First two liters of proteinaceous material lavaged, as it appears after sedimentation. Three layers can be visualized: an upper foamy layer, a clear white middle layer, and a thick layer of dense proteinaceous material at the bottom. Lavages are repeated until the return fluid is clear.
From Keller, CA, Frost, A, Cagle, PT, Abraham, JL, Chest 1995; 108:277.