Functional residual capacity and compliance of the respiratory system after surfactant treatment in premature infants with severe respiratory distress syndrome.
To understand the mechanisms behind improved oxygenation after intratracheal surfactant instillation, the immediate and late effects on lung volume and compliance of the respiratory system (CRS) were analysed. Infants received modified porcine surfactant (Curosurf) or modified bovine surfactant (Alveofact). Measurements of functional residual capacity (FRC) and CRS were successfully performed in 90 ventilated preterm infants (birth weight 1264 +/- 435 g; gestational age 28.2 +/- 2.5 weeks) with severe respiratory distress syndrome. FRC and CRS were measured during mechanical ventilation prior to and 1, 3, 6, 24, 48, 72, 96, 120 and 168 h after surfactant replacement. Oxygenation rapidly improved. FRC increased significantly from 7.64 +/- 1.58 ml/kg to 15.35 +/- 3.27 ml/kg (P < 0.01) at 1 h after surfactant instillation. CRS remained virtually unchanged during the first hours after surfactant replacement and a concomitant decrease in specific compliance was seen.


CONCLUSIONS
the changes in lung function following surfactant treatment can only be explained by initial stabilisation of already aerated alveoli followed by recruitment of new gas exchange units as mechanisms involved in mediating the effect of surfactant on gas exchange. However, since no significant correlation between changes in functional residual capacity and improvement in arterial-to-alveolar oxygen tension ratio was seen, other effects of surfactant must be considered. These include local and/or systemic changes in haemodynamics.
Klinik für Kinderheilkunde, Medizinische Fakultät, Technische Universität Dresden, Fetscherstrasse 74, 01307 Dresden, Germany. Dinger@ukd80.med.tu-dresden.de
Jürgen
J
Dinger
Andreas
A
Töpfer
Peter
P
Schaller
Roland
R
Schwarze
D005260:Female; D005652:Functional Residual Capacity / Q000187:drug effects; D006439:Hemodynamics; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008168:Lung / Q000187:drug effects* / Q000502:physiology; D008170:Lung Compliance / Q000187:drug effects; D008297:Male; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D011663:Pulmonary Surfactants / Q000008:administration & dosage / Q000627:therapeutic use*; D012127:Respiratory Distress Syndrome, Newborn / Q000188:drug therapy* / Q000503:physiopathology; D013997:Time Factors
D011663:Pulmonary Surfactants