Surfactant content in children with inflammatory lung disease.
OBJECTIVE
To determine surfactant profiles of tracheal secretions in mechanically ventilated children with respiratory failure secondary to bacterial pneumonia, viral pneumonitis, adult respiratory distress syndrome (ARDS), and cardiopulmonary bypass.


METHODS
Prospective, cohort study.


METHODS
Tertiary, multidisciplinary, pediatric intensive care unit.


METHODS
One hundred twenty pediatric patients with respiratory failure requiring mechanical ventilation.


METHODS
Routine tracheal aspirates were collected from children with bacterial pneumonia, viral pneumonitis, ARDS, postcardiopulmonary bypass, and a postsurgical control group. Samples were obtained on days 1, 2, 3, after every week of intubation and on the day of extubation.


RESULTS
The tracheal aspirates were analyzed by high-performance liquid chromatography for lecithin/sphingomyelin rations and by enzyme-linked immunosorbent assay for surfactant proteins A and B. Lung compliance and the oxygenation index were measured on each day of sample collection. On day 1, patients with bacterial pneumonia, viral pneumonitis, and ARDS had decreased lecithin/sphingomyelin ration (p < .001), and those patients with bacterial pneumonia and viral pneumonitis had decreased surfactant protein A/protein concentration (p < .001). The lecithin/sphingomyelin ratios and surfactant protein A/protein concentration were significantly different among the groups (p < .001), with the bacterial pneumonia and viral pneumonitis groups having higher lecithin/sphingomyelin ratios and increased surfactant protein concentrations before extubation. Pulmonary compliance was lower and the oxygenation index was higher than controls (p < .001) in patients with bacterial pneumonia, viral pneumonitis, and ARDS. Pulmonary compliance was correlated weakly with lecithin/sphingomyelin ratio (r2 = .11, p < .001) and surfactant protein A/protein concentration (r2 = .03, p < .05). Surfactant protein B was similar in the diagnostic groups. Surfactant content in tracheal secretions from cardiopulmonary bypass patients was equivalent to controls.


CONCLUSIONS
Abnormal tracheal aspirate surfactant phospholipids and surfactant protein A were noted in children with bacterial pneumonia, viral pneumonitis, and ARDS, but not in children on cardiopulmonary bypass.
LeVine
A M
AM
Section of Critical Care Medicine, Children's National Medical Center, Washington, DC, USA.
Lotze
A
A
Stanley
S
S
Stroud
C
C
O'Donnell
R
R
Whitsett
J
J
Pollack
M M
MM
D002315:Cardiopulmonary Bypass; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015278:Intensive Care Units, Pediatric; D008170:Lung Compliance; D008297:Male; D018410:Pneumonia, Bacterial / Q000150:complications; D011024:Pneumonia, Viral / Q000150:complications; D011446:Prospective Studies; D011663:Pulmonary Surfactants / Q000032:analysis*; D012121:Respiration, Artificial; D012128:Respiratory Distress Syndrome / Q000150:complications; D012131:Respiratory Insufficiency / Q000209:etiology / Q000473:pathology* / Q000628:therapy; D014132:Trachea / Q000737:chemistry*
D011663:Pulmonary Surfactants