Concentration of nitric oxide products in bronchoalveolar fluid obtained from infants who develop chronic lung disease of prematurity

Aims-To determine if nitric oxide (NO) products (nitrate and nitrite) are i ncreased in bronchoalveolar lavage (BAL) fluid obtained from infants who de velop chronic lung disease of prematurity (CLD). Methods-One hundred and thirty six serial bronchoalveolar lavages were perf ormed on 37 ventilated infants (12 with CLD, 18 with respiratory distress s yndrome (RDS), and seven control infants) who did not receive inhaled NO. Results-During the first week of life nitrate concentration was between 25- 31 mu mol/l in all three groups. Thereafter, the concentration of BAL fluid nitrate decreased to 14 mu mol/l and 5.5 mu mol/l. respectively in the RDS and control groups by 14 days of age. In contrast, nitrate in the CLD infa nts remained constant until 28 days of age (31.3 mu mol/l at day 14; p<0.05 ). In all BAL fluid samples the mean concentration of nitrite was <1.2 mu m ol/l throughout the first 28 days with no significant differences noted amo ng the three groups. Conclusion-The similar concentration of BAL fluid nitrate in all groups dur ing the first week of life suggest that NO may be important in the adaptati on of the pulmonary circulation after birth. However, persistence of nitrat e in the BAL fluid of infants with CLD during the second week may reflect p ulmonary maladaptation, or, more likely, persisting pulmonary inflammation.