重型颅脑外伤患者过度通气前后视神经鞘直径与颅内压的关系

Relationship between optic nerve sheath diameter and intracranial pressure after hyperventilation in patients with severe craniocerebral trauma

目的探索重型颅脑外伤(traumatic brain injury,TBI)患者过度通气前后超声测量神经鞘直径(optical nerve sheath diameter,ONSD)与颅内压(intracranial pressure,ICP)的关系。方法前瞻性收集2023年1月—2023年12月我院急诊重症监护病房住院治疗并接受有创ICP监测的74例重型TBI患者,其中男43例,女31例;平均年龄(57.09±4.03)岁。对入组患者完成4次ONSD监测[呼气末二氧化碳(end-tidal carbon dioxide,ETCO_(2))在基线水平、ETCO_(2)从基线水平调控至30 mmHg(1 mmHg=0.133 kPa)的起始及结束阶段、ETCO_(2)再次恢复至基线水平],在测量ONSD的同时记录同期ICP值,并收集同期平均动脉压、动脉血氧饱和度、pH和PaCO_(2)。记录ETCO_(2)变化前后ONSD的动态改变,采用Wilcoxon秩和检验比较ETCO_(2)变化前后ONSD的差异。采用Spearman方法评估ETCO_(2)在基线水平及30 mmHg时ONSD与ICP间的关系。结果ONSD在ETCO_(2)基线水平时中位数为5.15(4.02~6.63)mm,在ETCO_(2)为30 mmHg期间显著降低至4.73(3.67~5.91)mm(P=0.01)。ICP在ETCO_(2)基线水平时均数为(23.30±5.01)mmHg,在ETCO_(2)为30 mmHg期间显著降低至(17.22±3.14)mmHg(P=0.03)。PaCO_(2)、pH在ETCO_(2)基线水平及ETCO_(2)为30 mmHg时对比,差异有统计学意义(P<0.05)。Spearman相关分析显示,ETCO_(2)在基线水平及30 mmHg时,ONSD与有创ICP之间存在线性相关关系(基线水平:r2=0.74,95%CI:0.66~0.80,P<0.01;ETCO_(2)为30 mmHg:r2=0.70,95%CI:0.63~0.78,P<0.01)。结论重型TBI患者在过度通气下,ONSD呈下降趋势,且与同期ICP具有线性关系。提示对采取过度通气下的重型TBI患者,动态监测ONSD能够反映ICP的实时变化。

Objective To explore the relationship between optical nerve sheath diameter(ONSD)and intracranial pressure(ICP)before and after hyperventilation in patients with severe traumatic brain injury(TBI).Methods Patients with severe TBI who were hospitalized in our emergency intensive care unit and received invasive ICP monitoring from January 2023 to December 2023 were prospectively collected.A total of 74 patients with TBI were included in this study,43 males and 31 females with a mean age of(57.09±4.03)years.Four ONSDs monitoring(end-tidal carbon dioxide[ETCO_(2)]at the baseline level,at the beginning and end of ETCO_(2)modulation from the baseline level to 30 mmHg[1 mmHg=0.133 kPa],and the return of ETCO_(2)to the baseline level)were completed in the enrolled patients.ICP values for the same time period were recorded at the same time while ONSDs was measured,and mean arterial pressure,arterial oxygen saturation,pH,and PaCO_(2) were collected during the same period.The dynamic changes of ONSD before and after the changes of ETCO_(2)were recorded,and the Wilcoxon rank sum test was used to compare the differences of ONSD before and after the changes of ETCO_(2).Spearman method was used to evaluate the relationship between ONSD and ICP at baseline and 30mmHg ETCO_(2).Results The median baseline ETCO_(2)level of ONSD was 5.15(4.02-6.63)mm and reduced significantly to 4.73(3.67-5.91)mm during the period of ETCO_(2)of 30 mmHg(P=0.01).ICP at baseline of ETCO_(2)averaged(23.30±5.01)mmHg and significantly decreased to(17.22±3.14)mmHg during ETCO_(2)30 mmHg(P=0.03).The difference of PaCO_(2) and pH was statistically significant when compared at baseline level of ETCO_(2)and ETCO_(2)30 mmHg(P<0.05).Spearman correlation analysis showed a linear correlation between ONSD and invasive ICP at baseline and 30 mmHg of ETCO_(2)(baseline level:r2=0.74,95%CI:0.66-0.80,P<0.01;ETCO_(2)of 30 mmHg:r2=0.70,95%CI:0.63-0.78,P<0.01).Conclusion In patients with severe TBI under hyperventilation,ONSD showed a decreasing trend and had a linear relationship with ICP during the same period.This suggests that dynamic monitoring of ONSD can reflect real-time changes in ICP in patients with heavy TBI under hyperventilation.