Loss Of Resistance Technique Research Articles

Pro-Con Debate: Air or Saline for Loss-of-Resistance Technique of Interlaminar Epidural Access with Fluoroscopy-Guided Pain Medicine Procedures

In this Pro-Con commentary article, the Pro side advocates that using the loss of resistance (LOR) to air technique for interlaminar epidural access is safe as the risk of pneumocephalus is exceptionally low. They note that case reports detailing complications typically utilize at least 1 mL of air, frequently exceeding this amount. Even a 1-mL dosage surpasses the requirement, particularly when fluoroscopy is applied in the context of chronic pain management. The proponents also suggest a modified technique, where a syringe containing a drop of saline or contrast acts as a visual cue, minimizing air injection into the epidural space to a negligible quantity. Moreover, they emphasize that air facilitates the identification of any fluid as an indicator of unintended intrathecal access. The Con perspective argues against the utilization of air for epidural access and advocates for the use of LOR with saline instead. This stance is supported by evidence pointing to a greater occurrence of adverse events, such as postdural puncture headache (PDPH) and pneumocephalus, associated with LOR to air compared to LOR with saline. They also argue that saline’s physical properties enhance tactile feedback, potentially contributing to its increased safety. Both saline and air have been used for many years for epidural access via the interlaminar approach. Although both are generally accepted in practice, neither has been formally established as the standard of care. It would benefit the medical community to further delineate the pros and cons of each medium, enabling practitioners to make more informed decisions. This Pro-Con debate will provide 2 perspectives (Table) on the evidence and rationales for the use of air or saline for the LOR technique in interlaminar epidural access with fluoroscopy.

Long-term outcomes of caudal epidural steroid injection in failed back surgery syndrome patients with loss of resistance technique

Background: Failed back surgery syndrome (FBSS) is a complicated issue with various treatment approaches. This retrospective study assesses the success and safety of caudal epidural steroid injection (CESI) in FBSS patients utilizing the loss of resistance (LOR) strategy, focusing on long-term outcomes lasting up to two years. Methods: The 75 FBSS patients had CESI with triamcinolone and normal saline under local anesthesia. The visual analog score (VAS), Oswestry disability index (ODI), and patient satisfaction score (PSS) were measured at pre-intervention and 3, 6, 12, 18, and 24 months following the procedure. Result: Majority of patients (57.33%) reported bilateral sciatica, with recurrent disc herniation (54.67%) being the most prevalent MRI finding. Significant improvements (p<0.001) in VAS, ODI, and PSS scores were seen in all subsequent periods. Furthermore, no significant issues reported, demonstrating the safety and effectiveness of CESI with LOR. Conclusions: CESI with the LOR technique is helpful treatment in FBSS at three, six, twelve, eighteen, and twenty-four months. It is easy to perform, less technically demanding, has low complications, and lower costs than surgery. A CESI may offer an alternative approach to managing FBSS for short-term and long-term outcomes.

Determining the epidural space by loss of resistance technique with lidocaine 2% in comparing to normal saline 0.9% and effectiveness on onset of action and outcome of block

Determining the epidural space by loss of resistance technique with lidocaine 2% in comparing to normal saline 0.9% and effectiveness on onset of action and outcome of block

Ultrasound: A novel alternative technique for cervical epidural space visualization-A pilot study.

Neuraxial ultrasound (US), a newer modality, can be used for neuraxial imaging, helping in visualizing and aiding in epidural space catheterization. The aim of this study was to evaluate the efficacy of the US for cervical epidural access and to determine the failure rate and complication associated with this technique. A prospective single-arm pilot study was conducted on 21 participants. The neuraxial US image quality assessment by Ultrasound Visibility Score (UVS), epidural space depth measurement by US and by conventional loss of resistance (LOR) technique, and post-procedure epidural catheter confirmation by real-time US were the study parameters. Any procedural complications or failure rate were recorded. The Kolmogorov-Smirnov test, paired-samples t-test, and Chi-square test were used for the statistical comparison. The pre-procedural UVS by the transverse interlaminar view (x/21) was 2.81 ± 1.94 and by the oblique paramedian sagittal view was 16.66 ± 2.39 with UVS being best in the paramedian oblique sagittal view (P- value < 0.05). The comparison of depth of the epidural space identified by USG and that by the LOR technique was statistically insignificant (P = 0.83). The average puncture attempts were 1.1 ± 0.3. Post-procedure US epidural catheter confirmation score (x/3) was 1.44 ± 0.44 with either epidural space expansion or microbubbles seen or both. The pilot study has successfully demonstrated the implication of US for visualizing and aiding in epidural space catheterization. Also, the failure rate and procedural complications were drastically minimized with the help of US as compared to the traditional blind technique.

Interscalene Block in the Modern Era: When Stuck, Go Back to the Roots!

The traditional interscalene block has evolved over time to lower, lateral and posterior approaches, coinciding with the advent of Peripheral Nerve Stimulator and Ultrasonography. In limited infrastructure settings, such technology remains elusive and the classical paresthesia technique comes to the rescue. This approach is however very difficult to elicit in pediatric patients. It is here that the grassroot approach of a fascial “click” or “pop” emerges as the savior to administer a satisfactory block. We describe a case of a young boy with successful conduct of anaesthesia for K wire fixation of supracondylar fracture of humerus under lower interscalene block with loss of resistance technique. In light of recent research showing about 40-50% variation in the brachial plexus anatomy around the subclavian artery, use of technology in anaesthesia is the future. However, till such technology is made universally affordable, it is pertinent to remember the roots of interscalene block!

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.

Fluoroscopy-assisted epidural catheter placement: the effect of dye distribution in preoperative epidurograms on postoperative analgesia

BackgroundPostoperative epidural analgesia provides superior postoperative analgesia at rest and with activity, compared with systemic opioids. However, the impact of postoperative epidural analgesia on postoperative morbidity and/or mortality remains controversial, because of the sub-optimal reliability of epidural catheters that are placed preoperatively and used for postoperative pain control. The present study used the technique of lumbar epidurography. The study aims to better understand the possible correlation between the fluoroscopic characteristics of epidural catheters following injection of contrast medium and the postoperative functional characteristics regarding analgesia. In this single-arm clinical trial, 70 patients, aged 50 to 75 years old, underwent surgical urological procedures, involving incisions up to T8 dermatome, under combined general and epidural anesthesia. At the L2-L3 level, the epidural space was reached using the loss of resistance technique before general anesthesia was induced. The catheters were threaded upwards for 4–6 cm. Preoperative epidurograms were then done by injecting a 3-ml contrast medium OmnipaqueTM (240 mg I/ml) in the epidural catheters. The epidurograms were investigated for the location of the catheter tip in relation to the vertebral body, the extent of dye spread, laterality of dye spread (midline, right, or left), and the presence or absence of dye spread anterior to the spinal cord on the lateral image. The patients were followed postoperatively while epidural analgesia was infused.ResultsBoth the postoperative epidural infusion and postoperative visual analog scale (VAS) scores were lower when catheter tips ended at L1 than when they ended at L2. As the contrast’s vertical spread increases in preoperative epidurograms, the analgesic infusion rate and VAS score decrease, and the number of dermatomes insensitive to cold increases. Epidurographically right-sided catheters showed more dermatomes deficient to cold sensations on the right side, compared with mid-line and left-sided catheters. Restriction of contrast to the posterior epidural space was associated with lower VAS scores and wider anesthesia to cold.ConclusionsThe use of epidurography to study epidural catheters may have the potential advantage of predicting the functionality of catheters and improving the reliability of postoperative epidural analgesia.

203. Epidural pain catheter improves postoperative pain control following lumbar fusion compared to patient-controlled analgesia (PCA)

<h3>BACKGROUND CONTEXT</h3> Postoperative pain control for patients in the hospital after lumbar spinal fusion can be quite challenging. Reliance on opioids postoperatively can predispose patients to tolerance and abuse. Multimodal pain control regimens have become the standard of postoperative care, though protocols tend to vary by surgeon and institution. The mainstay of pain control following lumbar spinal fusion surgery involves narcotic pain medication administered by patient controlled intravenous analgesia (PCA), which is typically supplemented by oral pain medications. One potential alternative to PCA is patient-controlled analgesia via epidural catheter. Surgeon-placed epidural catheters under direct visualization have previously been described for their simplicity, efficacy and time efficiency. <h3>PURPOSE</h3> After experiencing clinical success with the use of epidural catheters placed via the loss of resistance technique one- to three- levels above the proximal lumbar fusion level in postoperative care regimens,the senior author (TFA) embarked upon this prospective, randomized trial to assess the relative utility and complication rate of the epidural catheter method of pain management when compared to standard PCA narcotic administration for pain control after one- or two-level circumferential lumbar fusion surgery. <h3>STUDY DESIGN/SETTING</h3> The surgeries in the trial were performed by three surgeons in a university spinal surgery practice. Patients who enrolled agreed to be randomized to either the epidural catheter (EC) or the commonly practiced PCA arm of the study. A power analysis demonstrated that a sample size of 50 patients, using a level of significance of 0.05, would have a power of 0.97 to detect a 2-point difference in pain scores. <h3>PATIENT SAMPLE</h3> Fifty patients from the University spinal surgery practice were recruited to enter the study. Candidates for the study were patients undergoing one- or two-level instrumented lumbar fusion. Patients were randomized over a 10-month period into either the epidural (EA) or IV analgesia (PCA) groups, 27 to EA and 23 to PCA. <h3>OUTCOME MEASURES</h3> Preoperative pain scores, as well as daily postoperative pain scores were recorded. <h3>METHODS</h3> If randomized to the EC arm, an epidural catheter was placed by the surgeon just prior to wound closure, 1-3 levels above the most proximal level of the fusion. A 17-gauge Tuohy epidural needle was used with a loss-of-resistance syringe to locate the epidural space under fluoroscopy if deemed appropriate by the surgeon, and then the catheter was inserted through it. A bolus of 5cc of 0.25% bupivacaine was typically given at the time of catheter placement. Postoperatively, a continuous infusion was begun of 0.125% bupivacaine at 6 cc/hr combined with hydromorphone at 0.2 mg/hr. A patient controlled epidural demand dose of 25mcg of fentanyl with a 10-minute lockout period was also started. If randomized to the PCA group, patients were placed on a patient-controlled analgesia pump administering intravenous hydromorphone with a demand dose of 0.2-0.4 mg with a 10-15-minute lockout <h3>RESULTS</h3> Postoperative pain scores were statistically lower in the EC group on Days 1, 2 and 3: 2.13 vs 4.92 (day 1); 2.71 vs 4.52 (day 2); 3.13 vs 4.52 (day 3). Postoperative complications were similar between the EC and PCA groups. The incidence of nausea/vomiting were 56% and 74% (p=0.43) in EC and PCA groups, respectively, while postoperative symptomatic hypotension was seen in 8% of EC patients and 12% of PCA patients (p=0.67). <h3>CONCLUSIONS</h3> In this prospective, randomized study comparing the use of EC to PCA narcotic for pain control after one- and two-level lumbar fusions, a significant improvement in pain control was noted in the EC group with differences in minor side effects that did not reach statistical significance. Epidural anesthesia for postoperative pain control should be considered for patients undergoing lumbar fusion. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Real-time ultrasound-guided versus anatomic landmark-based thoracic epidural placement: a prospective, randomized, superiority trial

BackgroundThoracic epidural placement (TEP) using the conventional anatomic landmark-based technique is technically challenging, may require multiple attempts, and is associated with a high failure rate (12–40%). We hypothesized that real-time ultrasound guidance would be superior in the “first-pass” success rate of TEP, when compared with the conventional technique.MethodsThis prospective, randomized, superiority trial was conducted in a University hospital, and recruited 96 patients undergoing elective major abdominal or thoracic surgery and scheduled to receive a TEP for postoperative analgesia. Patients were randomly allocated to receive TEP using either the conventional technique (Gp-Conv, n = 48) or real-time ultrasound guidance (Gp-Usg, n = 48). The success of TEP was defined as eliciting loss of resistance technique and being able to insert the epidural catheter. The primary outcome variable was the “first-pass success rate” meaning the successful TEP at the first needle insertion without redirection or readvancement of the Tuohy needle. The secondary outcomes included the number of skin punctures, number of attempts, the overall success rate, TEP time, and total procedure time.ResultsThe first-pass success rate of TEP was significantly higher (p = 0.002) in Gp-Usg (33/48 (68.8%); 95%CI 55.6 to 81.9) than in Gp-Conv (17/48 (35.4%); 95%CI 21.9 to 49.0). There was no statistically significant difference (p = 0.12) in the overall success rate of TEP between the 2 study groups (Gp-Usg; 48/48 (100%) vs. Gp-Conv; 44/48 (91.7%); 95%CI 83.9 to 99.5). Ultrasound guidance reduced the median number of skin punctures (Gp-Usg; 1 [1, 1] vs Gp-Conv; 2 [1, 2.2], p < 0.001) and attempts at TEP (Gp-Usg; 1 [1, 2] vs Gp-Conv; 3 [1, 7.2], p < 0.001) but the procedure took longer to perform (Gp-Usg; 15.5 [14, 20] min vs Gp-Conv; 10 [7, 14] min, p < 0.001).ConclusionsThis study indicates that real-time ultrasound guidance is superior to a conventional anatomic landmark-based technique for first-pass success during TEP although it is achieved at the expense of a marginally longer total procedure time. Future research is warranted to evaluate the role of real-time ultrasound guidance for TEP in other groups of patients.Trial registrationThai Clinical Trials Registry; http://www.thaiclinicaltrials.org/; Trial ID: TCTR20200522002, Registration date: 22/05/2020.

Comparison of Landmark-guided, Nerve Stimulation-guided, and Ultrasound-guided Techniques for Pediatric Caudal Epidural Anesthesia: A Prospective Randomized Controlled Trial.

Traditionally, caudal epidurals are performed by a landmark-guided approach using the loss of resistance technique. Improvisations to increase the success rate can be attained by implementing modalities, namely neurostimulation and ultrasound, but there is a paucity of literature comparing these 3 approaches. Here, we compare the 3 techniques in terms of the success rate. The primary outcome of this study was to compare the success rate of the 3 techniques, and the secondary outcome was the blood or cerebrospinal fluid aspiration during the procedure. It was a prospective, randomized, open-label parallel-group study. Three hundred children aged 1 to 5 years scheduled for circumcision, hypospadias repair, and minor lower extremity surgeries were enrolled after taking written informed consent from the parents. Demographic profiles were comparable in terms of age, weight, sex distribution, and types of surgeries. Success rates in landmark-guided, neurostimulation-guided, and ultrasound-guided were 97%, 97%, and 98%, respectively which was comparable (P=0.879). There was no significant difference in the incidence of blood or cerebrospinal fluid aspiration. We found a similar success rate of the caudal epidural block by using landmark-guided, nerve stimulation-guided, or ultrasound-guided techniques in children aged 1 to 5 years with normal anatomy.

An Operator's Experience of the Loss-of-Resistance Technique in Epidural Injections: An Observational Study.

A successful interlaminar epidural injection relies on correct epidural space needle placement. Most interlaminar epidural steroid injection (ESI) procedures are performed with a blind technique known as loss-of-resistance (LOR) without an imaging guide. This study aims to evaluate the success rate of the LOR technique in interlaminar epidural steroid injection under fluoroscopic control. Patients who underwent interlaminar ESI owing to a history of at least 3 months of chronic low back and leg pain not responding to medications and physical therapies were included in an observational trial. Participants' age was between 27 and 88 years, and they had an American Society of Anesthesiologists physical status of I-III. The patients were placed in a prone position, and a Tuohy needle was introduced at the level of the L5-S1 interlaminar foramen using fluoroscopic image with an anteroposterior view. A lateral view was obtained when the LOR was felt. The procedures that achieved epidural spread by contrast agent in the first attempt were deemed successful. Those that did not and those that had false positive LOR were regarded as unsuccessful. Interlaminar ESİ was administered to 150 patients. The procedure's success and failure rates were 76% (114 patients) and 24% (36 patients), respectively. A total of 58.3% (21 patients) of patients who underwent an unsuccessful procedure had a false LOR, whereas 41.6% (15 patients) of the same group exhibited other causes. Sex, age, and body mass index (BMI) showed no statistical significance in terms of procedural success. There were statistically significant differences in the distance between the skin and the epidural space according to the body mass index groups. The LOR technique identified the epidural space in most epidural procedures. However, in some cases, LOR was shown to be inadequate. Therefore, we suggest that the LOR technique must be supported by imaging such as fluoroscopy during epidural injections.

Place of the paravertebral block in post-operative analgesia in thoracic surgery

The thoracic epidural analgesia (TEA) remains the standard gold for analgesic support in thoracic surgery, there is an interesting alternative to epidural analgesia, which is the paravertebral block (PVB). The aim in our study was to assess the value of performing a PVB in the management of postoperative pain in thoracic surgery compared to TEA. Methods: 80 patients were randomized to receive either epidural analgesia (n = 38, 10 cc bupivacaine 0.5% + 10 ϒ Sufentanyl then 10 cc Bupivacain 0.1% + 10 ϒ Sufentanyl via a PCA device) or PVB analgesia loss of resistance technique (n = 40, 10 cc bupivacaine 0.5% + 10 ϒ Sufentanyl via a PCA device). All patients received standard general anesthesia. The peri-operative parameters studied include standard measurement, EVA scale at rest and mobilization, use of morphinics. Results: there is a significant difference between the two groups and the incidents of puncture were significantly more important for the APDT group. The postoperative pain assessment by EVA did not show a significant difference between TEA and PVB Conclusion: the comparison of PVB to TPDA did not find significant difference in the efficacy of analgesia and the side effects. The BPV could be proposed as a first intention for postoperative analgesia in thoracic surgery.

Concordance between the loss of resistance technique and ultrasound in measuring the distance from the skin to the epidural space in pediatric patients: Observational study

Introduction: The use of ultrasound in regional anesthesia has become a standard technique to improve nerve block accuracy and reduce associated complications. The literature reports a good correlation between the distance from the skin to the dura mater or the ligamentum flavum measured on ultrasound and the conventional technique of “loss of resistance”. Latin American populations have not been included in the studies conducted so far but, because of differences in physical build, it is important to determine whether this correlation is maintained in the various populations. This paper offers new information about the role of ultrasound in determining the distance to the ligamentum flavum and recognizing the proximity of the dura mater to avoid accidental puncture of this structure in Latin American populations.&#x0D; Objective: To determine correlation and concordance in estimating the distance from the skin to the epidural space between the loss of resistance technique and ultrasound measurement.&#x0D; Methodology: Observational study conducted in 52 pediatric patients who received general anesthesia plus peridural analgesia for acute perioperative pain management between July 2014 and November 2015 to assess correlation and concordance between loss of resistance and ultrasound measurement of distance to the epidural space.&#x0D; Results: There is a correlation between distances measured using the two techniques, which appears to be higher as patient age increases. As for concordance, the study found that 0.43 cm should be added to the ultrasound measurement to achieve agreement with the distance obtained using the loss of resistance technique; however, the interval between the two measurements is 1.15 cm.&#x0D; Conclusions: A correlation was found between the measurement taken from the skin to the peridural space using ultrasound and the measurement obtained with the traditional needle puncture and loss of resistance technique. Although concordance was not as expected and the distance measured with ultrasound may be smaller than the real measurement with the needle, ultrasound offers good guidance regarding proximity to the peridural space.

The Development of a Novel Device Based on Loss of Guidewire Resistance to Identify Epidural Space in a Porcine Model.

Background The application of additive manufacturing (3D printing) has been recently expanded to various medical fields. The new technique named loss of guide wire resistance (LOGR) was developed via 3D printing for the detection of epidural space using a guide wire instead of air or saline used in the loss of resistance (LOR) technique. Methods The prototype model of epidural space finder consists of a polyactic acid (PLA) or a resin. It was manufactured with 3D printing. Biocompatibility test (eluate and sterility tests) was performed in both products. The advantage of the newly developed device was compared with conventional loss of resistance (LOR) technique in a porcine model. Results Eluate and sterility tests revealed that the PLA was more biocompatible than the resin. The LOGR technique facilitated rapid access to epidural space compared with the LOR technique (41.64 ± 32.18 vs. 92.28 ± 61.46 seconds, N = 14, p=0.0102, paired sample t-test), without any differences in success rate (87.5%). Conclusion We conclude that LOGR technique is comparable to LOR technique to access the epidural space, although the advantage of either technique in terms of complications such as dural puncture or epidural hematoma is unknown. We demonstrated the potential benefit of 3D printer for the development of a new medical device for anesthesia.

Correlation of the epidural space measured intraoperatively and estimated by MRI or US: an observational study

Background and objectivesTo assess the agreement between the epidural depth measured from the surgical site with the epidural depths estimated with magnetic resonance imaging (MRI) and ultrasound scanning. MethodsFifty patients of either sex, scheduled for L4‒5 lumbar disc surgery under general anesthesia were enrolled in this prospective observational study, and the results of 49 patients were analyzed. The actual epidural depth was measured from the surgical site with a sterile surgical scale. The MRI-derived epidural depth was measured from the MRI scan. The ultrasound estimated epidural depth was measured from the ultrasound image obtained just before surgery. ResultsThe mean epidural depth measured from the surgical site was 53.80 ± 7.67 mm, the mean MRI-derived epidural depth was 54.06 ± 7.36 mm, and the ultrasound-estimated epidural depth was 53.77 ± 7.94 mm. The correlation between the epidural depth measured from the surgical site and MRI-derived epidural depth was 0.989 (r2 = 0.979, p < 0.001), and the corresponding correlation with the ultrasound-estimated epidural depth was 0.990 (r2 = 0.980, p < 0.001). ConclusionsBoth ultrasound-estimated epidural depth and MRI-derived epidural depth have a strong correlation with the epidural depth measured from the surgical site. Preprocedural MRI-derived estimates of epidural depth are slightly deeper than the epidural depth measured from the surgical site, and the ultrasound estimated epidural depths are somewhat shallower. Although both radiologic imaging techniques provided reliable preprocedural estimates of the actual epidural depth, the loss of resistance technique cannot be discarded while inserting epidural needles.

Correlação entre a profundidade do espaço peridural medida no intraoperatório e a estimada por RM ou US: estudo observacional

Background and objectivesTo assess the agreement between the epidural depth measured from the surgical site with the epidural depths estimated with magnetic resonance imaging (MRI) and ultrasound scanning. MethodsFifty patients of either sex, scheduled for L4‐5 lumbar disc surgery under general anesthesia were enrolled in this prospective observational study, and the results of 49 patients were analyzed. The actual epidural depth was measured from the surgical site with a sterile surgical scale. The MRI‐derived epidural depth was measured from the MRI scan. The ultrasound estimated epidural depth was measured from the ultrasound image obtained just before surgery. ResultsThe mean epidural depth measured from the surgical site was 53.80 ± 7.67mm, the mean MRI‐derived epidural depth was 54.06 ± 7.36mm, and the ultrasound‐estimated epidural depth was 53.77 ± 7.94mm. The correlation between the epidural depth measured from the surgical site and MRI‐derived epidural depth was 0.989 (r2 = 0.979, p < 0.001), and the corresponding correlation with the ultrasound‐estimated epidural depth was 0.990 (r2 = 0.980, p < 0.001). ConclusionsBoth ultrasound‐estimated epidural depth and MRI‐derived epidural depth have a strong correlation with the epidural depth measured from the surgical site. Preprocedural MRI‐derived estimates of epidural depth are slightly deeper than the epidural depth measured from the surgical site, and the ultrasound estimated epidural depths are somewhat shallower. Although both radiologic imaging techniques provided reliable preprocedural estimates of the actual epidural depth, the loss of resistance technique cannot be discarded while inserting epidural needles.

Fascia iliaca block, history, technique, and efficacy in clinical practice.

The facsia iliaca block (FIB) is a relatively new regional technique where local anesthetic is delivered within the fascia iliaca region. Indications for a FIB include surgical anesthesia to the lower extremity after knee, femoral shaft, hip surgery, management of cancer pain or pain secondary to inflammatory conditions of the lumbar plexus, as well as treatment of acute pain in the setting of trauma, fracture, or burns. The FIB may be performed using either a loss of resistance technique or an ultrasound (US)-guided technique; however, the use of US has become commonplace and resulted in improved femoral nerve and obturator nerve motor blocks. The main targets of the FIB are the predominant nerves contained in the fascia iliaca compartment (FIC), namely the femoral nerve and the lateral femoral cutaneous nerve. The FIB US guided technique is beneficial to patients and the possibility to perform FIB should be discussed and coordinated with surgical staff appropriately, considering its superiority to general or epidural anesthesia.

CLINICAL EFFECTIVENESS OF LUMBAR EPIDURAL INJECTION FOR SPINAL DISC HERNIATION: A RANDOMISED CONTROL TRIAL.

Purpose: Lumbar epidural is an established procedure, which is commonly used to control pain in cases of disc herniation secondary to lumbar disc disease. We conducted the present study to evaluate the clinical effectiveness of lumbar epidural injection using image intensifier comparing to injection using loss of resistance technique with no fluoroscopy. We also evaluated the outcome of these patients with patients treated conservatively with opioid or other analgesia as a control group. Setting: Epsom General Hospital, an elective part of Epsom &amp; St Helier’s University Hospital spine services. Study Design: Prospective randomized controlled trial. Period: April 2013 and October 2013. Material and Methods: Single center, after seeking appropriate ethical approval in our institution. Group allocation for loss of resistance and II was done by list schedulers independent to the knowledge of trial, operating list become available to research team on the day of procedure. Fifty-five patients were included in each group. A single clinician performed all procedures and the same combination of local anaesthetic and steroid were injected in all patients. Preoperative and postoperative visual analogue score (VAS) and Oswestry Disability Index (ODI) were obtained for each patient. Conclusions: There is a better outcome demonstrated in both injection groups when compared with control. The post-operative scores did not statistically differ significantly between fluoroscopic and loss of resistance groups. The final results of this trial question the efficacy and cost effectiveness of epidural injections using image intensifier and may be used as a reference to change the current practice within several hospitals as cost saving measure. Level of Evidence: 1.

Randomized comparison of two methods of the epidural space identification during regional labour analgesia.

Conventional loss of resistance (LOR) technique for identifying the epidural space (EDS) predominantly depends on experience of the anaesthetist. A technique using automated syringe for EDS identification was invented as an alternative to the traditional method. The aim of the study was to compare the efficacy and risk for complications between automatic LOR syringe - Epimatic® (Vygon, Ecouen, France) and conventional LOR - Perifix® (B.Braun Melsungen AG, Melsungen, Germany) techniques for EDS identification. A total of 170 patients were enrolled into the study and 153 cases were analysed. Number of at- tempts, time to EDS identification, ease of EDS identification, complication rate and patient procedure-related discomfort were evaluated and compared. No statistically significant differences were found in the number of needle insertion attempts (1.3 in both groups), time to EDS identification (31 sec. vs. 27 sec.), efficacy of epidural analgesia (100% in both groups), or complication rate between both groups. The automatic and the conventional LOR techniques are comparable in terms of efficacy and safety for the epidural space identification.

Thoracic paravertebral block: comparison of different approaches and techniques. A study on 27 human cadavers

Background and objectivesThe success rate and spread of thoracic paravertebral block (TPVB) are variable and difficult to predict. It is now recommended that an ultrasound guidance technique should replace the traditional landmark technique. The objective was to compare anatomical outcomes of both techniques on cadavers. MethodsA landmark technique (loss of resistance technique [LOR]) and a USG technique (three approaches: sagittal, transversal in-plane, transverse out-of-plane) were performed on 27 thawed non-embalmed cadavers. Each of the four approaches was performed in each body (T3–T5 and T9-T11 × right and left). A coloured solution (13 mL, saline 0.9%) was injected in the targeted thoracic paravertebral space (TPVS). A successful thoracic paravertebral injection (TPVI) was defined by the presence of dye in at least one TPVS during anatomical dissection. ResultsIn 104 TPVIs analysed, the overall success rate was 78%. Factors associated with success were: USG versus LOR technique (85% vs. 52%, P < 0.0007), sagittal versus both transversal approaches (93%/81%/83%, P < 0.0007) and right side (86% vs. 66%). The median spread was 2 TPVS (min – max 1–5) with a median cephalad-caudal spread of 5 cm (min - max 1-18). By multivariate analysis, the sagittal approach was an independent factor of success (OR 2.75). Dye spread and pleural entry were influenced by neither the approach nor the site of injection. ConclusionsParavertebral spread of TPVI is variable. USG technique has higher anatomical success rates than the LOR technique, the sagittal USG approach being the most successful.