Identification of the Lumbar Interspinous Spaces by Palpation and Verified by X-rays

Ultrasound-based Accuro system versus traditional palpation technique for neuraxial anaesthesia: A systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

This review evaluates the efficacy and safety of Accuro, a handheld ultrasound device, compared to the palpation technique for neuraxial anaesthesia. Accuro provides real-time imaging guidance, potentially improving accuracy and efficiency.

METHODS

A comprehensive search across six electronic databases identified randomised clinical trials comparing Accuro with palpation for neuraxial anaesthesia. Risk ratios or mean differences with 95% confidence intervals (CIs) were calculated using a random-effects model. Bias risk was evaluated using the Cochrane Risk of Bias tool.

RESULTS

Five studies (n=369) met the inclusion criteria. Accuro showed a favourable risk ratio for first insertion success (1.44 [95% CI [1.01, 2.05], p=0.05]). It significantly reduced needle skin passes (MD -0.63; 95% CI [-1.05, -0.21]; p<0.01), but not needle redirection (MD -1.31; 95% CI [-2.71, 0.11]; p=0.07). Procedure time was shorter in palpation (MD 127.82; 95% CI [8.68, -246.97]; p=0.04). Four studies had a low risk of bias; one had some concerns.

CONCLUSION

Accuro can potentially improve success rates and reduce skin passes in neuraxial anaesthesia. Further trials with larger samples are needed, especially in patients with anticipated difficulties.

Accuracy Evaluation Trial of Mixed Reality-Guided Spinal Puncture Technology

Purpose

To evaluate the accuracy of mixed reality (MR)-guided visualization technology for spinal puncture (MRsp).

Methods

MRsp involved the following three steps: 1. Lumbar spine computed tomography (CT) data were obtained to reconstruct virtual 3D images, which were imported into a HoloLens (2nd gen). 2. The patented MR system quickly recognized the spatial orientation and superimposed the virtual image over the real spine in the HoloLens. 3. The operator performed the spinal puncture with structural information provided by the virtual image. A posture fixation cushion was used to keep the subjects' lateral decubitus position consistent. 12 subjects were recruited to verify the setup error and the registration error. The setup error was calculated using the first two CT scans and measuring the displacement of two location markers. The projection points of the upper edge of the L3 spinous process (L3↑), the lower edge of the L3 spinous process (L3↓), and the lower edge of the L4 spinous process (L4↓) in the virtual image were positioned and marked on the skin as the registration markers. A third CT scan was performed to determine the registration error by measuring the displacement between the three registration markers and the corresponding real spinous process edges.

Results

The setup errors in the position of the cranial location marker between CT scans along the left-right (LR), anterior-posterior (AP), and superior-inferior (SI) axes of the CT bed measured 0.09 ± 0.06 cm, 0.30 ± 0.28 cm, and 0.22 ± 0.12 cm, respectively, while those of the position of the caudal location marker measured 0.08 ± 0.06 cm, 0.29 ± 0.18 cm, and 0.18 ± 0.10 cm, respectively. The registration errors between the three registration markers and the subject's real L3↑, L3↓, and L4↓ were 0.11 ± 0.09 cm, 0.15 ± 0.13 cm, and 0.13 ± 0.10 cm, respectively, in the SI direction.

Conclusion

This MR-guided visualization technology for spinal puncture can accurately and quickly superimpose the reconstructed 3D CT images over a real human spine.

Accuro ultrasound-based system with computer-aided image interpretation compared to traditional palpation technique for neuraxial anesthesia placement in obese parturients undergoing cesarean delivery: a randomized controlled trial

PURPOSE

Recently, a new handheld ultrasound-based device, called Accuro, has been commercialized with a real-time automated interpretation of lumbar ultrasound images. We hypothesized that the handheld ultrasound device would improve the efficacy and safety of combined spinal-epidural anesthesia (CSEA) for cesarean delivery in obese parturients.

METHODS

Eighty parturients with a body mass index > 30 kg∙m^-2 scheduled for elective cesarean delivery were randomly allocated equally (palpation group and ultrasound group). The primary outcome was the first insertion success rate. Secondary outcomes were the time taken to identify the needle puncture site, duration of CSEA procedure, the total time, the rate of parturients who require needle redirections, the number of skin punctures, changes in the intended interspace, and the incidence of complications.

RESULTS

Compared to the palpation group, the first insertion success rate was significantly higher (72.5% vs. 40.0%; P = 0.003), and time taken to identify the needle puncture site was less (30 [26-36] vs. 39 [32-49] seconds; P = 0.001) in the ultrasound group. The rate of parturients who required needle redirections (40.0% vs. 72.5%; P = 0.003) and the incidence of paresthesia were both lower (7.5% vs. 45.0%; P < 0.001). The other outcomes had no significant difference between groups. The mean difference between the epidural depth measured by the handheld ultrasound and needle depth was - 0.29 cm [95% limit of agreement, - 0.52 to - 0.05].

CONCLUSIONS

Our study suggests using the Accuro ultrasound device can enhance the efficacy and safety of CSEA in obese parturients when executed by experienced anesthesiologists, and its automated estimation of epidural depth is accurate.

Inadvertent neuraxial block placement at or above the L1-L2 interspace in the super-obese parturient: a retrospective study

BACKGROUND

Increasing body mass index (BMI) increases the difficulty of neuraxial procedures. We hypothesized that it may put patients at risk for inappropriately high dural puncture. The accuracy of anesthesiologists' estimates of the interspinous level in super-obese parturients has not been studied. We evaluated the frequency of inadvertently high epidural and/or intrathecal catheter placement (at or above the L1/L2 interspace) in parturients of BMI ≥50 kg/m².

METHODS

Inclusion criteria for this retrospective study were women with a BMI ≥50 kg/m² who delivered by cesarean with an epidural or intrathecal catheter. The primary outcome was the percentage of catheters placed at or above L1/L2, determined by reviewing the retained foreign object radiograph. Secondary outcomes were agreement between the estimated and actual catheter location and subgroup analysis of catheters placed under ultrasound guidance.

RESULTS

After excluding 15 cases for which the catheter location could not be determined and 10 cases for which the estimated level of insertion was not recorded, 125 cases were included. Inadvertent high placement occurred in 26/125 (21%, 95% confidence interval (CI) 15% to 29%) patients. There was poor agreement between the estimated and actual catheter location (27% accurate, unweighted κ-statistic 0.02). Eleven of 39 catheters placed with ultrasound (28%, 95% CI 17% to 44%) were at or above L1/L2 compared with 15/86 catheters placed without ultrasound (17%, 95% CI 11% to 27%, P=0.17). There were no neurological complications.

CONCLUSIONS

A high rate of inadvertently high epidural or intrathecal catheter placement occurs in super-obese parturients. Ultrasound did not prevent this.

Comparing Three Different Modified Sitting Positions for Ease of Spinal Needle Insertion in Patients Undergoing Spinal Anesthesia

Background

The most important point for performing a neuroaxial block in a sitting position is reducing lumbar lordosis, resulting in easier access to interspinous space and dura mater. There are a few studies comparing 2 different sitting positions including a traditional sitting position (TSP) versus forward bending or hamstring stretch position (HSP) as well as TSP versus squatting position (SP) for reversing the lumbar lordosis and improving access to intervertebral space for neuroaxial block.

Objectives

We compared 3 different sitting positions including traditional sitting position vs. hamstring stretch position vs. squatting position and hypothesized that squatting position reverses the lumbar lordosis and reduces the number of spinal needle bone contacts more than TSP and HSP.

Methods

A total of Thirty hundred and sixty ASA class I or II patients aged 18 to 60 years were scheduled for elective surgeries under spinal anesthesia were randomized into 3 groups. Our primary endpoint was the number of spinal needle-bone contacts and our secondary endpoint was ease of needle insertion or space identification.

Results

Demographic data were statistically different between the study groups. There was no statistical difference between the study groups regarding the number of needle bone contacts and the ease of finding intervertebral space (P = 0.63, P = 0.56, respectively).

Conclusions

There was no statistical difference between the TSP, HSP, and SP regarding the number of needle bone contacts and the ease of finding of intervertebral space. In this regard, each of these 3 positions can be used as an alternative sitting position for administration of spinal anesthesia.

Comparison of Successful Spinal Needle Placement Between Crossed-Leg Sitting Position and Traditional Sitting Position in Patients Undergoing Urology Surgery

BACKGROUND

The patient's position during spinal anesthesia administration plays a major role in the success of spinal needle insertion into the subarachnoid space. The traditional sitting position (TSP) is the standard position for spinal anesthesia administration, but the success rate for spinal anesthesia administration in the TSP is still quite low. The crossed-leg sitting position (CLSP) is one of the alternative positions for the administration of spinal anesthesia, which can increase the degree of lumbar flexion.

OBJECTIVES

This study aimed to compare successful spinal needle placement to patients in the CLSP and patients in the TSP prior to undergoing urology surgery.

METHODS

This study was a non-blinded, randomized controlled trial in patients undergoing spinal anesthesia for urologic procedures from March-October, 2015 in the central national hospital Dr. Cipto Mangunkusumo, Indonesia. After obtaining approval from the FMUI - RSCM (Faculty of Medicine Universitas Indonesia - Rumah Sakit Dr. Cipto Mangunkusumo) Ethical Committee and informed consent from patients, 211 subjects were allocated into two groups: the CLSP group (n = 105) and the TSP group (n = 106). The proportion of successful spinal needle placement to the subarachnoid space, ease of landmark palpation, and the number of needle-bone contacts in both groups were then assessed and analyzed.

RESULTS

The rate of first-time successful spinal needle insertion was not significantly different between the CLSP and TSP groups (62.9% versus 55.7%, P > 0.05). Ease of landmark palpation in the CLSP group was not significantly different from that in the TSP group (86.7% versus 76.4%, P > 0.05). The number of needle-bone contacts in both groups were not significantly different (P > 0.05). The complication rates were similar in both groups.

CONCLUSIONS

The rate of successful spinal needle placement in the CLSP group was not significantly different from that in the TSP group in patients undergoing urology surgery. The CLSP can be used as an alternative sitting position for administration of spinal anesthesia.

Abdominal circumference but not the degree of lumbar flexion affects the accuracy of lumbar interspace identification by Tuffier's line palpation method: an observational study

Background

Lumbar puncture for spinal or epidural anesthesia is commonly performed by palpating bony landmarks, but identification of the desired intervertebral level is often inaccurate. It is unclear whether such inaccuracy is related to patient factors, such as body mass index and degree of lumbar flexion. We hypothesized that overweight patients and patients with less of an ability to hyperflex their lumbar spines are prone to inaccurate lumbar spinous intervertebral level identification.

Methods

52 adult volunteers were included in this study. 7 anesthesiologists with different years of experience identified and marked subjects’ levels of the iliac crests, then marked the presumed interspaces. Lumbar X-ray was then performed with metal markers, and actual radiographic findings were identified and compared to the initial markings.

Results

Patients with larger abdominal circumferences (mean (SD), 94.0(12.1) cm), higher body mass indices (25.9(3.9) kg/m²), and aged between 50 and 70 years old had lumbar interspaces that were higher than the presumed level; patients with smaller abdominal circumferences (82.8(13.5) cm) and lower body mass indices (21.6(4.1) kg/m²) had intervertebral levels that were lower than the presumed level. Cobb’s angle, indicating the degree of lumbar flexion, did not affect the accuracy obtained.

Conclusions

Patients’ abdominal circumference, body mass index, and age are factors that may impact the accuracy of lumbar level identification. Tuffier’s line, as identified by palpation, does not seem to be a reliable landmark for proper lumbar interspace identification in all cases.