Disparity between tidal and static volumes of immature lungs
treated with reconstituted surfactants.
Kobayashi, Tsutomu, Wen-Zhi Li, Katsumi Tashiro, Reiko Takahashi, Yuko
Waseda, Ken Yamamoto, and Yasuhiro Suzuki.
Department of Anesthesiology and Intensive Care Medicine, School of
Medicine, Kanazawa University, Kanazawa 920; and Department of
Molecular Pathology, Chest Disease Research Institute, Kyoto
University, Kyoto 606, Japan
APStracts 2:0394A, 1995.
We biologically assessed functions of several reconstituted
surfactants with the same minimum surface tension (2-3 mN/m) as
"complete" porcine pulmonary surfactant (natural surfactant),
but longer surface adsorption times. Administration of natural
surfactant (adsorption time, 0.29 s) into the lungs of surfactant
-deficient immature rabbits brought a tidal volume of 16.1 +/- 4.4
(SD) ml/kg during mechanical ventilation with 40 breaths/min and 20
cmH2O insufflation pressure. In static pressure-volume recordings,
these animals showed a lung volume of 62.4 +/- 9.7 ml/kg at 30 cmH2O
airway pressure, and maintained 55% of this volume when the pressure
decreased to 5 cmH2O. With two reconstituted surfactants consisting
of synthetic lipids or isolated lipids from porcine lungs plus
surfactant-associated hydrophobic proteins (adsorption times, 0.57
and 0.78 s, respectively), tidal volumes were <38% of that with
natural surfactant (P < 0.05), but static pressure-volume
recordings were not different. Care is therefore needed in estimating
the in-vivo function of surfactant preparations from minimum surface
tension or static pressure-volume measurements.
Received 6 September 1994; accepted in final form 30 August 1995.
APS Manuscript Number A926-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 September 1995.