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Background Loss of resistance (LOR) for epidural catheter placement has been utilized for almost a century. LOR is a subjective endpoint associated with a high failure rate. Nerve stimulation (NS) has been described as an objective method for confirming placement of an epidural catheter. We hypothesized that the addition of NS to LOR would improve the success of epidural catheter placement. Methods One-hundred patients were randomized to thoracic epidural analgesia (TEA) utilizing LOR-alone or loss of resistance plus nerve stimulation (LOR + NS). The primary endpoint was rate of success, defined as loss of sensation following test dose. Secondary endpoints included performance time. An intention-to-treat analysis was planned, but a per-protocol analysis was performed to investigate the success rate when stimulation was achieved. Results In the intention-to-treat analysis there was no difference in success rates (90% vs 82% [LOR + NS vs LOR-alone]; P = 0.39). The procedural time increased in the LOR + NS group (33.9 ± 12.8 vs 24.0 ± 8.0 min; P P = 0.017) when only patients in whom stimulation was achieved were included. Conclusions Addition of NS technique did not statistically improve the success rate for epidural placement when analyzed in an intention-to-treat format and was associated with a longer procedural time. In a per-protocol analysis a statistically higher success rate for patients in whom stimulation was obtained highlights the potential benefit of adding NS to LOR. Trial registration ClinicalTrials.gov identifier NCT03087604 on 3/22/2017; Institutional Review Board Wake Forest School of Medicine IRB00039522, Food and Drug Administration Investigational Device Exemption: G160273.

Antibiotics resistance has caused much complication in the treatment of diseases, where the pathogen is no longer susceptible to specific antibiotics and the use of such antibiotics are no longer effective for treatment. A recent study that utilizes digital organisms suggests that complete elimination of specific antibiotic resistance is unlikely after the disuse of antibiotics, assuming that there are no fitness costs for maintaining resistance once resistance are established. Fitness cost are referred to as reaction to change in environment, where organism improves its' abilities in one area at the expense of the other. Our goal in this study is to use digital organisms to examine the rate of gain and loss of resistance where fitness costs have incurred in maintaining resistance. Our results showed that GC-content based fitness cost during de-selection by removal of antibiotic-induced selective pressure portrayed similar trends in resistance compared to that of no fitness cost, at all stages of initial selection, repeated de-selection and re-introduction of selective pressure. Paired t-tests suggested that prolonged stabilization of resistance after initial loss is not statistically significant for its difference to that of no fitness cost. This suggests that complete elimination of specific antibiotics resistance is unlikely after the disuse of antibiotics despite presence of fitness cost in maintaining antibiotic resistance during the disuse of antibiotics, once a resistant pool of micro- organism has been established.

BackgroundCervical epidural steroid injection is associated with rare but potentially catastrophic complications. The contralateral oblique (CLO) view may be a safe and feasible alternative to the lateral (LAT) view for fluoroscopic-guided cervical epidural steroid injection. However, evidence for the clinical usefulness of the CLO view for cervical epidural steroid injection is lacking. We assessed the clinical usefulness of the CLO view for cervical epidural steroid injection in managing cervical herniated intervertebral discs.MethodsPatients were randomly assigned to receive fluoroscopic-guided cervical epidural steroid injection under LAT view or CLO view at 50±5° degrees groups. The primary outcome was the needling time comparison between the two groups. Secondary outcomes were comparison of first-attempt success rate, needle tip visualization and location, total number of needle passes, final success rate, crossover success rate and false-positive/negative loss of resistance. Complications and radiation dose were also compared.ResultsThe needling time significantly decreased in the CLO than in the LAT group. The first-attempt success rate was significantly higher in the CLO compared with the LAT group. The needle tip was clearly visualized (pConclusionThe CLO view may be recommended for fluoroscopic-guided cervical epidural steroid injection, considering its better clinical usefulness over the LAT view.

Background and objectivesThe ‘loss of resistance’ technique is used to determine entry into the epidural space, often by a midline needle in the interspinous ligament before the ligamentum flavum. Anatomical explanations for loss of resistance without entry into the epidural space are lacking. This investigation aimed to improve morphometric characterization of the lumbar interspinous ligament by observation and measurement at dissection and from MRI.MethodsMeasurements were made on 14 embalmed donor lumbar spines (T12 to S1) imaged with MRI and then dissected along a tilted axial plane aligned with the lumbar interspace.ResultsIn 73 interspaces, median (IQR) lumbar interspinous plus supraspinous ligament length was 29.7 mm (25.5–33.4). Posterior width was 9.2 mm (7.7, 11.9), with narrowing in the middle (4.5 mm (3.0, 6.8)) and an anterior width of 7.3 mm (5.7, 9.8).Fat-filled gaps were present within 55 (75%). Of 51 anterior gaps, 49 (67%) were related to the ligamenta flava junction. Median (IQR) gap length and width were 3.5 mm (2.5, 5.1) and 1.1 mm (0.9, 1.7).Detection of gaps with MRI had 100% sensitivity (95% CI 93.5 to 100), 94.4% specificity (72.7, 99.9), 98.2% (90.4, 100) positive predictive value and 100% (80.5, 100) negative predictive value against dissection as the gold standard.ConclusionsThe lumbar interspinous ligament plus supraspinous ligament are biconcave axially. It commonly has fat-filled gaps, particularly anteriorly. These anatomical features may form the anatomical basis for false or equivocal loss of resistance.

Plant susceptibility to pathogens is usually considered from the perspective of the loss of resistance. However, susceptibility cannot be equated with plant passivity since active host cooperation may be required for the pathogen to propagate and cause disease. This cooperation consists of the induction of reactions called susceptible responses that transform a plant from an autonomous biological unit into a component of a pathosystem. Induced susceptibility is scarcely discussed in the literature (at least compared to induced resistance) although this phenomenon has a fundamental impact on plant-pathogen interactions and disease progression. This review aims to summarize current knowledge on plant susceptible responses and their regulation. We highlight two main categories of susceptible responses according to their consequences and indicate the relevance of susceptible response-related studies to agricultural practice. We hope that this review will generate interest in this underestimated aspect of plant-pathogen interactions.

Background: Psoas compartment block (PCB) is a frequently used techniques providing anesthesia for proximal lower limb surgeries. There are many methods of localization of peripheral nerves for regional anesthesiaas loss of resistance (LOR), electric nerve stimulation (ENS), ultrasound-guided (US) and combined ultrasound-guided and electric nerve stimulation (US/ENS). Objective: To compare between these four techniques to find out the method of better outcome and least complications. Patients and Methods: This study was a prospective randomized trial, conducted at Anesthesia and Intensive Care Department, Zagazig University Hospitals during the period from January 2018 to January, 2020. 140 patients undergoing unilateral elective proximal lower limb surgeries were included. Patients were categorized randomly, according to the used method for lumbar plexus localization, into four equal groups (each 35 patients). All groups were compared regarding efficacy and safety. Results: The success rates of PCB in ENS, US and US/ENS groups were higher than that in LOR group with combined US/ENS group was the best group (97.14%). The onset of sensory and motor blocks in ENS, US and US/ENS groups were shorter than that in LOR group. Times to ask for the 1st postoperative analgesia in ENS, US and US/ENS groups were longer than those in LOR group with the consumed amount of morphine for pain relief during the 1st 24 hours postoperatively in ENS, US and US/ENS groups were lower than that in LOR group. Conclusion: Usage of combined ultrasound and electric nerve stimulation was better regarding the outcome and complications.

Background: Thoracic paravertebral block (TPVB) entails injecting a local anesthetic inside the thoracic paravertebral space (TPVS). Loss of resistance to air injection (air-LOR) was the first technique described in humans to locate the TPVS. To date, no study has investigated the spread of any substance after injection into the TPVS using the air-LOR technique nor has described the cranial and caudal limits of the space. Aim: To identify the boundaries of the TPVS, to determine whether the air-LOR technique is reliable for the identification of the TPVS and to examine the relationship between the volume of injectate and its spread. Methods: After a preliminary phase, the thorax of five cat and five dog cadavers was accessed and eviscerated. After TPVS probing, the polyurethane foam was injected, and the cranial and caudal borders were recorded after its maximum spread. Different volumes of a mixture of new methylene blue and ioversol were injected in the TPVS after its localization with a Tuohy needle and air-LOR technique in fourteen dog and six cat cadavers. Lateral radiographs of the vertebral column were used to document needle positioning, spread pattern and extension. The thorax of these subjects was then accessed and eviscerated to observe and record the spread of the mixture. Results: Injecting a dye into the TPVS, localized by an air-LOR technique, resulted in multi-segmental and often bilateral subpleural staining of paravertebral, intercostal, and dorsal mediastinal structures in dog and cat cadavers. The lateral radiographs most often showed a mixed cloud-like and linear spread pattern, which could be a predictor of the longitudinal spread of the dye. The foam injected into the TPVS at the cranial and the caudal level revealed anatomical communication with the cervical, axillar, and lumbar paravertebral regions. Conclusion: TPVS localization by air-LOR technique and injection results in a longitudinal multi-segmental spread in dog and cat cadavers. The communication of the TPVS with the axillary and lumbar regions could be of clinical interest for the brachial plexus and the lumbar intercostal nerve blocks in a clinical setting.

Introduction: Currently, one has to rely on surface anatomical landmarks and loss of resistance technique for epidural analgesia. It frequently (70%) leads to incorrect identification of a given inter-space as it is a blind technique. Therefore a better alternative technique is desirable. Aims and Objectives: To evaluate and compare ultrasound guided thoracic epidural technique with landmark-based thoracic epidural technique via paramedian approach. Materials and Methods: A study was done on 34 patients in each group with age ? 20 years, undergoing any major surgery, requiring thoracic epidural. The procedure and aim of the study was explained and a written informed consent was taken. Group 1 – (US group) – ultrasound guided thoracic epidural placement was done via paramedian approach .Group 2 – ((Landmark group) - landmark paramedian approach was done. The following parameters were studied – 1) Number of needle punctures and redirections through the same puncture site; 2) Number of attempts at catheter advancement; 3) Time taken for epidural catheter placement; 4) Pain felt by the patient during the procedure. The data was analysed using chi square test and student t test. Results: The number of needle punctures required, redirections and attempts of catheter advancement in both the groups were not statistically significant. The time required and pain felt for the procedure was significantly less in US Group as compared to Landmark group. Conclusion: US guided thoracic epidural technique via paramedian approach took less time for the procedure and was associated with less pain as compared to landmark approach. Keywords: Paramedian approach, Thoracic epidural, Ultrasound Guided.

PRECIS With a newly designed blade, slicing of the Ahmed glaucoma valve (AGV) leaflets helped to convert the flow-restrictive AGV into a non-flow-restrictive device. Flow characteristics by our in-vitro study confirmed the loss of resistance of AGV valve leaflets. PURPOSE To describe a new blade to destroy the valve leaflets of AGV and to report the in-vitro flow characteristics of AGV after valve destruction. METHODS All the newly opened AGV implants and the Aurolab aqueous drainage implants (AADI, used as controls) were tested by connecting to a 27-G cannula, open manometer, digital manometer, and automated infusion pump. Data logging was done using a digital manometer at 4 Hz using computerized software. When the AGV's flow characterization reached the steady phase, their valve functionality was destroyed by disrupting the valve leaflets, using a specially designed blade. The flow characteristics after valve slicing were compared with that of AADI. RESULTS A total of 5 FP7 AGVs and 2 AADIs were tested. After initial resistance to flow (5, 8 mm Hg) observed in the case of AADI for 1 to 3 hours, it dropped to 1 mm Hg in both the implants. The flow-restrictive AGV showed 3 distinct phases in the flow characterization. The first phase included the transient phase followed by the steady phase wherein the pressure was 11.2±2.6 (min 7, max 14) mm Hg. The pressure resistance of the AGV dropped significantly (P

Background Loss of resistance (LOR) technique is a widely used method to identify the epidural space. However, cases of inadequate epidural anesthesia in cesarean section were frequently reported. Also, the success rate of epidural anesthesia with LOR technique varied depending on the proficiency of the practitioner. The purpose of this study was to assess the efficacy and safety of electrical stimulation to identify epidural spaces in cesarean section for novices or clinicians with recent gap in experience. Methods Pregnant women scheduled for elective cesarean section were randomly allocated to two groups. Groups were classified based on the methods used for identifying the epidural space: the LOR group (group L) and the LOR with epidural electrical stimulation group (group E). Clinicians with less than 10 epidural cesarean section experiences in the recent year performed epidural anesthesia for cesarean section. In the group E, a RegionalStim® conductive catheter was inserted through the Tuohy needle, and the guidewire passing through the catheter was connected to a peripheral nerve stimulator. The intensity of the stimulation was gradually increased from 0.25 mA to 1.5 mA until paresthesia was elicited and radiated. We assessed the success of epidural anesthesia (complete success, partial success or failure). Other clinical parameters including maternal satisfaction, time required for epidural anesthesia, neonatal Apgar scores, pain scores and adverse events were compared between the two groups. Results Except for 6 patients who withdrew consent, 54 patients were enrolled in this study (28 for the group L and 26 for the group E). The demographic data showed no difference between the two groups. There was no adverse event resulted from electrical stimulation. The group E showed higher rate of complete success, sensitivity in finding epidural space and maternal satisfaction compared to the group L (21/26 vs. 15/28, p = 0.034, 0.96 vs. 0.68, p = 0.012 and 4.04 vs. 3.39, p = 0.02, respectively). The other clinical parameters showed no differences between the two groups. Conclusion In addition to the conventional LOR technique, identifying epidural spaces using electrical stimulation led to better outcomes without additional risks for novices as well as clinicians with recent gap in experience. Trial registration This study was retrospectively registered in the ClinicalTrials.gov Registry (NCT03443466) on February 23, 2018.

Performing lumbar epidural anaesthesia in children for peri-operative analgesia necessitates attentive technique and has a higher success rate if the distance from the skin to the posterior epidural space can be predicted. The major goal of this observational study is to assess the skin to epidural distance (SED) in the lumbar region in Indian children and see if there is a correlation between age, weight, and height. The loss of resistance (LOR) to air is used to determine epidural space. The distance from the tip of the needle to the point where we encountered LOR is calculated. We looked at 52 children who had lumbar epidural anaesthesia for a variety of procedures. Age, weight, height, and SED all have a high association, and weight is the strongest predictor of all the variables. Based on the correlation between variables, we created a prediction equation.

Pneumomediastinum is a rare complication following epidural block using the loss of resistance (LOR) technique with air. It is speculated to result from the opening of potential space connecting the epidural space and the posterior mediastinum via intervertebral foramina through fascial planes. To date, only two cases of pneumomediastinum after epidural block have been reported. An incidental finding of pneumomediastinum two days after the procedure has not been reported before. Epidural block as a cause should be considered among multiple causes while interpreting the imaging of this life-threatening complication in the postoperative period.

Background and Aims Measuring the distance from the skin to posterior dura (SPD) before lumbar epidural placement may prevent accidental dural puncture.1 This study compares the accuracy of measurement of SPD using ultrasound versus body mass index (BMI) in obstetric patients. Methods An anonymous retrospective data of pre-procedural ultrasound and intraprocedural Tuohy needle measurements of SPD were collected from anaesthetic charts of thirty parturient with varying gestational stages, maternal age and ethnicity, all had received lumbar epidurals for labour analgesia using 18G Tuohy needle and loss of resistance to saline. Then, using the documented patient’s BMI the SPD was calculated using the general regression equation (Y = 2.52 + 0.11 BMI).2 The accuracy of measurement of SPD for the two groups: Ultrasound SPD versus BMI SPD compared to the Touhy needle SPD was analysed using Wilcoxon signed-rank test. Ethics approval is not required as per NHS Greater Glasgow and Clyde policy. Results Ultrasound measurement of SPD was equal to Touhy needle in 23/30 (76.7%), while overestimated in 1/30 (3.3%) by 0.2 cm and underestimated in 6/30 (20%) by a mean of 0.5 cm. BMI measurement of SPD was equal to Touhy needle in 0/30 (0%), while overestimated in 25/30 (83.3%) by a mean of 1.14 cm and underestimated in 5/30 (16.7%) by a mean of 0.29 cm. Ultrasound was more accurate than BMI in the measurement of SPD based on Wilcoxon signed-rank test (non-parametric) with a p-value Conclusions Compared to BMI, ultrasound offers more accurate measurement of SPD.

Epidural analgesia represents a clinical common practice aiming at pain mitigation. This loco-regional technique is widely used in several applications such as labor, surgery and lower back pain. It involves the injections of anesthetics or analgesics into the epidural space (ES). The ES detection is still demanding and is usually performed by the techniques named loss of resistance (LOR). In this study, we propose a novel soft system (SS) based on one fiber Bragg grating sensor (FBG) embedded in a soft polymeric matrix for LOR detection during the epidural puncture. The SS was designed to allow instrumenting the syringe’s plunger without relevant modifications of the anesthetist’s sensations during the procedure. After the metrological characterization of the SS, we assessed the capability of this solution in detecting LOR by carrying it out in silico and in clinical settings. For both trials, results revealed the capability of the proposed solutions in detecting the LOR and then in recording the force exerted on the plunger.

Epidural injection represents a widely accepted clinical practice in the management of pain relief caused by musculoskeletal disorders, labour and during surgery. The main purpose of this technique is to mitigate the painful feeling in the affected area by injecting anaesthetics and analgesics in the epidural space (the area between the ligamentum flavum and the dura mater). Correct epidural space detection is still challenging because of the small size, and the failure rate is not negligible. Including the existing techniques employed for identifying the epidural space, loss of resistance (LOR) is the most popular method used in clinical practice. It is based on the LOR feeling experienced by the anesthesiologist when the Tuohy needle moves from the ligamentum flavum to the epidural space due to the different density of these two tissues. In the last decades, several systems have been developed to support clinicians during the procedure. Recently, fiber Bragg grating sensors (FBG) have shown promising results for developing techniques able to detect the LOR. In this study, we proposed a novel FBG-based system for LOR detection during epidural puncture. We instrumented the syringe plunger with a flexible polymeric matrix. To assess its performance in LOR detection, we enrolled five users who performed the epidural procedure using a commercial simulator. The results obtained showed the ability of our system to detect LOR.

Performance of epidural anesthesia and analgesia depends on successful identification of the epidural space (ES). While multiple investigations have described objective and alternative methodologies to identify the ES, traditional loss of resistance (LOR) and fluoroscopy (FC) are currently standard of care in labor and delivery (LD) and chronic pain (CP) management, respectively. While FC is associated with high success, it exposes patients to radiation and requires appropriate radiological equipment. LOR is simple but subjective and consequently associated with higher failure rates. The purpose of this investigation was to compare continuous, quantitative, real-time, needle-tip pressure sensing using a novel computer-controlled ES identification technology to FC and LOR for lumbar ES identification.A total of 400 patients were enrolled in this prospective randomized controlled noninferiority trial. In the CP management arm, 240 patients scheduled to receive a lumbar epidural steroid injection had their ES identified either with FC or with needle-tip pressure measurement. In the LD arm, 160 female patients undergoing lumbar epidural catheter placements were randomized to either LOR or needle-tip pressure measurement. Blinded observers determined successful ES identification in both arms. A modified intention-to-treat protocol was implemented, with patients not having the procedure for reasons preceding the intervention excluded. Noninferiority of needle-tip pressure measurement regarding the incidence of successful ES identification was claimed when the lower limit of the 97.27% confidence interval (CI) for the odds ratio (OR) was above 0.50 (50% less likely to identify the ES) and P value for noninferioirty.023.Demographics were similar between procedure groups, with a mild imbalance in relation to gender when evaluated through a standardized difference. Noninferiority of needle-tip pressure measurement was demonstrated in relation to FC where pain management patients presented a 100% success rate of ES identification with both methodologies (OR, 1.1; 97.27% CI, 0.52-8.74; P = .021 for noninferiority), and LD patients experienced a noninferior success rate with the novel technology (97.1% vs 91%; OR, 3.3; 97.27% CI, 0.62-21.54; P = .019) using a a priori noninferiority delta of 0.50.Objective lumbar ES identification using continuous, quantitative, real-time, needle-tip pressure measurement with the CompuFlo Epidural Computer Controlled Anesthesia System resulted in noninferior success rates when compared to FC and LOR for CP management and LD, respectively. Benefits of this novel technology may include nonexposure of patients to radiation and contrast medium and consequently reduced health care costs.

MicroRNA (miRNA) is a non-coding RNA involved in regulating both cancer gene promotion and suppression. We investigated the role of miRNA in inducing radiation resistance in cancer cell lines using clinically relevant radioresistant (CRR) cells. Analysis using miRNA arrays and qPCR revealed that miR-7-5p is highly expressed in all examined CRR cells. Additionally, CRR cells lose their radioresistance when daily irradiation is interrupted for over 6 months. MiR-7-5p expression is reduced in these cells, and treating CRR cells with a miR-7-5p inhibitor leads to a loss of resistance to irradiation. Conversely, overexpression of miR-7-5p in CRR cells using a miR-7-5p mimic shows further resistance to radiation. Overexpression of miR-7-5p in parent cells also results in resistance to radiation. These results indicate that miR-7-5p may control radioresistance in various cancer cells at the clinically relevant dose of irradiation. Furthermore, miR-7-5p downregulates mitoferrin and reduces Fe2+, which influences ferroptosis. Our findings have great potential not only for examining radiation resistance prior to treatment but also for providing new therapeutic agents for treatment-resistant cancers.

Zur Identifizierung des Epiduralraums bei Anlage ruckenmarknaher Regionalverfahren bedienen sich die meisten Anasthesisten der Widerstandsverlustmethode („Loss-of-resistance“-Technik). Diese Technik hat einerseits einen subjektiven Charakter und ist in gewissen Fallen nur bedingt verlasslich, weshalb wiederholt Ansatze zur Objektivierung unternommen worden sind. Die sog. CompuFlo®-Technologie wurde bereits vor einigen Jahren beschrieben und lieferte in ersten Studien vielversprechende Ergebnisse. Anhand dieser Fallserie werden die ersten Anwendungen im deutschsprachigen Raum illustriert.

Objectives: 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. Material and methods: 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. Results: 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. Conclusions: The automatic and the conventional LOR techniques are comparable in terms of efficacy and safety for the epidural space identification.

Several approaches of locating the epidural space have been proposed. However, loss of Resistance method (LOR) remains the most common method for epidural anesthesia. Different optical signals were received from the ligamentum flavum and the epidural space allows operator to pinpoint position of the needle and determine whether the needle tip has entered the epidural space. Optical signals throughout the penetration process was recorded and position of needle tip was confirmed with a C-arm fluoroscopy. 60 lumbar punctures were performed in 20 vivo porcine models, and success rate of locating the epidural space with the optical auxiliary is calculated statistically. The data are expressed in mean ± SD. During all the lumber puncture processes, the strength of optical signals received decreased significantly while the needle tip penetrates the ligamentum flavum and entered the epidural space. The strength of optical signal received when needle tip was in the ligamentum flavum was 1.38 ± 0.57. The signal strength at epidural space was 0.46 ± 0.35. Strength of signal decreased by 67% when entered epidural space, and there is no significant differences in decrease of strength from data obtained from thevertebrae (lumbar segments)L2-L3, L3-L4, and L4-L5. Finally, we calculated with assistance of the proposed optical auxiliary, the success rate for guiding the needle tip to the epidural space using was as high as 87%. It is evidently believed that the optical auxiliary equipped is visualized to assist operators inserting needle accurately and efficiently into epidural space during epidural anesthesia operation.

Introduction. The aim of this open, prospective, single operator study was to report the clinical experience with the CompuFlo? Epidural Instrument. Method. Epidural block was performed with the CompuFlo? Epidural Instrument in all consecutive patients undergoing an epidural or thoracic block under the author’s care over a two years period. The epidural needle was considered to have reached the epidural space when an increase in pressure (accompanied by an increase of the pitch of the audible tone) was followed by a sudden and sustained drop in pressure of more than 5 seconds accompanied by a sudden decrease of the pitch of the audible tone, resulting in the formation of a low and stable pressure plateau on the instrument’s visual display. The following outcomes were evaluated: incidence of accidental dural puncture, success of anesthesia, procedure time, volume of saline used for the epidural procedure, number of epidural attempts to reach the epidural space, number of needle redirections, and the operator’s agreement with his tactile sensation of loss of resistance and the CompuFlo? pattern. Results. A total of 600 cases were studied. All the epidural blocks were successful and no accidental dural punctures were noted. Epidural space was correctly identified on the first attempt in 91% of cases, in 95% of cases the operator judged as a perfect correlation between his tactile sensations and the CompuFlo? recordings. Conclusion. The major finding of this paper is the very high success rate of the epidural blocks, no matter in what clinical setting (obstetrical, surgical or blood patch intervention) or at which vertebral level (thoracic or epidural) were done. Most importantly, the reporting of zero incidence of any accidental dural puncture.

Background: Anesthesia management in obesity is quite challenging. Epidural anesthesia become one of the choices. The attention should be addressed in order to prevent the misidentification of epidural space. The estimation of the depth extent of epidural space becomes crucial, especially in obese patients due to an accumulation of subcutaneous and epidural adipose tissue, which consequently complicate the epidural catheter insertion. This study aimed to analyze the correlation of the depth extent of Tuohy epidural needle to achieve loss of resistance between normal-weighted and obese patients. Method: This study was conducted with 56 adult patients aged 17 to 65 years who underwent elective surgery by epidural anesthesia inserted at level L2-L3 or L3-L4 interspace. Subjects are divided into normal and obese groups. Shapiro-Wilk and chi-square tests were used in the normality test. For normally distributed data, an independent t-test was used to test the hypothesis, otherwise, we used Mann-Whitney test Results: The results showed that the loss of resistance in epidural needle insertion procedures was 60 mm in a patient with BMI more than 30 kg/m2 and 50 mm in those with BMI < 30 kg/m2 (p< 0.001). Conclusion: The loss of resistance depth in epidural Tuohy needle insertion is significantly determined by BMI.

We present a model to investigate the effects of vector resistance to control strategies. The model captures the development of resistance as well as loss of resistance in mosquitoes and how these affect the progress in malaria control. Important thresholds were calculated from mathematical analysis and numerical results presented. Mathematical results reveal the existence of the disease free and endemic equilibria whose existence and stability depends on the control reproduction number, Rc. The disease persist when the Rc>1 and dies out when Rc

OBJECTIVES Traditionally caudal epidurals are performed by landmark guided approach using the loss of resistance technique. Improvisations to increase the success rate can be attained by implementing modalities namely the neuro-stimulation and ultrasound but there is paucity of literature comparing these three approaches. Here we compare the three techniques in terms of the success rate. MATERIALS AND METHODS The primary outcome of this study was to compare the success rate of the three 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. RESULTS Demographic profiles were comparable in term of age, weight, gender distribution and types of surgeries. Success rates in landmark guided, neuro-stimulation guided and Ultrasound guided were 97, 97, and 98 percent respectively which was comparable (P=0.879). There was no significant difference in the incidence of blood or cerebrospinal fluid aspiration. DISCUSSION We found similar success rate of the caudal epidural block (CEB) by using landmark-guided, nerve stimulation-guided or ultrasound-guided techniques in children aged 1- 5 years with normal anatomy.

Evolutionary theory predicts that adaptations, including antibiotic resistance, should come with associated fitness costs; yet, many resistance mutations seemingly contradict this prediction by inducing no growth rate deficit. However, most growth assays comparing sensitive and resistant strains have been performed under a narrow range of environmental conditions, which do not reflect the variety of contexts that a pathogenic bacterium might encounter when causing infection. We hypothesized that reduced niche breadth, defined as diminished growth across a diversity of environments, can be a cost of antibiotic resistance. Specifically, we test whether chloramphenicol-resistant Escherichia coli incur disproportionate growth deficits in novel thermal conditions. Here we show that chloramphenicol-resistant bacteria have greater fitness costs at novel temperatures than their antibiotic-sensitive ancestors. In several cases, we observed no resistance cost in growth rate at the historic temperature but saw diminished growth at warmer and colder temperatures. These results were consistent across various genetic mechanisms of resistance. Thus, we propose that decreased thermal niche breadth is an under-documented fitness cost of antibiotic resistance. Furthermore, these results demonstrate that the cost of antibiotic resistance shifts rapidly as the environment changes; these context-dependent resistance costs should select for the rapid gain and loss of resistance as an evolutionary strategy.

Our group previously presented a case series aided by a three-dimensional (3D) magnetic resonance imaging (MRI) reconstruction that described injection into the space of Okada as a possible cause of unsuccessful epidural analgesia or injection following the commonly used loss of resistance to air (LORA) technique (Reina et al., (2021).

One behavioral feature of drug addiction is continued drug use despite awareness that this causes negative consequences. Attempts to model this feature in animals typically involve punishing drug self-administration with a brief electrical footshock and look for resistance to punishment. Though all individual animals eventually stop self-administering the drug with increasing intensity of punishment, some individuals do so at higher intensities than other individuals. The greater relative resistance to punishment of the former individuals is generally interpreted as evidence for a compulsion-like behavior. Here we show that resistance to footshock punishment is in fact not a stable individual behavioral feature. Specifically, when rats are retested for their resistance to increasing intensity of footshock punishment, they become much less resistant. As a result, they suppress their cocaine intake even when punished with an initially low and ineffective intensity. A series of original behavioral experiments reveals that this low resistance to footshock punishment is rapidly acquired after rats experience a punishment intensity that leads them to near-completely suppress their cocaine intake. Passive exposure to the same intensity does not induce this effect. Once acquired, low resistance to punishment persists during at least one month, but can nevertheless be extinguished by retesting rats on a daily basis. Interestingly, this acquired low resistance to footshock punishment does not generalize to a non-painful form of punishment (i.e., histamine) that is also seldom used in animal drug self-administration studies. We discuss some possible theoretical and methodological implications of these findings for future research on animal models of compulsion-like behavior.

Background The EpiFaith® syringe is a novel loss-of-resistance syringe that utilizes a spring-loaded plunger that automatically moves forward within the syringe when there is a loss of resistance. We evaluated the syringe in a clinical setting among a cohort of pregnant women receiving neuraxial labor analgesia. Methods In a non-randomized observational study, four anesthesiologists used the EpiFaith® syringe 10 times each while placing epidural catheters for labor analgesia. The anesthesiologists scored each placement on an 11-point Likert scale (−5 = absolutely worse, 0 = the same, and 5 = absolutely better than using their regular loss-of-resistance syringe technique). Results All 40 neuraxial placements correctly located the epidural space. Air was used in the syringe in 35 of the 40 cases. In 50%, 27.5% and 22.5% of cases the anesthesiologists reported that using the EpiFaith® syringe was better than, the same as, or worse than using their regular syringe, respectively. There were no inadvertent dural punctures. Conclusions This feasibility study found that three of the four anesthesiologists scored the EpiFaith® syringe as better or the same as using their regular loss-of-resistance syringe. More extensive studies are required to determine if the EpiFaith® syringe reduces adverse outcomes such as unintentional dural punctures.