Bronchopulmonary lavage of small laboratory animals

A procedure was developed for performing multiple-wash, saline, bronchopulmonary lavages in living small animals. Animals were anesthetized with halothane in oxygen, intubated with tracheal catheters made from intravenous cannulas, and maintained on a flow-through anesthetic system which allowed positive pressure ventilation and fluid instillation. Wash volumes were calculated from lung pressure-volume measurements of individual animals, and lavages were accomplished by instillation and withdrawal of four washes of warmed saline. Wash volume for the mouse, gerbil, hamster, rat, guinea pig, and rabbit ranged from 0.7 ml for the mouse to 31 ml for the rabbit. The percent of wash fluid recovered ranged from 73% for the rabbit to 90% for the rat. Cell recovery data for the hamster, rat, guinea pig, and rabbit were related to body size with the hamster having the lowest count and the rabbit the highest count. The mouse, hamster, and rabbit tolerated the procedure well, but evidence of lung damage was found in the rat, guinea pig, and gerbil. Cell recovery was similar to that reported for lavages of excised lungs.