Surfactant replacement therapy improves ventilation inhomogeneity in infants with respiratory distress syndrome

• Published in: Pediatric pulmonology Vol. 24; no. 5; pp. 337 - 343
• Main Authors: Sandberg, Kenneth L., Lindstrom, Daniel P., Sjöqvist, Bengt Arne, Parker, Robert A., Cotton, Robert B.
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01-11-1997; Wiley-Liss
• Subjects: Analysis of Variance; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Biological Products; Breath Tests; Double-Blind Method; Drug Combinations; Emergency and intensive care: neonates and children. Prematurity. Sudden death; Fatty Alcohols - therapeutic use; Humans; hyaline membrane disease; infant pulmonary function; Infant, Newborn; Intensive care medicine; Linear Models; lung volumes; Medical sciences; Nitrogen - analysis; Phosphorylcholine; Polyethylene Glycols - therapeutic use; Positive-Pressure Respiration; premature infants; Pulmonary Gas Exchange - drug effects; pulmonary surfactants; Pulmonary Surfactants - therapeutic use; Pulmonary Ventilation - drug effects; Respiratory Distress Syndrome, Newborn - drug therapy; Respiratory Distress Syndrome, Newborn - physiopathology; ventilation inhomogeneity; Human; Premature; Lung disease; Exogenous; Respiratory disease; Treatment efficiency; Functional residual capacity; Heterogeneity; Newborn diseases; Chemotherapy; Newborn; Treatment; Prematurity; Pulmonary surfactant; Respiratory distress; Ventilation; Hyaline membrane disease
• ISSN: 8755-6863; 1099-0496
• DOI: 10.1002/(SICI)1099-0496(199711)24:5<337::AID-PPUL6>3.0.CO;2-F

Surfactant deficiency in newborn infants with hyaline membrane disease (HMD) reduces peripheral airway stability, leading to lung atelectasis, inhomogeneity of distribution of ventilation, ventilation/perfusion mismatch, and hypoxemia. The aim of this study was to evaluate the immediate effect of exogenous surfactant treatment on ventilation inhomogeneity (VIH) in infants with HMD. Homogeneity of ventilation was measured repeatedly in ten infants (median gestational age 30 weeks and birthweight 1.50 kg) after Exosurf®, and in six infants (median gestational age 30 weeks and birthweight 1.42 kg) after Survanta® treatment. Lung function was measured before and 0.5, 2, and 6 hours after administration of a single dose of surfactant. The multiple breath nitrogen washout method was used to measure the time pattern of nitrogen elimination from the lungs. VIH was evaluated by using both a compartmental lung model and a model‐independent moment analysis.
The two‐compartment lung model was found to dominate before surfactant treatment, while a single‐compartment model (implying homogeneous ventilation) fitted the washout data best 6 hours after Exosurf® treatment (P < 0.01). The same pattern occurred 2 hours after Survanta® administration. Moment analysis confirmed the reduction in VIH by both surfactants. This study supports the hypothesis that the improved oxygenation after surfactant treatment in infants with HMD results from a reduction in VIH and an increase in functional residual capacity (FRC). Pediatr. Pulmonol. 1997; 24:337–343. © 1997 Wiley‐Liss, Inc.