Hanique G, Dugernier T, Laterre P F, Roeseler J, Dougnac A, Reynaert M S
Intensive Care Department, Saint-Luc University Hospital, Brussels, Belgium.
Intensive Care Med. 1994;20(1):19-26. doi: 10.1007/BF02425049.
The evaluation of oxygen consumption (VO2) and oxygen delivery (DO2) has gained increasing importance in the monitoring of critically ill patients. They can be obtained from either direct measurements or by indirect calculations based on the Fick principle. However the choice between these two approaches remains controversial. The aim of the study was to investigate whether these 2 methods provide similar results, and if not, to define the best one in terms of reproducibility.
Oxygen delivery and oxygen consumption were prospectively analyzed in 171 consecutive critically ill patients. Metabolic data were obtained simultaneously.
The study was completed in the intensive care unit as part of the management of the patients studied.
A first "group" of 279 evaluations was carried out in 73 consecutive critically ill patients. The results were subsequently validated by 423 observations performed in the 98 following patients.
Before and during each evaluation, the patients were kept in stable hemodynamic and metabolic conditions. All were mechanically ventilated.
VO2 was evaluated by calculation (Fick principle) and direct measurement using indirect calorimetry. Cardiac output was both measured by the thermodilution technique and calculated (Fick principle) and the data were used for the evaluation of the directly measured and indirectly calculated DO2. For both VO2 and DO2 the agreement between direct and indirect evaluations was not satisfactory. Differences as great as 55 ml/min.m2 and 267 ml/min.m2 between simultaneously measured and calculated VO2 and DO2 respectively may be expected. Finally, the indirect calculated methods were less reproducible than the measured ones. These observations resulted mainly from the cumulative effects of the random errors in the metabolic data entering into the calculation of VO2 and DO2.
Our data suggested that the indirect calculation (Fick equation) and the direct measurement (indirect calorimetry, thermodilution) of both VO2 and DO2 did not provide similar results. Direct measurements are more reproducible methods and must be preferred.
在重症患者监测中，对氧耗量（VO2）和氧输送量（DO2）的评估愈发重要。它们既可以通过直接测量获得，也可以基于菲克原理进行间接计算得出。然而，这两种方法之间的选择仍存在争议。本研究的目的是调查这两种方法是否能提供相似的结果，如果不能，则从可重复性角度确定最佳方法。
对171例连续的重症患者进行前瞻性的氧输送和氧耗量分析。同时获取代谢数据。
该研究在重症监护病房完成，作为所研究患者管理的一部分。
对73例连续的重症患者进行了第一组279次评估。随后对接下来98例患者进行的423次观察验证了结果。
在每次评估之前和期间，使患者保持稳定的血流动力学和代谢状态。所有患者均接受机械通气。
通过计算（菲克原理）和使用间接量热法进行直接测量来评估VO2。通过热稀释技术测量心输出量并进行计算（菲克原理），这些数据用于评估直接测量和间接计算的DO2。对于VO2和DO2，直接和间接评估之间的一致性均不令人满意。同时测量和计算的VO2和DO2之间分别可能存在高达55 ml/min·m²和267 ml/min·m²的差异。最后，间接计算方法的可重复性低于测量方法。这些观察结果主要源于代谢数据中随机误差在VO2和DO2计算中的累积效应。
我们的数据表明，VO2和DO2的间接计算（菲克方程）和直接测量（间接量热法、热稀释法）结果并不相似。直接测量是更具可重复性的方法，应优先选择。
