developed to assist with the assessment of novel, therapeutic coatings, drugs and inhaled treatments positioned to combat the microorganisms that lead to this HAI.
How The MoDel works:
example data:
advantages and disadvantages of this model:
On the day prior to the VAP test, a pure culture of one type of microbe or a mixture of up to three microbes is prepared for inoculation into the ET tube cuff. The animals are intubated and general anesthesia is maintained by endotracheal intubation. Fluids are delivered via an IV jugular catheter.
Once the animal is sedated, intubated and catheterized, a general exposure and treatment plan follows, such as the one below.
The graph above shows the growth of Pseudomonas in this VAP model over 24 hours post-inoculation. Note that the Hypopharynx and Oral Cavity were not swabbed at 24 hours, so no data are shown at that time point.
The pig VAP model provides an aggressive and difficult to defeat microbial challenge that closely approximates human patient responses to microbial contamination while under ventillators. The ability to use a wide range of pathogens and to monitor the changes in those pathogens over time greatly enhances the models utility.
The primary disadvantage to the pig VAP model is its high cost. The cost is a direct relationship to the high levels of veterinary care required to run the model as well as the overtime hour charges necessary for any round-the-clock animal study. With that said, the model is often less expensive than the alternative primary model (dogs) and is accepted by the FDA as suitable for product submissions.