COMPARISON OF PULMONARY INFLAMMATORY MEDIATORS IN PRETERM INFANTS TREATED WITH INTERMITTENT POSITIVE PRESSURE VENTILATION OR HIGH-FREQUENCYOSCILLATORY VENTILATION

Ventilated preterm infants prone to the development of bronchopulmonar y dysplasia have been shown to have increased inflammatory mediators i n their tracheal aspirates. High frequency oscillatory ventilation (HF OV) is thought to be less traumatic than intermittent positive pressur e ventilation (IPPV) in premature infants with surfactant deficiency, and therefore may reduce the inflammatory response in tracheobronchial aspirates. We randomized 76 premature infants requiring mechanical ve ntilation (birth weight 420-1830 g, median 840 g, gestational age 233/ 7 to 292/7 wk, median 264/7 to receive either an IPPV with a high rate (60-80/min) and low peak pressures, or an HFOV aiming at an optimizat ion of lung volume, within 1 h of intubation. Tracheal aspirates were systematically collected during the first 10 d of life and analyzed fo r albumin, IL-8, leukotriene B-4 (LTB4), and the secretory component ( SC) for IgA as a reference protein. Bacterially colonized samples were excluded. On the treatment d 1, 3, 5, 7, and 10, the resulting median values of albumin (milligrams/mg of SC) were 28, 23, 24, 18, and 10, in IPPV-ventilated infants, and 33, 28, 18, 25, and 39 in HFOV-ventila ted infants, respectively. Median IL-8 values (nanograms/mg of SC) wer e 671, 736, 705, 1362, and 1879 (IPPV) and 874, 1713, 1029, 1426, and 1823 (HFOV), respectively, and Ventilated preterm infants prone to the development of bronchopulmonary dysplasia have been shown to have inc reased median LTB4 values (nanograms/mg of SC) were 26, 13, 27, 22, an d 11 (IPPV) and 15, 12, 7, 12, and 16 (HFOV), respectively. Values wer e similar in IPPV- and HFOV-ventilated infants, and no significant dif ferences were noted. We conclude that HFOV, when compared with a high rate low pressure IPPV, does not reduce concentrations of albumin, IL- 8, and LTB4 in tracheal aspirates of preterm infants requiring mechani cal ventilation.