Table 2.

The number of cells in the BAL fluid before and after ventilation with CMV or HFO

	CMV	HFO
First BAL*
Total cell count	(7.8 ± 1.2) × 106	(8.1 ± 1.3) × 106
Last BAL†
Total cell count	(47.0 ± 8.8) × 105	(13.6 ± 3.5) × 105 ‡
Neutrophils	(19.7 ± 5.5) × 105	(1.6 ± 1.0) × 105 ‡
Macrophages	(22.6 ± 3.5) × 105	(10.9 ± 2.3) × 105 ‡
Lymphocytes	(4.7 ± 0.5) × 105	(1.1 ± 0.3) × 105 ‡

BAL = bronchoalveolar lavage; CMV = conventional mechanical ventilation; HFO = high-frequency oscillatory ventilation. ^*Before ventilation; ^†after 4 h ventilation; ^‡P <0.05.