Presented at the Neonatal Society 2002 Summer Meeting.
Theilen U1, Lyon AJ1, Fitzgerald T2, Hendry M3, Keeling J4
1 Neonatal Unit, Simpson Memorial Maternity Pavilion, Edinburgh, UK
2 Department of Radiology, Simpson Memorial Maternity Pavilion, Edinburgh, UK
3 Department of Radiology, Royal Hospital for Sick Children, Edinburgh, UK
4 Department of Pathology, Royal Hospital for Sick Children, Edinburgh, UK
Background: Infection with Ureaplasma urealyticum (Uu) has been associated with chronic lung disease in preterm infants.
Aim: To determine if infection with Uu from birth causes a specific acute respiratory disease which may be the precursor of long term lung damage.
Methods: 60 ventilated babies <30 weeks had tracheal secretions cultured for Uu. Clinical details in the first 10 days were reviewed retrospectively. Chest X-rays around days 1, 5 and 10 were independently reported, for agreed features, by 2 radiologists, blinded to the baby’s Uu status. Each feature was scored 0-4 dependent on the lung quadrants involved. Comparisons were by Chi square and Mann Whitney U test.
Results: 25 were Uu positive and in these chorioamnionitis was more common (13/24 vs 5/30, p=0.005) and maximum white count higher (median (range) 28 (8-92) vs 19 (7-70), p=0.015). Despite being less mature (25 (24-29) vs 26 (24-29) weeks, p=0.016) the Uu+ve group were weaned earlier to the same mean airway pressure and FiO2 as the Uu-ve group (day of lowest MAP 4 (2-10) vs 6 (1-10), p=0.039); day of lowest FiO2 2 (1-6) vs 3 (1-10), p=0.052). The Uu+ve group then deteriorated, needing increased ventilatory support (day 10: MAP 7 (5-14) vs 5 (0-12), p=0.002; FiO2 39 (25-66) vs 25 (21-72), p=0.001). Changes of RDS were less widespread on day 1 X-rays in the Uu +ve group (median score 1 (0-2) vs 3 (0-4), p=0.038). By day 5 the Uu+ve group had more emphysema and this increased further by day 10 (score 1 (0-3) vs 0 (0-1) p=0.009).
Conclusion: Ventilated preterm infants infected with Uu have a specific clinical and radiological course in the first 10 days. Their initial respiratory disease is less severe but they then deteriorate with increasing ventilatory requirements and more emphysematous change on X-ray. They have significantly higher white cell counts suggesting ongoing inflammation.
References
Lyon A. Eur J Pediatr 2000; 159: 798-802