A randomized controlled trial of ultrasound-assisted lumbar puncture

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of ultrasound guidance and anatomical landmarks for neuraxial puncture in adults using electronic databases and unpublished studies.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.

The 2023 Core Content of advanced emergency medicine ultrasonography

In February 2023, the American Board of Emergency Medicine (ABEM) approved modifications to the Advanced Emergency Medicine Ultrasonography (AEMUS) Core Content, which defines the areas of knowledge considered essential for the practice of AEMUS. This manuscript serves as a revision of the AEMUS Core Content originally published in 2014. The revision of the Core Content for AEMUS training aims to establish standardized education and qualifications necessary for AEMUS fellowship program leadership, clinical application, administration, quality improvement, and research. The Core Content provides the organizational framework and serves as the basis for the development of content for the Focused Practice Examination (FPE) administered by ABEM. AEMUS fellowship directors may reference the Core Content when designing AEMUS fellowship curricula to help prepare graduates for the autonomous practice of AEMUS and the FPE. In this article, an updated revision of the previously published AEMUS Core Content is detailed, and the entire development of the Core Content is presented.

Ultrasound-assisted Lumbar Puncture for Obese Pediatric Oncology Patients: A Feasibility Study

Lumbar punctures (LPs) are performed frequently on children with leukemia and lymphoma as part of the standard of care. They are typically performed by pediatric oncology providers for both diagnostic and therapeutic interventions with the aid of moderate or deep sedation. Point-of-Care Ultrasound (POCUS) has emerged as a promising strategy to aid in LP procedures and has been found to be associated with lower number of attempts, and higher success rates. We describe our experience using POCUS to assist with LPs in a subgroup of pediatric oncology patients identified to be procedurally difficult secondary to obesity. This collaboration was well received and resulted in successful LPs in most (8/9) cases. This is a promising modality to improve the delivery of care and LP success in pediatric oncology patients.

Ultrasound Measurement of the Intervertebral Space in the Lateral Recumbent Versus Sitting Positions

BACKGROUND

Diagnostic lumbar puncture (LP) is an invasive procedure routinely performed within the emergency department (ED). LP is traditionally performed with the patient in either the lateral recumbent or sitting position. We investigated if the intervertebral space is larger in one of these positions. If one position is larger than the other, this would imply that one position offers a higher chance of a successful lumbar puncture than the other position.

OBJECTIVE

We sought to determine if there is a significant size difference of the L4/L5 intervertebral space in the lateral recumbent compared with the sitting position.

METHODS

Point-of-care ultrasound (POCUS) was performed to measure the size of each volunteer's L4/L5 intervertebral space in both the seated and lateral recumbent positions. All volunteers >18 years of age were eligible for the study. Thirty volunteers had measurements taken. Three measurements were taken by each investigator in both positions for each volunteer.

RESULTS

The median L4/L5 intervertebral space distance was 1.7511 cm in the lateral recumbent position and 1.9511 cm in the seated position with a Wilcoxon signed rank p value <.0001. The interspinous space in the seated position was found to be significantly larger than in the lateral recumbent position.

CONCLUSION

The size of the interspinous space in the seated position on ultrasound was found to be larger than the lateral recumbent position, suggesting that LP may be more successful in the seated position.

Real-time ultrasound-guided lumbar puncture in the neonatal intensive care unit

OBJECTIVE

To determine the rates of traumatic lumbar puncture (LP) and overall success rates using the real-time ultrasound-guided technique when performed by a neonatal point-of-care ultrasound provider.

STUDY DESIGN

Retrospective observational study of 17 infants in the neonatal intensive care unit who underwent a real-time ultrasound-guided LP between March 2015 and November 2016. Spearman's correlation was calculated.

RESULTS

The first attempt and overall success rates were 65% and 100%, respectively. The rate of nontraumatic LP was 69%. CSF RBC count was inversely correlated with both PMA (Spearman's correlation coefficient (r_s) = -0.74, p = 0.0017) and weight (r_s = -0.74, p = 0.0015) at the time of LP.

CONCLUSIONS

This study is the first to provide evidence of high success rates with real-time ultrasound-guided LP when performed by a neonatologist. Our data demonstrate feasibility in neonates over a broad range of weights, including premature infants as small as 750 g.

Number Needed to Scan: Evidence-Based Point-of-Care Ultrasound (POCUS)

Interest and enthusiasm, regarding the use of point-of-care ultrasound (POCUS), continues to grow among clinicians in multiple medical specialties. Ultrasound machines technology has advanced to allow for smaller, even handheld machines. Integration of automated imaging technology has made these machines more user-friendly. However, one of the concerns with the widespread availability of POCUS is the overuse and misuse of this technology. In order to maximize the clinical impact of POCUS, this manuscript seeks to discuss a novel concept called the “Number needed to scan” (NNS). The NNS is an expression of the number of POCUS examinations needed to be performed to attain a benefit to the patient or to prevent an adverse outcome of a procedure. NNS serves a dual purpose: it can help clinicians understand the magnitude of clinical impact when they apply POCUS, and it can help clinicians explain this magnitude in layman terms to their patients. In this manuscript, we have focused our NNS calculations on landmark articles in three major categories: change in management; safety and accuracy; and catching a missed diagnosis. As clinicians seek to be good stewards of POCUS, NNS should be a concept used to consider which patients will be most likely to benefit from a clinician performed ultrasound.

Retrospective analysis of predisposing factors for difficult lumbar punctures requiring image guidance in pediatric oncology patients

Success rates of lumbar punctures (LPs) in children are reportedly as low as 50%. In addition to procedural complications and failure, difficult LPs are a risk factor for traumatic LPs (TLPs), which can potentially affect diagnostic utility and alter treatment plans for pediatric oncology patients. To identify the intrinsic factors associated with technically difficult LPs in the pediatric oncology population, we performed a retrospective review of patients who required diagnostic imaging modalities for LP procedures at a single pediatric oncology institution between September 2008 and November 2018. We evaluated data from 64 LPs performed in 33 patients who were referred for image-guided LPs after undergoing technically difficult LPs that were unsuccessful using anatomic landmarks. In these cases, 96.9% of patients had at least one of the following intrinsic factors: body mass index (BMI) ≥ 25, anatomic spinal abnormalities, history of ≥ 5 previous LPs, age < 12 months, and history of back surgery. Elevated BMI was the most common factor associated with difficult LP (81.8%), followed by spinal abnormalities (51.5%), and history of ≥ 5 previous LPs (33.3%). Age < 12 months and history of back surgery were also associated with difficult LPs, but at a lower frequency. On the basis of these findings, we propose clinical recommendations for preprocedural identification of patients at risk of difficult LPs to reduce complications, including TLP, failure, and exposure to general anesthesia.

Conventional landmark palpation versus preprocedural ultrasound for neuraxial procedures in nonobstetric patients: A systematic review with meta-analysis and trial sequential analysis of randomised controlled trials

BACKGROUND

Central neuraxial modalities can occasionally be challenging to perform, particularly if the underlying anatomy is altered or obscured.

OBJECTIVES

To compare the efficacy, efficiency and the safety of preprocedural ultrasound to landmark palpation in the nonobstetric adult population.

DESIGN

Systematic review of randomised controlled trials with meta-analysis and trial sequential analysis.

DATA SOURCES

Systematic search of Central, CINAHL, Embase, Global Health, MEDLINE, Scopus and Web of Science to 13th February 2020.

ELIGIBILITY CRITERIA

Randomised controlled trials of nonobstetric adult patients having diagnostic and/or therapeutic neuraxial procedures using standard preprocedural ultrasound interpreted by the operator as the intervention and conventional landmark palpation as the comparator.

KEY DEFINITIONS

A skin puncture was defined as the insertion or reinsertion of the needle through the skin; needle redirection was the backward followed by the forward movement of the needle without its removal from the skin; first skin puncture referred to a single skin puncture with or without needle redirections; and first pass was a single skin puncture with no needle redirection.

RESULTS

In all, 18 randomised controlled trials with 1800 patients were included. The first pass success rate was not different between landmark and ultrasound methods [risk ratio 1.46; 95% confidence interval (CI), 0.99 to 2.16; P = 0.06, I2 = 76%; moderate quality of evidence] and the trial sequential analysis demonstrated the futility of further randomisation of patients in modifying this finding. Preprocedural ultrasound increased the total time taken (mean difference 110.8 s; 95% CI, 31.01 to 190.65; P = 0.006; I2 = 96%; moderate quality of evidence). Subgroup analyses revealed no influence of the predicted difficulty of the neuraxial procedure on outcomes. Compared with the landmark method, ultrasound increased the first skin puncture success rate (risk ratio 1.36; 95% CI, 1.18 to 1.57; P < 0.001; I2 = 70%), and decreased the need for three or more skin punctures (risk ratio 0.46; 95% CI, 0.33 to 0.64; P < 0.001; I2 = 29%) and the number of needle redirections (mean difference -1.24; 95% CI, -2.32 to -0.17; P = 0.020; I2 = 83). The incidence of bloody tap was reduced with the use of ultrasound (risk ratio 0.61; 95% CI, 0.40 to 0.93; P = 0.020; I2 = 42%).

CONCLUSIONS

The use of preprocedural ultrasound for neuraxial procedures in the nonobstetric adult population did not enhance the first pass success rate and increased the total time taken to a clinically insignificant extent. Improvement in secondary outcomes, including other markers of efficacy, should be interpreted with caution.

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.

Feel It, See It, Get It: Is Internal Medicine Residents' Use of Ultrasound in Lumbar Puncture Associated With Higher Success Rate?

INTRODUCTION

 Multiple emergency medicine and anesthesiology research studies suggest that ultrasound (US) is potentially useful in assisting with needle insertion in a lumbar puncture (LP). However, little is known about its value when utilized by internal medicine (IM) residents. The objective of this study is to examine whether the use of ultrasound in LPs performed by internal medicine residents is associated with a higher success rate than the traditional palpation method.

MATERIALS AND METHODS

 We reviewed all LP procedure notes in our hospital's records written by IM residents from June 2017 to December 2018 in a single community teaching hospital. We examined the association between the US use and success using the Chi-squared test and logistic regression model.

RESULTS

Among the 152 lumbar punctures documented, 130 specified whether US was used or not. Among these, 39 were ultrasound-assisted and 91 were not. Use of ultrasound was associated with a higher success rate compared to the non-ultrasound-use (87% vs 73%; p=0.1). The association was strengthened using logistic regression but did not reach statistical significance (OR 3.5; CI: 0.9 -13.8; p=0.07). Success was significantly associated with a fewer number of attempts (p<0.001). No statistically significant association was found between success and patients' body mass index (BMI; p=0.57), or level of training (p=0.11).

CONCLUSIONS

 Use of ultrasound for needle insertion in lumbar punctures performed by internal medicine residents was associated with a higher success rate compared to the palpation method but without statistical significance. Ultrasound is a non-invasive, quick, and safe tool. Our study favors its use as an aid during lumbar puncture when performed by internal medicine residents. Larger studies are needed to gather more evidence in support of this conclusion.

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.

Ultrasound-guided lumbar puncture improves success rate and efficiency in overweight patients

Background

Approximately 400,000 diagnostic lumbar punctures (LPs) are performed by neurologists yearly in the United States. There has been a transition from neurologists performing >40% of LPs 2 decades ago to now <15% of the time. High body mass index (BMI) is one of the key obstacles of LP for neurology residents, and the success rates drop to 58% when BMI is >35 kg/m².

Methods

A prospective intervention study was conducted from March 2017 to March 2018 at an academic medical center. Patients were divided into ultrasound-guided LP or conventional LP. The primary outcome was the success rate of LP. The secondary outcome was the parameters regarding LP performance, the patients' feedback after procedures, and the residents' feedback about the learning modules.

Results

Eighty-two patients were enrolled with inclusion criteria of age >18 years, BMI ≥25 kg/m², and able to give written informed consent. The ultrasound-guided LP group showed higher success rate (92.7% vs 68.3%, p < 0.05) and less duration of time (17.02 vs 37.63 minutes, p < 0.05) compared with the conventional LP group. It also showed advantages of decreased trials of needle insertions and redirections and reduced pain levels perceived by patients.

Conclusions

This study suggests that using ultrasound to localize before LP could increase the LP success rate and improve other related LP outcomes in the overweight populations. Our study also provides evidence that brief, targeted teaching modules are feasible and effective for ultrasound-guided LP training.

Classification of evidence

This study provides Class III evidence that for patients with BMI ≥25 kg/m² undergoing LP, ultrasound guidance increases the LP success rate.

Bedside Ultrasound for the Evaluation of Epidural Hematoma After Infant Lumbar Puncture

BACKGROUND

Unsuccessful lumbar puncture (LP) attempts may lead to epidural hematoma (EH) formation within the spinal canal at the site of needle insertion, which can affect subsequent attempts. We aimed to determine the rate of EH formation after infant LP using bedside ultrasound (US). Furthermore, we aimed to correlate both perceived trauma during LP and cerebral spinal fluid (CSF) red blood cell (RBC) counts with EH formation.

METHODS

We enrolled infants younger than 6 months who underwent LP in the emergency department. The primary investigator performed a bedside US of the lumbar spine, which was reviewed and interpreted by a pediatric radiologist. Treating clinicians performed the procedure and were asked to classify each attempt as "traumatic" or "atraumatic." Cerebral spinal fluid RBC counts were recorded.

RESULTS

Thirty-one percent of patients had evidence of post-LP EH, 17% of which completely effaced the thecal sac. Forty percent of patients with at least 1 traumatic attempt had evidence of EH, whereas 25% without reported trauma showed EH (P = 0.17). Patients with EH had a median CSF RBC cell count of 186 cells/mm (range, 0-239,525) compared with 5 cells/mm (range, 0-3429) in patients without evidence of EH (P = 0.008).

CONCLUSIONS

Epidural hematomas are frequent after LP. Perceived trauma during LP and CSF RBC counts are not adequate predictors of EH formation. Point-of-care US may be a valuable adjunct to help guide subsequent needle insertions sites for repeat attempts after an unsuccessful LP.

Feasibility study of a force-sensing resistor device for landmark detection for neuraxial procedures and anesthesiologists' impact on device improvement

The standard of care for neuraxial procedures is landmark palpation to determine the site of placement. This research study aimed to test the primary feasibility of VerTouch™, a force-sensing resistor device, to identify landmarks for the initiation of neuraxial procedures. Patients were recruited at the time of labour epidural, or when consenting for spinal anaesthesia for caesarean delivery at a single centre. The clinical team used the device to create a pressure map image of the bony spine. If they felt confident, they used the device guide to make a mark on the patient's back. If the mark was used, total insertions and redirections, combined as passes, of the needle during the procedure were counted for secondary outcome analysis. A total of 101 parturients were recruited, and the provider felt confident making a mark based on the imaging in 96.9% of cases. Device success (completion using the mark and ≤4 total passes) occurred in 91.4% of cases. This feasibility study showed that the primary outcome, the provider using the device to make a mark, was successful. In addition, based on comparing passes with historical data, the Vertouch™ device showed promise for future use to minimise needle manipulation in neuraxial procedures.

Role of routine use of ultrasonographic guidance for performing lumbar punctures

PURPOSE OF STUDY

Ultrasound (US) for lumbar puncture has seen the most success in obese patients and in patients with difficult to palpate landmarks. We aimed to elucidate the advantage of the use of routine US for performing lumbar punctures over the traditional landmark method.

STUDY DESIGN

This was a prospective study with consecutive sampling with a sample size of convenience. Three residents were chosen to perform the lumbar punctures after a training session. Patients were assigned to either the US group or the landmark group. The outcomes studied were number of attempts at needle insertion, patient and physician anxiety, pain experienced, time to procedure, number of traumatic attempts and the difficulties faced during the procedure.

RESULTS

A total of 77 patients were included in this study, of which 36 patients (46.8%) underwent landmark-based lumbar puncture and 41 (53.2%) underwent US-guided lumbar puncture. There was no statistically significant difference between the two groups among the following characteristics: number of attempts to a successful procedure, number of traumatic punctures, procedure time, preprocedure anxiety of the participants and physicians and pain score rating of the procedure.

CONCLUSION

There was no significant difference between the landmark method and US-guided method for performing lumbar puncture in the number of successful attempts, number of traumatic punctures, procedure time and pain during the procedure. Further studies are required to elucidate the advantage of the use of ultrasonography in subsets of the population such as the low body mass index population.

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

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.

Risk factors for blood-contaminated cerebrospinal fluid collection in dogs

OBJECTIVE

To determine the risk factors for blood contamination during cerebrospinal fluid (CSF) collection in dogs.

STUDY DESIGN AND METHODS

This is a prospective study of 170 CSF samples. Data collected included signalment of the patient, body condition score, site of CSF collection (cerebellomedullary cistern (CMC) or lumbar cistern (LC)), number of attempts, clinician expertise, final diagnosis, time of day, skull conformation and day of the week. Analysis of the CSF samples was then performed, and the presence of blood contamination (red blood cells >500/µl) was recorded. Logistic regression was used to quantify the association of potential risk factors of the procedure. Multivariate analysis was performed on the variables that were statistically significant.

RESULTS

Of the 170 CSF samples, 53 per cent were collected from the CMC (n=90) and 47 per cent from the LC (n=80). Blood contamination was seen in 20 per cent (n=34) of the samples, 8.9 per cent (n=8) in CMC and 32.5 per cent (n=26) in LC samples. Increased odds of obtaining a contaminated CSF sample were associated with lower level of clinician expertise (odds ratio: 2.5; 95 per cent confidence interval: 0.9-6.7; P=0.046) and with LC versus CMC collection site (odds ratio: 8.1; 95 per cent confidence interval: 2.1-12.9; P=0.001).

CLINICAL SIGNIFICANCE

There is increased likelihood of blood contamination when collecting CSF from the LC compared with the CMC site. Increased clinician experience reduced the risk of CSF blood contamination, but none of the other variables examined significantly influenced this.

Point-of-Care Ultrasound for the Pediatric Hospitalist's Practice

Point-of-care ultrasound (POCUS) has the potential to provide real-time valuable information that could alter diagnosis, treatment, and management practices in pediatric hospital medicine. We review the existing pediatric POCUS literature to identify potential clinical applications within the scope of pediatric hospital medicine. Diagnostic point-of-care applications most relevant to the pediatric hospitalist include lung ultrasound for pneumothorax, pleural effusion, pneumonia, and bronchiolitis; cardiac ultrasound for global cardiac function and hydration status; renal or bladder ultrasound for nephrolithiasis, hydronephrosis, and bladder volumes; soft tissue ultrasound for differentiating cellulitis from abscess; and procedural-guidance applications, including line placement, lumbar puncture, and abscess incision and drainage. We discuss POCUS applications with reviews of major pathologic findings, research gaps, the integration of POCUS into practice, and barriers to implementation.

Comparison of Ultrasound-Guided and Landmark-Based Lumbar Punctures in Inexperienced Resident Physicians

OBJECTIVES

We sought to determine whether US-guided lumbar puncture reduced the rate of lumbar puncture failures for providers at an academic teaching hospital with variable lumbar puncture and US experience compared to the traditional landmark-based technique.

METHODS

We conducted a prospective randomized controlled trial to compare US-guided lumbar puncture to the traditional landmark technique in an academic emergency department. Thirty-five patients were randomized to either have their lumbar puncture performed either via the landmark or US-guided technique. All procedures were completed by an emergency medicine resident with variable lumbar puncture and US experience. Procedural failures, the number of attempts, the time to completion, and patient pain scores were all recorded.

RESULTS

The adjusted odds ratio of successfully obtaining cerebrospinal fluid (CSF) in the US-guided lumbar puncture group was 2.31 compared to the landmark-based lumbar puncture group (P = .377). It took 1.54 times more attempts to obtain CSF in the landmark group as it did in the US group (P = .046). It seemed to have no effect on postprocedural pain or the time to obtain CSF.

CONCLUSIONS

The use of US guidance to assist in lumbar punctures did not improve the procedural success rate over traditional landmark techniques in an academic setting with novice providers. Although using US for procedural guidance significantly decreased the number of attempts, it seemed to have no effect on postprocedural pain or the time to obtain CSF.

Efficacy of three-dimensional rotational fluoroscopic unit guidance for lumbar cerebrospinal fluid drainage among patients with unsuccessful initial attempt at bedside

Lumbar cerebrospinal fluid drainage has been widely performed in patients at the bedside; however, technical failure can occasionally occur as a result of blind maneuvering. Herein, we present the use of rotational fluoroscopic unit-guided lumbar drainage for patients with an unsuccessful initial attempt at bedside. In four of the 24 patients with aneurysmal subarachnoid hemorrhage, initial lumbar drainage could not be performed at bedside. Thus, a three-dimensional rotational technology guided by a high-quality fluoroscopic unit was used. After a cone-beam computed tomography scan was performed, an accurate puncture point and a target thecal sac were identified using the software. The fluoroscopic unit helped us to identify the puncture point and trajectory with a laser pointer on the patient. A needle was inserted along the tract until the cerebrospinal fluid was collected. The lumbar drainage tube was successfully inserted with a single puncture in all four patients. Rotational fluoroscopic technology helps to identify a suitable puncture point, trajectory and target site for lumbar spinal drainage. Our technique is considerably useful in an era wherein minimally invasive procedures are preferred.

Ultrasound-assisted Lumbar Punctures: A Systematic Review and Meta-Analysis

BACKGROUND

Lumbar punctures (LPs) are a common procedure in emergency medicine. However, studies have found that failed procedure rates can be as high as 50%. Ultrasound has been suggested to improve success rates by visually identifying the location and trajectory for the LP procedure. This systematic review and meta-analysis was performed to determine whether the use of ultrasound improved the rate of successful LP performance.

METHODS

PubMed, CINAHL, Scopus, LILACS, the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, and bibliographies of selected articles were assessed for all randomized controlled trials comparing the success rates of ultrasound-assisted LP with landmark-based LP. Secondary outcomes included the rate of traumatic LPs, time to procedural success, number of needle passes, and patient pain score. Data were dual extracted into a predefined worksheet, and quality analysis was performed using the Cochrane Risk of Bias tool. Data were summarized and a meta-analysis was performed with subgroup analyses by pediatric versus adult patients and by operator training level.

RESULTS

Twelve studies (n = 957 total patients) were identified. Ultrasound-assisted LP was successful in 90.0% of patients and landmark-based LP was successful in 81.4% of patients. The calculated risk difference (RD) was 8.9% (95% confidence interval [CI] = 1.2% to 16.7%) with an odds ratio (OR) of 2.22 (95% CI = 1.03 to 4.77) in favor of the ultrasound-assisted group. There were fewer traumatic LPs in the ultrasound-assisted group (10.7% vs. 26.5%; RD = -16.4%, 95% CI = -27.6% to -5.2%; OR = 0.28, 95% CI = 0.18 to 0.45). Ultrasound-assisted LP was also associated with a shorter time to successful LP (6.87 minutes vs. 7.97 minutes), fewer mean needle passes (2.07 vs. 2.66), and lower patient pain scores (3.75 vs. 6.31).

CONCLUSIONS

Ultrasound-assisted LPs were associated with higher success rates, fewer traumatic LPs, shorter time to successful LP, fewer needle passes, and lower patient pain scores. Ultrasound should be considered prior to performing all LPs, especially in patients with difficult anatomy. Further studies are recommended to determine whether this effect is consistent in both adult and pediatric subgroups, as well as the impact of transducer type and body habitus on this technique.

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.

Ultrasound-Assisted Lumbar Puncture in a Neuromuscular Clinic has a High Success Rate and Less Pain

BACKGROUND

Lumbar puncture (LP) performed with the assistance of ultrasound (US) may improve success rate, with fewer puncture attempts and less pain.

OBJECTIVES

To explore the utility of US-assisted LP in a neuromuscular clinic.

METHODS

We performed a prospective, randomized, open-label study between May 2016 and January 2017. The primary outcome measure was LP success rate, and the secondary outcome measures included procedure time, number of attempts, and the levels of pain, anxiety, and satisfaction.

RESULTS

Lumbar puncture was performed in 40 consecutive patients. Ultrasound-assisted LP had a 100% success rate, compared with 85% (95% confidence interval: 58%-96%) without US assistance, although this difference failed to reach statistical significance. Ultrasound-assisted LP was associated with less pain and, also in patients &gt;60 years of age, with fewer needle insertions. Both groups reported high satisfaction rates, regardless of the use of US.

CONCLUSION

Ultrasound-assisted LP has a high success rate and less pain than unassisted LP, and can be accomplished easily in the outpatient neuromuscular clinic setting equipped with US.

Ultrasonography in Emergency Department; a Diagnostic Tool for Better Examination and Decision-Making

Context:

The aim of this study is to evaluate the applications of ultrasonography (US) as a diagnostic tool in emergency settings.

Evidence acquisition:

In the present review article, search engines and scientific databases of Google Scholar, Science Direct, PubMed, Medline, Scopus, and Cochrane were searched for the applications of US in emergencies. Finally, related articles which were published between 2000 and 2017, were selected and by reviewing them an attempt was made to evaluate various applications of US for examining and facilitating decision-making in emergency department (ED).

Results:

As a diagnostic tool, US can be of diagnostic help in emergency settings for the specialists and the treatment team regarding trauma, measuring intracranial pressure (ICP), hemothorax pneumothorax, abscess and its drainage, deep vein thrombosis (DVT), dyspnea, acute abdomen, appendicitis and biliary problems, renal colic and renal stones, shock, foreign object, bone fracture, peripheral nerve block, establishing central and peripheral venous access, lumbar puncture (LP), and confirmation of nasogastric tube (NGT) and endotracheal tube (ETT) placement.

Conclusion:

The results of this review study showed that US can be of help to EMPs as a diagnostic tool in a wide range of diseases and clinical conditions, which in turn can result in a decrease in the time needed for diagnosis and treatment, and therefore improve both the quality and quantity of the service provided in ED.

Ultrasound-Assisted Lumbar Puncture in Pediatric Emergency Department

BACKGROUND

Lumbar puncture (LP) is one of the essential diagnostic tools in pediatric emergency services. Recently, ultrasound-assisted LP was reported to be beneficial in the emergency service by facilitating the procedure and improving the successful procedure rates. In addition, this method may be effective in reducing patient and parent anxiety due to the LP procedure.

OBJECTIVES

The aim of this study was to investigate the effect of ultrasound-assisted LP on the outcomes of puncture procedures and traumatic LP.

METHODS

The study included patients younger than 18 years, who were admitted to the pediatric emergency service and underwent LP because of suspected central nervous system infection. The patients requiring LP were randomly divided into 2 groups designated as odd and even. One group received LP using the conventional method, whereas the other group had LP after spinal space measurement by ultrasound. The patients who did and who did not undergo ultrasound-assisted LP were compared for demographics, number of puncture attempts, and traumatic LP. Statistical analysis was performed using the Mann-Whitney U test and the Student t test. The χ test was used when nominal data were compared between the 2 groups.

RESULTS

Ultrasound-assisted LP was performed in 56 patients, and LP by using conventional method was performed in 55 patients. There was traumatic LP in 5 (8.9%) of the patients who underwent ultrasound-assisted LP and 9 (16.3%) of the patients who underwent LP using the conventional method (P > 0.05). The number of puncture attempts was 2 or more in 2 (3.5%) of the patients who underwent ultrasound-assisted LP and 5 (9%) of the patients who had LP using the conventional method (P > 0.05).

CONCLUSIONS

Ultrasound-assisted LP reduced traumatic LP and the number of puncture attempts in pediatric patients; however, the results were not statistically significant.

Ultrasound guidance for difficult lumbar puncture in children: pearls and pitfalls

Pediatric lumbar puncture can be challenging or unsuccessful for several reasons. At the same time, the excellent sonographic window into the pediatric spine provides a distinct opportunity for ultrasound-guided lumbar puncture. Minimal cerebrospinal fluid and thecal displacement by subdural or epidural hematomas are common after failed clinical attempts. Ultrasound is useful for determining a safe infraconal level for subarachnoid access. Real-time guidance increases not only the success rate but also the safety of diagnostic lumbar puncture and injections for chemotherapy and myelography. In this article, we discuss clinical and technical factors for ultrasound-guided pediatric lumbar puncture.

Preprocedural ultrasound examination versus manual palpation for thoracic epidural catheter insertion

Background and Aims:

Ultrasound imaging before neuraxial blocks was reported to improve the ease of insertion and minimize the traumatic trials. However, the data about the use of ultrasound in thoracic epidural block are scanty. In this study, pre-insertion ultrasound scanning was compared to traditional manual palpation technique for insertion of the thoracic epidural catheter in abdominal operations.

Subjects and Methods:

Forty-eight patients scheduled to midline laparotomy under combined general anesthesia with thoracic epidural analgesia were included in the study. Patients were divided into two groups with regard to technique of epidural catheter insertion; ultrasound group (done ultrasound screening to determine the needle insertion point, angle of insertion, and depth of epidural space) and manual palpation group (used the traditional manual palpation technique). Number of puncture attempts, number of puncture levels, and number of needle redirection attempts were reported. Time of catheter insertion and complications were also reported in both groups.

Results:

Ultrasound group showed lower number of puncture attempts (1 [1, 1.25] vs. 1.5 [1, 2.75], P = 0.008), puncture levels (1 (1, 1) vs. 1 [1, 2], P = 0.002), and needle redirection attempts (0 [0, 2.25] vs. 3.5 [2, 5], P = 0.00). Ultrasound-guided group showed shorter time for catheter insertion compared to manual palpation group (140 ± 24 s vs. 213 ± 71 s P = 0.00).

Conclusion:

Preprocedural ultrasound imaging increased the incidence of first pass success in thoracic epidural catheter insertion and reduced the catheter insertion time compared to manual palpation method.

Prospective Investigation of a Novel Ultrasound-assisted Lumbar Puncture Technique on Infants in the Pediatric Emergency Department

OBJECTIVE

The objective was to describe a novel ultrasound-assisted lumbar puncture (UALP) technique and to compare it to standard lumbar puncture (SLP) technique in infants.

METHODS

A prospective, randomized, controlled study in infants 60 days old and younger undergoing a lumbar puncture (LP) in a pediatric emergency department. Patients with a spinal anomaly or ventriculoperitoneal shunt were excluded. Eligible infants were randomized to UALP or SLP. A spinal sonogram was performed on all patients by an investigator not involved in performing the LP. Spinal landmarks and maximum safe depth were identified for the UALP providers. Providers in the SLP group were blinded to sonographic measurements. A successful LP was defined as the collection of cerebrospinal fluid (CSF) with a red blood cell count of less than 10,000 cells/mm³ . Statistical analysis included chi-square, Mann-Whitney U-test, and number needed to treat (NNT).

RESULTS

Forty-three patients were enrolled, 21 in the UALP group and 22 in the SLP group. Prematurity, weight, length, provider experience, anesthesia use, stylet technique, and number of attempts were similar between groups. The median age in the UALP group was 38 days (interquartile range [IQR] = 33 days) versus 45 days (IQR = 19 days) in the SLP group (p = 0.02). CSF was obtained in all UALP subjects (100%) versus in 18 of 22 (82%) in the SLP group (p = 0.04); 20 (95%) UALP subjects versus 15 (68%) SLP subjects met our definition of success (p = 0.023). The odds ratio of successful LP using UALP technique was 9.33 (95% confidence interval [CI] = 1.034 to 84.026) and the NNT was 3.7 (95% CI = 2.02 to 24.18).

CONCLUSION

The UALP technique increases the rate of a successful LP in infants compared to standard technique.

Pediatric emergency medicine point-of-care ultrasound: summary of the evidence

The utility of point-of-care ultrasound is well supported by the medical literature. Consequently, pediatric emergency medicine providers have embraced this technology in everyday practice. Recently, the American Academy of Pediatrics published a policy statement endorsing the use of point-of-care ultrasound by pediatric emergency medicine providers.  To date, there is no standard guideline for the practice of point-of-care ultrasound for this specialty. This document serves as an initial step in the detailed "how to" and description of individual point-of-care ultrasound examinations.  Pediatric emergency medicine providers should refer to this paper as reference for published research, objectives for learners, and standardized reporting guidelines.

How to do it: bedside ultrasound to assist lumbar puncture

For many neurologists, lumbar puncture is the only practical procedure that they undertake on a regular basis. Although anaesthetists and emergency physicians routinely employ ultrasound to assist lumbar puncture, neurologists do not. In this article, we outline the technique that we use for an ultrasound-assisted lumbar puncture, together with the evidence base that suggests that ultrasound has significant benefits. We aim to raise awareness of a method that can make lumbar puncture more likely to succeed and to be more comfortable for the patient.

A pictorial review of signature patterns living in musculoskeletal ultrasonography

The musculoskeletal system is mainly composed of the bones, muscles, tendons, and ligaments, in addition to nerves and blood vessels. The greatest difficulty in an ultrasonographic freeze-frame created by the examiner is recognition of the targeted structures without indicators, since an elephant's trunk may not be easily distinguished from its leg. It is not difficult to find descriptive ultrasonographic terms used for educational purposes, which help in distinguishing features of these structures either in a normal or abnormal anatomic condition. However, the terms sometimes create confusion when describing common objects, for example, in Western countries, pears have a triangular shape, but in Asia they are round. Skilled experts in musculoskeletal ultrasound have tried to express certain distinguishing features of anatomic landmarks using terms taken from everyday objects which may be reminiscent of that particular feature. This pictorial review introduces known signature patterns of distinguishing features in musculoskeletal ultrasound in a normal or abnormal condition, and may stir the beginners' interest to play a treasure-hunt game among unfamiliar images within a boundless ocean.

Prospective evaluation of point-of-care ultrasound for pre-procedure identification of landmarks versus traditional palpation for lumbar puncture

BACKGROUND

The objective of this study is to determine if point-of-care ultrasound (POCUS) pre-procedure identification of landmarks can decrease failure rate, reduce procedural time, and decrease the number of needle redirections and reinsertions when performing a lumbar puncture (LP).

METHODS

This was a prospective, randomized controlled trial comparing POCUS pre-procedure identification of landmarks versus traditional palpation for LP in a cohort of patients in the emergency department and intensive care unit.

RESULTS

A total of 158 patients were enrolled. No significant difference was found in time to completion, needle re-direction, or needle re-insertion when using POCUS when compared to the traditional method of palpation.

CONCLUSION

Consistent with findings of previous studies, our data indicate that there was no observed benefit of using POCUS to identify pre-procedure landmarks when performing an LP.

Ultrasound guidance for lumbar puncture

PURPOSE OF REVIEW

To review the literature and describe techniques to use ultrasound to guide performance of lumbar puncture (LP).

RECENT FINDINGS

Ultrasound evaluation of the lumbar spine has been shown in randomized trials to improve LP success rates while reducing the number of attempts and the number of traumatic taps.

SUMMARY

Ultrasound mapping of the lumbar spine reveals anatomical information that is not obtainable by physical examination, including depth of the ligamentum flavum, width of the interspinous spaces, and spinal bone abnormalities, including scoliosis. Using static ultrasound, the lumbar spine anatomy is visualized in transverse and longitudinal planes and the needle insertion site is marked. Using real-time ultrasound guidance, the needle tip is tracked in a paramedian plane as it traverses toward the ligamentum flavum. Future research should focus on efficient methods to train providers, cost-effectiveness of ultrasound-guided LP, and the role of new needle-tracking technologies to facilitate the procedure.

Point-of-care ultrasonography by pediatric emergency physicians. Policy statement

Point-of-care ultrasonography is increasingly being used to facilitate accurate and timely diagnoses and to guide procedures. It is important for pediatric emergency physicians caring for patients in the emergency department to receive adequate and continued point-of-care ultrasonography training for those indications used in their practice setting. Emergency departments should have credentialing and quality assurance programs. Pediatric emergency medicine fellowships should provide appropriate training to physician trainees. Hospitals should provide privileges to physicians who demonstrate competency in point-of-care ultrasonography. Ongoing research will provide the necessary measures to define the optimal training and competency assessment standards. Requirements for credentialing and hospital privileges will vary and will be specific to individual departments and hospitals. As more physicians are trained and more research is completed, there should be one national standard for credentialing and privileging in point-of-care ultrasonography for pediatric emergency physicians.