Brain Physics Laboratory, Department of Clinical Neurosciences, Division of Neurosurgery, Cambridge Biomedical Campus, Addenbrooke's Hospital, University of Cambridge.
Neurocritical Care Unit, Addenbrooke's Hospital, Cambridge University Hospitals Trust.
J Neurosurg Anesthesiol. 2020 Oct;32(4):349-353. doi: 10.1097/ANA.0000000000000622.
Transcranial Doppler (TCD) ultrasonography has been described for the noninvasive assessment of intracranial pressure (ICP). This study investigates the relationship between standard, invasive intracranial pressure monitoring (ICPi) and noninvasive ICP assessment using a simple formula based on TCD-derived flow velocity (FV) and mean arterial blood pressure values (ICPTCD).
We performed a prospective observational study on 100 consecutive traumatic brain injury patients requiring invasive ICP monitoring, admitted to the Neurosciences and Trauma Critical Care Unit of Addenbrooke's Hospital, Cambridge, UK. ICPi was compared with ICPTCD using a method based on the "diastolic velocity-derived estimator" (FVd), which was initially described for the noninvasive estimation of cerebral perfusion pressure but subsequently utilized for ICP assessment.
Median ICPi was 13 mm Hg (interquartile range: 10, 17.25 mm Hg). There was no correlation between ICPi and ICPTCD (R=-0.17; 95% confidence interval [CI]: -0.35, 0.03; P=0.097). Bland-Altman analysis demonstrated wide 95% limits of agreement between ICPi and ICPTCD (-27.58, 30.10; SD, 14.42). ICPTCD was not able to detect intracranial hypertension (ICPi >20 mm Hg); the area under the receiver operating characteristic curve for prediction was 34.5% (95% CI, 23.1%-45.9%) with 0% sensitivity and 74.4% specificity for ICPTCD to detect ICPi>20 mm Hg.
Using a formula based on diastolic FV, TCD is an insufficiently accurate method for the noninvasive assessment of ICP. Further studies are warranted to confirm these results in a broader patient cohort.
经颅多普勒（TCD）超声检查已被用于评估颅内压（ICP）的非侵入性方法。本研究旨在通过基于 TCD 衍生流速（FV）和平均动脉血压值的简单公式（ICPTCD），调查标准、侵入性颅内压监测（ICPi）与非侵入性 ICP 评估之间的关系。
我们对英国剑桥 Addenbrooke's 医院神经科学和创伤危重病监护病房的 100 例连续外伤性脑损伤患者进行了前瞻性观察性研究，这些患者需要进行侵入性 ICP 监测。通过一种基于“舒张期速度衍生估计器”（FVd）的方法将 ICPi 与 ICPTCD 进行比较，该方法最初用于非侵入性脑灌注压的估计，但后来也用于 ICP 评估。
中位 ICPi 为 13mmHg（四分位距：10、17.25mmHg）。ICPi 与 ICPTCD 之间无相关性（R=-0.17；95%置信区间：-0.35，0.03；P=0.097）。Bland-Altman 分析显示 ICPi 与 ICPTCD 之间的 95%一致性界限较宽（-27.58，30.10；SD，14.42）。ICPTCD 无法检测颅内高压（ICPi>20mmHg）；预测的受试者工作特征曲线下面积为 34.5%（95%CI，23.1%-45.9%），ICPTCD 检测 ICPi>20mmHg 的敏感性为 0%，特异性为 74.4%。
使用基于舒张期 FV 的公式，TCD 是一种不够准确的 ICP 非侵入性评估方法。需要进一步的研究来证实这些结果在更广泛的患者群体中的可靠性。
