Murine model of oropharyngeal gastric fluid aspiration-A new assessment method for intrapulmonary liquid distribution using digital pixel calculation.

Aim of the Study: The aim of this study was to investigate a new method for visualization and quantification of intrapulmonary liquid distribution after oropharyngeal gastric fluid aspiration in mice. Material and Methods: Eleven mice received oropharyngeal aspiration with a gastric fluid, India ink, and saline solution. Digital imaging and pixel calculation were used to analyze intrapulmonary fluid distribution selectively. Results: Digital pixel analysis and orophanryngeal aspiration are both safe techniques in mice and deliver reproducible/valid results. Analysis revealed an average aspirate distribution of 86.8% of the total lung area. The proportional amount of the left lung was significantly greater than that of the right lung (P = 0.023). The lobe with the lowest mean distribution was the right lower lobe (79.2% +/- 4.4%). Conclusion: Digital pixel calculation is a reliable method for quantitative, macroscopic evaluation of fluid distribution in the lung. This method is a useful tool for training purposes and it can be used to ensure interinvestigator reproducibility.