This study addresses concerns regarding the variability in alveolar deposition of surfactant between two minimally invasive administration techniques: Less Invasive Surfactant Administration (LISA) and Intubate-Surfactant-Extubate (INSURE). Ultrasound evaluation of diaphragm kinetics was used as an indirect measure of respiratory system compliance, providing insights into the effects of these methods. This prospective observational pilot study included 52 infants, each born at ≤32 weeks gestational age, who required CPAP support and were diagnosed with respiratory distress syndrome (RDS). Infants were randomly assigned to receive surfactant via either LISA or INSURE, and the right diaphragm’s global mean peak velocity (MPV) was measured with Pulsed-Wave Tissue Doppler Imaging (PTDI) both before and two hours after surfactant administration. Simultaneous assessments of oxygen saturation/fraction of inspired oxygen (SF ratio) were also recorded.
Results indicated that infants receiving LISA had a significantly higher gestational age, birth weight, and lower CRIB-II scores than those in the INSURE group. Baseline measurements showed higher median MPV for the LISA group, but after surfactant administration, no significant differences in MPV or other variables were found once adjusted for gestational age and sedation. Treatment failure, defined as the need for mechanical ventilation within 72 hours of birth, occurred in 15% (8/52) of infants. Those who required mechanical ventilation had a significantly lower SF ratio and higher MPV following surfactant administration, despite receiving higher CPAP support. Additionally, a full course of antenatal steroids was shown to be protective against mechanical ventilation. The study concluded that the LISA and INSURE methods do not appear to differentially impact diaphragm kinetics as evaluated by RD-PTDI ultrasound.
