Department of General Anesthesiology, Cleveland Clinic, Cleveland, OH, USA; Department of Outcomes Research, Cleveland Clinic, Cleveland, OH, USA. Electronic address: http://www.OR.org.
Best Pract Res Clin Anaesthesiol. 2021 Dec;35(4):543-549. doi: 10.1016/j.bpa.2020.09.004. Epub 2020 Sep 28.
Oxygen delivery is dependent on pulmonary gas exchange, cardiac output, blood oxygen-carrying capacity, and tissue oxygen extraction. Reduction in oxygen delivery or higher oxygen consumption can initiate complex protective cellular processes precipitating oxygen debt. In critically ill and potentially surgical patients, stress and consequent hormonal or metabolic changes can trigger oxygen debt which is associated with worse morbidity and mortality. Increase in oxygen delivery by augmenting cardiac output or by increasing fraction of inspired oxygen (FiO) can help reduce oxygen debt. However, the extent of oxygen debt in an individual patient is poorly defined and difficult to measure. Furthermore, large heterogeneity in clinical trials assessing outcomes benefit of increasing oxygen delivery limits our ability to recommend goal directed fluid therapy aimed at increasing cardiac ouput or higher FiO. To understand and prevent oxygen debt in critically ill and surgical patients, we need to develop continuous monitoring techniques to assess the balance of oxygen delivery and consumption. Furthermore, methods of increasing oxygen delivery like goal-directed fluid therapy, higher FiO and anemia prevention should be rigorously evaluated with focus on establishing outcomes benefit.
氧输送取决于肺气体交换、心输出量、血液携氧能力和组织氧摄取。氧输送减少或氧消耗增加会引发复杂的保护性细胞过程，导致氧债。在危重病和潜在手术患者中，应激及随之而来的激素或代谢变化可引发氧债，与更高的发病率和死亡率相关。通过增加心输出量或增加吸入氧分数（FiO）来增加氧输送有助于减少氧债。然而，个体患者的氧债程度定义不明确，难以测量。此外，评估增加氧输送对结局获益的临床试验中存在很大的异质性，限制了我们推荐旨在增加心输出量或更高 FiO 的目标导向液体治疗的能力。为了理解和预防危重病和手术患者的氧债，我们需要开发连续监测技术来评估氧输送和消耗的平衡。此外，应严格评估增加氧输送的方法，如目标导向液体治疗、更高 FiO 和预防贫血，并侧重于确定结局获益。
