Surfactant replacement therapy for meconium aspiration syndrome.
OBJECTIVE
The pathophysiology of meconium aspiration syndrome (MAS) is related not only to mechanical obstruction of the airways and chemical injury to the respiratory epithelium but also to surfactant inactivation by meconium. A randomized, controlled study was performed to determine whether high-dose surfactant therapy improves the pulmonary morbidity of term infants ventilated for MAS.


METHODS
Forty term infants receiving mechanical ventilation for MAS were enrolled in this trial, in which the infants in the study group (n = 20) received up to four doses of 150 mg (6 mL)/kg beractant (Survanta), instilled every 6 hours by continuous infusion for 20 minutes via a side hole endotracheal tube adapter, and the infants in the control group (n = 20) received 6 mL/kg air placebo.


RESULTS
Mean arterial-to-alveolar PO2 ratio values increased from 0.09 to 0.11 at 1 and 6 hours with a concomitant slight decrease in oxygenation index values from 23.7 to 19.7 at 1 hour and 20.7 at 6 hours after the first dose of surfactant. Oxygenation improved cumulatively after the second and third dose of surfactant, with mean arterial-to-alveolar PO2 ratios and oxygenation indices of 0.18 and 12.1 at 6 hours after the second dose of surfactant and 0.31 and 5.9 at 6 hours after the third dose of surfactant, eliminating the need for a fourth dose in any infant in the study group. After three doses of surfactant, persistent pulmonary hypertension had resolved in all but one of the infants in the study group versus none of the infants in the control group. No air leaks developed in any of the 20 infants in the study group after surfactant therapy, and only 1 infant required extracorporeal membrane oxygenation. Air leaks developed in 5 of the 20 infants in the control group, and 6 underwent extracorporeal membrane oxygenation. The duration of mechanical ventilation, oxygen therapy, and admission was significantly shorter in the surfactant group than in the control group.


CONCLUSIONS
Surfactant replacement therapy, if started within 6 hours after birth, improves oxygenation and reduces the incidence of air leaks, severity of pulmonary morbidity, and hospitalization time of term infants with MAS.
Findlay
R D
RD
Department of Pediatrics, Martin Luther King, Jr Hospital/Charles R. Drew University of Medicine and Science, Los Angeles, CA 90059, USA.
Taeusch
H W
HW
Walther
F J
FJ
D001688:Biological Products; D001784:Blood Gas Analysis; D015199:Extracorporeal Membrane Oxygenation; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007231:Infant, Newborn; D007902:Length of Stay; D008297:Male; D008471:Meconium Aspiration Syndrome / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D010101:Oxygen Consumption; D011663:Pulmonary Surfactants / Q000627:therapeutic use*; D012121:Respiration, Artificial; D013997:Time Factors
D001688:Biological Products; D011663:Pulmonary Surfactants; C072197:beractant