McIntosh D, Baun M M, Rogge J
College of Nursing, University of Nebraska Medical Center, Omaha 68198-5330.
Am J Crit Care. 1993 Jul;2(4):317-25.
To explore the effects of endotracheal suctioning on mixed venous oxygen tension and other measures of arterial and tissue oxygenation, to determine if these would be clinically useful outcome measures of endotracheal suctioning.
Measuring arterial oxygenation only as an outcome of endotracheal suctioning can be misleading in that it may appear adequate in the presence of marked decreases in mixed venous oxygen tension, a good indicator of the adequacy of tissue oxygenation.
Eighteen instrumented and oleic acid-injured animal models of acute respiratory failure undergoing closed-system endotracheal suctioning were studied according to a 2 x 2 factorial design to measure the effects of oxygen inflations at tidal volume or 135% of tidal volume either in the presence or absence of positive end-expiratory pressure.
Using multivariate analysis of variance for repeated measures, protocol by time effects for mixed venous oxygen tension, arterial oxygen saturation, arterial oxygen tension, oxygen delivery and oxygen extraction ratio were statistically significant. Changes in mixed venous oxygen tension and arterial oxygen saturation were parallel.
Continuous measurement of mixed venous oxygen tension allows the calculation of oxygen delivery and oxygen extraction ratio, which provide a better estimation of the effects of endotracheal suctioning on tissue oxygenation than arterial oxygen tension alone.
探讨气管内吸引对混合静脉血氧分压及其他动脉和组织氧合指标的影响，以确定这些指标是否为气管内吸引临床有用的结果指标。
仅将动脉氧合作为气管内吸引的结果进行测量可能会产生误导，因为在混合静脉血氧分压显著降低（组织氧合充足的良好指标）的情况下，动脉氧合可能看起来是充足的。
根据2×2析因设计，对18只仪器化且油酸损伤的急性呼吸衰竭动物模型进行闭系统气管内吸引研究，以测量在有或没有呼气末正压的情况下，潮气量或潮气量135%时充氧的影响。
采用重复测量的多变量方差分析，混合静脉血氧分压、动脉血氧饱和度、动脉血氧分压、氧输送和氧摄取率的方案随时间的效应具有统计学意义。混合静脉血氧分压和动脉血氧饱和度的变化是平行的。
持续测量混合静脉血氧分压可计算氧输送和氧摄取率，与单独的动脉血氧分压相比，这能更好地评估气管内吸引对组织氧合的影响。
