PDF(Pubmed)
Abstract：
Current guidelines suggest a target of partial pressure of carbon dioxide (PaCO2) of 32-35 mmHg (mild hypocapnia) as tier 2 for the management of intracranial hypertension. However, the effects of mild hyperventilation on cerebrovascular dynamics are not completely elucidated. The aim of this study is to evaluate the changes of intracranial pressure (ICP), cerebral autoregulation (measured through pressure reactivity index, PRx), and regional cerebral oxygenation (rSO2) parameters before and after induction of mild hyperventilation. Single center, observational study including patients with acute brain injury (ABI) admitted to the intensive care unit undergoing multimodal neuromonitoring and requiring titration of PaCO2 values to mild hypocapnia as tier 2 for the management of intracranial hypertension. Twenty-five patients were included in this study (40% female), median age 64.7 years (Interquartile Range, IQR = 45.9-73.2). Median Glasgow Coma Scale was 6 (IQR = 3-11). After mild hyperventilation, PaCO2 values decreased (from 42 (39-44) to 34 (32-34) mmHg, p < 0.0001), ICP and PRx significantly decreased (from 25.4 (24.1-26.4) to 17.5 (16-21.2) mmHg, p < 0.0001, and from 0.32 (0.1-0.52) to 0.12 (-0.03-0.23), p < 0.0001). rSO2 was statistically but not clinically significantly reduced (from 60% (56-64) to 59% (54-61), p < 0.0001), but the arterial component of rSO2 (ΔO2Hbi, changes in concentration of oxygenated hemoglobin of the total rSO2) decreased from 3.83 (3-6.2) μM.cm to 1.6 (0.5-3.1) μM.cm, p = 0.0001. Mild hyperventilation can reduce ICP and improve cerebral autoregulation, with minimal clinical effects on cerebral oxygenation. However, the arterial component of rSO2 was importantly reduced. Multimodal neuromonitoring is essential when titrating PaCO2 values for ICP management.
摘要：
当前的指南建议将二氧化碳分压（PaCO2）的目标定为32-35mmHg（轻度低碳酸血症），作为颅内高压治疗的第2级。然而,轻度过度通气对脑血管动力学的影响尚未完全阐明。这项研究的目的是评估颅内压（ICP）的变化，大脑自动调节(通过压力反应指数测量，PRx),和轻度过度通气诱导前后的局部脑氧合（rSO2）参数。单中心,观察性研究包括急性脑损伤(ABI)患者入住重症监护病房接受多模式神经监测,需要将PaCO2值滴定至轻度低碳酸血症作为颅内高压治疗的第2级.这项研究包括25名患者（40％为女性），平均年龄64.7岁(四分位数范围，IQR=45.9-73.2)。格拉斯哥昏迷评分中位数为6（IQR=3-11）。轻度换气过度后,PaCO2值下降（从42（39-44）下降到34（32-34）mmHg，p<0.0001),ICP和PRx显着下降（从25.4（24.1-26.4）降至17.5（16-21.2）mmHg，p<0.0001，从0.32（0.1-0.52）到0.12（-0.03-0.23），p<0.0001)。rSO2在统计学上但在临床上没有显着降低（从60％（56-64）降低到59％（54-61），p<0.0001),但是rSO2的动脉成分(ΔO2Hbi，总rSO2中氧合血红蛋白浓度的变化）从3.83（3-6.2）μM降低。厘米至1.6（0.5-3.1）μM。cm,p=0.0001。轻度过度换气可以降低ICP并改善脑自动调节，对脑氧合的临床影响最小。然而,rSO2的动脉成分显著减少。在为ICP管理滴定PaCO2值时，多模式神经监测是必不可少的。
