Federal University of Technology, Parana, Brazil.
Am J Crit Care. 2011 Sep;20(5):388-94. doi: 10.4037/ajcc2011537.
Respiratory monitoring is important after surgery to prevent pulmonary complications. End-tidal carbon dioxide (Petco(2)) measurement by capnometry is an indirect and noninvasive measurement of Pco(2) in blood and is accepted and recognized in critical care.
To determine the correlation and level of agreement between Petco(2) and Paco(2) in spontaneously breathing children after cardiac surgery and to determine whether Petco(2) measured by using tidal volume (Vt-Petco(2)) or vital capacity (VC-Petco(2)) shows more or less significant correlation with Paco(2).
Vt-Petco(2) and VC-Petco(2) by capnometry and Paco(2) by blood gas analysis were measured once a day after tracheal extubation. The determination coefficient and degree of bias between the methods were assessed in children with and without supplemental oxygen.
A total of 172 Vt-Petco(2), VC-Petco(2), and Paco(2) values from 48 children were analyzed. The overall coefficients of determination were 0.84 (P < .001) for Vt-Petco(2) and Paco(2) and 0.62 (P = .02) for VC-Petco(2) and Paco(2). The mean gradient for Paco(2) to Petco(2) in all groups increased with the increase in supplemental oxygen; the gradient was significantly larger in the groups given 2 to 5 L of oxygen per minute.
In spontaneously breathing children, Vt-Petco(2) provided a more accurate estimate of Paco(2) than did VC-Petco(2), especially in children given little or no supplemental oxygen. The difference between the methods was significantly larger in the groups given 2 to 5 L of oxygen per minute.
呼吸监测对于预防手术后肺部并发症非常重要。呼气末二氧化碳（Petco(2)）的测量是一种通过二氧化碳描记术对血液中 Pco(2)的间接、非侵入性测量方法，在重症监护中得到认可和应用。
确定心脏手术后自主呼吸的儿童 Petco(2)与 Paco(2)之间的相关性和一致性水平，并确定通过潮气量（Vt-Petco(2)）或肺活量（VC-Petco(2)）测量的 Petco(2)与 Paco(2)之间的相关性是否更高或更低。
气管拔管后每天测量一次通过二氧化碳描记术测量的 Vt-Petco(2)和 VC-Petco(2)以及血气分析测量的 Paco(2)。在有和没有补充氧气的儿童中评估方法之间的决定系数和偏差程度。
共分析了 48 名儿童的 172 个 Vt-Petco(2)、VC-Petco(2)和 Paco(2)值。对于 Vt-Petco(2)和 Paco(2)，整体决定系数为 0.84（P <.001），对于 VC-Petco(2)和 Paco(2)，决定系数为 0.62（P =.02）。所有组的 Paco(2)到 Petco(2)的平均梯度随着补充氧气的增加而增加；每分钟给予 2 至 5 升氧气的组中，梯度明显更大。
在自主呼吸的儿童中，Vt-Petco(2)比 VC-Petco(2)更能准确估计 Paco(2)，尤其是在给予少量或不给予补充氧气的儿童中。每分钟给予 2 至 5 升氧气的组中，两种方法之间的差异明显更大。
