Epidural Needle Research Articles

Case Series: Novel Use of a Erector Spinae Plane Block At A Lumbar Spinal Level For Coverage Of Sacral Dermatomes

The erector spinae plane (ESP) block is a recent and novel regional anesthesia procedure used primarily for the thoracic region. There is limited use of this block for the lumbar and sacral regions. Here we investigate the use of lumbar ESP blocks for three cases; hip disarticulation, penile burn, and perineal injury. For each case, an 18-gauge Tuohy needle was inserted into the paraspinous region at the L4 level and caudally directed towards the interfacial plane posterior to the transverse process via ultrasound. Once in place, 20-30 mL of 0.5% bupivacaine was injected. Opioid consumption was measured before and after block placement to evaluate for pain control. The ESP block yielded a significant reduction in opioid use for the penile burn and perineal injury cases, while a non-significant reduction was observed in the hip disarticulation case. The use of lumbar ESP block has shown the feasibility and effectiveness for sacral innervated injuries. This nerve block technique has strong potential to improve patient satisfaction and pain control while minimizing opioid reliance in the postoperative and traumatic injury recovery periods for lumbar and perineal injury patients.

Unilateral neurostimulation-assisted cervical epidural anesthesia for upper limb surgeries—a case series

BackgroundThe role of neurostimulation-aided cervical epidural anesthesia (CEA) in shoulder surgery has been described in the literature. The use of nerve stimulators and the infusion of local anesthetic (LA) in the cervical epidural space has also been mentioned. Epidural needle rotation prior to insertion of the catheter is not described, and it is not clear if general anesthesia was administered in these cases.Case presentationIn this case series, we performed CEA at the level of C7-T1 in 12 patients undergoing various surgeries on the proximal open shoulder and mid humerus after informed consent. Ipsilateral motor responses elicited by continuous electrical stimulation were used to identify lateralization of the epidural catheter tip. The placement of catheters was confirmed under an intraoperative image intensifier. Using the median approach at the level of C7-T1, an ipsilateral twitch was noted in all patients. Neurostimulation persisted with an advancement of stimulating catheter 3–4 cm in the cervical epidural space in all patients. A cervical radiograph confirmed the placement of an ipsilateral catheter and contrast injection there upon revealing the spread of the LA agent. All patients had successful awake shoulder and mid-humerus surgeries under sole cervical epidural anesthesia as evidenced by the absence of pain response at the surgical incision.ConclusionsIpsilateral CEA can be offered for unilateral upper limb surgeries. Low volumes of LA can be injected after precise placement of the tip of the catheter corresponding to the level of surgical incision.

Comparison of Clonidine with Bupivaicaine vs Plain Bupivaicaine in Transversus Abdominis Plane (TAP) Block in Women Undergoing Cesarean Delivery Under Spinal Anesthesia: Randomized Clinical Trial.

Transversus abdominis plane (TAP) block is a technique of regional anesthesia, introduced by Rafi in 2001. Various additives have been added to prolong the duration of effect of TAP block. We conducted this study to see if addition of clonidine to bupivacaine significantly increases the duration of effect of TAP block. This randomized, parallel group, placebo controlled double blind clinical trial was conducted on 100 healthy participants (ASAII) undergoing LSCS under Spinal anesthesia (SA) from Jan 2021 to July 2021 after consent of Institutional Ethics Committee. Women with contraindications to spinal anesthesia, allergy to any of the drugs or not-suitable for cesarean under SA were excluded. After written informed consent, eligible participants were randomly allocated into two groups using computer generated random number tables using serially numbered opaque sealed envelopes. 48 out of 50 participants in group A (Bupivacaine) were given TAP block with 20 ml of 0.25% bupivacaine bilaterally. 2 women were excluded because of conversion to General Anesthesia. Similarly, 47 out of 50 participants in Group B (Bupivacaine + Clonidine) were given TAP block with 20 ml of 0.25% bupivacaine plus 1.0 mcg/kg clonidine bilaterally after completion of surgery using 18 G Tuohy needle. Separate person used to fill the drugs for block. Participants were assessed for duration of analgesic effect of TAP block measured as the time to request for additional analgesia. Additional analgesic requirement was noted. Participants were assessed for side effects of clonidine like hypotension, bradycardia, sedation and dryness of mouth. Overall patient satisfaction was also noted. Data was analysed using Graphpad Prism 9, using Student's t-test for primary outcome and Mann-Whitney U test for secondary outcomes. The mean 'duration of analgesic effect with TAP block' was 6.34 (SD1.26) hrs for 'Bupivacaine' group and 10.56 (SD2.12) hrs for 'Bupivacaine + Clonidine' group. None of the patients developed hypotension or bradycardia. 25% participants in Bupivacaine only group and 40.42% in Bupivacaine + Clonidine group were sedated (P < 0.05). 20.8% in 'Bupivacaine' group and 51.06% in 'Bupivacaine + Clonidine' group had dryness of mouth (P < 0.001). Patient satisfaction was equal in both the groups. Addition of clonidine to bupivacaine in the dose of 1 mcg/kg significantly increases the duration of analgesic effect of TAP block, decreases analgesic usage without significant increase in side effects.

The contralateral oblique fluoroscopic view is associated with a lower incidence of postdural puncture headache in patients undergoing percutaneous spinal cord stimulation.

Spinal cord stimulation (SCS) is a minimally invasive therapy that is increasingly used to treat refractory neuropathic pain. Although this technique has a low incidence of serious long-term adverse sequelae, the risk of complications such as inadvertent dural puncture remains. The goal of this article was to determine the impact of the contralateral oblique (CLO) fluoroscopic view incidence of postdural puncture headache (PDPH) during spinal cord stimulator implantation as compared to lateral fluoroscopic view. This was a single academic institution retrospective analysis of electronic medical records spanning an approximate 20-year time period. Operative and postoperative notes were reviewed for details on dural puncture, including technique and spinal level of access, the development of a PDPH, and subsequent management. Over nearly two decades, a total of 1637 leads inserted resulted in 5 PDPH that were refractory to conservative measures but responded to epidural blood patch without long-term complications. The incidence of PDPH per lead insertion utilizing loss of resistance and lateral fluoroscopic guidance was 0.8% (4/489). However, adoption of CLO guidance was associated with a lower rate of PDPH at 0.08% (1/1148), p < 0.02. The incorporation of the CLO view to guide epidural needle placement can decrease the odds of a PDPH during percutaneous SCS procedures. This study further provides real-world data supporting the potential enhanced accuracy of epidural needle placement in order to avoid unintentional puncture or trauma to deeper spinal anatomic structures.

ID: 205475 An Unfolding, Injectable Micro-Paddle for Efficient Spinal Cord Stimulation

Approximately 60% of all spinal cord stimulation (SCS) and peripheral nerve stimulation (PNS) doses for pain management are reduced by the 360° stimulation field limitations of the cylindrical percutaneous lead (CPL). With CPL, only 30% of the therapy dose is pointed towards the nerve target. [1] Poor dosing efficiency results in higher stimulation therapy amplitude, 2x higher recharge burden and more frequent battery replacement surgery. [2, 3] Multi-contact programming and novel high frequency waveforms further multiply these dosing inefficiencies. We demonstrate a self-opening injectable micro-paddle in cadavers and sheep. After deploying through a 13-gauge Tuohy needle, the lead self-opens to form a 4 mm wide micro-paddle with a unidirectional stimulation field. We performed fluoroscopy during deployment and benchmarked the retraction forces in comparison with cylindrical leads. We further developed a platinum-iridium surface processing which improves the charge injection density by 2x over conventional leads.

Comparison of the incidence of intravascular injection using the Tuohy and Quincke needles during ultrasound-guided caudal epidural block: a prospective randomized controlled study

IntroductionIntravascular injection of a local anesthetic can lead to life-threatening complications, such as deficits in neurological function after caudal epidural block. This study aimed to determine whether the intravascular injection...

Evaluation of an automatic approach device to the epidural space of Beagle dogs

ObjectiveTo compare the epidural anesthesia device (EPIA), which facilitates an automatic approach to location of the epidural space, with the performance of clinicians using tactile sensation and differences in pressure when inserting an epidural needle into the epidural space of a dog. Study designProspective, crossover experiment. AnimalsA total of 14 Beagle dogs weighing 7.5 ± 2.4 kg (mean ± standard deviation). MethodsEach dog was anesthetized three times at 2 week intervals for three anesthesiologists (two experienced, one novice) to perform 14 epidural injections (seven manual and EPIA device each). The sequence of methods was assigned randomly for each anesthesiologist. The dogs were anesthetized with medetomidine (10 μg kg–1), alfaxalone (2 mg kg–1) and isoflurane and positioned in sternal recumbency with the pelvic limbs extended cranially. Epidural puncture in the manual method was determined by pop sensation, hanging drop technique and reduced injection pressure, whereas using the device a sudden decrease in reaction force on the device was detected. A C-arm identified needle placement in the epidural space, and after administration of iohexol (0.3 mL), the needle length in the epidural space was defined as the mean value measured by three radiologists. Normality was tested using the Kolmogorov–Smirnov test, and significant differences between the two methods were analyzed using an independent sample t test. ResultsIn both methods, the success rates of epidural insertion were the same at 95.2%. The length of the needle in the epidural space using the device and manual methods was 1.59 ± 0.50 and 1.68 ± 0.88 mm, respectively, with no significant difference (p = 0.718). Conclusions and clinical relevanceEPIA device was comparable to human tactile sense for an epidural needle insertion in Beagle dogs. Further research should be conducted for application of the device in clinical environments.

Intervertebral Foramen - A Gateway to Epidural Space in Severe Lumbar Scoliosis.

We describe cases in which a preoperative computed tomography was used to guide the placement of an epidural catheter through the defect in the intervertebral foramina in patients with severe lumbar scoliosis. We demonstrate the adroitness with which epidural catheters were inserted through the intervertebral foramina. Computed tomography scan illustrates and plots the needle path creating a 3-dimensional image of the vertebral body rotation, needle trajectory, and the distance from the skin to the intervertebral foramina. Severe scoliosis is defined as a lateral curvature (Cobb's angle) of more than 50 degrees. It was proposed in severe idiopathic scoliosis that interventional pain management techniques are managed with fluoroscopic imaging or an alternative form. However, after a computed tomography evaluation of the scoliotic spine, we assumed that the intervertebral foraminal anatomy would facilitate a safe and efficient epidural needle and subsequent catheter positioning in severe scoliotic patients.

Lumboperitoneal shunt using fluoroscopy and a peel-away sheath

BackgroundAfter placement of the spinal catheter into the spinal canal during lumboperitoneal shunt (LPS) placement, the spinal catheter needs to be connected to the programmable valve. Although surgeons always try to secure the spinal catheter position during procedures, it may be accidentally pulled and displaced. This article aimed to introduce a “one-piece method” of LPS using fluoroscopy and peel-away sheath without connecting the spinal catheter to the programmable valve. MethodsAn abdominal shunt catheter, valve, and spinal shunt catheter were connected and tunneled to the back for insertion into the lumbar spinal subarachnoid space. The spinal catheter was cut to a length of 15 cm. Lumbar puncture was performed using a 14-gauge Tuohy needle inserted at the L2-3 intervertebral space using an image-guided paramedian technique, and a 0.035-inch guidewire was passed gently through the Tuohy needle under fluoroscopic guidance. The Tuohy needle was withdrawn, and a 5-Fr peel-away sheath was advanced over the wire. The dilator and guide wire were removed, the distal end of the 5-Fr peel-away sheath was checked to ensure that the cerebrospinal fluid flowed out, and the spinal shunt catheter was passed down the sheath. After confirming under fluoroscopic guidance that the catheter was properly positioned, the peel-away sheath was removed. ResultsLPS was performed using this method in seven patients without complications. ConclusionThis simple “one-piece method” using fluoroscopy and peel-away sheath is safe and effective for positioning the spinal catheter.

Accidental subdural block after epidural anesthesia in obstetric patient: Case report

Background: Although often overlooked, subdural anesthesia is a relatively common complication. It can present with a wide range of symptoms, from unexpectedly high sensory and limited motor blocks to significant hemodynamic and respiratory effects.&#x0D; Case Presentation: This case report documents the labor and delivery of a 26-year-old primigravida at 40 weeks gestation who requested an epidural at 4 cm. A 500 ml lactated Ringer's solution bolus was initiated prior to the procedure and a Tuohy needle, size 18-gauge, was utilized to locate the epidural space. Following a negative aspiration and falling meniscus test, a bolus of 8 ml containing a combination of 0.2% ropivacaine with 2 mcg/ml fentanyl was administered, resulting in a brief drop in blood pressure, which responded to ephedrine. An epidural infusion of 0.2% ropivacaine with 2 mcg/ml fentanyl was then started and continued until the decision was made to perform a caesarean section due to lack of progress. Prior to surgery, the epidural was supplemented with 15 ml of 0.75% ropivacaine and 50 mcg of fentanyl. Following the successful delivery of a healthy baby, the patient reported difficulty breathing, and her oxygen saturation dropped to 90%. She was intubated without medication and later extubated after the completion of surgery. The epidural provided pain relief for six hours postoperatively and the patient recovered fully without any neurological deficits.&#x0D; Conclusion: The case report describes an epidural anesthesia that resulted in respiratory depression and unconsciousness without sympatholysis. The local anesthetic diffused into the dura- arachnoid interface, or the subdural space, which facilitated the movement of the anesthetic cephalad. However, the patient experienced complete neurological recovery. This case demonstrates the importance of careful monitoring and prompt intervention in the event of complications during epidural anesthesia.&#x0D; Keywords: subdural anesthesia, primigravida, ropivacaine, unconsciousness.

Comparison of Magnetic Resonance Imaging and Intraprocedural Cervical Epidural Depth: A Case Series

BACKGROUND: Cervical epidural depth is assessed intraprocedurally using loss-of-resistance technique and fluoroscopy. It would be helpful if this depth could be predicted using magnetic resonance imaging (MRI) images. METHODS: This is a case series of 10 patients undergoing cervical epidural steroid injections (CESIs). The following measurements were made: intraprocedural depth, measured on Tuohy needles intraprocedurally, and MRI depth, measured from the MRI cervical spine. Linear regression models were used to compare the 2 depths. RESULTS: For intraprocedural depth vs sagittal MRI depth, R (Version 4.2.0, R Foundation for Statistical Computing, Vienna, Austria, 2021) was 0.8744, P value &lt; 0.0001. For intraprocedural depth vs axial MRI depth, R was 0.8582, P value &lt; 0.001. CONCLUSIONS: Knowledge of the cervical epidural depth prior to CESIs may improve the safety and efficacy of these procedures. KEY WORDS: Cervical epidural depth, cervical radiculopathy, cervical epidural steroid injections, MRI depth, case series

Measurements of Epidural Space Depth Using Pre-Existing CT-Scan Correlate with Loss of Resistance Depth during Lumber Epidural Catheter Placement

Background: The use of epidural catheters provides the best quality intra- and post-operative pain relief for various major thoraco-abdominal and lower limb surgeries. The process of placing an epidural catheter into the epidural space between the vertebrae can be challenging due to variations in spinal anatomy of different level, narrow intervertebral spaces and can cause catastrophic neurological complications. Though various studies have been shown to overcome the placement of epidural catheter using standard ultrasound method, using the pre-existing computer tomography depth correlate with loss of resistance in placing the epidural catheter would be a well adjunct tool for the procedure. Objectives: To correlate measurements taken from pre-existing computed tomography (CT) imaging to the loss of resistance depth as recorded during epidural placement. Methods: This Single procedural observational study was performed in Combined Military Hospital (CMH), Dhaka from 1st December 2018 to 30th November 2019. Fifty adult patients scheduled for lower abdominal and lower limb surgery under epidural anaesthesia (EA). The patient’s advised/routine abdominal CT film was inspected by a radiologist, who was blinded to the results of the actual needle length, to determine the distance from the skin to the ligamentum flava the corresponding level of L2 to L5 interspinous spaces. The distance on the CT film in the midline was measured using a ruler against the measurement scale, conventionally represented as a 5 cm-10 cm scale with 1-cm divisions. The CT-derived depth was calculated using the principle of Pythagorean triangle trigonometry. Result: In this study, Sixty eight percentages of patients (68%) Epidural- skin distance (ESD) had 4.7-6.8cm. Mean Epidural-skin distance 5.8±1.7cm. On evaluation of Loss of Resistance Depth, 46% of patients had 5.2-7.3cm depth of LOR, followed by 30% patients had 3.0-5.1cm and 12% patients had 7.4-9.5cm. Mean loss of resistance depth was 6.3±1.4 cm. It was evident from this study that positive significant correlation (r=0.941; p=0.001) between the CT-derived distance and Loss of Resistance Depth. Conclusion: It is conclude that using pre-existing CT-scan derived distance is helpful in prediction of the epidural space depth and it is correlates with actual loss of resistance epidural needle insertion depth placing the catheter in lumber region.

Quality of Labor Analgesia With Dural Puncture Epidural Versus Standard Epidural Technique in Obese Parturients: A Double-blind Randomized Controlled Study

(Anesthesiology. 2022;136:678–687) Dural puncture epidural technique is a nested needling procedure wherein a spinal needle is passed through the epidural needle and through the dura, without the injection of intrathecal (IT) medications. Delivery of neuraxial analgesia is initiated only through the epidural catheter. Even in the absence of additional medication, dural puncture’s purported advantage over standard epidural placement is the unambiguous return of cerebrospinal fluid (CSF) through the spinal needle, confirming midline placement. Dural puncture may also facilitate the transfer of epidural drugs through the dural breach to help establish onset and quality of analgesia. Evidence for the efficacy of this approach is limited with some mixed data showing no clear clinical advantage. Obese parturients are particularly susceptible to epidural failure, and also at higher risk for emergency cesarean delivery wherein well-initiated neuraxial analgesia would be a further asset to avoid general anesthesia. The ostensible advantage of improved analgesic effect with the use of dural puncture vs standard epidural technique is investigated in obese patients who have the potential to draw strong benefit from an enhanced success rate for quality analgesia given the challenges inherent to this patient population.

Dural Puncture Epidural for Labor Analgesia: Is It Really an Improvement Over Conventional Labor Epidural Analgesia?

(Anesthesiology. 2022;136:667–669) Continued innovations of the standard epidural technique have allowed for improvement of the quality of analgesia experienced by laboring women. The introduction of conventional neuraxial analgesia offered effective and safe pain relief to parturients, with relatively infrequent adverse outcomes, and is utilized in &gt;73% of contemporary births in the United States. Procedural refinements over time have offered improvement in analgesia quality, including continuous local anesthetic infusions, optimizations of volume and concentrations of medications delivered, the addition of opioids to the injectate, timed bolus injections, and patient-controlled epidural analgesia. As protocol variations, both combined spinal-epidural and dural puncture epidural utilize a smaller spinal needle that is passed through the epidural needle. In combined spinal-epidural, small doses of opioid and local anesthetic are injected into the intrathecal (IT) space. With dural puncture epidural, the spinal needle is used to intentionally puncture the dura, but no drugs are injected. Initial evidence suggested improved analgesia with this technique over standard epidural and combined spinal-epidural, but the literature has produced mixed results since. In the same issue of this journal, Tan et al deliver results from a randomized clinical trial of obese parturients receiving dural puncture epidural vs conventional epidural to determine if analgesia quality is enhanced by dural puncture in this population at higher risk for epidural failure.

Effects of catheter orifice configuration (triple-hole versus end-hole) in continuous infraclavicular brachial plexus block on analgesia after upper limb surgery.

The configuration of a nerve block catheter may affect the local anesthetic spread in epidural analgesia and continuous peripheral nerve blocks. This prospective and randomized study aims to compare the multi-orifice nerve block catheter with an end-hole catheter in ultrasound-guided continuous infraclavicular brachial plexus block (BPB) in terms of providing postoperative analgesia for the orthopedic upper limb surgery below the shoulder. The primary outcome measure was mean pain scores. Secondary outcome measures were the consumption of rescue analgesic and the amount of local anesthetics delivered by a Patient-Controlled Analgesia (PCA) device. A total of 58 adult patients who underwent orthopedic upper limb surgery below the shoulder were randomly assigned into two groups: group end-hole catheter (EHC) (n=31) and group multi-orifice catheter (MOC) (n=27). All patients received a single-shot infraclavicular BPB using 100 mg lidocaine 2% and 75 mg bupivacaine 0.5% administrated through a Tuohy needle. Then, a multi-orifice (triple-hole) nerve catheter was placed in the group MOC and an end-hole (one-hole) catheter in the group EHC at the same location. Bupivacaine 0.125% was infused through the catheters via PCA (infusion rate: 2 mlh-1, automated regular bolus: 5 mlh-1, patient-controlled bolus: 3 ml, lock-out time: 1 hour, 4 hours limit: 40 ml). Pain intensity was evaluated using a visual analogue scale (VAS). Mean VAS scores were higher in group EHC than group MOC in the first postoperative day (p=0.001). Mean rescue analgesic consumption, the number of bolus demand on PCA, PCA bolus demand dose, and total PCA dose were higher in group EHC than group MOC during the first postoperative day (p<0.05). It is concluded that the use of MHC is more effective than EHC for continuous infraclavicular brachial plexus blocks in providing postoperative pain relief during the first 24 hours.

Combined Serratus Intercostal Fascial Block (SIFB) and Rectus Sheath Block (RSB) for Chest Wall Fracture

Purpose: Rib fractures are common in patients presenting chest trauma and are associated with significant morbidity and mortality. Traditional pain management options for rib fractures include thoracic epidural and/or paravertebral blocks. However, novel regional anesthesia techniques have been demonstrated to improve pain scores and aid patient recovery. We describe the application of a combined Serratus-Intercostal Fascial (SIFB) and Rectus Sheath (RS) nerve blocks to provide analgesia for a patient with lower anterior and lateral rib fractures. Clinical Features: To perform the combined block, an 18-gauge Tuohy needle was inserted deep to the rectus sheath muscle above the transversus muscle with obvious spread of local anesthetic superficial to the posterior rectus sheath where 10mls of 0.375% bupivacaine was injected. The needle continued laterally under the external oblique until it was positioned deep to the left serratus anterior muscle where an additional 15ml was injected. In both blocks, CPNB catheters were inserted beyond the end of the Tuohy needles. On postoperative day 2, the patient reported no pain in his anterior chest and abdomen with improved inspiratory capacity and was able to ambulate. After postoperative day 7 the patient no longer required his oral scheduled opioids and continued to report no chest pain. Conclusion: A combined SIFB and RS block using a single-incision was effective in providing analgesia while being less invasive and providing more control over potential infection sites. The technique also allows for lower dosage of anesthetics which can be relevant in other clinical settings.

Preprocedural ultrasonography as an adjunct to landmark technique for identification of epidural space in parturients for labor analgesia.

Pregnancy-induced softening of tissues and ligaments may increase the false-positive rates when identifying the epidural space in parturients by the landmark technique. To mitigate these problems, Ultrasonography (USG), which has now become the eye of anesthesiologists, can be used as a reliable tool to facilitate more accurate epidural needle placement in parturients. This study was conducted to know the efficacy of USG when compared to the traditional landmark method. After the approval from the institutional ethics committee and CTRI registration, 62 parturients of ASA-2 requesting labor analgesia were randomized into 2 groups of 31 each: Group-L (conventional landmark technique) and Group-U (preprocedural USG done before epidural). In group-U, Tuohy's needle was introduced through the USG predetermined insertion point and epidural space was located using the LOR technique. USG increased the success rate of epidural at first attempt from 51.6% in group "L" to 87% in group "U." Fewer needle attempts (P-value - 0.001) were required in group "U" as compared to group "L." No accidental dural puncture in group-U, compared to 2 in group-L. Mean Depth of epidural space (cm) ultrasound depth (UD) = 3.89 ± 0.45 cm and needle depth (ND) = 4.05 ± 0.37 cm. Side effects profile in the ultrasound group was better. Preprocedural ultrasonography is a simple safe, accurate tool with less number of attempts to determine the needle insertion site, decrease the incidence of accidental dural punctures, and assess epidural space depth in parturients.

Management and outcomes of persistent headache after accidental dural puncture in the obstetric population: A 9-year prospective audit.

To assess the effectiveness and safety of a novel management pathway in the obstetric population presenting to a pain medicine clinic with persistent headache after accidental dural puncture (PHADP). Accidental dural puncture (ADP) can result in headaches that persist for months to years. These headaches can be a therapeutic challenge, often cause severe disability, and management pathway remains obscure. Obstetric patients with PHADP referred to a pain medicine physician were prospectively followed up in a longitudinal audit of a novel management pathway. ADP reports dated from 2008 until 2019. Initial management included brain imaging and pharmacological agents. Patients who failed to respond were offered greater occipital nerve (GON) block with depot methylprednisolone followed by pulsed radiofrequency (PRF) treatment. A headache diary was completed for 4 weeks prior to commencing treatment and maintained for 24 weeks following an intervention. Data collected included use of epidural blood patch to manage postdural puncture headache, past history of headache, severity of headache, duration of persistent headache, low back pain, and employment status. Over the 9-year period, a cohort of 54 obstetric patients with PHADP with a 16-gauge Tuohy needle were reviewed in the pain clinic. Forty patients presented with chronic daily headache (40/54, 74%). Brain imaging did not reveal any sign of intracranial hypotension in 50 patients (50/54, 93%). Mean follow-up period was 5.7 years. Two patients were lost to follow-up (2/54, 4%). Pharmacological management was effective in 17 patients (17/52, 33%). Medical management failed to improve symptoms in 35 patients (35/52, 67%), and they were offered GON block. Fourteen (14/35, 40%) patients refused the intervention. Nerve block was performed in 21 patients and produced durable benefit lasting 24 weeks in 18 patients (18/21, 86%). Three patients underwent PRF treatment to GONs and all three (100%) reported durable benefit. At final follow-up, mean monthly headache frequency was 5.9 for the medical management group, 8.6 for the refused nerve block group, and 4.1 in patients who received GON treatment (p < 0.001). ADP can cause chronic headaches that persist beyond 3 years. Interventions targeting the GONs appear to have a role in the management of PHADP.

Identification of cervical epidural space: A comparison study between contrast spread and loss of resistance techniques.

Early epidural space identification is critical to the efficacy and safety of cervical epidural steroid injections (CESI). Currently, the accepted method for epidural space recognition is the loss of resistance technique (LORT). I hypothesized that the contrast spread technique might recognize epidural space concurrently with or sooner than LORT and that smaller needles might be employed with the fluoroscopy only method but not with LORT. To test my hypotheses, I conducted a comparison study. The study participants were patients from my practice with a clinical diagnosis of cervical radiculitis divided into two groups of 20 each, who underwent CESI with either an 18 G or a 25 G Tuohy needle. All CESIs were performed utilizing the fluoroscopy only method. Then, LOR was tested using an Epidrum device that was observed for 30 s; if the Epidrum deflated, the result was positive. LOR was positive in 12 out of 20 patients in the 18 G group and 2 out of 20 in the 25 G group. The 95% confidence interval test for proportion revealed a statistically significantly lower rate for epidural space detection by LORT in both groups: [0.385, 0.815] in the 18 G and [-0.031, 0.231] in the 25 G group. Statistical significance of the difference between groups in LOR accuracy rate (60% vs. 10%) was confirmed by z-test for independent proportions: z = 3.31 (p < 0.001), Cohen's h = 1.13. Fluoroscopy only method might be a safer alternative to LORT as it employs a different concept, might recognize epidural space sooner, and favors smaller needles. NCT05260294.

Research in Ideal Epidural Needles and a Metal Device for the Hanging Drop Technique

硬膜外麻酔による合併症を減らすためには，安全で確実な硬膜外腔穿刺ができるhanging-drop法用のディスポーザブル硬膜外針を作る必要性を強く感じた．そこで，いろいろな硬膜外針の針先の形状等の調査と水滴吸引試験を施行してみた．針基（hub）にアルミホイルを装填すると，どこの会社のディスポーザブル硬膜外針でも水滴の吸引が明瞭になることがわかった．日本のメーカーに針基の改造を相談したところ，新しい針の製造には時間がかかるので，針基（hub）に付けた水滴の吸引を見るだけの小さな金属ピンの製作を提案いただいた．その結果，hanging drop法ばかりでなくloss of resistance法もできるAタイプの金属ピンとhanging drop法しかできないBタイプの金属ピンを作成してくれた．これらの金属ピンを自分の医院でテストしてみると，水滴吸引が明瞭となるので，安全で確実な硬膜外腔穿刺率が高まり，直ちに重大な合併症が減少できると確信できた．将来的に良い針ができるまで，この器具を用いてhanging drop法を行うことをお勧めしたい．