Cardiopulmonary bypass reduces pulmonary surfactant activity in infants.
OBJECTIVE
Infants younger than 1 year of age undergoing cardiopulmonary bypass surgery often have severe lung injury necessitating increased postoperative respiratory mechanical support. Inasmuch as the mechanisms may involve an impairment of the pulmonary surfactant system, our aim was to determine whether changes of surfactant occur in such infants.


METHODS
From the day of the operation to day 7 after the operation, serial tracheobronchial small-volume lavages of 19 infants (aged 166 +/- 29 days) were fractionated into a small and a large surfactant aggregate fraction and compared with those of 13 infants without lung disease (aged 203 +/- 33 days).


RESULTS
After cardiac operations with cardiopulmonary bypass surgery, total protein in lavages was increased 3-fold to 4-fold and decreased linearly with time. Surfactant protein A was increased on day 1 and day 2 and then decreased, whereas surfactant protein B and total phospholipids were increased on day 1. The ratio of phospholipids in small and large surfactant fractions was unchanged, but the surface activity of the large-aggregate surfactant was impaired on days 1 to 3.


CONCLUSIONS
Lung injury in infants after cardiopulmonary bypass surgery involves significant biochemical and functional disturbances of the pulmonary surfactant system. Inasmuch as substitution with natural surfactant might correct these deficiencies, the potential of this approach to reduce postoperative morbidity needs to be investigated.
Griese
M
M
Ludwig-Maximilians-University, Munich, Germany.
Wilnhammer
C
C
Jansen
S
S
Rinker
C
C
D015415:Biomarkers; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006023:Glycoproteins / Q000378:metabolism*; D006330:Heart Defects, Congenital / Q000601:surgery; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010743:Phospholipids / Q000378:metabolism; D011510:Proteolipids / Q000378:metabolism*; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000378:metabolism*; D012127:Respiratory Distress Syndrome, Newborn / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D013500:Surface Tension
D015415:Biomarkers; D006023:Glycoproteins; D010743:Phospholipids; D011510:Proteolipids; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants