Department of Anesthesiology, Marie Lannelongue Hospital, Paris Saint Joseph Hospital, Le Plessis Robinson, France; Cardiothoracic Intensive Care Unit, Marie Lannelongue Hospital, Paris Saint Joseph Hospital, Le Plessis Robinson, France.
Department of Vascular and Thoracic Surgery, Marie Lannelongue Hospital, Paris Saint Joseph Hospital, Le Plessis Robinson, France.
J Cardiothorac Vasc Anesth. 2024 Dec;38(12):2990-2996. doi: 10.1053/j.jvca.2024.09.013. Epub 2024 Sep 19.
The aim of this physiological pilot study was to investigate the effect of deep hypothermia on oxygen extraction (OE) and consumption (VO) in normothermic conditions (36-37°C), and at different stages of cooling: 30°C, 25°C, and 18°C.
For 3 months, a prospective study was conducted on patients who underwent pulmonary thromboendarterectomy.
This was a single-center study done in a university teaching hospital.
Patients who underwent pulmonary thromboendarterectomy during the inclusion period.
Hemodynamic and biological data were recorded from arterial and venous blood gas samples withdrawn first at normothermia, then at 30°C, 25°C, and 18°C.
24 patients were included in the final analysis. Indexed VO decreased from 65.9 mL to 25.1 mL of O/min/m between 36°C and 18°C (p < 0.001). The OE decreased from 18% to 9% between 36°C and 18°C (p < 0.001). At normal temperature and 18°C, the median venoarterial difference of O bound to hemoglobin was 2.22 [1.68-2.58] and 0.03 mL [0.01-0.07] of O/100 mL of blood, respectively (p < 0.001). Whereas the median venoarterial differences in dissolved O were 0.78 [0.66-0.92] and 1.09 mL [1.03-1.32] of O/100 mL of blood, respectively (p = 0.0013).
There were VO and OE decreases of more than half their baseline values at 18°C. Given that metabolic needs are essentially supplied by dissolved O during cooling from 30°C to 18°C, the authors suggest that PaO should be increased during the period of cooling and/or deep hypothermia to prevent hypoxia.
本生理初步研究旨在探讨深低温对正常体温（36-37°C）以及冷却不同阶段（30°C、25°C 和 18°C）时氧摄取量（O2E）和耗氧量（VO2）的影响。
在 3 个月期间，对接受肺动脉血栓内膜切除术的患者进行了前瞻性研究。
这是一项在大学教学医院进行的单中心研究。
在纳入期间接受肺动脉血栓内膜切除术的患者。
从动脉和静脉血气样本中记录血流动力学和生物学数据，首先在正常体温下采集，然后在 30°C、25°C 和 18°C 下采集。
最终有 24 名患者纳入了最终分析。从 36°C 到 18°C，指数 VO2 从 65.9 毫升降至 25.1 毫升/分钟/米（p < 0.001）。O2E 从 18%降至 9%（p < 0.001）。在正常体温和 18°C 时，与血红蛋白结合的 O2 的静脉动脉差值中位数分别为 2.22 [1.68-2.58]和 0.03 毫升 [0.01-0.07]的 O2/100 毫升血液（p < 0.001）。而溶解 O2 的静脉动脉差值中位数分别为 0.78 [0.66-0.92]和 1.09 毫升 [1.03-1.32]的 O2/100 毫升血液（p = 0.0013）。
在 18°C 时，VO2 和 O2E 下降超过其基线值的一半。鉴于从 30°C 冷却到 18°C 期间代谢需求主要由溶解的 O2 提供，作者建议在冷却和/或深低温期间增加 PaO2，以防止缺氧。
