Inhaled Nitric Oxide with Helium Enhances its Vasodilatory Effects on Pulmonary Vessels

Research Project

Project/Area Number	09470285
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Research Field	Thoracic surgery
Research Institution	Kitasato University
Principal Investigator	YOSHIMURA Hirokuni Kitasato Univ. School of Medicine, Professor, 医学部, 教授 (40050554)
Co-Investigator(Kenkyū-buntansha)	SHINADA Jun Kitasato Univ., School of Medicine, Assistant Professor, 医学部, 講師 (00170879) KOBAYASHI Hirosuke Kitasato Univ., School of Medicine, Assistant Professor, 医学部, 講師 (70153632) NIE Masaki Kitasato Univ., School of Medicine, Research Associate, 医学部, 助手 (60228137) GOTO Takeshi Kitasato Univ., School of Medicine, Research Associate, 医学部, 助手 (50296480) HIROSE Minoru Kitasato Univ., School of Health Sciences, Assistant Professor, 医療衛生学部, 講師 (50286382) 高橋愛典 (たか橋愛典) 北里大学, 医学部, 助手 (20265672) 三藤久北里大学, 医学部, 助手 (40260856)
Project Period (FY)	1997 – 1999
Project Status	Completed (Fiscal Year 1999)
Budget Amount *help	¥13,200,000 (Direct Cost: ¥13,200,000) Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000) Fiscal Year 1998: ¥3,400,000 (Direct Cost: ¥3,400,000) Fiscal Year 1997: ¥9,200,000 (Direct Cost: ¥9,200,000)
Keywords	backward wave / NO inhalation / NO in helium / diffusion / pulmonary hypertension / impedance / wave intensity / multisensor catheter / NO in Helium / No.He inhalation / multisensor catheter. / 圧脈波反射波 / 圧反射波 / ヘリウム吸入 / NO吸入 / Wave intensity / nuttisensor catheter
Research Abstract	There are theoretical and experimental indications that the presence of Helium as a balance gas markedly increase the diffusion velocity of other gases contained in a gas mixture. The aim of this study was to establish the system of inhaled NO in He for pulmonary hypertension. Wave intensity (dP x dU) is a hemodynamic index derived by analysis of wave characteristics, I.e., forward compression, backward compression, forward expansion, and backward expansion waves. In 1997 we organized the real time expression Wave Intensity system. We allowed dogs with pulmonary vasoconstriction induced by hypoxia to inhale a mixture of NO and OィイD22ィエD2 balanced with He (NO in He) instead of NィイD22ィエD2 (NO in NィイD22ィエD2). The dilating effect of NO in He and NO in NィイD22ィエD2 on the pulmonary artery was evaluated by determining conventional pulmonary hemodynamic parameters (mean pulmonary artery pressure [MPAP] and total pulmonary resistance indexed to body surface area [TPRI]), pulmonary impedance (Z), and the recently developed hemodynamic index, time-corrected wave intensity (WI). The main findings of this study were as follows. 1) Hypoxia increased MPAP, TPRI, ZィイD20ィエD2, ZィイD2cィエD2, Γ, and the first peak of WI, and decreased CI. 2) NO inhalation in NィイD22ィエD2 reduced ZィイD20ィエD2 and Γ. 3) NO inhalation in He reduced MPAP and the first peak of WI significantly, and further decreased ZィイD20ィエD2 and Γ. In conclusion, NO inhalation balanced with He is a potential tool for enhancing the vasodilator effect of NO on pulmonary vessels or for reducing the NO concentration while maintaining adequate pulmonary vasodilation.