Related Experiment Videos
Phospholipids in tracheal effluent from infants with severe respiratory distress syndrome
Insights
Infants with Respiratory Distress Syndrome (RDS) have normal surfactant lecithin levels. The presence of phosphatidylglycerol (PG) in tracheal effluent does not determine the absence of RDS.
Area of Science:
- Neonatal physiology
- Pulmonary surfactant biochemistry
Background:
- Respiratory Distress Syndrome (RDS) in infants is linked to abnormal alveolar surface tension.
- Pulmonary surfactant, particularly its phospholipid components, plays a critical role in lung function.
Purpose of the Study:
- To investigate the physiologic basis of abnormal alveolar surface tension in infants with RDS.
- To analyze surfactant-related phospholipids in tracheal effluent of infants with and without RDS.
Main Methods:
- Measurement of relative quantities of surfactant-related phospholipids in tracheal effluent.
- Preliminary study in premature lambs to validate tracheal effluent as a sample source.
- Comparison of phospholipid profiles (DSPC and PG) between RDS and non-RDS infants.
Main Results:
- The percentage of disaturated phosphatidylcholine (DSPC) in tracheal effluent was similar in RDS and non-RDS infants and remained constant.
- Phosphatidylglycerol (PG) was absent in RDS infants' effluent during the first two days but appeared later.
- PG was present in only a subset of non-RDS infants on the first day.
Conclusions:
- Surfactant from infants with RDS appears qualitatively normal regarding surface-active lecithin (DSPC) content.
- The absence of RDS is not solely dependent on the presence of phosphatidylglycerol (PG).
Abstract:
The physiologic aberration that causes abnormal alveolar surface tension in the lungs of infants with RDS was investigated by measuring relative quantities of surfactant-related phospholipids in tracheal effluent from infants with RDS. A preliminary study in premature lambs demonstrated that the percent DSPC (molar ratio of DSPC to total phospholipid) is similar in tracheal effluent and lung lavagate. The percent DSPC in tracheal effluent from human infants with RDS was similar to the percent DSPC in effluent from non-RDS infants on the first day of life (47.4% +/- 2.9 vs 46.7% +/- 1.2), and remained constant during the first 8 days of life. Phosphatidylglycerol (PG) was universally absent in effluent from RDS infants on the first and second day of life but appeared by the eighth day of life in all infants who remained intubated. PG was present in tracheal effluent from only 10 of 16 non-RDS infants on the first day of life. These findings suggest that, in regard to the surface-active lecithin content, surfactant from RDS infants is qualitatively normal and that the absence of RDS is not dependent on the presence of PG.