Dosing of porcine surfactant: effect on kinetics and gas exchange in respiratory distress syndrome.
OBJECTIVE
The goal was to study exogenous surfactant disaturated phosphatidylcholine (DSPC) kinetics in preterm infants with respiratory distress syndrome (RDS) who were treated with 100 or 200 mg/kg porcine surfactant.


METHODS
Sixty-one preterm infants with RDS undergoing mechanical ventilation received, within 24 hours after birth, 100 mg/kg (N = 40) or 200 mg/kg (N = 21) porcine surfactant mixed with [U-(13)C]dipalmitoylphosphatidylcholine. Clinical and respiratory parameters were recorded, and DSPC half-life and pool size and endogenous DSPC synthesis rate were calculated.


RESULTS
Clinical characteristics and short-term outcomes did not differ between groups. In the 100 mg/kg group, 28 infants (70%) received a second dose after 25 +/- 11 hours and 9 (22.5%) a third dose after 41 +/- 11 hours; in the 200 mg/kg group, 6 infants (28.6%) received a second dose after 33 +/- 8 hours and 1 a third dose. The DSPC half-life was longer in the 200 mg/kg group (first dose: 32 +/- 19 vs 15 +/- 15 hours [P = .002]; second dose: 43 +/- 32 vs 21 +/- 13 hours [P = .025]). DSPC synthesis rates and pool sizes before the first and second doses did not differ between the groups. The 200 mg/kg group exhibited a greater reduction in the oxygenation index than did the 100 mg/kg group after the first (P = .009) and second (P = .018) doses.


CONCLUSIONS
Porcine surfactant given to preterm infants with RDS at a dose of 200 mg/kg resulted in a longer DSPC half-life, fewer retreatments, and better oxygenation index values.
Cogo
Paola Elisa
PE
Departments of Pediatrics, University of Padua, Padua, Italy. cogo@pediatria.unipd.it
Facco
Maddalena
M
Simonato
Manuela
M
Verlato
Giovanna
G
Rondina
Clementina
C
Baritussio
Aldo
A
Toffolo
Gianna Maria
GM
Carnielli
Virgilio Paolo
VP
D001688:Biological Products / Q000008:administration & dosage* / Q000493:pharmacokinetics; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000188:drug therapy* / Q000503:physiopathology; D010713:Phosphatidylcholines / Q000493:pharmacokinetics; D010743:Phospholipids / Q000008:administration & dosage* / Q000493:pharmacokinetics; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D011663:Pulmonary Surfactants / Q000008:administration & dosage* / Q000493:pharmacokinetics; D012121:Respiration, Artificial; D012127:Respiratory Distress Syndrome, Newborn / Q000188:drug therapy* / Q000503:physiopathology; D014132:Trachea / Q000378:metabolism
D001688:Biological Products; D010713:Phosphatidylcholines; D010743:Phospholipids; D011663:Pulmonary Surfactants; C017463:lecithins, disaturated; C068291:poractant alfa