Bellezza M, Kerbaul F, Roussel L, Imbert M, Guidon C
Dépt d'Anesthésie-Réanimation Adulte, Groupe Hospitalier de La Timone, Marseille, France.
Eur Respir J. 2002 Oct;20(4):965-71. doi: 10.1183/09031936.02.00253402.
Hypoxic pulmonary vasoconstriction (HPV) is a regulatory mechanism by which blood is diverted from poorly ventilated to better ventilated areas of the lung. The aim of the present study was to assess the extent to which hypertonic saline dextran and dextran solutions modify the magnitude of HPV during isovolumic haemodilution in intact acutely instrumented piglets. Eighteen large white piglets were anesthetised and assigned to two groups. Mean pulmonary arterial pressure (PAP) and cardiac output (Q), systemic arterial pressure and left arterial pressure (LAP) were measured. A decrease in Q was obtained by reducing venous return. This enabled measurement of transpulmonary pressures (mean PAP minus LAP) at four levels of Q in hyperoxia (inspiratory oxygen fraction (FiO2)=0.4) then in hypoxia (Fi,O2=0.1) in the two groups before blood soustraction (10 mL x kg(-1)) and after loading with sodium chloride (NaCl) 7.5% and dextran 6% or with dextran 6% alone. Dextran alone led to a decrease in mean PAP-LAP/Q values, and NaCl with dextran was associated with a significant shift of mean PAP-LAP/Q plots to higher pressures in hypoxia. Hypertonic saline dextran solution, as replacement fluid in isovolaemic haemodilution increased the magnitude of hypoxic pulmonary vasoconstriction, whereas dextran solution reduced it.
缺氧性肺血管收缩（HPV）是一种调节机制，通过该机制血液从肺通气不良区域分流至通气较好区域。本研究的目的是评估在完整的急性插管仔猪等容性血液稀释过程中，高渗盐水右旋糖酐溶液和右旋糖酐溶液对HPV强度的改变程度。18只大白仔猪麻醉后分为两组。测量平均肺动脉压（PAP）、心输出量（Q）、体动脉压和左动脉压（LAP）。通过减少静脉回流使Q降低。这使得在两组仔猪采血（10 mL·kg⁻¹）前以及输注7.5%氯化钠（NaCl）和6%右旋糖酐或仅输注6%右旋糖酐后，能在高氧（吸入氧分数（FiO₂）=0.4）和低氧（FiO₂=0.1）状态下的四个Q水平测量跨肺压（平均PAP减去LAP）。单独使用右旋糖酐导致平均PAP-LAP/Q值降低，而NaCl与右旋糖酐联用在低氧状态下使平均PAP-LAP/Q曲线显著向更高压力偏移。高渗盐水右旋糖酐溶液作为等容性血液稀释中的替代液增加了缺氧性肺血管收缩的强度，而右旋糖酐溶液则降低了该强度。
