Am. J. Respir. Crit. Care Med.,
Volume 161, Number 2, February 2000, 581-588
Prevention of Rabbit Acute Lung Injury by Surfactant,
Inhaled Nitric Oxide, and Pressure Support Ventilation
ZHAO-HUI
ZHOU,
BO
SUN,
KE
LIN,
and
LIE-WEI
ZHU
Children's Hospital Research Institute, Shanghai Medical University; Shanghai Shen-Ning Institute of Applied Biochemistry,
Shanghai, Peoples Republic of China
Improvement of pulmonary perfusion and blood oxygenation and prevention of acute lung injury
(ALI) may rely on ventilation strategy. We hypothesized that application of a combined surfactant, inhaled nitric oxide (iNO), and pressure support ventilation (PSV) should more effectively protect the
lungs from injury. Anesthetized and intubated adult rabbits weighing 2.8 ± 0.3 kg were allowed to
breathe room air while receiving oleic acid intravenously (60 µl/kg). Within 90 min this caused a reduction of PaO2 from 94 ± 7 to 48 ± 3 mm Hg and dynamic lung compliance (Cdyn) from 1.59 ± 0.22 to 0.85 ± 0.10 ml/cm H2O/kg (both p < 0.01), and increase of intrapulmonary shunting (
S/ T)
from 9.4 ± 1.2 to 27 ± 5% (p < 0.05). PSV was subsequently applied with 3 cm H2O of continuous positive airway pressure and FIO2 of 0.3, and the animals were randomly allocated to four groups, receiving: (1) PSV only (Control, n = 10); (2) iNO at 20 ppm (NO, n = 9); (3) surfactant phospholipids at 100 mg/kg (Surf, n = 8); and (4) surfactant at 100 mg/kg and iNO at 20 ppm (SNO, n = 8). PSV
level was varied to maintain a tidal volume of 8 to 10 ml/kg for another 12 h or until early animal
death. Five animals in the SNO, three each in the NO and Surf group, and one in the Control group
survived 12 h (SNO versus Control, p < 0.05). The NO, Surf, and SNO groups had significantly improved mean PaO2 (> 70 mm Hg, p < 0.05), and reduced S/ T (15, 19, and 17%, respectively, p < 0.05) at 6 and 12 h, but not in the Control group. The SNO group had the highest values of Cdyn at
12 h, alveolar aeration and disaturated phosphatidylcholine-to-total protein ratio in bronchoalveolar
lavage fluid, and the lowest wet-to-dry lung weight ratio and lung injury score (p < 0.05). The results
indicate that early alleviation of ALI by surfactant, iNO, and PSV is due to synergistic effects, and only
PSV in this model had limited effects. Zhou Z-H, Sun B, Lin K, Zhu L-W. Prevention of rabbit
acute lung injury by surfactant, inhaled nitric oxide, and pressure support ventilation.
