Sun Tsim Christopher, Makara Mariano, Martinez-Taboada Fernando
Department of Anaesthesia, The University Veterinary Teaching Hospital, School of Veterinary Science, The University of Sydney, Sydney, NSW 2050, Australia.
Diagnostic Imaging Unit, The University Veterinary Teaching Hospital, School of Veterinary Science, The University of Sydney, Sydney, NSW 2050, Australia.
Vet Sci. 2020 Dec 3;7(4):196. doi: 10.3390/vetsci7040196.
The current clinical techniques for neuraxial needle placement in dogs are predominantly blind without prior knowledge of the depth required to reach the desired space. This study investigated the correlation and defined the relationship between easily obtainable external landmark variables in the dog; occipital-coccygeal length (OCL) and ilium wings distance (IWD), with the skin to epidural and intrathecal space distances using computed tomography (CT). The CT images of 86 dogs of different breeds were examined in this retrospective observational study. Images of dogs in sternal recumbency were optimized to the sagittal view. The distances between the skin and lumbosacral epidural space (LSE) and skin to sacrococcygeal space (SCE) were measured to the ligamentum flavum surrogate (LFS) line. The distance between the skin and the intrathecal space (ITS) was measured from the skin to the vertebral canal at the interlumbar (L-L) space. Measurements of the IWD and OCL were performed on dorsal and scout views, respectively. Linear regression equations and Pearson's correlation coefficients were calculated between variables. Data were reported as mean (standard deviation). Significance was set as alpha < 0.05. After exclusion of four dogs, 82 CT scans were included. The depths were LSE 45 (15) mm, SCE 23 (10) mm, and ITS 50 (15) mm. There was a moderate correlation between OCL with LSE (=14.2 + OCL * 0.05 ( = 0.59, < 0.0001)), and a strong correlation with ITS (=11.4 + OCL * 0.07 ( = 0.76, < 0.0001)), while a very weak correlation was found with SCE (=14.0 + OCL * 0.02 ( = 0.27, < 0.0584)). Similarly, with IWD, there was a moderate correlation with LSE (=10.8 + IWD * 0.56 ( = 0.61, < 0.0001)), and strong correlation with ITS (=9.2 + IWD * 0.67 ( = 0.75, < 0.0001)), while a weak correlation was found with SCE (=11.2 + IWD * 0.2 ( = 0.32, < 0.0033)). Mathematical formulae derived from the multiple regression showed that the body condition score (BCS) improved the relationship between IWD and OCL and the LSE, SCE and ITS, while the addition of body weight was associated with multicollinearity. Further studies are required to determine the accuracy of the algorithms to demonstrate their ability for prediction in a clinical setting.
目前犬类神经轴穿刺针放置的临床技术主要是盲穿，事先并不知道到达目标间隙所需的深度。本研究调查了犬类中易于获得的外部标志变量；枕尾长度（OCL）和髂翼距离（IWD）与皮肤至硬膜外腔和鞘内间隙距离之间的相关性，并使用计算机断层扫描（CT）确定了它们之间的关系。在这项回顾性观察研究中，检查了86只不同品种犬的CT图像。将处于胸骨卧位的犬的图像优化为矢状视图。测量皮肤与腰骶硬膜外腔（LSE）以及皮肤与骶尾间隙（SCE）之间至黄韧带替代物（LFS）线的距离。测量皮肤与鞘内间隙（ITS）之间在腰（L-L）间隙处从皮肤到椎管的距离。分别在背视图和定位视图上测量IWD和OCL。计算变量之间的线性回归方程和Pearson相关系数。数据报告为平均值（标准差）。显著性设定为α<0.05。排除4只犬后，纳入82例CT扫描。深度分别为LSE 45（15）mm、SCE 23（10）mm和ITS 50（15）mm。OCL与LSE之间存在中度相关性（=14.2 + OCL * 0.05（= 0.59，< 0.0001）），与ITS存在强相关性（=11.4 + OCL * 0.07（= 0.76，< 0.0001）），而与SCE的相关性非常弱（=14.0 + OCL * 0.02（= 0.27，< 0.0584））。同样，对于IWD，与LSE存在中度相关性（=10.8 + IWD * 0.56（= 0.61，< 0.0001）），与ITS存在强相关性（=9.2 + IWD * 0.67（= 0.75，< 0.0001）），而与SCE的相关性较弱（=11.2 + IWD * 0.2（= 0.32，< 0.0033））。多元回归得出的数学公式表明，身体状况评分（BCS）改善了IWD和OCL与LSE、SCE和ITS之间的关系，而增加体重则与多重共线性相关。需要进一步研究以确定算法的准确性，以证明它们在临床环境中的预测能力。
