Does Preprocedural Ultrasound Increase the First-Pass Success Rate of Epidural Catheterization Before Cesarean Delivery? A Randomized Controlled Trial

Ultrasound assisted versus landmark based intrathecal administration of nusinersen in adults with spinal muscular atrophy disease: A randomized trial

INTRODUCTION/AIMS

Nusinersen intrathecal administration can be challenging in spinal muscular atrophy (SMA) adults. We aimed to determine if the ultrasound (US)-assistance reduces the number of needle attempts and needle redirections needed for intrathecal drug administration and its impact on the procedure time, the incidence of adverse events (AEs), and patient satisfaction in these patients.

METHODS

Fifty-eight patients aged 18 years and older scheduled for intrathecal nusinersen injection were enrolled and randomized (1:1 ratio) into Group 1 (nusinersen infusion with US-assisted technique) or Group 2 (nusinersen infusion with landmark-based technique). The number of attempts, number of redirections, periprocedural time, AEs and patient satisfaction were reported. Continuous variables were compared with the Student t-test or Wilcoxon rank sum test. Categorical variables were evaluated with the Chi-square test or Fisher's exact test in case of expected frequencies <5. The p-values <.05 were considered statistically significant.

RESULTS

There were no statistical differences in the number of attempts, AEs, or patient satisfaction between the two groups. The number of needle redirections was significantly lower in the ultrasound group versus landmark-based group (p < .05) in both the overall group of patients and in the subgroup with difficult spines. The periprocedural time was about 40 seconds longer in US-group versus landmark-based group (p < .05).

DISCUSSION

In SMA adults, US assistance reduces the number of needle redirections needed for intrathecal drug administration. These results suggest that the US assistance may be advantageous for nusinersen therapy to reduce the therapeutic burden of intrathecal infusion.

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.

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.

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.

Impact of Ultrasound-Assisted Method on Success Rate of Spinal Anesthesia Performed by Novice Trainees: A Retrospective Comparative Study

In current practice, single-shot spinal anesthesia has traditionally been performed using the conventional surface-anatomic-Landmark-Guided technique. This "blind" technique has significant critical issues such as a high risk of complications due to the numerous attempts at spinal needle placement and the negative impact on the learning curve of the trainees. Ultrasound-Assisted spinal anesthesia could reduce these critical issues and allow trainees to perform the procedure more easily and with fewer complications for the patient. We performed a before-and-after monocentric retrospective comparative study at the University of Naples "Federico II" (Naples, Italy). Inclusion criteria were as follows: patients aged 18 years or older; ASA physical status between I and IV; and elective orthopedic surgery under single-shot spinal anesthesia performed by supervised trainees between January 2022 and December 2022. In the selected cohort, 88 patients were included in group A (Landmark-Guided spinal anesthesia) and 91 in group B (Ultrasound-Assisted spinal anesthesia). The number of attempts by trainees (p-value < 0.005), procedure performing time (<0.001), and patient discomfort (<0.001) were significantly lower in group B than in group A. Ultrasound-Assisted single-shot spinal anesthesia performed by novice trainees reduces the number of attempts, complication rate, periprocedural pain, and patient discomfort.

Usage of augmented reality for interventional neuraxial procedures: A phantom-based study

BACKGROUND

Neuraxial access is necessary for an array of procedures in anaesthesia, interventional pain medicine and neurosurgery. The commonly used anatomical landmark technique is challenging and requires practical experience.

OBJECTIVE

We aimed to evaluate the technical feasibility of an augmented reality-guided approach for neuraxial access and tested the hypothesis that its use would improve success as the primary outcome. As secondary outcomes, we measured accuracy and the procedural duration compared with the classical landmark approach.

DESIGN

A randomised phantom-based study.

SETTING

The three-dimensional image of a thoracolumbar phantom spine model with the surrounding soft tissue was created with a neurosurgical planning workstation and ideal trajectories to the epidural space on the levels T10-L1 were planned using a paramedian approach. Both the three-dimensional holographic image of the spine and the trajectories were transferred to an augmented reality-headset. Four probands (two anaesthesiologists, one neuroradiologist and one stereotactic neurosurgeon) performed 20 attempts, 10 each of either conventional landmark or augmented reality-guided epidural punctures, where anatomical level, side and sequence of modality were all randomised.

OUTCOME MEASURES

Accuracy was assessed by measuring Euclidean distance and lateral deviation from the predefined target point. Success of epidural puncture on the first attempt was compared between the conventional and the augmented reality-guided approaches.

RESULTS

Success was achieved in 82.5% of the attempts using augmented reality technique, compared with 40% with the conventional approach [ P  = 0.0002, odds ratio (OR) for success: 7.07]. Euclidean distance (6.1 vs. 12 mm, P  < 0.0001) and lateral deviation (3.7 vs. 9.2 mm, P  < 0.0001) were significantly smaller using augmented reality. Augmented reality-guided puncture was significantly faster than with the conventional landmark approach (52.5 vs. 67.5 s, P  = 0.0015).

CONCLUSION

Augmented reality guidance significantly improved the accuracy and success in an experimental phantom model of epidural puncture. With further technical development, augmented reality guidance might prove helpful in anatomically challenging neuraxial procedures.

A novel ultrasound software system for lumbar level identification in obstetric patients

PURPOSE

Using machine learning, we developed a proprietary ultrasound software called the Spine Level Identification (SLIDE) system, which automatically identifies lumbar landmarks in real time as the operator slides the transducer over the lumber spine. Here, we assessed the agreement between SLIDE and manual palpation and traditional lumbar ultrasound (LUS) for determining the primary target L3-4 interspace.

METHODS

Upon institutional ethics approval and informed consent, 76 healthy term parturients scheduled for elective Caesarean delivery were recruited. The L3-4 interspace was identified by manual palpation and then by the SLIDE method. The reference standard was located using traditional LUS by an experienced operator. The primary outcome was the L3-4 interspace identification agreement of manual palpation and SLIDE with the reference standard, as percentage agreement and Gwet's agreement coefficient (AC1).

RESULTS

The raw agreement was 70% with Gwet's agreement coefficient (AC1) = 0.59 (95% confidence interval [CI], 0.41 to 0.77) for manual palpation and 84% with Gwet's AC1 = 0.82 (95% CI, 0.70 to 0.93) for SLIDE. When the levels differ from the reference, the manual palpation method identified L2-3 more often than L4-5 while the SLIDE method identified equally above or below L3-4. The SLIDE system had greater agreement than palpation in locating L3-4 and all other lumber interspaces after controlling for body mass index (adjusted odds ratio, 2.99; 95% CI, 1.21 to 8.7; P = 0.02).

CONCLUSION

The SLIDE system had higher agreement with traditional ultrasound than manual palpation did in identifying L3-4 and all other lumber interspaces after adjusting for BMI in healthy term obstetric patients. Future studies should examine factors that affect agreement and ways to improve SLIDE for clinical integration.

STUDY REGISTRATION

www.

CLINICALTRIALS

gov (NCT02982317); registered 5 December 2016.

Usefulness and accuracy of a handheld ultrasound device for epidurssal landmark and depth assessment by anesthesiology residents

PURPOSE

The aim of this study was to assess the usefulness and accuracy of a handheld ultrasound device (Accuro, Rivanna Medical, Charlottesville, VA, USA) for epidural landmark and depth assessment when epidural anesthesia is performed by residents.

METHODS

Patients scheduled to receive epidural anesthesia were randomly assigned to the Accuro group (group A) or control group (group C). In group A, the depth to the epidural space and the appropriate place for epidural insertion according to Accuro was recorded. In group C, epidural anesthesia was performed using a conventional method. The following were recorded and compared between the groups: time from puncture of the Tuohy needle to loss of resistance, number of Tuohy needle redirects, and epidural-related complications. In group A, depth to the epidural space estimated by Accuro (Accuro Depth) and the actual depth measured with a marker on the needle (Needle Depth) were recorded and compared.

RESULTS

Sixty patients were enrolled during the study period. There was no significant difference between the groups regarding the median or range of time required to locate the epidural space. The number of Tuohy needle redirects was 0 (0-3) in group A and 1.5 (0-7) in group C (P = 0.012). Accuro Depth was less than Needle Depth [mean difference, 0.85 cm (95% CI-1.10 to - 0.62), SD = 0.62].

CONCLUSIONS

Although there was no significant difference in time from Tuohy needle puncture to loss of resistance, Accuro reduced the number of Tuohy needle redirects and accurately indicated the depth to the epidural space. Accuro may be useful for identifying the needle insertion point and estimating depth to the epidural space when residents perform epidural anesthesia.

Neuraxial labor analgesia: Initiation techniques

The ideal technique for labor analgesia would have a quick onset, predictable quality, and adjustable depth and duration. Moreover, it would be easy to perform and have minimal maternal and fetal side effects. A catheter-based neuraxial approach encompasses these desirable characteristics and includes the epidural, combined spinal epidural, dural puncture epidural, and intrathecal catheter techniques. In this review, we outline the unique technical considerations, analgesic characteristics, and side effect profiles for each technique that can ultimately impact the maternal-fetal dyad. The selection of neuraxial analgesia techniques should consider the patient and team's goals and expectations, the clinical context, and the institutional culture. Labor analgesic techniques that initiate with an intentional dural puncture component have a faster onset, greater bilateral and sacral spread, and lower rates of epidural catheter failure. Further elucidation of the mechanisms, benefits, and risks of each neuraxial initiation technique will continue to benefit patients and care providers.

Anatomical dimensions of the lumbar dural sac predict the sensory block level of continuous epidural analgesia during labor

BACKGROUND

The anatomical dimensions of the lumbar dural sac determine the sensory block level of spinal anesthesia; however, whether they show the same predictive value during continuous epidural anesthesia (CEA) remains undetermined. We designed the present study to verify the efficacy of the anatomical dimensions of the lumbar dural sac in predicting the sensory block level during labor analgesia.

METHODS

A total of 122 parturients with singleton pregnancies requesting labor analgesia were included in this study. The lumbar dural sac diameter (DSD), lumbar dural sac length (DSL), lumbar dural sac surface area (DSA), and lumbar dural sac volume (DSV) were measured with an ultrasound color Doppler diagnostic apparatus. CEA was performed at the L2-L3 interspace. After epidural cannulation, an electronic infusion pump containing 0.08% ropivacaine and sufentanil 0.4 μg/ml was connected. The sensory block level was determined with alcohol-soaked cotton, a cotton swab, and a pinprick. The analgesic efficacy of CEA was determined with a visual analog scale (VAS). The parturients were divided into two groups, "ideal analgesia" and "nonideal analgesia," and the groups were compared by t test. Pearson's correlation was performed to evaluate the association between the anatomical dimensions of the lumbar dural sac and sensory block level. Multiple linear regression analysis was used to create a model for predicting the sensory block level.

RESULTS

In the ideal analgesia group, the height, DSL, DSA, DSV and DSD were significantly smaller, and the body mass index (BMI) was significantly larger (P < 0.05). In addition, the DSL demonstrated the strongest correlation with the peak level of pain block (r = - 0.816, P < 0.0001; Fig. 2A), temperature block (r = - 0.874, P < 0.0001; Fig. 3A) and tactile block (r = - 0.727, P < 0.0001; Fig. 4A). Finally, the multiple linear regression analysis revealed that DSL and BMI contributed to predicting the peak sensory block level.

CONCLUSION

In conclusion, our study shows that the sensory block level of CEA is higher when the DSL, DSA, DSV and DSD of puerperae are lower. DSL and BMI can be treated as predictors of the peak sensory block level in CEA during labor analgesia.

Mathematical Models for the Skin to Lumbosacral Epidural Distance in Dogs: A Cadaveric Computed-Tomography Study

This study aimed to validate previously published computed tomography (CT) derived mathematical equations with the true skin to lumbosacral epidural distance (SLED) in dog cadavers. Phase 1: The lumbar region of 11 dog cadavers were scanned in sternal recumbency to determine the effect of cranial, neutral, and caudal pelvic limb positioning on the CT derived lumbosacral epidural distance (CLED). Phase 2: The epidural space was determined using contrast epidurography, and the SLED was analysed against the mathematical equations using a body condition score (BCS) and either the cadaveric occipital-coccygeal length (OCL) (Equation (1): = 7.3 + 0.05*OCL + 16.45*BCS) or the ilium wing distance (IWD) (Equation (2): = 3.5 + 0.56*IWD + 16.6*BCS). There were no differences detected between the pelvic limb positions and the CLED. Both equations demonstrated strong correlations (Equation (1): r = 0.7196; Equation (2): r = 0.7590) with the SLED. The level of agreement was greater for Equation (1) than with Equation (2) (concordance coefficient 0.6061 and 0.3752, respectively). Equation (1) also demonstrated a closer fit to the concordance line compared with Equation (2) (bias correction factor 0.8422 and 0.4960, respectively). Further studies in live anaesthetised dogs will help to determine the usefulness of the pre-procedural knowledge when performing lumbosacral epidurals.

A randomized trial to investigate needle redirections/re-insertions using a handheld ultrasound device versus traditional palpation for spinal anesthesia in obese women undergoing cesarean delivery

BACKGROUND

Ultrasound may be useful to identify the spinal anesthesia insertion point, particularly when landmarks are not palpable. We tested the hypothesis that the number of needle redirections/re-insertions is lower when using a handheld ultrasound device compared with palpation in obese women undergoing spinal anesthesia for cesarean delivery.

METHODS

Study recruits were obese (body mass index (BMI) >30 kg/m²) women with impalpable bony landmarks who were undergoing spinal anesthesia for elective cesarean delivery. Women were randomized to ultrasound or palpation. The primary study outcome was a composite between-group comparison of total number of needle redirections (any withdrawal and re-advancement of the needle and/or introducer within the intervertebral space) or re-insertions (any new skin puncture in the same or different intervertebral space) per patient. Secondary outcomes included insertion site identification time and patient verbal numerical pain score (0-10) for comfort during surgical skin incision.

RESULTS

Forty women completed the study. The mean BMI (standard deviation) for the ultrasound group was 39.8 (5.5) kg/m² and for the palpation group 37.3 (5.2) kg/m². There was no difference in the composite primary outcome (median (interquartile range) [range]) between the ultrasound group (4 (2-13) [2-22]) and the (6 (4-10) [1-17]) palpation group (P=0.22), with the 95% confidence interval of the difference 2 (-1.7 to 5.7). There were no differences in the secondary outcomes.

CONCLUSIONS

Handheld ultrasound did not demonstrate any advantages over traditional palpation techniques for spinal anesthesia in an obese population undergoing cesarean delivery, although the study was underpowered to show a difference.

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

Preprocedure ultrasound imaging combined with palpation technique in epidural labor analgesia

BACKGROUND

For parturients with paroxysmal uterine contraction pain, rapid analgesia is needed. We used preprocedure ultrasound imaging combined with the palpation technique in epidural analgesia for labor, and evaluated the usefulness of this technique in epidural labor analgesia.

AIM

To evaluate the usefulness of preprocedure ultrasound imaging in epidural analgesia for labor.

METHODS

In this prospective randomized observational study, 72 parturients were assigned to two groups (combined or palpation group). The target interspace of all parturients was first identified by the palpation technique. Then in the combined group, preprocedure ultrasound imaging was used before epidural puncture. In the palpation group, only the traditional anatomical landmarks technique (palpation technique) was performed. The primary outcome was total duration of the epidural procedure (for the ultrasound group, the duration of the preprocedure ultrasound imaging was included). The secondary outcomes were the number of skin punctures, the success rate at first needle pass, the number of needle passes, the depth from the skin to epidural space, and the complications of the procedure.

RESULTS

Total duration of the epidural procedure was similar between the two groups (406.5 ± 92.15 s in the combined group and 380.03 ± 128.2 s in the palpation group; P = 0.318). A significant improvement was demonstrated for epidural puncture and catheterization in the combined group. The number of needle passes was 1.14 in the combined group and 1.72 in the palpation group (P = 0.001). The number of skin puncture sites was 1.20 in the combined group and 1.25 in the palpation group (P = 0.398). The success rate at first needle pass was 88.89% in the combined group and 66.67% in the palpation group (P = 0.045).

CONCLUSION

This study demonstrated that the total duration of epidural procedures with preprocedure ultrasound imaging combined with the palpation technique was not longer than the traditional anatomical landmarks technique, which were performed by six experienced anesthesiologists in parturients with normal weights undergoing labor analgesia.

Comparison of the time taken for subarachnoid block using ultrasound-guided method versus landmark technique for cesarean section - A randomized controlled study

Background and Aims:

Spinal anesthesia is the regional technique preferred for cesarean section and is usually administered using the traditional landmark technique. Ultrasonography of the spine appears to be helpful in locating the puncture site and increasing the success rate. The primary objective of this study was to assess the use of ultrasonogram in locating the lumbar interspinous space for spinal anesthesia in laboring parturients brought for elective cesarean section.

Material and Methods:

Sixty parturients scheduled to undergo elective cesarean section under spinal anesthesia were included in this prospective randomized controlled trial, after obtaining the institutional ethical clearance. In Group I, 30 patients received spinal anesthesia by landmark technique and in Group II, 30 patients underwent ultrasound-guided spinal anesthesia. The statistical analysis was done using SPSS software version 17 (SPSS Inc., Chicago, Illinois, USA) for Microsoft windows.

Results:

The time taken for spinal in Group I was longer than in Group II (62 ± 18s; 41 ± 11s; P = 0.0001). The number of attempts of needle insertion was significantly less in Group II (group I 1.86 ± 1.04: group II 1.06 ± 0.25). However, the total preparation time (28 8.30 ± 92 vs 804.73 ± 77; P = 0.0001) was more in the ultrasound-guided than in the landmark group. The patients had better satisfaction in group II.

Conclusion:

Preprocedural ultrasound is a useful tool for successful lumbar puncture in parturients as it minimizes the number of attempts of needle insertion and provides better patient satisfaction.

Ease of lumbar epidural catheter insertion with prepuncture ultrasound as guidance compared with conventional palpatory technique when performed by anesthesiology residents: A randomized controlled trial

Background and Aims:

Lumbar epidural catheter insertion is conventionally performed by anesthesia residents by palpation of anatomical landmarks with relatively blind localization of epidural space which may lead to an increase in failure rate. We aim to compare the ease of lumbar epidural catheterization using prepuncture ultrasound as guidance with that of conventional palpatory technique. Comparisons were made with reference to number of insertion attempts, total time taken for the procedure, frequency of dural puncture, and overall satisfaction score as assessed by Likert's scale.

Material and Methods:

Eighty, ASA 1-3, patients undergoing elective surgeries requiring lumbar epidural catheterization were recruited for the study. Study participants were randomized into two groups. In group P, epidural catheterization was performed using the conventional palpatory method and in group U, it was performed with the help of ultrasound determined parameters. Number of insertion attempts, total time taken for successful insertion of epidural catheter, frequency of dural puncture, and overall satisfaction of ease of insertion as determined by Likert's scale were compared between both the groups. Data were analyzed using SPSS statistical software version 17 and P value <0.05 was considered statistically significant.

Results:

The number of insertion attempts was significantly lesser in Group U (P = 0.019). The total procedure time was significantly higher in group U (P < .001). There was no significant difference in ease of insertion score, as measured by Likert's scale between both the groups (P = 0.45).

Conclusion:

Prepuncture ultrasound guidance improves the first attempt success rate of lumbar epidural catheterization with reduced incidence of dural puncture with similar overall satisfaction score but increases the total time taken for the procedure when compared to conventional palpatory technique.

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.

The Incidence of and Risk Factors for Localized Pain at the Epidural Insertion Site After Epidural Anesthesia: A Prospective Survey of More Than 5000 Cases in Nonobstetric Surgery

Background

This prospective research aimed to determine the incidence of and risk factors for localized pain at the epidural insertion site following nonobstetric surgery performed with epidural anesthesia.

Methods

A total of 5083 surgical inpatients at the teaching hospital undergoing epidural anesthesia were included in the study. The characteristics of the patients, preoperative basic diseases, details of the epidural techniques, surgical procedures and complications were recorded pre-anesthesia until the complications resolved. Multivariate logistic regression analysis was performed to identify predictors of localized pain at the epidural insertion site.

Results

In our analysis, target complications were reported in 532 (10.5%) patients; localized pain at the epidural insertion site occurred in 460 (9.05%) patients, while other major complications occurred in 72 (1.45%) patients. A total of 334 patients had mild pain, and 126 patients had moderate pain. The incidence of localized pain at the epidural insertion site was highest among all complications, and the identified risk factors in the multivariate analysis were as follows: lumbar insertion (odds ratio, 1.77; 95% CI 1.33–2.35), age less than 50 years old (odds ratio, 1.56; 95% CI 1.29–1.89), multiple block attempts (odds ratio, 3.39; 95% CI 2.68–4.31), and postoperative patient-controlled epidural analgesia (odds ratio, 0.46; 95% CI 0.33–0.63).

Conclusion

Localized pain at the epidural insertion site is the most common complaint after epidural anesthesia and requires adequate clinical attention. Improving the proficiency of anesthesiologists to avoid repeated punctures is the best way to reduce injuries.

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.

Ultrasound increases the success rate of spinal needle placement through the epidural needle during combined spinal-epidural anaesthesia: A randomised controlled study

BACKGROUND

Combined spinal-epidural anaesthesia (CSEA) using a needle-through-needle technique is currently widely used. However, successful epidural needle placement does not mean a successful spinal needle placement during CSEA. Whether ultrasound assistance could increase the first-pass success rate of spinal needle placement for CSEA remains unknown.

OBJECTIVE

The aim of this study was to investigate if ultrasound assistance could increase the first-pass success rate of spinal needle placement through the epidural needle during CSEA performed by experienced anaesthesiologists in patients undergoing caesarean section.

DESIGN

A prospective, randomised, double-blind study.

SETTING

Single centre, Department of Anaesthesiology, Shengjing Hospital, China Medical University, China, from June 2019 to September 2019.

PATIENTS

A total of 185 patients (aged 24 years to 52 years, American Society of Anesthesiologists grade (ASA) II-III, 38 to 40 weeks gestation) scheduled to undergo elective caesarean section under CSEA were enrolled.

INTERVENTION

The patients were randomised to either an ultrasound group (patients received a preprocedural ultrasound scan, and the puncture site was identified by ultrasound imaging) and a palpation group (patients received a sham procedural ultrasound scan, and the puncture site was identified by conventional palpation).

MAIN OUTCOME MEASURES

The primary outcome measure was the first-pass success rate for spinal needle placement through the epidural needle. Secondary outcome measures were total duration of CSEA, time required for successful epidural needle and spinal needle placement, number of epidural needle redirections and complications.

RESULTS

Preprocedural ultrasound imaging significantly increased the first-pass success rate of spinal needle placement through the epidural needle compared with conventional palpation (93.8 vs. 68.8%, P < 0.001). Preprocedural ultrasound imaging also decreased the total duration of CSEA (186.9 ± 37.1 vs. 213 ± 60.4 s, P = 0.0015) and the time required for successful spinal needle placement (78.3 ± 22.9 vs. 100.1 ± 53.7 s, P < 0.01) compared with conventional palpation. Fewer patients in the ultrasound group needed epidural needle redirections during the spinal needle placement procedure than in the palpation group (four patients vs. 20 patients, P < 0.01).

CONCLUSION

For experienced anaesthesiologists, preprocedural ultrasound imaging significantly increased the first-pass success rate of spinal needle placement through the epidural needle for obstetric patients undergoing caesarean section under CSEA.

TRIAL REGISTRATION

chictr.org.cn, identifier: ChiCTR1900024132.

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.

European Society of Anaesthesiology and Intensive Care Guidelines on peri-operative use of ultrasound for regional anaesthesia (PERSEUS regional anesthesia): Peripheral nerves blocks and neuraxial anaesthesia

Nowadays, ultrasound-guidance is commonly used in regional anaesthesia (USGRA) and to locate the spinal anatomy in neuraxial analgesia. The aim of this second guideline on the PERi-operative uSE of UltraSound (PERSEUS-RA) is to provide evidence as to which areas of regional anaesthesia the use of ultrasound guidance should be considered a gold standard or beneficial to the patient. The PERSEUS Taskforce members were asked to define relevant outcomes and rank the relative importance of outcomes following the GRADE process. Whenever the literature was not able to provide enough evidence, we decided to use the RAND method with a modified Delphi process. Whenever compared with alternative techniques, the use of USGRA is considered well tolerated and effective for some nerve blocks but there are certain areas, such as truncal blocks, where a lack of robust data precludes useful comparison. The new frontiers for further research are represented by the application of USG during epidural analgesia or spinal anaesthesia as, in these cases, the evidence for the value of the use of ultrasound is limited to the preprocedure identification of the anatomy, providing the operator with a better idea of the depth and angle of the epidural or spinal space. USGRA can be considered an essential part of the curriculum of the anaesthesiologist with a defined training and certification path. Our recommendations will require considerable changes to some training programmes, and it will be necessary for these to be phased in before compliance becomes mandatory.

Predicting difficult spinal anesthesia: development of a neuraxial block assessment score

BACKGROUND

Spinal anesthesia is a commonly performed procedure with unpredictable difficulty. The objective of this study was to predict a difficult lumbar spinal anesthesia with clinical elements that are easy to collect.

METHODS

A questionnaire-based, observational study named NBA, conducted from February 2018 to June 2018. The questions regarded clinical elements and the eventual spinal anesthesia difficulty encountered. A total of 427 questionnaires were filled by the operators. The clinical elements were selected upon literature search and have been integrated with new ones. All the answers were recorded from the anesthesiologist performing the procedure.

RESULTS

The NBA Score was derived from a total number of 427 questionnaires. Among them, 26 patients had "previous history of difficult spinal anesthesia;" 277 had "spinous processes not visible;" 83 had "spinous processes not palpable;" 77 had "spinal deformities" and 28 had "previous spinal surgery" in the puncture area; 138 patients received lumbar spinal anesthesia in lateral position. There were 328 (76.8%) single puncture successes. Seventy-nine (18.5%) patients required more than one skin puncture to obtain a successful spinal anesthesia. 20 (4.7%) required an alternative anesthesia technique (general anesthesia). Multivariate analysis indicated that each element is a risk factors for difficult spinal anesthesia, except for previous spinal surgery.

CONCLUSIONS

The combination of more than one element increased the chance of a second skin puncture of more than 50%. This work proposes a simple clinical scoring system predicting the probability of a difficult spinal anesthesia.

Preprocedural Ultrasonography Versus Landmark-Guided Spinal Anesthesia in Geriatric Patients with Difficult Anatomy: A Prospective Randomized Trial

Objective

This study was aimed to determine whether preprocedural ultrasonography (USG) affects the technical performance of spinal anesthesia in elderly patients with difficulty in palpating landmarks, scoliosis, or previous spine surgery.

Materials and Methods

This prospective study was conducted in 156 elderly patients scheduled for elective orthopedic lower extremity surgery. The patients were randomly divided into 2 groups to receive spinal anesthesia by the preprocedural USG examination (group U) or conventional landmark palpation technique (group P). The primary finding of our study was the rate of successful access to the subarachnoid space on initial needle insertion attempt. Secondary achievements included number of needle insertion attempts, number of needle redirections, total procedure time, needle pain scores, patient satisfaction, and complications of spinal anesthesia.

Results

The rate of successful access to the subarachnoid space at the first needle insertion attempt was significantly higher in group U than in group P (74.4% vs 53.8%, p=0.008). Medians (interquartile range) of both needle insertion attempts (group P, 2 [1-3] vs group U, 1 [1-2]; p=0.038) and needle redirections (group P, 3 [2-5] vs group U, 2 [1-4]; p=0.028), requiring to achieve dural puncture, were significantly higher among the patients in group P than those in group U. No statistically significant difference was found between the groups regarding total procedure time, pain scores, patient satisfaction scores, and spinal anesthesia-induced complications (p>0.05).

Conclusion

Our study findings showed that preprocedural neuroaxial USG improves technical performance of spinal anesthesia in elderly patients with difficult anatomy.

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.

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.

A protocol to reduce self-reported pain scores and adverse events following lumbar punctures in older adults

OBJECTIVE

Lumbar punctures (LPs) are important for obtaining CSF in neurology studies but are associated with adverse events and feared by many patients. We determined adverse event rates and pain scores in patients prospectively enrolled in two cohort studies who underwent LPs using a standardized protocol and 25 g needle.

METHODS

Eight hundred and nine LPs performed in 262 patients age ≥ 60 years in the MADCO-PC and INTUIT studies were analyzed. Medical records were monitored for LP-related adverse events, and patients were queried about subjective complaints. We analyzed adverse event rates, including headaches and pain scores.

RESULTS

There were 22 adverse events among 809 LPs performed, a rate of 2.72% (95% CI 1.71-4.09%). Patient hospital stay did not increase due to adverse events. Four patients (0.49%) developed a post-lumbar puncture headache (PLPH). Twelve patients (1.48%) developed nausea, vasovagal responses, or headaches that did not meet PLPH criteria. Six patients (0.74%) reported lower back pain at the LP site not associated with muscular weakness or paresthesia. The median pain score was 1 [0, 3]; the mode was 0 out of 10.

CONCLUSIONS

The LP protocol described herein may reduce adverse event rates and improve patient comfort in future studies.

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.

Preprocedural Ultrasound Estimates of Epidural Depth: Transverse Median Plane is Comparable to Paramedian Sagittal Oblique Plane in Non-Pregnant Patients

Objective

The aim of this study was to assess the accuracy and precision of the actual epidural depth (ND) and ultrasound (US) estimates of the distance from the skin to the epidural space in the transverse median plane (ED/TM) and paramedian sagittal oblique plane (ED/PSO) in patients who were not pregnant and who were undergoing unilateral inguinal hernia repair surgery under combined spinal epidural anaesthesia.

Methods

A total of 100 patients with the American Society of Anaesthesiology status I–III of either gender were recruited. All epidurals were inserted at the L3–4 intervertebral space, and the epidural needle was marked with a sterile marker. The ND was measured between the marker and the tip of the needle. The ED/TM and ED/PSO were assessed with a 2–5 MHz curved array probe at the L3–4 intervertebral space. The Pearson correlation coefficient and Lin’s concordance correlation coefficient were used to assess the precision and the Bland–Altman test was used to assess the 95% limit of agreement.

Results

The ND was 48.98±6.91 mm, the ED/PSO was 48.92±6.91 mm and the ED/TM was 48.90±6.91 mm. The Pearson correlation coefficient between ND and ED/PSO was 0.995 (p<0.001) and 0.994 (p<0.001) with ED/TM. Lin’s concordance correlation coefficient for ND and ED/PSO was 0.995 (95%CI [confidence interval]: 0.992–0.997), and 0.993 for ND and ED/TM (95% CI: 0.990–0.996). The 95% limit of agreement between ND and ED/PSO was 0.70–1.37, and for ND and ED/TM, it was 0.79–1.54.

Conclusion

Preprocedural ultrasound (US) scanning in both planes provides reliable estimates for actual epidural depth in non-pregnant patient population.

Recommendations on the Use of Ultrasound Guidance for Adult Lumbar Puncture: A Position Statement of the Society of Hospital Medicine

EXECUTIVE SUMMARY

When ultrasound equipment is available, along with providers who are appropriately trained to use it, we recommend that ultrasound guidance should be used for site selection of lumbar puncture to reduce the number of needle insertion attempts and needle redirections and increase the overall procedure success rates, especially in patients who are obese or have difficult-to-palpate landmarks. We recommend that ultrasound should be used to more accurately identify the lumbar spine level than physical examination in both obese and nonobese patients. We suggest using ultrasound for selecting and marking a needle insertion site just before performing lumbar puncture in either a lateral decubitus or sitting position. The patient should remain in the same position after marking the needle insertion site. We recommend that a low-frequency transducer, preferably a curvilinear array transducer, should be used to evaluate the lumbar spine and mark a needle insertion site. A high-frequency linear array transducer may be used in nonobese patients. We recommend that ultrasound should be used to map the lumbar spine, starting at the level of the sacrum and sliding the transducer cephalad, sequentially identifying the lumbar spine interspaces. We recommend that ultrasound should be used in a transverse plane to mark the midline of the lumbar spine and in a longitudinal plane to mark the interspinous spaces. The intersection of these two lines marks the needle insertion site. We recommend that ultrasound should be used during a preprocedural evaluation to measure the distance from the skin surface to the ligamentum flavum from a longitudinal paramedian view to estimate the needle insertion depth and ensure that a spinal needle of adequate length is used. We recommend that novices should undergo simulation-based training, where available, before attempting ultrasound-guided lumbar puncture on actual patients. We recommend that training in ultrasound-guided lumbar puncture should be adapted based on prior ultrasound experience, as learning curves will vary. We recommend that novice providers should be supervised when performing ultrasound-guided lumbar puncture before performing the procedure independently on patients.

The Accuracy of a Handheld Ultrasound Device for Neuraxial Depth and Landmark Assessment: A Prospective Cohort Trial

This study investigated the accuracy of a wireless handheld ultrasound with pattern recognition software that recognizes lumbar spine bony landmarks and measures depth to epidural space (Accuro, Rivanna Medical, Charlottesville, VA) (AU). AU measurements to epidural space were compared to Tuohy needle depth to epidural space (depth to loss of resistance at epidural placement). Data from 47 women requesting labor epidural analgesia were analyzed. The mean difference between depth to epidural space measured by AU versus needle depth was -0.61 cm (95% confidence interval, -0.79 to -0.44), with a standard deviation of 0.58 (95% confidence interval, 0.48-0.73). Using the AU-identified insertion point resulted in successful epidural placement at first attempt in 87% of patients, 78% without redirects.

Feasibility of Spinal Anesthesia Placement Using Automated Interpretation of Lumbar Ultrasound Images: A Prospective Randomized Controlled Trial

Background:

This study evaluated the efficacy of spinal anesthesia administration by resident physicians when using an ultrasound system with automated neuraxial landmark detection capabilities.

Methods:

150 patients were enrolled in this trial. Anesthesiology residents placed spinals in subjects undergoing scheduled cesarean delivery using one of three techniques to identify neuraxial landmarks: palpation, ultrasound, or combined palpation and ultrasound. Ultrasound was performed using a handheld system that automatically identified neuraxial landmarks (e.g. midline, intervertebral spaces). All residents watched a 10-minute video and received 20 minutes of hands-on training prior to participating in the study. First insertion success rate was the primary end point.

Results:

Among all patients, use of ultrasound resulted in a 11% greater first-insertion success rate (RR: 1.11 [0.85–1.47], p=0.431), a 15% reduction in needle insertions (RR: 0.85, p=0.052), and a 26% decrease in needle passes (RR: 0.74, p=0.070). In obese patients of BMI ≥ 30 kg/m², use of ultrasound resulted in 26% greater first-insertion success rates (RR: 1.26, p=0.187), a 21% decrease in needle insertions (RR: 0.79, p=0.025), a 38% decrease in needle passes (RR: 0.62, p=0.030), and a 75% decrease in patients reporting neutral or low patient satisfaction with anesthesia administration (RR: 0.25, p=0.004).

Discussion:

Resident anesthesiologists competently utilized the ultrasound system after receiving minimal training. Technical endpoints and patient satisfaction trended towards improvement when ultrasound was used prior to spinal placement, with stronger trends observed in obese patients. Additional study is required to fully characterize the impact of the ultrasound system on clinical efficacy.

The comparative accuracy of a handheld and console ultrasound device for neuraxial depth and landmark assessment

BACKGROUND

The study aimed to compare the accuracy of epidural depth estimation of a handheld ultrasound device, with an integrated algorithm that estimates epidural depth (AU; Accuro, Rivanna Medical), to that of a console ultrasound machine (GU; GE LOGIC^TM S8).

METHODS

Women requesting labor epidural analgesia consented to this prospective cohort study. The L2/3, L3/4, and L4/5 interspaces and the respective depths to the epidural space were identified, marked and measured using an AU and GU. An anesthesia provider who was blinded to ultrasound depth measurements performed epidural analgesia at one of the ultrasound identified insertion points and recorded the Tuohy needle depth at loss-of-resistance. Bland Altman analysis was used to measure the agreement between the epidural depths measured by the AU and GU.

RESULTS

A total of 47 women were analyzed. The mean ± standard deviation body mass index of the study cohort was 29 ± 5 kg/m² [range 23-45]. The mean difference between the epidural depths measured by the AU and GU was -0.29 cm [95% limit of agreement 0.50 to -0.91]. The mean difference between the depth to the epidural space measured by the GU versus the needle depth was -0.33 cm [95% CI -0.49 to -0.16]. The previously reported AU versus needle depth was -0.61 cm [95% CI -0.79 to -0.44].

CONCLUSION

The AU and GU provided comparable epidural depth estimates. The AU device may be a reasonable alternative to more sophisticated ultrasound devices in determining the epidural space and depth in a non-obese obstetric population.

Point-of-Care Ultrasound in Established Settings

The original and most widely accepted applications for point-of-care ultrasound (POCUS) are in the settings of trauma, shock, and bedside procedures. Trauma was the original setting for the introduction of POCUS and has been standardized under the four-plus view examination called the Focused Assessment with Sonography in Trauma (FAST). This examination was found to be especially practice changing for achieving rapid diagnoses in critically ill patients who are too unstable for the delays and transportation inherent in more advanced imaging with computed tomography. This application was broadened from the critically ill trauma patient to any critically ill patient, particularly the patient in undifferentiated shock. Although the Focused Assessment with Sonography in Trauma examination originally focused on sources of hemorrhage causing hypovolemic shock, POCUS also can quickly differentiate cardiogenic, obstructive, and distributive shock and help identify the more specific etiology such as massive pulmonary emboli, pericardial tamponade, and pneumothoraces. By expediting diagnosis, POCUS facilitates faster definitive treatment of life-threatening conditions. In pursuing treatment, US continues to serve a role in the form of visually guiding many procedures that were previously done blindly. US guidance of procedures has improved the safety of central line insertion, thoracentesis, and paracentesis, and has an emerging role in lumbar puncture. Experience in bedside US is becoming a vital tool in the clinician's bedside assessment and management, filling a void between the stethoscope and the more advanced studies and interventions available through radiology. Understanding the strengths and limitations of US enables clinicians to identify the appropriate situations in which they can apply this tool confidently.

Epidural needle insertion : A large registry analysis

BACKGROUND

Dural puncture, paraesthesia and vascular puncture are the most common complications of epidural catheter insertion. Their association with variation in midline needle insertion depth is unknown.

OBJECTIVE

This study evaluated the risk of dural and vascular punctures and the unwanted events paraesthesia and multiple skin punctures related to midline needle insertion depth.

MATERIAL AND METHODS

A total of 14,503 epidural catheter insertions including lumbar (L1-L5; n = 5367), low thoracic (T7-T12, n = 8234) and upper thoracic (T1-T6, n = 902) insertions, were extracted from the German Network for Regional Anaesthesia registry between 2007 and 2015. The primary outcomes were compared with logistic regression and adjusted (adj) for confounders to determine the risk of complications/events. Results are presented as odds ratios (OR, [95% confidence interval]).

MAIN RESULTS

Midline insertion depth depended on body mass index, sex, and spinal level. After adjusting for confounders increased puncture depth (cm) remained an independent risk factor for vascular puncture (adjOR 1.27 [1.09-1.47], p = 0.002) and multiple skin punctures (adjOR 1.25 [1.21-1.29], p < 0.001). In contrast, dural punctures occurred at significantly shallower depths (adjOR 0.73 [0.60-0.89], p = 0.002). Paraesthesia was unrelated to insertion depth. Body mass index and sex had no influence on paraesthesia, dural and vascular punctures. Thoracic epidural insertion was associated with a lower risk of vascular puncture than at lumbar sites (adjOR 0.39 [0.18-0.84], p = 0.02).

CONCLUSION

Variation in midline insertion depth is an independent risk factor for epidural complications; however, variability precludes use of depth as a reliable guide to insertion in individual patients.

Lumbar Ultrasonography for Obstetric Neuraxial Blocks: Sonoanatomy and Literature Review

Ultrasonography has gained popularity in recent years among anaesthesiologists and being used widely for regional blocks and central venous catheterization. Ultrasonography for neuraxial blocks was found beneficial especially for determining the correct needle insertion site and estimating the needle insertion depth of epidural space. In many recent studies, ultrasound guided epidural and spinal blocks have been evaluated among obstetric patients. Pre-procedural lumbar ultrasonography and real time ultrasound guidance for neuraxial blocks was the subject of these studies. We aimed to evaluate lumbar ultrasonography for obstetric neuraxial blocks. We describe the principles of lumbar ultrasound scanning techniques and present a practical review of lumbar sonoanatomy. We discuss the potential impact and benefits of the ultrasound-guided technique in improving obstetric neuraxial blocks and limitations of its use in clinical practice, based on previous studies.

Observational Study Using Ultrasound to Assess Midline Labor Epidural Analgesia Placement and Analgesic Efficacy

OBJECTIVES

Labor epidural analgesia failure may relate to nonmidline placement of epidural catheters. We hypothesized that greater deviations of the epidural catheter insertion point from the ultrasound (US)-determined midline would be associated with less effective labor analgesia.

METHODS

A prospective ethically approved cohort study was conducted. Fifty-two healthy average-sized women receiving labor epidural analgesia, inserted by the landmark technique, were approached after delivery. Immediately after removing the epidural catheter, we determined the epidural space midline using US and compared it to the epidural catheter insertion point and to the patient-identified midline (assessed by a pinprick in 1-mm increments). Correlations between the US midline-to-catheter insertion point distance and additional epidural local anesthetic requirements (primary outcome), pain verbal numeric rating scale scores (0-10) 1 hour after epidural insertion, and maternal satisfaction with analgesia were determined. The differences in distances were assessed by a Bland-Altman analysis.

RESULTS

There were no significant correlations between the US midline-to-epidural catheter insertion point distance and additional epidural local anesthetic requirements (R²  = 0.138; P = .33), pain verbal numeric rating scale scores 1 hour after the epidural (R²  = 0.121; P = .40) or maternal satisfaction (R²  = 0.085; P = .57). The Bland-Altman analysis revealed that the mean ± SD US midline-to-epidural catheter insertion point distance and patient-identified midline distances were 0.38 ± 0.31 and 0.35 ± 0.46 cm, respectively.

CONCLUSIONS

In our laboring population, the hypothesis that nonmidline epidural insertion is associated with less-effective labor analgesia was not confirmed in this study cohort. We found minimal differences in distances between the US midline to epidural catheter insertion point and US midline to patient-identified midline.