Abstract
Purpose: Technology of reflectance spectroscopy incorporated with auto-fluorescence spectroscopy were employed to increase the safety of epidural placement in regional anesthesia which is generally used for surgery, epidural anesthesia, post-operative pain control and painless childbirth. Method: Ex vivo study of auto-fluorescence spectroscopy was performed for the para-vertebral tissues contained fat, interspinous ligament, supraspinous ligament and ligamentumflavum by multimode microplate reader at wavelength 405 nm for the purpose of tissue differentiation. A specially designed optic-fiber-embedded needle was employed to incorporate with both reflectance and autofluorescence spectroscopies in order to probe the epidural space as double assurance demands. In vivo study was carried out in a Chinese native swine weighted about 30 kg under intubated general anesthesia with ventilation support. The reflective (405 nm) and autofluorescence signals (λ and λ*) were recorded at 5 different sites by an oscilloscope during the needle puncture procedure from skin to epidural space in the back of the swine. Results: Study of either autofluorescence spectroscopy for tissue samples or ex vivo needle puncture in porcine trunk tissues indicates that ligmentumflavum has at least 10-fold higher fluorescence intensity than the other tissues. In the in vivo study, ligamentumflavum shows a double-peak character for both reflectance and autofluorescence signals. The epidural space is located right after the drop from the double-peak. Both peaks of reflectance and fluorescence are coincident which ensures that the epidural space is correctly detected. Conclusions: The fiber-optical technologies of double-assurance demands for tissue discrimination during epidural needle puncture can not only provide an objective visual information in a real-time fashion but also it can help the operator to achieve much higher success rate in this anesthesia procedure.
Highlights
Epidural block is a widely used and low-complication-rate procedure which has been applied to many fields of anesthesia such as epidural anesthesia [1,2,3], postoperative analgesia [4] and painless labor [5,6]
Anesthesiologists are still looking for a new convenient, real-time and reliable tool for epidural catheter placement to replace the old technique of loss-of-resistance (LOR) which was reported with up to 10% of procedures failure rate due to incorrect epidural space recognition and wrong catheter placement leading to low specificity [10,11,12]
It has been shown that patient positioning, the use of a midline or paramedian approach and the method used for catheter fixation can all influence the success rate for catheter placement [27]
Summary
Epidural block is a widely used and low-complication-rate procedure which has been applied to many fields of anesthesia such as epidural anesthesia [1,2,3], postoperative analgesia [4] and painless labor [5,6] It has been reported as an effective clinical technique with lower morbidity and mortality [7]. A receiver operating characteristic curve (ROC) was reported up to 0.887 (95% confidence interval (CI) 0.8131–0.9) in terms of the optimal cutoff values for signal amplitudes of 650-nm red laser light [14] If this technology is going to be applied to clinical use, it should provide more convincing evidence in safety aspect
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
