Real-time Ultrasound-Guided Lumbar Epidural with Transverse Interlaminar View: Evaluation of an In-Plane Technique

Combining Fiber Bragg Grating and Artificial Intelligence Technologies for Supporting Epidural Procedures

OBJECTIVE

Loss of resistance (LOR) is a widely accepted method for performing epidural punctures in clinical settings. However, the risk of failure associated with LOR is still high. Solutions based either on Fiber Bragg grating sensors (FBG) or on artificial intelligence (AI) are gaining ground for supporting clinicians during this kind of procedure. Here, for the first time, we combined the mentioned two technologies to perform an AI-driven LOR identification based on data collected by a custom FBG sensor.

METHODS

This study presented two contributions (i.e., automatic labeling and identification) based on machine learning to support epidural procedures by enhancing LOR detection. The methods were tested using data collected by a customized FBG-based flexible cap on 10 patients affected by chronic back pain.

RESULTS

The automatic labeling can retrospectively identify every LOR event for each subject under consideration. This serves as the labeling for the automatic identification task, which emulates the real-time application of LOR detection. A Support Vector Machine, trained using a Leave-One-Out strategy, demonstrates high accuracy in identifying all LOR events while maintaining a minimal rate of false positives.

CONCLUSION

Our findings revealed the promising performance of the proposed AI-based approach for automatic LOR detection. Thus, their combination with FBG technology can potentially improve the level of support offered to clinicians in this application.

SIGNIFICANCE

The integration of AI and FBG technologies holds the promise of revolutionizing LOR detection, reducing the likelihood of unsuccessful epidural punctures and advancing pain management.

Conventional anatomical landmark versus preprocedural ultrasound for thoracic epidural analgesia: A systematic review and meta-analysis

BACKGROUND

Thoracic epidural analgesia is the gold standard for major thoracic and abdominal surgeries.

AIM

Ultrasound-guided and landmark-based thoracic epidural insertion are compared in this systematic review.

METHODS

Randomised controlled trials were sought in six databases for a systematic review and meta-analysis. With a 95% confidence interval, a fixed-effects model calculated risk ratio or mean difference. Cochrane risk of bias assessed bias. Four randomised controlled trials were examined.

FINDINGS

Preprocedural ultrasound increased thoracic epidural placement first-puncture success rate (risk ratio = 1.28, 95% confidence interval (1.05 to 1.56), p value = 0.02) and decreased the need for two or more skin punctures (mean difference = -2.41, 95% confidence interval (-3.34 to -1.47), p value = 0.00001). The ultrasound group reduced needle redirections (risk ratio = 0.6, 95% confidence interval (0.38 to 0.94), p value = 0.02). The epidural block success rate was equal in both groups (risk ratio = 1.02, 95% confidence interval (0.96 to 1.07), p value = 0.6).

CONCLUSION

Thoracic epidural insertion is improved by ultrasound but not the success rate. Quality research with larger samples is needed to emphasise these conclusions.

Enhancing epidural needle guidance using a polarization-sensitive optical coherence tomography probe with convolutional neural networks

Epidural anesthesia helps manage pain during different surgeries. Nonetheless, the precise placement of the epidural needle remains a challenge. In this study, we developed a probe based on polarization-sensitive optical coherence tomography (PS-OCT) to enhance the epidural anesthesia needle placement. The probe was tested on six porcine spinal samples. The multimodal imaging guidance used the OCT intensity mode and three distinct PS-OCT modes: (1) phase retardation, (2) optic axis, and (3) degree of polarization uniformity (DOPU). Each mode enabled the classification of different epidural tissues through distinct imaging characteristics. To further streamline the tissue recognition procedure, convolutional neural network (CNN) were used to autonomously identify the tissue types within the probe's field of view. ResNet50 models were developed for all four imaging modes. DOPU imaging was found to provide the highest cross-testing accuracy of 91.53%. These results showed the improved precision by PS-OCT in guiding epidural anesthesia needle placement.

Landmark-guided versus Real-time Ultrasound-guided Combined Spinal-epidural Anesthesia Techniques: Paramedian Sagittal Oblique and Transverse Interlaminar Approach

Background

There are different types of real-time ultrasound (US)-guided combined spinal epidural (CSE) anesthesia techniques. We aimed to investigate the effect of real-time US-guided paramedian sagittal oblique (PSO), transverse interlaminar (TI) approach method, and landmark-guided (LG) CSE anesthesia.

Methods

Ninety patients who underwent CSE block were included in the study. Patients were randomized into LG (n = 30), PSO (n = 30), and TI (n = 30) groups. The primary outcome was number of needle manipulations. The secondary outcomes are the number of attempts, needle visibility, procedure time, procedure success rate, catheter placement difficulty, posterior complex distance, and complications.

Results

The number of needle manipulations was statistically significantly lower in the LG technique group (P < 0.000). When the number of attempts, the difficulty of catheter placement, and the procedure's success rate were compared between the three groups, we did not find a statistically significant difference (P > 0.05). In addition, when the procedure times were compared, the time measured for the LG group was statistically significantly lower than in the PSO and TI groups (P < 0.000).

Conclusion

In the results of this study, the real-time US-guided CSE anesthesia application had a similar success and complication level with LG technique. The LG method had a shorter processing time and fewer needle manipulations.

Comparison of sitting and prone positions for real-time ultrasound-guided thoracic epidural catheter placement: a randomized controlled trial

Introduction

Real-time ultrasound-guided thoracic epidural catheter placement (US-TECP) has been recently introduced. Patient’s position is associated with the success of spine interventions; however, the effects of position on the outcome of the procedure remain unknown. We aimed to assess the clinical usefulness of patient positioning during real-time US-TECP.

Methods

Patients were randomly assigned to the prone position group (group P) and sitting position group (group S). The primary outcome was needling time during the procedure. The secondary outcomes were time to mark space, total number of needle passes, number of skin punctures, first-pass success, final success, crossover success, and visibility of ultrasound (US) views. Global Rating Scale (GRS) score, Patient Comfort Scale score, procedural pain intensity, patient satisfaction, and procedure-related complications were also determined.

Results

Sixty-four patients were included in this study. The needling time was significantly shorter in group P than in group S (36.5 (26.5–51.0) vs 59.5 (34.5–152.0) s, p<0.01). The numbers of needle passes and skin punctures were significantly lesser in group P than in group S. First-pass success was higher in group P than in group S. Group P had higher GRS compared with group S. The time to mark space, final success, US visibility score, Patient Comfort Scale score, procedural pain intensity, and patient satisfaction did not differ between the groups. One patient in group S developed a vasovagal reaction.

Discussion

This study shows that prone position may be preferred for real-time US-TECP, considering its better clinical usefulness.

Trial registration number

KCT0005757.

Ultrasonography for lumbar neuraxial block

Ultrasonography can be useful to perform a lumbar neuraxial block. It aids in understanding the anatomy of the lumbar spine before the procedure. Pre-procedural ultrasound imaging provides information about the accurate intervertebral level for puncture, optimal needle insertion point, and depth of needle advancement for a successful neuraxial block. The key ultrasonographic views for lumbar neuraxial block include the transverse midline interlaminar and parasagittal oblique views. Ultrasonography can facilitate lumbar neuraxial block in difficult cases, such as the elderly, obese patients, and patients with anatomical abnormality of the lumbar spine. This review elucidates the basics of spinal ultrasonography for lumbar neuraxial block and the current evidence regarding ultrasound-guided neuraxial block in adults.

[Identification of the epidural space using pressure waveform analysis (CompuFlo® technology): a case series]

Anesthesiologists commonly perform the loss of resistance technique in order to identify the epidural space during neuraxial procedures; however, this technique is subjective and lacks reliability in certain cases. The so-called CompuFlo® technology provides objective information about the position of the epidural needle by means of a pressure curve and acoustic signals. The technology was introduced several years ago and was evaluated in several trials, which showed promising results. The purpose of the present publication is to report on the first experiences with the CompuFlo® technology in German-speaking countries. A series of 24 epidural procedures using the CompuFlo® device was carried out in routine daily practice. The epidural space was successfully identified in 23 cases. Conversion to the conventional loss of resistance technique was performed during the initial cases in a prolonged procedure. The CompuFlo® technique is considered to be a promising technology, which might help to reduce complications after epidural anesthesia, e.g. postdural puncture headache.