All issues > Volume 44(4); 2001

Original Article

J Korean Pediatr Soc. 2001;44(4):413-417. Published online April 15, 2001.

The Weaning Method of Inhaled Nitric Oxide

Hyun Woo HW Lee¹, Jae Woong JW Lee¹, Sung Yeul SY Hyun¹, Ha Chang HC Lee¹, Chul Hyun CH Park¹, Kook Yang KY Park¹, Hyeon Su HS Yoo², Kyung Cheon KC Lee³, Young Jin YJ Jang³

¹Department of Thoracic and Cardiovascular Surgery, Gachon Medical School, Inchon, Korea
²Department of Pediatrics, Gachon Medical School, Inchon, Korea
³Department of Anesthesiology, Gachon Medical School, Inchon, Korea

Correspondence Hyun Woo HW Lee ,Email: ljh@ghil.com

Abstract

Purpose
: Inhaled nitric oxide(iNO) is an excellent method for the postoperative pulmonary hypertension in congenital heart disease. But more detailed care is needed because of the development of rebound pulmonary hypertension after NO withdrawal. We performed this study in order to discontinue the iNO successfully by way of presenting the adequate weaning and supplying methods.
Methods
: Between January, 1998 and August, 1999 we studied 10 patients who had rebound pulmonary hypertension(RPH) after iNO withdrawal. We completed the iNO in these patients through the second trial of the weaning process. We tried to discover the differences between the first and second weaning process. We measured NO concentration at the start and just before NO withdrawal and during the period of weaning process. Moreover, to identify the iNO effects during the weaning of the iNO, we counted the degree of the change of PaO2/FiO2 and mean PAP/ SAP between initial and at half of the initial NO concentration.
Results
: Second weaning had a longer duration weaning process(11¡¾10 versus 5¡¾3 hours, P< 0.05), lower NO concentration just before NO withdrawal(2¡¾0.6 versus 4¡¾1ppm, P<0.05). In the change of the mean PAP/SAP and PaO2/FiO2 as iNO was weaning from the initial iNO concentration to a half of the initial iNO concentration, the degree of increase in mean PAP/SAP(0.026¡¾0.07 versus 0.054¡¾0.07, P<0.05) and the degree of decrease in PaO2/FiO2(49¡¾54 versus 65¡¾72, P<0.05) were smaller in the second weaning process than the first weaning process.
Conclusion
: A successful weaning of iNO can be performed with a low iNO concentration at the start and just before withdrawal and with the long duration iNO weaning process. Moreover, We speculate that the degree of change in the mean PAP/SAP and PaO2/FiO2 at the half of the iNO weaning process are an indicator for the development of RPH.

Keywords :Inhaled nitric oxide, Weaning, Rebound pulmonary hypertension