Department of Anaesthesiology, Government Medical College, Thiruvananthapuram, Kerala, India.
Department of Neuroanesthesia and Pain Medicine, Fortis Hospital, Noida, Uttar Pradesh, India.
Neurol India. 2022 Jul-Aug;70(4):1460-1467. doi: 10.4103/0028-3886.355178.
Measuring optic nerve sheath diameter (ONSD) by transbulbar ultrasonography (TBUS) can suffice non-invasive ICP measurement with considerable accuracy.
The primary objective of this study was to evaluate the perioperative variation in ONSD by TBUS in Traumatic Brain Injury (TBI) patients undergoing emergency craniectomy.
We prospectively compared bilateral ONSD measurements in 45 consecutive TBI cases undergoing decompressive craniectomy under general anesthesia; before and after surgery. A total of 180 ONSD images were obtained and measurements were done by the same investigator blinded to the pre/postoperative nature of the image.
Based on preoperative Glasgow Coma Scores, 34 cases (75.5%) had severe TBI; 10 cases (22.2%) moderate TBI; and 1 case (2.2%) mild TBI. Preoperative ONSD in the study population were as 6.625 ± 0.414mm. Average ONSD reduced significantly by 0.249 ± 0.148 mm (P < 0.001) after craniectomy. On pooled analysis of cases undergoing right versus left sided craniectomy average ONSD reduced significantly by 0.252 ± 0.173 mm (P < 0.001) and 0.259 ± 0.139 mm (P < 0.001), respectively. ONSD of right eye with left eye and vice-versa were strongly correlated both pre/postoperatively with Pearson correlation coefficients (r)=0.879 (P < 0.001) and r = 0.827 (P < 0.001), respectively.
In TBI cases undergoing decompressive craniectomy ONSD is bilaterally increased preoperatively. ONSD reduces significantly immediately after craniectomy; however, the diameters did not near the normal range. There hold a strong correlation between right/left ONSD measurements irrespective of the laterality of injury or side of surgery. Variable elastic properties of ONS in an injured brain can possibly explain our findings.
经眶超声（TBUS）测量视神经鞘直径（ONSD）可以通过相当准确的非侵入性 ICP 测量来满足需要。
本研究的主要目的是评估外伤性脑损伤（TBI）患者行紧急去骨瓣减压术时经 TBUS 测量的围手术期 ONSD 变化。
我们前瞻性比较了 45 例连续 TBI 患者在全身麻醉下行减压性颅骨切开术的双侧 ONSD 测量值；术前和术后。共获得 180 个 ONSD 图像，由同一位研究人员进行测量，该研究人员对图像的术前/术后性质不知情。
根据术前格拉斯哥昏迷评分（GCS），34 例（75.5%）为重度 TBI；10 例（22.2%）为中度 TBI；1 例（2.2%）为轻度 TBI。研究人群的术前 ONSD 为 6.625 ± 0.414mm。颅骨切开术后 ONSD 平均降低 0.249 ± 0.148mm（P<0.001）。对行右侧与左侧颅骨切开术的病例进行汇总分析，平均 ONSD 分别降低 0.252 ± 0.173mm（P<0.001）和 0.259 ± 0.139mm（P<0.001）。右眼与左眼的 ONSD 以及左眼与右眼的 ONSD 术前和术后均呈强烈正相关，Pearson 相关系数（r）分别为 0.879（P<0.001）和 0.827（P<0.001）。
在接受去骨瓣减压术的 TBI 患者中，ONSD 在术前双侧增加。颅骨切开术后 ONSD 显著降低，但直径仍未接近正常范围。无论损伤的侧别或手术的侧别，右侧/左侧 ONSD 测量值之间存在强烈的相关性。受伤大脑中 ONS 的弹性特性不同可能解释了我们的发现。
