[Influence of surfactants on hemodynamics during neonatal respiratory distress syndrome]

The neonatal respiratory distress syndrome tends to delay the circulatory adaptation to extra-uterine life and leads to systematic hypotension. Haemodynamic changes following the instillation of surfactant are not stereotyped. They depend on the type of surfactant, the time of the instillation, the degree of prematurity, the severity of the respiratory disease and the mode of instillation. They are characterized by a transient haemodynamic instability with variable consequences on arterial pressure and systemic blood flow. The use of surfactant tends to decrease pulmonary arterial resistances and pulmonary arterial pressures but this effect is variable and is not obviously accompanied by long-term deleterious effect on the arterial duct. Haemodynamics and blood gases changes due to surfactant instillation have a variable effect on cerebral blood flow. The potential role of blood gas and haemodynamics changes on the occurrence of pulmonary haemorrhage or cerebral damage following instillation of surfactant remains poorly established but has to be taken into account.