Synthetic surfactant replacement therapy decreases estimated pulmonary artery pressure in respiratory distress syndrome
P. Kaapa, P. Kero and M. Saraste
Department of Pediatrics, University of Turku, Finland.
OBJECTIVE--To evaluate the effects of surfactant replacement therapy on the
pulmonary artery pressure in infants with respiratory distress syndrome.
DESIGN--Nonrandomized, "before-after" trial. SETTING--Neonatal intensive
care unit at a referral center. PARTICIPANTS--Ten preterm infants with
respiratory distress syndrome. INTERVENTIONS--Administration of two or four
doses of an exogenous synthetic surfactant at 12-hour intervals.
MEASUREMENTS AND RESULTS--Systolic pulmonary artery pressure was estimated
by measuring tricuspid regurgitant flow velocity with the Doppler method
before and, on average, 45 minutes after administration of synthetic
surfactant. Measurable recordings were technically obtainable on 18 of 23
occasions. Surfactant instillation decreased pulmonary artery pressure
significantly on 17 of 18 occasions, but did not change the systemic blood
pressure. Twelve hours after surfactant treatment, pulmonary artery
pressure measured on nine occasions returned to the pretreatment level. No
change in the velocity or magnitude of the ductal left-to-right shunting
due to exogenous surfactant was found. CONCLUSIONS--Synthetic surfactant
replacement therapy in infants with respiratory distress syndrome induces a
significant, but transient decrease in systolic pulmonary artery pressure
with no effect on the ductal shunt.
