Raffiz Mohd, Abdullah Jafri M
Kuala Lumpur Hospital, Jalan Pahang, 50586, Kuala Lumpur, Malaysia.
Centre for Neuroscience Services and Research, Universiti Sains Malaysia, Jalan Sultanah Zainab 2, Kota Bharu, Kelantan, Malaysia; Department of Neurosciences, Hospital Universiti Sains Malaysia, Jalan Hospital USM, 16150 Kubang Kerian, Kelantan, Malaysia.
Am J Emerg Med. 2017 Jan;35(1):150-153. doi: 10.1016/j.ajem.2016.09.044. Epub 2016 Sep 23.
Bedside ultrasound measurement of optic nerve sheath diameter (ONSD) is emerging as a non-invasive technique to evaluate and predict raised intracranial pressure (ICP). It has been shown in previous literature that ONSD measurement has good correlation with surrogate findings of raised ICP such as clinical and radiological findings suggestive of raised ICP.
The objective of the study is to find a correlation between sonographic measurements of ONSD value with ICP value measured via the gold standard invasive intracranial ICP catheter, and to find the cut-off value of ONSD measurement in predicting raised ICP, along with its sensitivity and specificity value.
A prospective observational study was performed using convenience sample of 41 adult neurosurgical patients treated in neurosurgical intensive care unit with invasive intracranial pressure monitoring placed in-situ as part of their clinical care. Portable SonoSite ultrasound machine with 7 MHz linear probe were used to measure optic nerve sheath diameter using the standard technique. Simultaneous ICP readings were obtained directly from the invasive monitoring.
Seventy-five measurements were performed on 41 patients. The non-parametric Spearman correlation test revealed a significant correlation at the 0.01 level between the ICP and ONSD value, with correlation coefficient of 0.820. The receiver operating characteristic curve generated an area under the curve with the value of 0.964, and with standard error of 0.22. From the receiver operating characteristic curve, we found that the ONSD value of 5.205 mm is 95.8% sensitive and 80.4% specific in detecting raised ICP.
ONSD value of 5.205 is sensitive and specific in detecting raised ICP. Bedside ultrasound measurement of ONSD is readily learned, and is reproducible and reliable in predicting raised ICP. This non-invasive technique can be a useful adjunct to the current invasive intracranial catheter monitoring, and has wide potential clinical applications in district hospitals, emergency departments and intensive care units.
床边超声测量视神经鞘直径（ONSD）正在成为一种评估和预测颅内压（ICP）升高的非侵入性技术。先前的文献表明，ONSD测量与ICP升高的替代指标具有良好的相关性，如提示ICP升高的临床和影像学表现。
本研究的目的是找出超声测量的ONSD值与通过金标准有创颅内ICP导管测量的ICP值之间的相关性，确定ONSD测量在预测ICP升高时的临界值及其敏感性和特异性。
采用前瞻性观察性研究，对41例在神经外科重症监护病房接受治疗的成年神经外科患者进行便利抽样，这些患者在临床护理中已放置有创颅内压监测装置。使用配备7MHz线性探头的便携式SonoSite超声仪，采用标准技术测量视神经鞘直径。同时直接从有创监测中获取ICP读数。
对41例患者进行了75次测量。非参数Spearman相关性检验显示，ICP与ONSD值在0.01水平上具有显著相关性，相关系数为0.820。受试者工作特征曲线生成的曲线下面积值为0.964，标准误差为0.22。从受试者工作特征曲线中，我们发现ONSD值为5.205mm时，检测ICP升高的敏感性为95.8%，特异性为80.4%。
ONSD值为5.205时，在检测ICP升高方面具有敏感性和特异性。床边超声测量ONSD易于掌握，在预测ICP升高方面具有可重复性和可靠性。这种非侵入性技术可以作为当前有创颅内导管监测的有用辅助手段，在地区医院、急诊科和重症监护病房具有广泛的潜在临床应用。
