Application Of 3D Printing Transparent Spinal Canal Model To Study The Effect Of Volume Factor Of Local Anesthetics On Spinal Anesthesia Plane

Background :Subarachnoid anesthesia is one of the commonly used anesthesia methods in clinical work.The premise of successful implementation of subarachnoid anesthesia is accurate anesthesia puncture and accurate anesthesia plane regulation,which has been the difficulty of subarachnoid anesthesia teaching.Due to the hidden and abstract anatomical system in the spinal canal,it is difficult for medical students and junior residents to have a rational understanding of the diffusion phase of local anesthetics in the spinal canal.Previously limited to conditions,this problem has been a bottleneck restricting anesthesiologists to learn to master spinal anesthesia.In recent years,3D printing technology has become increasingly mature and has made breakthroughs in many medical fields.Inspired by this,the 3D printing transparent subarachnoid experimental platform invented by our group can accurately simulate the morphology of human spinal canal according to the principle of bionics,and intuitively observe the diffusion state of local anesthetics with different capacities dyed in the spinal canal.In previous experience,capacity is considered to be one of the main factors affecting the local diffusion of subarachnoid anesthesia.We intend to conduct physical experiments on this model to explore whether there is a significant correlation between capacity and the diffusion plane of subarachnoid anesthetics,and to explore the influence of different capacities on the diffusion of local anesthetics in the spinal canal.Objective :By observing the diffusion state of local anesthetics with different capacities in 3D spinal canal,the diffusion law of local anesthetics with different capacities in spinal canal was explored,and the factors that may affect the diffusion phase were discussed so as to have a more rational understanding of the diffusion of local anesthetics in spinal canal anesthesia.Methods:A three-dimensional database was established based on the standard person ’ s supine spine CT data model,and the transparent arachnoid model of the standard person was printed by digital technology printer.The experimental group was divided into five groups,each group were1.0ml,1.5ml,2.0ml,2.5ml,3.0ml methylene blue staining0.75 %bupivacaine through the lumbar2lumbar3 space with constant speed electronic pump at0.1ml / h speed into artificial cerebrospinal fluid filled transparent arachnoid model.At the end of injection,photographs of the longitudinal axis plane of the spinal cord were taken at 2 min,5 min,10 min and 15 min after injection,and the diffusion distance of the liquid was recorded.And video recording of liquid diffusion during injection.Each experiment was repeated five times.All the data were processed and analyzed by SPSS19.0 statistical software.The results of measurement data were expressed as mean ±standard deviation(x ± s).For measurement data,the normality test was carried out first.The measurement data that conformed to the normal distribution were analyzed by repeated measurement analysis of variance.The measurement data that did not conform to the normal distribution were transformed into the advanced normality.Then the parameter test was used.The independent sample t test was used for comparison between groups.P < 0.05 was considered as the difference,which was statistically significant.Results :1.The liquid diffusion state of local anesthetics during injection,when the dosage is less than2.0ml,the diffusion distance increases with the increase of the dosage of local anesthetics.When the dosage was greater than 2.0 m L,the circulation was formed due to the injection resistance,which led to the accumulation of drugs around the injection needle.Under the action of certain circulation,there was a phenomenon of diffusion to the tail,making the growth rate of diffusion distance to the head smaller.2.The diffusion distance of local anesthetics in 15 minutes : when the dosage is less than 2.5 ml,the maximum diffusion distance of local anesthetics in 15 minutes increases with the increase of dosage.When the dosage is more than 2.5 ml,the maximum diffusion distance of local anesthetics in 15 minutes is no longer significantly increased.3.The diffusion law of local anesthetics can be visually observed through the 3D printing transparent spinal canal experimental platform.Conclusion :1.Using 3D printing transparent spinal canal model experimental platform,we can intuitively observe the diffusion state and diffusion law of local anesthetics in the spinal canal,and increase the rational understanding of subarachnoid anesthesia.2.The isobaric local anesthetic is injected at a constant rate of0.1ml/s.The distribution and diffusion of the local anesthetic in the subarachnoid space can be divided into two phases: the injection phase and the diffusion phase.During the injection phase,the drug distribution range was positively correlated with the drug volume,and the drugs were compactly gathered in a small range.As the drug increases from 1.0ml to3.0ml,the distribution range of the drug in the injection phase can reach between L1-T12 in the head-end direction,and there is a process of surrounding aggregation and redistribution.The diffusion distance depends on the total amount of local anesthetic distributed in the injection phase.capacity.The drug distributions of different volumes in the diffusion phase diffuse with almost similar linear correlation coefficients at each time point based on the distribution range of the respective injection phases.3.The proportion of local anesthetics and posture can be directly observed during the experiment is also an important factor affecting the anesthesia plane,which needs further study.