All issues > Volume 38(5); 1995

Original Article

J Korean Pediatr Soc. 1995;38(5):591-601. Published online May 15, 1995.

Comparison of Oxygenation and Lung Damage of High Frequency Flow Interruption to Conventional Ventilation in Surfactant Deficient Rabbits

Chang Keun CK Kim¹, Churl Young CY Chung¹, Hye Jae HJ Cho²

¹Department of Pediatrics, College of Medicine, Inje University, Paik Hospital, Sanggye, Seoul, Korea
²Department of Pathology, College of Medicine, Inje University, Paik Hospital, Sanggye, Seoul, Korea

Abstract

Purpose
: This study was performed kto evaluate the High frequency flow interruption(HFF I) can prevent the lung injury and achieve a bettre oxygenation than conventional ventilation(C V) in surfactant deficient lungs when associated with lung volume recruitment and maintenance, and the need of background intermittent mandatory ventilation(IMV) to prevent the progressive atelectasis during HFFI.
Methods
: Surfactant deficiency was produced in 18 anesthetized adult white rabbits by rep-eated saline lavage of the lungs. Following lavage 8(CV and Control group) were treated with C V and 10(HFV group) were treated with HFFI with same mean airway pressure for 15 minutes and then arterial blood gas was determined. Thereafter a sustained inflation(SI) at 24-29cmH20 for 15-20 seconds was performed to all, and then among 8 rabbits treated with CV, 2(control gr-oup) were killed and 6(CV group) were treated with CV for 4 hours, and among HFV group, 5 (HFFI group) were treated with HFFI but other 5(HFFI-IMV group) were threated with HFFI with 4 breaths per minute of backgroud IMV for 4 hours. After completion of experiment, all were kil-led and pathologic findings were assessed. Fi02 was 1.0 during the entire experimental period.
Results
: 1) Before SI, there was no difference in oxygenation between CMV and HFV groups. 2) None of CV group but all of HFV group responded(post-SI improvement in oxygenation (>30 mmHg) to SI). 3) During the 4 hours of experiment after SI, oxygenation of HFV group was significntly bet-ter than that of CMV group(p<0.05), but there was no difference between HFFI group and HFF I-IMV groups. 4) During the experiment, 2 of CMV group died form pulmonary hemorrhage or pneumotho- rax, but all of HFV group survived Pnemothorax was developed in 2 of CMV group and 1 in ea-ch HFFI and HFFI-IMV groups. 5) Pathologically, severe hyaline membrane formation(HMF) was noted in all of CV group, b ut slight or no HMF in all of HFV group. There was no difference in HMF between HFFI and HF FI-IMV groups.
Conclusion
: Like high frequency oscillatory ventilation and high frequency jet ventilation, HFFI can prevent lung injury and achieve a better oxygenation than CMV in sufactant deficient lung when assiciated with lung volume recruitment and maintenance, and the backgroud IMV d uring HFFI may not necessary to prevent the progressive atelectasis.

Keywords :High frquency flow interruption, Surfactant deficiency, Conventional ventilation, B-arotrauma, Hyaline membrane formation, White rabbit