1、視神經(jīng)鞘直徑(ONSD)與顱內(nèi)壓(ICP),重癥醫(yī)學(xué)科,1,解剖學(xué)基礎(chǔ),2,解剖學(xué)基礎(chǔ),Pulillary aperature 瞳孔 Iris 虹膜 Cornea 角膜 Ciliary body 睫狀體 Lens 晶狀體 Vitreous body 玻璃體 Retina 視網(wǎng)膜 Choroid 脈絡(luò)膜 Sclera 鞏膜,3,4,眼部結(jié)構(gòu)及超聲圖像 眼球及眶周結(jié)構(gòu),5,6,視路MRI圖像,視神經(jīng)： 眼內(nèi)部 眶部（ONSD段） 管內(nèi)部 顱內(nèi)部,7,8,Critical Care 2008, 12:R114,ONSD,視神經(jīng),ONSD臨界值5.82mm ICP20mmHg,9,共納入231例 敏感

2、性 0.90（95%CI 0.80-0.95） 特異性 0.85（95%CI 0.73-0.93）,Intensive Care Med (2011)37:10591068,10,11,Conclusions Sonographic measurement of ONSD may be a potentially useful technique for assessing IH in a binary mode (present/ absent) when invasive/monitoring methods are not desirable or available.,12,視神經(jīng)鞘直

3、徑可準確評估顱內(nèi)壓增高？,13,14,Conclusion This study suggests that ONSD assessment throughout the acute phase may not be a reliable method to monitor ICP. ONSD expansion can persist even after ICP control, and this may be the reason for ONSD expansions seen in our study even with normal ICPs. Further larger siz

4、e studies are needed to confirm these findings.,15,影響因素,16,1、 體位,Effects of Prone Position and Positive End-Expiratory Pressure on Noninvasive Estimators of ICP: A Pilot Study. Results: The mean values of ONSD, ICPFVd, and ICPPI significantly increased after change from supine to prone position. Rec

5、eiver operating characteristic analyses demonstrated that, among the noninvasive methods, the mean ONSD measure had the greatest area under the curve signifying it is the most effective in distinguishing a hypothetical change in ICP between supine and prone positioning (0.86+/-0.034 0.79 to 0.92). A

6、 cutoff of 0.43 cm was found to be a best separator of ONSD value between supine and prone with a specificity of 75.0 and a sensitivity of 86.7. Conclusions: Noninvasive ICP estimation may be useful in patients at risk of developing intracranial hypertension who require prone positioning.,Journal of

7、 Neurosurgical Anesthesiology. 18 March 2016,17,2 肥胖、氣腹,There were 62 subjects, 28 females (45.2 %) and 34 males (54.8 %), with a mean age of 44.22 10.44 years (range 2366). Forty-eight percent of patients were non-obese, and 52 % of patients were obese. The mean body mass index was 30.70 7.61 kg/m2

8、 (range 20.059.5). The mean ONSD of non-obese and obese patients was 4.7 and 5.5 mm at baseline (p = 0.01), 5.4 and 6.2 mm at 15 min (p = 0.01), 5.8 and 6.6 mm at 30 min (p = 0.01), and 5.1 and 5.7 mm after deflation of pneumoperitoneum (p = 0.03), respectively.,Surgical Endoscopy June 2016, Volume

9、30, Issue6, pp 23212325,18,測量方法,19,探頭的選擇和放置,1 選擇高頻線陣探頭 (7.5 MHz or greater) . 2 無菌貼膜覆蓋眼球 3 充分耦合，避免擠壓眼球（以面頰或者額頭為受力點） 4 深度在視網(wǎng)膜下1-2cm,20,21,測量的方法和注意事項,1 測量位置：位于視網(wǎng)膜和視神經(jīng)交界處深部3mm 2 分別測量長軸和短軸的視神經(jīng)鞘直徑并求出平均值。 3 測量對側(cè)視神經(jīng)鞘的直徑。,22,視神經(jīng)鞘是顱內(nèi)硬腦膜與蛛網(wǎng)膜下腔的延續(xù)，因此顱內(nèi)壓增高將直接增大視神經(jīng)鞘直徑。測量主要在眼球后3mm處，因為該處隨顱內(nèi)壓變化的彈性伸縮性最大。,23,ONSD評估顱內(nèi)

10、壓力 測量方法： 冠狀位測量球后3mm處ONSD,3次均值 正常上限值5mm 矢狀位測量球后3mm 處ONSD,3次均值 正常上限值5.8mm,24,參考值,25,1、 單側(cè)異常,The presence of unilateral increased ONSD suggests a lateralizing process, such as optic neuritis or compressive optic neuropathy. Papill edema（視乳頭水腫） may also be noted as optic disc bulging into the retina and

11、 protruding into the vitreous body.,26,2、 雙側(cè)異常,The cutoff value for increased ONSD correlating with increased ICP has been debatable. Based on the initial study of ultrasound measurement of ONSD,11 many authors cite a diameter 5 mm as elevated in patients older than age 4. Two recent meta-analyses of six studies evaluated the correlation between ONSD and ICP 20 cm H2O and calculated a pooled sensitivity and specificity