Ultrasound-Assisted Technology Versus the Conventional Landmark Location Method in Spinal Anesthesia for Cesarean Delivery in Obese Parturients: A Randomized Controlled Trial

Efficacy and safety of ultrasound-guided versus landmark-guided neuraxial puncture: a systematic review, network meta-analysis and trial sequential analysis of randomized clinical trials

BACKGROUND

Data suggest that preprocedural ultrasound may improve the efficacy of central neuraxial puncture. However, it remains uncertain whether these findings can be extended to various clinical scenarios, including diverse patient populations and the application of real-time ultrasound guidance. Additionally, it is unclear whether ultrasound-guided techniques improve safety and patient-centered outcomes.

METHODS

We searched six databases for randomized trials of adult patients undergoing neuraxial puncture, comparing real-time ultrasound, preprocedural ultrasound, and landmark palpation for efficacy, safety and patient-centered outcomes. Our primary outcome was a failed first-attempt neuraxial puncture. After two-person screening and data extraction, meta-analyses were conducted and the Grading of Recommendations Assessment, Development and Evaluation approach was applied to assess the certainty of evidence.

RESULTS

Analysis of 71 studies involving 7153 patients, both real-time ultrasound (OR 0.30; 95% credible interval (CrI) 0.15 to 0.58; low certainty) and preprocedural ultrasound (OR 0.33; 95% CrI 0.24 to 0.44; moderate certainty) showed a significant reduction in the risk of a failed first neuraxial puncture. Real-time ultrasound had the best performance for preventing first-attempt failures (low certainty evidence). Although real-time ultrasound was also the leading method for reducing the risk of complete neuraxial puncture failure, the results did not show a statistically significant difference when compared with landmark palpation. Preprocedural ultrasound, however, significantly reduced the odds of complete puncture failure (OR 0.29; 95% CrI 0.11 to 0.61). These ultrasound-guided approaches also contributed to a reduction in certain complications and increased patient satisfaction without any other significant differences in additional outcomes. Trial sequential analysis confirmed that sufficient information was achieved for our primary outcome.

CONCLUSIONS

Ultrasound-guided neuraxial puncture improves efficacy, reduces puncture attempts and needle redirections, reduces complication risks, and increases patient satisfaction, with low to moderate certainty of evidence. Despite real-time ultrasound's high ranking, a clear superiority over preprocedural ultrasound is not established. These results could prompt anesthesiologists and other clinicians to reassess their neuraxial puncture techniques.

Comparative efficacy of ultrasound guidance or conventional anatomical landmarks for neuraxial puncture in adult patients: a systematic review and network meta-analysis

BACKGROUND

Preprocedural, real-time, and computer-aided three-dimensional ultrasound has been widely used for neuraxial puncture; however, the optimal guidance is unclear. We examined the comparative efficacy of three ultrasound guidance and anatomical landmarks for neuraxial puncture in adults.

METHODS

We searched for randomised controlled studies comparing the efficacy of ultrasound guidance and anatomical landmarks for neuraxial puncture in adults using electronic databases and unpublished studies. The primary outcomes were first-pass success and patient satisfaction. A random-effects network meta-analysis (NMA) was used.

RESULTS

We identified 74 eligible studies (7090 patients). Preprocedural ultrasound and real-time ultrasound-guided neuraxial puncture improved first-pass success compared with anatomical landmarks (risk ratio [RR] 1.6; 95% credible interval [CrI] 1.3-1.9; RR 1.9; 95% CrI 1.3-2.9, respectively, moderate confidence). Computer-aided ultrasound-guided neuraxial puncture also increased first-pass success (RR 1.8; 95% CrI 0.97-3.3, low confidence), although estimates were imprecise. However, real-time ultrasound-guided neuraxial puncture resulted in minimal difference in first-pass success compared with preprocedural ultrasound (RR 1.2; 95% CrI 0.8-1.8, moderate confidence). Preprocedural ultrasound improved patient satisfaction slightly compared with anatomical landmark use (standardised mean differences 0.28; 95% CrI 0.092-0.47, low confidence).

CONCLUSIONS

This NMA provides evidence supporting ultrasound-guided neuraxial puncture compared with use of anatomical landmarks, including indirect comparisons. Among the three ultrasound guidance methods, preprocedural ultrasound appears to be a better adjunctive option.

Ultrasonography versus palpation for spinal anesthesia in obese parturients undergoing cesarean delivery: a randomized controlled trial

INTRODUCTION

Ultrasonography may facilitate neuraxial blocks in obstetrics. This randomized controlled trial aimed to compare preprocedural ultrasonography with landmark palpation for spinal anesthesia in obese parturients undergoing cesarean delivery.

METHODS

280 American Society of Anesthesiologists (ASA) physical status II-III parturients with body mass index ≥35 kg/m2, full-term singleton pregnancy, undergoing elective cesarean delivery under spinal anesthesia, were randomly assigned to two equal groups (ultrasonography and palpation); preprocedural systematic ultrasound approach and conventional landmark palpation were performed, respectively. Patients and outcome assessors were blinded to the study group. All ultrasound and spinal anesthetic procedures were performed by a single experienced anesthesiologist. The primary outcome was the number of needle passes required to obtain free cerebrospinal fluid (CSF) flow. Secondary outcomes were the number of skin punctures required to obtain free CSF flow, success rate at the first needle pass, success rate at the first skin puncture, duration of the spinal procedure, patient satisfaction and incidence of vascular puncture, paresthesia, failure to obtain CSF flow and failed spinal block.

RESULTS

There were no significant differences in primary or secondary outcomes between the two groups. The median (IQR) of the number of needle passes required to obtain free CSF flow was 3 (1-7) in ultrasonography group and 3 (1-7) in palpation group; p=0.62.

CONCLUSIONS

Preprocedural ultrasonography did not decrease the number of needle passes required to obtain free CSF flow or improve other outcomes compared with landmark palpation during spinal anesthesia performed by a single experienced anesthesiologist in obese parturients undergoing cesarean delivery.

TRIAL REGISTRATION NUMBER

NCT03792191; : https://clinicaltrials.gov/ct2/show/NCT03792191.

Administration of combined spinal epidural anesthesia with ultrasound-assisted positioning in obese patients undergoing open hysterectomy: A randomized controlled trial

BACKGROUND

Administration of combined spinal epidural anesthesia (CSEA) with traditional landmark-guided positioning can be challenging in patients with high body mass index (BMI). The popularization of ultrasound technology may effectively solve these problems. However, reports on the administration of CSEA ultrasound-assisted positioning in obese populations are relatively limited and have made inconsistent conclusions. We aimed to investigate the ability of ultrasound-assisted positioning to improve the success rate of CSEA in obese patients.

METHODS

Overall, 118 adult women with a BMI ≥ 30 kg/m2 who scheduled to undergo open hysterectomy and received CSEA were recruited. Finally, 108 patients were enrolled and randomly assigned to 2 groups: the ultrasound-assisted positioning group (group A) and traditional landmark-guided positioning group (group B). Ultrasound-assisted or landmark-guided positioning was employed to locate the puncture interspace before anesthesia. The primary outcomes were the success rate of first attempt and number of attempts. The secondary outcomes were the patient positioning accuracy, positioning time, CSEA operation time, patient-satisfaction scores, anesthesia characteristics, and complications of CSEA.

RESULTS

The success rate of patient first puncture attempt in group A was significantly higher than that in group B (78.4% vs 52.9%, P = .007). The total number of punctures was lower in group A than that in groups B (average rank 44.54 vs 58.46, P = .005). Using ultrasound positioning as the gold standard, the accuracy of landmark-guided location was only 67%. Positioning time in croup A was longer in group A than that in group B (P = .004), while CSEA operation time spent in Group A was less than that in Group B (P < .001). Patient satisfaction score in group A was significantly higher than that in group B (P = .002). The successful puncture interspace in group A were more likely at L3-4 than that in group B (P = .02).

CONCLUSION

The success rate of first puncture attempt and positioning accuracy in CSEA with ultrasound-assisted is significantly higher than those based on landmark-guided location in obese patients.

Comparison of ultrasound-guided and traditional localisation in intraspinal anesthesia: a systematic review and network meta-analysis

OBJECTIVES

The optimal puncture technique for neuraxial anaesthesia in different populations is unclear. We sought to obtain data from randomised controlled trials comparing the impact of ultrasound-guided technology and traditional positioning technology on the success rate of neuraxial anaesthesia.

DESIGN

Systematic review and network meta-analysis using study populations, interventions, intervention comparisons, outcome measures and study types.

DATA SOURCES

PubMed, Embase, Cochrane Library and Web of science were searched until 31 September 2022.

ELIGIBILITY CRITERIA

We included randomised controlled trials comparing three types of neuraxial anaesthesia: ultrasound-assisted, ultrasound real-time guidance and conventional positioning to describe which neuraxial anaesthesia modality is best for patients and to recommend the appropriate one for different populations.

DATA EXTRACTION AND SYNTHESIS

Five independent reviewers retrieved, screened and edited included studies using standardised methods. Assess risk of bias using the Cochrane Collaboration and Evidence Project tools. Network meta-analysis was performed using STATA V.15 statistical software.

RESULTS

Twenty-two studies containing three different interventions were included. The SUCRA values of first-pass success rates for the three neuraxial anaesthesia methods were real-time guidance (82.8%), ultrasound-assisted (67.1%) and traditional positioning (0.1%). Both ultrasound techniques improved first-pass success rates compared with traditional localization, but there was no significant difference between the two. Subgroup analysis showed that the use of real-time ultrasound guidance for neuraxial anaesthesia in pregnant and patients with obesity improved first-pass success rates. Ultrasound-assisted technology can improve first-attempt success rates in older patients with abnormal lumbar spine anatomy.

CONCLUSION

Compared with conventional positioning, ultrasound guidance technology can improve the first-pass success rate of neuraxial anaesthesia, but there is no significant difference between ultrasound-assisted and real-time guidance technology. The results of subgroup analysis tell us that the most suitable neuraxial anaesthesia method is different for different groups of people.

PROSPERO REGISTRATION NUMBER

PROSPERO number: CRD42022376041.

Ultrasound-assisted bony landmark palpation in untrained palpators

CONTEXT

Medical students with no previous experience may find it difficult to identify and palpate bony landmarks while learning physical examination skills. In a study of 168 medical schools, 72.6 % have indicated that they are utilizing ultrasound in their curriculum. Although the integration of ultrasound curriculum has become more widespread, the depth of instruction is inconsistent. Ultrasound is not commonly taught in conjunction with palpation of bony landmarks in osteopathic structural examination.

OBJECTIVES

The objective of this analysis was to identify whether utilizing ultrasound assistance in teaching palpation of specific thoracic vertebral bony landmarks would improve palpation accuracy in first-year medical students with no previous palpatory experience.

METHODS

First-year medical students were given video instructions to palpate and identify a thoracic vertebral transverse process and to mark it with invisible ink. The participants were then taught and instructed to utilize ultrasound to identify the same landmark and mark it with a different color. The accuracy of palpation was measured with digital calipers.

RESULTS

A test of the overall hypothesis that participants will show improved accuracy utilizing ultrasound compared with hand palpation was not significant (F=0.76, p>0.05). When separating students into groups according to patient body mass index (BMI), however, there was a trend toward significance (F=2.90, p=0.071) for an interaction effect between patient BMI and the repeated measures variable of palpation/ultrasound. When looking specifically at only those participants working with a normal BMI patient, there was a significant improvement in their accuracy with the use of ultrasound (F=7.92, p=0.017).

CONCLUSIONS

The analysis found increased accuracy in bony landmark identification in untrained palpators utilizing ultrasound vs. palpation alone in a normal BMI model, but not in obese or overweight BMI models. This study shows promise to the value that ultrasound may have in medical education, especially with respect to early palpation training and landmark identification.

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.

The lumbar subcutaneous fat gradient in spinal anesthesia seen for morbidly obese patient with pre-procedure ultrasonography - A case report

It has been reported that pre-procedure ultrasonography rises the success rate of spinal anesthesia in obese patients. In this article, we performed spinal anesthesia for morbidly obese patient with pre-procedure ultrasonography. And recognizing the lumbar subcutaneous fat gradient in morbidly obese patient was the key to success. A cesarean section was scheduled for a primigravida in her 30 s with BMI 61 kg/m2. The lumbar spine was not palpable. Pre-procedure ultrasonography revealed lumbar subcutaneous tissue getting thicker caudally in the sagittal view. Considering this fact, we adjusted the puncture site and succeeded. Postoperative complications were not observed. The pre-procedure ultrasonography is effective even in morbidly obese patients. It is important to recognize the lumbar subcutaneous fat gradient, the so-called back fat slope, for spinal anesthesia in obese patients.

Dual- vs. Single-Plane Ultrasonic Scan-Assisted Positioning during Lumbar Spinal Puncture in Elderly Patients: A Randomized Controlled Trial

The purpose of this study was to investigate the ability of single- versus dual-plane ultrasound scan-assisted spinal anesthesia techniques to improve the success rate and efficacy of spinal anesthesia in elderly patients undergoing lower extremity surgery. A total of 120 elderly patients undergoing lower extremity surgery were randomly assigned to either receive single-plane (Group A) or dual-plane ultrasonic scan-assisted spinal anesthesia (Group B). The primary outcome analyzed by this study was first-attempt success rate. Secondary outcomes analyzed included number of needle insertion attempts, needle redirections, locating time, procedural time, total time, puncture depth, quality of ultrasound images, level of block, adverse reactions, and complications. The first-attempt success rate was significantly higher in Group B compared to Group A (88.3% vs. 68.3%, p = 0.008). In comparison with Group A, the number of needle insertion attempts (1 (1−2) vs. 1 (1−1), p = 0.005) and needle redirections (2 (1−3) vs. 1 (0−2), p < 0.001) were both significantly lower in Group B; Group B also had a shorter procedural time (249.2 ± 30.1 vs. 380.4 ± 39.4 s, p < 0.001) but a longer locating time (250.1 ± 26.2 vs. 137.8 ± 13.5 s, p < 0.001). The dual-plane ultrasonic scan-assisted spinal anesthesia technique warrants consideration for application in elderly patients.

Femoral Positioning of the Anterolateral Ligament Graft With and Without Ultrasound Location of the Lateral Epicondyle

BACKGROUND

In anterior cruciate ligament (ACL) reconstruction with anterolateral ligament (ALL) reconstruction, precise positioning of the ALL graft on the femur and tibia is key to achieve rotational control. The lateral femoral epicondyle is often used as a reference point for positioning of the ALL graft and can be located by palpation or with ultrasound guidance.

PURPOSE

To compare the ALL graft positioning on the femoral side between an ultrasound-guided technique and a palpation technique for the location of the lateral epicondyle.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 120 patients receiving a primary combined ACL and ALL reconstruction between June and December 2019 were included. The location of the lateral epicondyle was determined by palpation in the palpation group (n = 60) and with preoperative ultrasound guidance in the ultrasound group (n = 60). Groups were comparable in age, sex, body mass index (BMI), and operated side. The planned positioning of the femoral ALL graft was proximal and posterior to the lateral epicondyle. The effective positioning of the femoral ALL graft was evaluated on postoperative lateral radiographs. The primary outcome was location of the graft in a 10-mm quadrant posterior and proximal to the lateral epicondyle. Results were analyzed in 2 subgroups according to BMI.

RESULTS

All 60 anterolateral grafts (100%) in the ultrasound group were positioned in a 10-mm quadrant posterior and proximal to the lateral epicondyle, as opposed to 52 (87%) in the palpation group (P = .006). Errors in graft positioning with palpation occurred in overweight patients (BMI >25) as well as nonoverweight patients (P = .3).

CONCLUSION

Femoral positioning of the ALL graft posterior and proximal to the lateral epicondyle is more reproducible with ultrasound guidance when compared with palpation alone, regardless of BMI.

The role of ultrasonography in anesthesia for bariatric surgery

Bariatric surgeries are effective long-term management for morbid obesity with its adverse sequelae. Anesthesia of bariatric surgeries poses unique challenges for the anesthesiologist in every step starting with vascular access till tracheal extubation. The usage of ultrasound in anesthesia is becoming more prevalent with a variety of benefits, especially in the obese population. Ultrasound is successfully used for obtaining vascular access, with more than 15 million catheters placed in the United States alone. Ultrasound can also be used to predict difficult intubation, as it can confirm the tracheal intubation and assess the gastric content to prevent pulmonary aspiration. Ultrasound is also used in the management of mechanically ventilated patients to monitor lung aeration and to identify respiratory complications during positive pressure ventilation. Moreover, intraoperative echocardiography helps to discover the pulmonary embolism and guides the fluid therapy. Finally, ultrasound can be used to perform neuraxial and fascial plane block with a less overall time of the procedures and minimal complications. The wide use of ultrasound in bariatric anesthesia reflects the learning curve of the anesthesiologists and their mounting efforts to provide safe anesthesia utilizing the updated technology. In this review, we highlight the role of ultrasonography in anesthesia of bariatric surgery and discuss the recent guidelines.

A comparative study of ultrasound assisted versus landmark technique for combined spinal-epidural anaesthesia in patients undergoing lower limb orthopaedic surgery

Background and Aims:

Spinal anatomy is better visualised in the para sagittal oblique view with the aid of ultrasonography. The present study was undertaken to investigate whether preprocedural ultrasonography can facilitate the ease of establishing combined spinal epidural (CSE) via paramedian approach versus landmark approach in patients undergoing lower limb orthopaedic surgery.

Methods:

This prospective randomised study was conducted in 100 American Society of Anesthesiologists (ASA) grade I-II patients, aged 18-60 years requiring CSE and randomly divided into two groups: Ultrasound-assisted (USG) group (n = 50) and Surface landmark (SLG) group (n = 50). The primary outcome was to compare the first pass needle success rate to establish CSE and the secondary outcomes were to compare the number of needle puncture attempts, time to establish landmarks (t1), time to accomplish CSE (t2) and complications.

Results:

First pass needle success rate in USG group was 43 (86.0%) versus 36 (60.0%) in SLG group (P = 0.001). Number of attempts taken to establish CSE was lower in USG group as compared to SLG group (P = 0.023). t1 was greater in USG group (1.45 ± 0.47) minutes as compared to (0.79 ± 0.34) minutes in SLG group (P = 0.003). t2 was reduced in USG group (1.47 ± 0.55) minutes versus (2.73 ± 1.36) minutes in SLG group (P = 0.005).

Conclusion:

Preprocedural USG for CSE via paramedian approach increases first pass needle success rate and reduces needle puncture attempts in patients undergoing lower limb orthopaedic surgery.

Real-Time Ultrasound-Guided Versus Ultrasound-Assisted Spinal Anesthesia in Elderly Patients With Hip Fractures: A Randomized Controlled Trial

BACKGROUND

Traditional landmark-guided spinal anesthesia can be challenging in elderly patients with hip fractures. Ultrasound assistance (USAS) and real-time ultrasound guidance (USRTG) techniques can facilitate lumbar neuraxial blocks. However, it remains undetermined which method is optimal for use in elderly patients. This study aimed to evaluate which technique was associated with a higher success rate of spinal anesthesia in elderly patients with hip fractures: USAS or USRTG technique.

METHODS

A total of 114 elderly patients (≥70 years of age) with hip fractures were randomly assigned to receive spinal anesthesia using either the USAS or USRTG technique. The primary outcome was the first-attempt success rate, analyzed using the χ2 test. Secondary outcomes included first-pass success rate, the number of needle attempts and passes, locating time, procedure time, total time, adverse reactions and complications, patient satisfaction, and procedural difficulty score.

RESULTS

The first-attempt success rate (80.7% vs 52.6%; 95% confidence interval [CI], for the difference, 11.6-44.6) and first-pass success rate (63.2% vs 31.6%; 95% CI for the difference, 14.2-49) were both significantly higher in the USAS compared with the USRTG group (both P = .001). The number of attempts (1 [1-1] vs 1 [1-3]; P = .001) and median passes (1 vs 3; P < .001) were both significantly lower in the USAS group than in the USRTG group. The USRTG group had a shorter locating time (175 seconds [129-234 seconds] vs 315 seconds [250-390 seconds]; P < .001) but a longer procedure time (488 seconds [260-972 seconds] vs 200 seconds [127-328 seconds]; P < .001) and total time (694 seconds [421-1133 seconds] vs 540 seconds [432-641 seconds]; P = .036). There were no significant differences between the 2 groups with regard to the adverse reactions and complications. More patients in the USAS group had a high satisfaction score of 3 to 5 (P = .008). Overall, anesthesiologists rated the USRTG group procedure as "more difficult" (P = .008).

CONCLUSIONS

In elderly patients with hip fractures, spinal anesthesia with the USRTG technique is not superior to the USAS technique since it has a lower success rate, longer procedure time, lower satisfaction score, and is more difficult to perform. So USAS technique may be more suitable for elderly patients.

Comparison of different approaches to combined spinal epidural anesthesia (CSEA) under the guidance of ultrasound in cesarean delivery of obese patients: a randomized controlled trial

Background

Combined spinal epidural anesthesia (CSEA) is commonly performed in cesarean deliveries. However, it is difficult to perform in obese parturients because of positioning challenges. The aim of this study was to compare the effect of different approaches to CSEA under the guidance of ultrasound.

Methods

One hundred obese patients (BMI ≥ 30 kg/m²) who underwent elective cesarean section were randomly enrolled. Patients were assigned to a median approach group and a paramedian approach group randomly. Clinical characteristics were compared between groups. First-attempt success rate, the median positioning time and total operation time, ultrasonic predicted anesthesia puncture depth, actual puncture depth, anesthesia adverse reactions, complications after anesthesia, and patients’ satisfaction with the epidural puncture were recorded.

Results

The first-attempt success rate was significantly different between the two groups [92% (46/50) vs. 76% (38/50), P  =  0.029]. The median positioning time and total operation time in the paramedian approach group were higher than those in the median approach group (227.7 s vs. 201.6 s, P  =  0.037; 251.3 s vs. 247.4 s, P  =  0.145). The incidence of postanesthesia complications in the paramedian approach group was significantly lower than that in the median approach group (2% vs. 12%, P  =  0.026), and patient satisfaction was higher in the paramedian approach group than in the median approach group (P  =  0.032).

Conclusion

The ultrasound-guided paramedian approach for CSEA is time-consuming, but it can effectively improve the success rate of the first puncture, reduce the incidence of anesthesia-related adverse reactions, and improve patient satisfaction.

Trial registration: This study was registered with the Chinese Clinical Trial Registry (ChiCTR1900024722) on July 24, 2019

Ultrasound Imaging of the Spine for Central Neuraxial Blockade: a Technical Description and Evidence Update

Purpose of Review

This article describes the anatomy of the spine, relevant ultrasonographic views, and the techniques used to perform the neuraxial blocks using ultrasound imaging. Finally, we review the available evidence for the use of ultrasound imaging to perform neuraxial blocks.

Recent Findings

Central neuraxial blockade using traditional landmark palpation is a reliable technique to provide surgical anesthesia and postoperative analgesia. However, factors like obesity, spinal deformity, and previous spine surgery can make the procedure challenging. The use of ultrasound imaging has been shown to assist in these scenarios.

Summary

Preprocedural imaging minimizes the technical difficulty of spinal and epidural placement with fewer needle passes and skin punctures. It helps to accurately identify the midline, vertebral level, interlaminar space, and can predict the depth to the epidural and intrathecal spaces. By providing information about the best angle and direction of approach, in addition to the depth, ultrasound imaging allows planning an ideal trajectory for a successful block. These benefits are most noticeable when expert operators carry out the ultrasound examination and for patients with predicted difficult spinal anatomy. Recent evidence suggests that pre-procedural neuraxial ultrasound imaging may reduce complications such as vascular puncture, headache, and backache. Neuraxial ultrasound imaging should be in the skill set of every anesthesiologist who routinely performs lumbar or thoracic neuraxial blockade. We recommend using preprocedural neuraxial imaging routinely to acquire and maintain the imaging skills to enable success for challenging neuraxial procedures.

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.

Pre-Procedural Lumbar Neuraxial Ultrasound-A Systematic Review of Randomized Controlled Trials and Meta-Analysis

A pre-procedural ultrasound of the lumbar spine is frequently used to facilitate neuraxial procedures. The aim of this review is to examine the evidence sustaining the utilization of pre-procedural neuraxial ultrasound compared to conventional methods. We perform a systematic review of randomized controlled trials with meta-analyses. We search the electronic databases Medline, Cochrane Central, Science Direct and Scopus up to 1 June 2019. We include trials comparing a pre-procedural lumbar spine ultrasound to a non-ultrasound-assisted method. The primary endpoints are technical failure rate, first-attempt success rate, number of needle redirections and procedure time. We retrieve 32 trials (3439 patients) comparing pre-procedural lumbar ultrasounds to palpations for neuraxial procedures in various clinical settings. Pre-procedural ultrasounds decrease the overall risk of technical failure (Risk Ratio (RR) 0.69 (99% CI, 0.43 to 1.10), p = 0.04) but not in obese and difficult spinal patients (RR 0.53, p = 0.06) and increase the first-attempt success rate (RR 1.5 (99% CI, 1.22 to 1.86), p < 0.0001, NNT = 5). In difficult spines and obese patients, the RR is 1.84 (99% CI, 1.44 to 2.3; p < 0.0001, NNT = 3). The number of needle redirections is lower with pre-procedural ultrasounds (SMD = −0.55 (99% CI, −0.81 to −0.29), p < 0.0001), as is the case in difficult spines and obese patients (SMD = −0.85 (99% CI, −1.08 to −0.61), p < 0.0001). No differences are observed in procedural times. Ιn conclusion, a pre-procedural ultrasound provides significant benefit in terms of technical failure, number of needle redirections and first attempt-success rate. Τhe effect of pre-procedural ultrasound scanning of the lumbar spine is more significant in a subgroup analysis of difficult spines and obese patients.

Epidural analgesia in the obese obstetric patient: a retrospective and comparative study with non-obese patients at a tertiary hospital

Background and objectives

Obesity is becoming a frequent condition among obstetric patients. A high body mass index (BMI) has been closely related to a higher difficulty to perform the neuraxial technique and to the failure of epidural analgesia. Our study is aimed at analyzing obese obstetric patients who received neuraxial analgesia for labor at a tertiary hospital and assessing aspects related to the technique and its success.

Methods

Retrospective observational descriptive study during one year. Women with a BMI higher than 30 were identified, and variables related to the difficulty and complications of performing the technique, and to analgesia failure rate were assessed.

Results and conclusions

Out of 3653 patients, 27.4% had their BMI ≥ 30 kg.m-². Neuraxial techniques are difficult to be performed in obese obstetric patients, as showed by the number of puncture attempts (≥ 3 in 9.1% obese versus 5.3% in non-obese being p < 0.001), but the incidence of complications, as hematic puncture (6.6%) and accidental dural puncture (0.7%) seems to be similar in both obese and non-obese patients. The incidence of cesarean section in obese patients was 23.4% (p <  0.001). Thus, an early performance of epidural analgesia turns out to be essential to control labor pain and to avoid a general anesthesia in such high-risk patients.

Anesthetic Management of a Super Morbidly Obese Obstetric Patient With a Body Mass Index of 109 kg/m2 Presenting for Her Fourth Caesarean Delivery

Morbidly obese obstetric patients undergoing anesthesia present many unique challenges. Previous caesarean sections (CSs) further complicate their management. We present the successful anesthetic management of a super morbidly obese obstetric patient with body mass index (BMI) of 109 kg/m² who underwent her fourth CS. As per our review, this patient has the highest recorded BMI in the obstetric anesthesia literature.

A 27-year-old female, G4P3003, presented for fourth repeat CS at 38 weeks’ gestation. She had obstructive sleep apnea, hypertension, atrial fibrillation, and type 2 diabetes. Her first CS was emergent under general anesthesia (GA), and the other two were performed under neuraxial anesthesia, with the most recent one complicated by intraoperative cardiac arrest requiring cardiopulmonary resuscitation. Preoperative preparation involved multidisciplinary preparation, planning, and risk stratification. Although neuraxial anesthesia is preferred over GA for CS, she refused neuraxial anesthesia due to her prior traumatic experience and the potential that it caused her prior cardiac arrest. In addition, her inability to position for a block or lay flat, poor anatomical landmarks, unknown length of surgery, plan for periumbilical incision, uncertain placental status, and risk of massive hemorrhage convinced us to consider GA. Surprisingly, her airway examination was reassuring. Two 18G peripheral intravenous lines and an arterial line were obtained prior to induction. With optimum patient positioning and preoxygenation, modified rapid sequence induction with mask ventilation and endotracheal intubation with direct laryngoscopy were performed. A healthy baby was delivered without significant intraoperative complications. Intraoperative lung-protective strategy with recruitment maneuvers, multimodal analgesia, and elective postoperative continuous positive airway pressure aided in successful extubation. Postoperatively, pulmonary toilet, early mobilization, physical therapy, and venous thromboembolism prophylaxis were employed. Her postoperative course was complicated by severe preeclampsia and pulmonary embolism, which were managed successfully in the intensive care unit. She was discharged initially to outpatient rehabilitation followed by home. This case highlights the complexities and significance of an individualized approach in managing super morbidly obese obstetric patients.

Efficacy of ultrasound guidance for lumbar punctures: a systematic review and meta-analysis of randomised controlled trials

Ultrasound guidance has been reported to facilitate the performance of lumbar punctures (LPs). However, the use of ultrasound guidance has not yet received consistent conclusions. We performed a systematic review and meta-analysis to determine the efficacy of ultrasound-guided LPs. PubMed, Embase and the Cochrane Library were searched for randomised controlled trials comparing ultrasound guidance with traditional palpation for LPs in adults. The primary outcome was risk of failed procedures. A random-effects Mantel-Haenzsel model or random-effects inverse variance model was used to calculate relative risks (RRs) or standardised mean differences (SMDs) with 95% CIs. Twenty-eight trials (N=2813) met the inclusion criteria. Ultrasound-guided LPs were associated with a reduced risk of failed procedures (RR=0.58, 95% CI 0.39 to 0.85, p=0.005). No significant heterogeneity was detected (I2=27%) among these trials. It further decreased first attempt to failure (RR=0.43, 95% CI 0.30 to 0.62, p<0.00001), mean attempts to success (SMD=-0.61, 95% CI -0.80 to -0.43, p=0.00001) and incidences of complications of headache and backache (RR=0.63, 95% CI 0.46 to 0.85, p=0.003). Ultrasound guidance is an effective technique for LPs in adults.

Landmark-guided versus modified ultrasound-assisted Paramedian techniques in combined spinal-epidural anesthesia for elderly patients with hip fractures: a randomized controlled trial

Background

Combined spinal-epidural (CSE) anesthesia is considerably challenging for elderly patients with hip fractures due to spine degeneration and limitations in positioning. This study aimed to investigate the ability of a modified preprocedural ultrasound-guided technique to improve the success rate and efficacy of CSE anesthesia for elderly patients with hip fractures.

Methods

This prospective, single-blinded, parallel-group randomized controlled trial included 80 patients (aged ≥65 years) who were scheduled for elective hip fracture surgery with CSE anesthesia. Patients were randomly allocated into landmark group (n = 40) or the ultrasound group (n = 40). The primary outcome was first-pass success rate. Secondary outcomes included first-attempt success rate; number of needle insertion attempts; number of needle passes; locating, puncture, and total time; level of block; procedural adverse reactions and postoperative complications; and patient satisfaction score. Patients were blinded to group allocation.

Results

Eighty patients completed the study and were included in the final analysis. The first-pass success rates for the landmark and ultrasound groups were 20 and 70%, respectively (P < 0.001). The first-attempt success rates in the landmark and ultrasound groups were 42.5 and 85%, respectively (P < 0.001). The median number of attempts was lower in ultrasound-assisted group (1 [1]) than landmark-guided group (2 [1, 2]), P < 0.001). The median number of needle passes was lower in ultrasound group (1 [1, 2]) than in landmark-guided group (3 [2, 4], P < 0.001). The locating time (P < 0.001) and total time (P = 0.001) were longer in the ultrasound group, while puncture time was shorter (P = 0.003). No significant difference was found regarding the incidence of adverse reactions and complications. More patients in the ultrasound group had a high satisfaction score of 4–5 (P = 0.007). Interestingly, subgroup analysis demonstrated benefits for ultrasound in patients with scoliosis.

Conclusions

Modified ultrasound-assisted CSE anesthesia increases first-pass and first-attempt success rates, and reduces needle insertion attempts, passes, and puncture time for elderly patients with hip fracture, especially those with scoliosis. This technique improves patient satisfaction and warrants consideration for application in clinical practice.

Trial registration

Chinese Clinical Trial Register (identifier, ChiCTR1900020819; date of registration, January 20, 2019).

Conventional landmark palpation vs. preprocedural ultrasound for neuraxial analgesia and anaesthesia in obstetrics - a systematic review and meta-analysis with trial sequential analyses

The aim of this systematic review and meta-analysis was to examine the efficacy, time taken and the safety of neuraxial blockade performed for obstetric patients with the assistance of preprocedural ultrasound, in comparison with the landmark palpation method. The bibliographic databases Central, CINAHL, EMBASE, Global Health, MEDLINE, Scopus and Web of Science were searched from inception to 13 February 2020 for randomised controlled trials that included pregnant women having neuraxial procedures with preprocedural ultrasound as the intervention and conventional landmark palpation as the comparator. For continuous and dichotomous outcomes, respectively, we calculated the mean difference using the inverse-variance method and the risk ratio with the Mantel-Haenszel method. In all, 22 trials with 2462 patients were included. Confirmed by trial sequential analysis, preprocedural ultrasound increased the first-pass success rate by a risk ratio (95%CI) of 1.46 (1.16-1.82), p = 0.001 in 13 trials with 1253 patients. No evidence of a difference was found in the total time taken between preprocedural ultrasound and landmark palpation, with a mean difference (95%CI) of 50.1 (-13.7 to 113.94) s, p = 0.12 in eight trials with 709 patients. The quality of evidence was graded as low and very low, respectively, for these co-primary outcomes. Sub-group analysis underlined the increased benefit of preprocedural ultrasound for those in whom the neuraxial procedure was predicted to be difficult. Complications, including postpartum back pain and headache, were decreased with preprocedural ultrasound. The adoption of preprocedural ultrasound for neuraxial procedures in obstetrics is recommended and, in the opinion of the authors, should be considered as a standard of care, in view of its potential to increase efficacy and reduce complications without significant prolongation of the total time required.

Could preprocedural ultrasound increase the first-pass success rate of neuraxial anesthesia in obstetrics? A systematic review and meta-analysis of randomized controlled trials

Neuraxial anesthesia is a common practice in obstetrics. Evidence suggests that preprocedural ultrasound versus the conventional landmark location method accurately identifies a given intervertebral space and predicts the needle insertion depth required to reach the spinal canal. However, whether the preprocedural ultrasound examination improves the first-pass success (FPS) rate remains elusive. Major databases were systematically searched for all relevant studies published in English up to June 2019. Eighteen randomized controlled trials including 1844 patients were enrolled. The quality of eligible studies was assessed, and predefined outcomes were synthesized by meta-analysis. The primary results showed that preprocedural ultrasound increased the FPS rate in patients with predicted puncture difficulty but not in patients who were easily punctured. Preprocedural ultrasound reduced the number of redirections and punctures and decreased the incidence of vascular puncture and backache. There was no evidence of a reduction in failed punctures. We also noted that preprocedural ultrasound prolonged the identification time but not the procedure time. Thus, this systematic review provides evidence that preprocedural ultrasound does not improve the FPS rate of neuraxial anesthesia in patients who are easily palpated, although it increases the FPS rate in patients who are difficult to palpate.