Lumbar Puncture.

Lumbar puncture (LP) is a procedural skill that is required for practice in the emergency care setting, most often for diagnostic purposes. Rarely, it can also be used therapeutically, to alleviate the pain of patients presenting to the emergency department with acute headache from idiopathic intracranial hypertension. In either case, LP constitutes an invasive procedure in which the subarachnoid space is entered in order to obtain a sample of cerebrospinal fluid from one of the most vulnerable areas of the human anatomy. It is essential for the emergency clinician to carefully weigh the risks and benefits of LP, to ensure informed consent when possible, and to proceed in a manner that ensures optimal patient safety and effectiveness. This article reviews current recommendations and considerations around performing LP, in addition to the process for performing the procedure.

Predicting post-surgical outcomes in idiopathic normal pressure hydrocephalus using clinically important changes from the cerebrospinal fluid tap test.

OBJECTIVE: Patients diagnosed with idiopathic Normal Pressure Hydrocephalus (iNPH) typically experience symptom improvements after undergoing a cerebrospinal fluid-tap test (CSF-TT), These improvements are recognized as indicative of potential improvements following surgical intervention. As gait disturbance is the most common iNPH symptom, gait improvements are of predominant interest. The purpose of this study was to examine if clinically important changes in gait and balance from CSF-TT predict meaningful changes following surgery. METHOD: The study involved analysis of data collected in a prospective observational study for 34 iNPH patients who underwent a CSF-TT and subsequent surgery. Linear regression, logistic regression and classification trees were used for predictive modelling comparing changes from CSF-TT with post-surgical changes in Tinetti, Timed Up and Go (TUG) and Berg Balance Scale (BBS) outcomes. RESULTS: Predictive models for minimal clinically important differences (MCIDs) from CSF-TT to surgery were significant for Tinetti (odds ratio = 1.42, p = 0.02) and BBS (odds ratio = 1.57, p < 0.01). Four items on Tinetti and two items on BBS were identified with a predictive accuracy of 79% and 76% respectively. BBS has the highest sensitivity (85%) and negative predictive value (77%). TUG had a 100% specificity and 100% positive predictive value. The predictive model using MCIDs for TUG was not significant (odds ratio = 1.13, p = 0.06). CONCLUSION: Clinically important changes from CSF-TT are useful in predicting post-surgical outcomes in iNPH patients. Tinetti and BBS, both have predictive value using MCID scores as cut off values, of which BBS is a stronger outcome measure for prediction.

The Incidence of Postoperative Complications Following Lumbar and Bone Marrow Punctures in Pediatric Anesthesia: Insights From APRICOT.

OBJECTIVE: Bone marrow aspiration and lumbar puncture are procedures frequently performed in pediatric oncology. We aimed at assessing the incidence and risk factors of perioperative complications in children undergoing these procedures under sedation or general anesthesia. METHODS: Based on the APRICOT study, we performed a secondary analysis, including 893 children undergoing bone marrow aspiration and lumbar puncture. The primary outcome was the incidence of perioperative complications. Secondary outcomes were their risk factors. RESULTS: We analyzed data of 893 children who underwent 915 procedures. The incidence of severe adverse events was 1.7% and of respiratory complications was 1.1%. Prematurity (RR 4.976; 95% CI 1.097-22.568; P = 0.038), intubation (RR: 6.80, 95% CI 1.66-27.7; P =0.008), and emergency situations (RR 3.99; 95% CI 1.14-13.96; P = 0.030) increased the risk for respiratory complications. The incidence of cardiovascular instability was 0.4%, with premedication as risk factor (RR 6.678; 95% CI 1.325-33.644; P =0.021). CONCLUSION: A low incidence of perioperative adverse events was observed in children undergoing bone marrow aspiration or lumbar puncture under sedation and/or general anesthesia, with respiratory complications being the most frequent. Careful preoperative assessment should be undertaken to identify risk factors associated with an increased risk, allowing for appropriate adjustment of anesthesia management.

Ultrasound-Assisted Lumbar Punctures in Children: An Updated Systematic Review With Meta-Analysis.

CONTEXT: Lumbar puncture (LP) is a common procedure in children, but the rates of unsuccessful and traumatic LPs remain high. Point-of-care ultrasound (POCUS) has been proposed as a tool for improvement. OBJECTIVES: Our aim was to systematically review current evidence on the usefulness of POCUS assisted LP in children. DATA SOURCES: PubMed, Embase, and the CENTRAL were searched up to November 2022. STUDY SELECTION: We searched for randomized control trials assessing the effectiveness of POCUS assisted LP in children. DATA EXTRACTION: Data were extracted by 2 reviewers independently. RESULTS: Seven randomized control trials involving 618 participants were included. Overall, the first attempt POCUS assisted LP was successful in 72% compared with 59.6% in the standard group, regardless of the definition used. The calculated risk difference was 13.0% (95% confidence interval [CI]: 3% to 23%) I2:53%, odds ratio: 2.00 (95% CI: 1.13 to 3.53), I2: 45% and risk ratio:1.21 (95% CI: 1.01 to 1.44) I2:64%. Additionally, fewer traumatic LPs occurred in the US-assisted group, with a risk difference of -12% (95% CI: -0.22 to -0.03), odds ratio: 0.45 (95% CI: 0.26 to 0.78) and risk ratio: 0.53 (95% CI: 0.35 to 0.79). POCUS did not extend the duration of LP procedure with mean difference: -1.11 (95% CI: -2.88 to 0.66). CONCLUSIONS: POCUS improved the first attempt success rate and reduced the incidence of traumatic LPs compared with standard LP procedure in children. Therefore, if it is available, POCUS should be used routinely before every LP, especially when performed by less experienced physicians.

Efficacy of therapies for post dural puncture headache.

PURPOSE OF REVIEW: Clinical management of postdural puncture headache (PDPH) remains an interdisciplinary challenge with significant impact on both morbidity and quality of life. This review aims to give an overview of the most recent literature on prophylactic and therapeutic measures and to discuss novel findings with regard to currently published consensus practice guideline recommendations. RECENT FINDINGS: Although current evidence does not support a recommendation of any specific prophylactic measure, new data is available on the use of intrathecal catheters to prevent PDPH and/or to avoid invasive procedures. In case of disabling or refractory symptoms despite conservative treatments, the epidural blood patch (EBP) remains the therapeutic gold standard and its use should not be delayed in the absence of contraindications. However, recent clinical studies and meta-analyses provide additional findings on the therapeutic use of local anesthetics as potential noninvasive alternatives for early symptom control. SUMMARY: There is continuing research focusing on both prophylactic and therapeutic measures offering promising data on potential alternatives to invasive procedures, although there is currently no treatment option that comes close to the effectiveness of an EBP. A better understanding of PDPH pathophysiology is not only necessary to identify new therapeutic targets, but also to recognize patients who benefit most from current treatments, as this might enhance their therapeutic efficacy.

Physician's conceptions of the decision-making process when managing febrile infants ≤ 60 days old: a phenomenographic qualitative study.

BACKGROUND: The management of febrile infants aged ≤ 60 days and adherence to guidelines vary greatly. Our objective was to describe the process of decision-making when managing febrile infants aged ≤ 60 days and to describe the factors that influenced this decision. METHODS: We conducted 6 focus group discussions with 19 clinically active physicians in the pediatric emergency departments of 2 university hospitals in Skåne region, Sweden. We followed an inductive qualitative design, using a phenomenological approach. A second-order perspective was used, focusing on how physicians perceived the phenomenon (managing fever in infants) rather than the phenomenon itself. The transcribed interviews were analyzed using a 7-step approach. RESULTS: Performing a lumbar puncture (LP) was conceived as a complex, emotionally and mentally laden procedure and dominated the group discussions. Three central categories emerged as factors that influenced the decision-making process on whether to perform an LP: 1) a possible focus of infection that could explain the origin of the fever, 2) questioning whether the temperature at home reported by the parents was a fever, especially if it was ≤ 38.2°C, and 3) the infant's general condition and questioning the need for LP in case of well-appearing infants. Around these 3 central categories evolved 6 secondary categories that influenced the decision-making process of whether to perform an LP or not: 1) the physicians' desire to be able to trust their judgement, 2) fearing the risk of failure, 3) avoiding burdensome work, 4) taking others into account, 5) balancing guidelines and resources, and 6) seeing a need to practice and learn to perform LP. CONCLUSIONS: The difficulty and emotional load of performing an LP were important factors that influenced the decision-making process regarding whether to perform an LP. Physicians highlighted the importance of being able to rely on their clinical judgment and make independent decisions. Guidelines may consider allowing a degree of flexibility and independent thinking to take into account patients' characteristics and needs.

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.

Dural puncture epidural with 25-G spinal needles versus conventional epidural technique for labor analgesia: A systematic review of randomized controlled trials.

BACKGROUND: Dural mater is punctured by using a spinal needle without drugs administrated into intrathecal space directly in dural puncture epidural (DPE) analgesia. OBJECTIVE: This study aimed to summarize the evidence of benefits and risks of DPE analgesia with 25-G spinal needles for labor pain relief. METHODS: DPE analgesia with EP analgesia for labor pain relief were systematically searched. The Embase, MEDLINE, Cochrane Central Register of Controlled Trials, Scopus and Web of Science databases were systematically searched till 6th November 2022 to find out randomized controlled trials (RCTs) comparing DPE (using 25-G spinal needles) with conventional epidural (EP) analgesia. The risk of bias was assessed with the Cochrane tool. Risk ratio, mean difference, and 95% confidence intervals were calculated. RESULTS: Seven RCTs with 761 parturients were identified. Pool data showed that DPE technique was associated with shorter time to pain score ⩽ 3/10, higher percentage with pain score ⩽ 3/10 at 10 min and 20 min, lower incidence of epidural top-up bolus and no S2 block, higher incidence of bilateral S2 blockade at 10 min and during labor, lower incidence of epidural top-up bolus and incidence of asymmetric block. No statistical difference in side effect and parturient satisfaction between DPE and EP technique. CONCLUSION: DPE technique with 25-G spinal needles was associated with faster analgesia onset and sacral coverage, greater sacral spread, lesser requirement of epidural top-up and lower incidence of asymmetric block. DPE technique with 25-G spinal needles showed a greater benefit to parturients.

Simple detecting of elevated ICP through liquor flow after lumbar puncture.

Elevated intracranial pressure (ICP) is defined as a cerebrospinal fluid (CSF) opening pressure (OP) greater than 25 cmH2O. When a diagnostic lumbar puncture is performed it is useful to estimate also intracranial pressure. To do this it is required a presence of pressure gauges, which are currently the gold standard, not available in most resource-constrained contexts. We decided to evaluate whether it is possible to estimate it simply by counting the drops of cerebrospinal liquor, which are collected after lumbar puncture, according to Poiseuille's law. Was examined a sample of 52 patients, aged between 18 and 85 years, belonging to the emergency room of "Santa Maria delle Grazie" Hospital in Pozzuoli (Naples) who needed a diagnostic lumbar puncture (LP). The ICP was initially measured using a standard narrow-gauge manometer by attaching it to the spinal needle. After removing the pressure gauge, the number of drops of cerebrospinal fluid flowing from the spinal needle in 30  seconds was counted. A statistical analysis was made with linear regression and ROC analysis. OP as measured by standard manometry was raised on 17 occasions with CSF drop rate median of 47 drops/30 seconds and range 30-74 drops/30 seconds. OP was normal on 35 occasions with CSF drop rate median of 23 drops/30 seconds  with range of 14-34 drops/30 seconds. A linear regression analysis was performed which resulted in a Pearson correlation of 0.936 an adjusted R square of 0.874 (see Fig. 1). Analysis through ANOVA documented an F of 355.301 with p < 0.01 and Dubin Watson of 1.642. The analysis through ROC showed an AUC of 0.980, with a sensitivity of 100% and a specificity of 91% if chosen as a limit, 29 drops in 30 seconds  (Youden Index of 0.9140). Therefore, we have concluded, that although there are several precautions, like patient's position, it is technically feasible to indirectly estimate cerebrospinal fluid pressure with good accuracy by counting the drops of cerebrospinal fluid flowing from a 22 G spinal needle.

Ultrasound-assisted lumbar puncture with a horizontal and perpendicular paramedian approach based on positioning in patients with abnormal spinal anatomy: a case report and technical description.

BACKGROUND: The use of ultrasound has been reported to be beneficial in challenging neuraxial procedures. The angled probe is responsible for the main limitations of previous ultrasound-assisted techniques. We developed a novel technique for challenging lumbar puncture, aiming to locate the needle entry point which allowed for a horizontal and perpendicular needle trajectory and thereby addressed the drawbacks of earlier ultrasound-assisted techniques. CASE PRESENTATION: Patient 1 was an adult patient with severe scoliosis who underwent a series of intrathecal injections of nusinersen. The preprocedural ultrasound scan revealed a cephalad probe's angulation (relative to the edge of the bed) in the paramedian sagittal oblique view, and then the probe was rotated 90° into a transverse plane and we noted that a rocking maneuver was required to obtain normalized views. Then the shoulders were moved forward to eliminate the need for cephalad angulation of the probe. The degree of rocking was translated to a lateral offset from the midline of the spine through an imaginary lumbar puncture's triangle model, and a needle entry point was marked. The spinal needle was advanced through this marking-point without craniocaudal and lateromedial angulation, and first-pass success was achieved in all eight lumbar punctures. Patient 2 was an elderly patient with ankylosing spondylitis who underwent spinal anesthesia for transurethral resection of the prostate. The patient was positioned anteriorly obliquely to create a vertebral rotation that eliminated medial angulation in the paramedian approach. The procedure succeeded on the first pass. CONCLUSIONS: This ultrasound-assisted paramedian approach with a horizontal and perpendicular needle trajectory may be a promising technique that can help circumvent challenging anatomy. Larger case series and prospective studies are warranted to define its superiority to alternative approaches of lumbar puncture for patients with difficulties.

A previous champagne tap reduces the probability of traumatic lumbar puncture in the following procedure.

A cerebrospinal fluid (CSF) sample containing no red blood cells (RBC), colloquially known as a champagne tap, is an ideal outcome of a lumbar puncture (LP). In this pseudoprospective study of 2573 patients aged from 0 days to 95 years, we examined in four different age categories (neonates and infants, children and adolescents, adults, and older adults) whether a champagne tap in the patient's first LP procedure and a shorter time than 1 week between the two successive procedures are independently associated with fewer blood-contaminated CSF samples (traumatic LP) in the following procedure. One out of five CSF samples from the patient's first LP procedures were RBC-free on average, varying from about 9% in neonates and infants to about 36% in children and adolescents. The mean incidence of champagne taps was 19.5%. According to binary logistic regression, a champagne tap in the previous LP procedure significantly determined whether the following procedure was not blood-contaminated. The odds of traumatic LP were halved or even reduced tenfold after a champagne tap. Less than a week between the two successive procedures, in turn, multiplied the odds of traumatic LP in the latter even more than tenfold. A champagne tap was not significantly associated with traumatic LP in the following procedure among pediatric patients. If the patient's condition or therapy plan permits and the blood contamination can compromise the reliability of the CSF-based analysis and consequent diagnosis, postponing the LP procedure by several days is advisable to improve the odds of receiving a high-quality CSF sample.

First-Person Point-of-View Instructional Video on Lumbar Puncture Procedure.

OBJECTIVES: Tutorial videos filmed from a first-person point of view (FP-POV) are generally well received. Pediatric residents are expected to be competent in performing the lumbar puncture (LP). The educational effectiveness of a FP-POV in lumbar puncture procedure training for resident physicians has yet to be evaluated. We compared a FPPOV LP video with a standard in-person demonstration of the LP. METHODS: We designed an assigned cohort study to compare a FP-POV procedural instructional video of a simulated pediatric LP to the standard in-person procedure demonstration.After the intervention, residents completed an LP observed by one of two blinded reviewers who assessed the procedure using a modified, published assessment tool.Participants completed preintervention and postintervention surveys to rate self-confidence and usefulness of the FP-POV educational method. The data was analyzed using a Wilcoxon Rank sum test. z Scores were calculated on the raw assessment scores. RESULTS: Eighteen first year pediatric residents participated, nine in each group. The median modified assessment tool score was 17 in the FP-POV group (min, 14; max, 17; IQR:, 1.5) and 14 in the standard demonstration group (min, 6; max, 17; IQR, 4.5), with the higher score being more successful. There was a statistical difference between the assessment scores between the 2 groups (z score = 2.18, P = 0.04). Postintervention survey data demonstrated relative satisfaction with the FPPOV educational method. CONCLUSIONS: This study supports the educational effectiveness of a FP-POV procedure tutorial.Future studies with a larger sample size are needed.

Simple methods for cerebrospinal fluid collection in fetal, neonatal, and adult rat.

BACKGROUND: Cerebrospinal fluid (CSF) collection and its analysis are common medical practices useful in the diagnosis, therapy, and prevention of central nervous system (CNS) disorders. In recent years, several types of research have improved our insight into CSF and its role in health and disease. Yet, many characteristics of this fluid remain to be fully understood. NEW METHODS: Here, we describe how to collect CSF from embryonic, postnatal, and adult stages of the rat. In adults, CSF can be collected through simple stereotaxic surgery to expose the membrane overlying the cisterna magna (CM) of an anesthetized rat and collection of CSF through micropipette puncture through the membrane. In embryos and pups, CSF is aspirated, using a fire-polished micro-capillary pipette, from the CM of animals. RESULTS: Application of these methods provides the maximum volume of pure, uncontaminated CSF (embryonic day 19: 10-15 microliter, postnatal day 5: 20-30 microliter, adults: 100-200 microliter) with a success rate of approximately 95% in every age. COMPARISON WITH EXISTING METHODS: Compared to the existing protocols, these methods obtain considerable volumes of CSF, which may accelerate the measurement of biological markers in this fluid. Also, these techniques do not require surgical skills and according to the practical points mentioned during sampling, the procedures can be performed in rapid fashion. CONCLUSION: We describe simple methods for collecting CSF in live rats. These protocols provide clean, uncontaminated CSF for experiments to understand the exact role of this fluid in the development and maintenance of the CNS health.

Recent Advances in Smart Epidural Spinal Needles.

Lumbar puncture is a minimally invasive procedure that utilizes a spinal needle to puncture the lumbar epidural space to take a sample from the cerebrospinal fluid or inject drugs for diagnostic and therapeutic purposes. Physicians rely on their expertise to localize epidural space. Due to its critical procedure, the failure rate can reach up to 28%. Hence, a high level of experience and caution is required to correctly insert the needle without puncturing the dura mater, which is a fibrous layer protecting the spinal cord. Failure of spinal anesthesia is, in some cases, related to faulty needle placement techniques since it is blindly inserted. Therefore, advanced techniques for localization of the epidural space are essential to avoid any possible side effects. As for epidural space localization, various ideas were carried out over recent years to provide accurate identification of the epidural space. Subsequently, several methodologies based on mechanical and optical schemes have been proposed. Several research groups worked from different aspects of the problem, namely, the clinical and engineering sides. Hence, the main goal of this paper is to review this research with the aim of remedying the gap between the clinical side of the problem and the engineering side by examining the main techniques in building sensors for such purposes. This manuscript provides an understanding of the clinical needs of spinal needles from an anatomical point of view. Most importantly, it discusses the mechanical and optical approaches in designing and building sensors to guide spinal needles. Finally, the standards that must be followed in building smart spinal needles for approval procedures are also presented, along with some insight into future directions.

Success and complications in lumbar punctures of pediatric patients with leukemia: a study protocol for a randomized clinical crossover trial of a bioimpedance needle system versus conventional procedure.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most common malignancy diagnosed in children. At present, the long-term survival from pediatric ALL is well over 90%. However, the probability of event-free survival is reduced if the lumbar puncture (LP) procedures at the beginning of the patient's intrathecal therapy cause blood leakage into the spinal canal and blast cells contaminate the cerebrospinal fluid. According to the literature, such traumatic LP procedures concern one out of five pediatric patients with ALL. Recently, a novel medical device measuring the tissue bioimpedance at the tip of a spinal needle was found feasible in pediatric patients with ALL. The LP procedure was successful at the first attempt in 80% of procedures, and the incidence of traumatic LPs was then 11%. The purpose of the present study is to compare the bioimpedance spinal needle system with the standard clinical practice resting on a conventional spinal needle and investigate its efficacy in clinical practice. METHODS: The study is a multicenter, randomized, two-arm crossover noninferiority trial of pediatric hemato-oncology patients that will be conducted within the usual clinical workflow. Patients' LP procedures will be performed alternately either with the IQ-Tip system (study arm A) or a conventional Quincke-type 22G spinal needle (study arm B). For each enrolled patient, the order of procedures is randomly assigned either as ABAB or BABA. The total number of LP procedures will be at least 300, and the number of procedures per patient between two and four. After each study LP procedure, the performance will be recorded immediately, and 1-week diary-based and 4-week record-based follow-ups on symptoms, complications, and adverse events will be conducted thereafter. The main outcomes are the incidence of traumatic LP, first puncture success rate, and incidence of post-dural puncture headache. DISCUSSION: The present study will provide sound scientific evidence on the clinical benefit, performance, and safety of the novel bioimpedance spinal needle compared with the standard clinical practice of using conventional spinal needles in the LP procedures of pediatric patients with leukemia. TRIAL REGISTRATION: ISRCTN ISRCTN16161453. Registered on 8 July 2022.

Safety and predictors of the success of lumbar punctures performed by a medicine procedure service.

BACKGROUND: Medicine procedure services (MPS) increasingly perform bedside procedures, including lumbar punctures (LPs). Success rates and factors associated with LP success performed by MPS have not been well described. OBJECTIVE: We identified patients undergoing LP by an MPS September 2015 to December 2020. We identified demographic and clinical factors, including patient position, body mass index (BMI), use of ultrasound, and trainee participation. We performed multivariable analysis to identify factors associated with LP success and complications. MAIN OUTCOME AND MEASURES: We identified 1065 LPs among 844 patients. Trainees participated in 82.2%; ultrasound guidance was used in 76.7% of LPs. The overall success rate was 81.3% with 7.8% minor and 0.1% major complications. A minority of LPs were referred to radiology (15.2%) or were traumatic (11.1%). In multivariable analysis, BMI > 30 kg/m2 (odds ratio [OR] 0.32, 95% confidence interval [CI] 0.21-0.48), prior spinal surgery (OR 0.50, 95% CI 0.26-0.87), and Black race (OR 0.62, 95% CI 0.41-0.95) were associated with decreased odds of successful LP; trainee participation (OR 2.49, 95% CI 1.51-4.12) was associated with increased odds. Ultrasound guidance (OR 0.53, 95% CI 0.31-0.89) was associated with lower odds of traumatic LP. RESULTS: In a large cohort of patients undergoing LP by an MPS, we identified high success and low complication rates. Trainee participation was associated with increased odds of success, while obesity, prior spinal surgery, and Black race were associated with decreased odds of success. Ultrasound guidance was associated with lower odds of a traumatic LP. Our data may help proceduralists in planning and assist in shared decision-making.

A novel approach to CSF pressure measurement via lumbar puncture that shortens the measurement time with a high level of accuracy.

Intracranial pressure (ICP) is an important parameter in clinical management and diagnosis of several neurological diseases which is indirectly measured via lumbar puncture (LP). In routine measurements of cerebrospinal fluid pressure (PCSF) from lumbar region, a spinal needle and a spinal manometer are used. PCSF measurement via LP with the use of a spinal manometer may not yield correct PCSF results due to prolonged times required to obtain an accurate pressure value. Equilibrium pressure may be underestimated in circumstances where spinal manometry procedure is terminated prematurely, with the wrong assumption that equilibrium pressure is reached. Elevated PCSF levels can lead to visual loss and brain damage when go undiagnosed. In this study, the spinal needle-spinal manometer combination was modelled with a first-order differential equation and a time constant (τ) was defined as the product of the resistance to flow of the needle with the bore area of the manometer divided by the dynamic viscosity of CSF, i.e. τ= RA/ρCSF. Each needle/manometer combination had a unique constant as a predictor of the equilibrium pressure. The fluid pressure in the manometer rose in an exponential manner which was tested in a simulated environment using 22G spinal needles namely Braun-Spinocan, Pajunk-Sprotte and M.Schilling. Curve fitting of the manometer readings were obtained with regression coefficients of R2 ≥ 0.99 to determine measurement time constants. The residual differences between predicted and true values were less than 1.18 cmH2O. For a given needle/manometer combination, time required to reach equilibrium pressure was identical for all pressure levels. PCSF measured at reduced times can easily be interpolated to their equilibrium level allowing clinicians to obtain PCSF values with high accuracy within seconds. This method can be used as an indirect estimation of ICP in routine clinical practice.

The Development and Application of a Cost-Effective Cervical Spine Phantom for Use in Fluoroscopically Guided Lateral C1-C2 Spinal Puncture Training.

BACKGROUND AND PURPOSE: Lateral C1-C2 spinal punctures are uncommon procedures performed by radiologists for access to CSF and contrast injection when a lumbar approach is contraindicated and an alternate method of access becomes necessary. There are limited opportunities to learn and practice the technique. We aimed to develop and assess the efficacy of a low-cost, reusable cervical spine phantom for training in fluoroscopically guided lateral C1-C2 spinal puncture. MATERIALS AND METHODS: The phantom was constructed with a cervical spine model, an outer tube representing the thecal sac, an inner balloon representing the spinal cord, and polyalginate to replicate soft tissue. The total cost of materials was approximately US $70. Workshops were led by neuroradiology faculty experienced in the procedure using the model under fluoroscopy. Survey questions were assessed on a 5-point Likert scale. Participants were given pre- and postsurveys assessing comfort, confidence, and knowledge of steps. RESULTS: Twenty-one trainees underwent training sessions. There was significant improvement in comfort level (Δ: 2.00, SD: 1.00, P value < .001); confidence (Δ: 1.52 points, SD: 0.87, P value < .001); and knowledge (Δ: 2.19, SD: 0.93, P value < .001). Eighty-one percent of participants found the model "very helpful" (5/5 on Likert scale), and all participants were "very likely" to recommend this workshop to others. CONCLUSIONS: This cervical phantom model is affordable and replicable and demonstrates training utility to prepare residents for performing lateral C1-C2 spinal puncture. This is a rare procedure, so the use of a phantom model before patient encounters is invaluable to resident education and training.

What is the place of dural puncture epidural in labour analgesia?

Epidural analgesia is the gold standard for labour analgesia. Dural puncture epidural analgesia is a modification of the conventional technique, where the dura is intentionally perforated with a spinal needle but no intrathecal medication is given. This article reviews the evidence for and against the clinical use of dural puncture epidural.

Comparison of accuracy between augmented reality/mixed reality techniques and conventional techniques for epidural anesthesia using a practice phantom model kit.

BACKGROUND: This study used an epidural anesthesia practice kit (model) to evaluate the accuracy of epidural anesthesia using standard techniques (blind) and augmented/mixed reality technology and whether visualization using augmented/mixed reality technology would facilitate epidural anesthesia. METHODS: This study was conducted at the Yamagata University Hospital (Yamagata, Japan) between February and June 2022. Thirty medical students with no experience in epidural anesthesia were randomly divided into augmented reality (-), augmented reality (+), and semi-augmented reality groups, with 10 students in each group. Epidural anesthesia was performed using the paramedian approach with an epidural anesthesia practice kit. The augmented reality (-) group performed epidural anesthesia without HoloLens2Ⓡ and the augmented reality (+) group with HoloLens2Ⓡ. The semi-augmented reality group performed epidural anesthesia without HoloLens2Ⓡ after 30 s of image construction of the spine using HoloLens2Ⓡ. The epidural space puncture point distance between the ideal insertion needle and participant's insertion needle was compared. RESULTS: Four medical students in the augmented reality (-), zero in the augmented reality (+), and one in the semi-augmented reality groups failed to insert the needle into the epidural space. The epidural space puncture point distance for the augmented reality (-), augmented reality (+), and semi-augmented reality groups were 8.7 (5.7-14.3) mm, 3.5 (1.8-8.0) mm (P = 0.017), and 4.9 (3.2-5.9) mm (P = 0.027), respectively; a significant difference was observed between the two groups. CONCLUSIONS: Augmented/mixed reality technology has the potential to contribute significantly to the improvement of epidural anesthesia techniques.