Volume guarantee versus high-frequency ventilation: lung inflammation in preterm infants

BACKGROUND: Appropriate ventilation together with improvement of clinical care of premature babies can contribute to reducing lung inflammation, known to represent the "primum movens" of bronchopulmonary dysplasia (BPD). High-frequency oscillatory ventilation (HFOV) and volume-guarantee (VG) ventilation are effective in the treatment of neonatal respiratory distress syndrome (RDS). OBJECTIVE: To assess the potential of HFOV and VG to prevent BPD in the acute phase of RDS, by a randomised clinical study evaluating lung inflammation in premature infants. STUDY DESIGN: Forty infants (gestational age 25-32 weeks) with RDS were assigned to assist-control ventilation plus VG (Vt = 5 ml/kg) or HFOV (both with a Dräger Babylog 8000 plus ventilator). Levels of interleukin (IL) 6, IL8 and tumour necrosis factor were determined in tracheal aspirate on days 1, 3 and 7 of life. RESULTS: In the HFOV group IL6 levels were significantly higher on day 3 (0.5 (0.2) vs assisted-control ventilation plus VG group 0.1 (0.2) ng/ml) and oxygen dependency was significantly longer (36 (23) vs assisted-control ventilation plus VG group 19 (11) days). CONCLUSION: VG ventilation is an effective lung-protective strategy to be used in acute RDS, inducing a lower expression of early inflammation markers than HFOV. Whether the use of this initial ventilatory strategy contributes to the prevention of BPD requires further studies.