Point de perfusion intra-osseux alternatif théorique chez les enfants gravement hypovolémiques

BACKGROUND : Studies have shown that the venous system tends to collapse during hypovolemic shock. The use of the bone marrow space for infusions is an effective alternative, with the tibial insertion site being the norm. OBJECTIVES : This study was conducted to determine a quick intraosseous infusion method that could be an alternative to the tibial route in neonates during emergency situations. METHOD : A sample of 30 neonatal cadavers was dissected to explore a possible alternative to the tibial insertion site. The needle was inserted in the superolateral aspect of the humerus. The needle infusion site was then dissected to determine possible muscular and neurovascular damage that might occur during the administration of this procedure, with the greatest concern being the posterior circumflex humeral artery and axillary nerve exiting the quadrangular space. The distance of the needle insertion site was measured in relation to the soft tissue as well as to bony landmarks. RESULTS : The calculated 95% confidence interval shows that the needle can be safely inserted into the intraosseous tissue at the greater tubercle of the humerus 9.5 mm – 11.1 mm from the acromion. This is about a little finger’s width from the acromioclavicular joint. CONCLUSION : Anatomically, the described site is suggested to offer a safe alternative access point for emergency infusion in severely hypovolemic newborns and infants, without the risk of damage to any anatomical structures.CONTEXTE : Des études ont montré que le système veineux tendait à l’effondrement lors d’un choc hypovolémique. L’utilisation de l’espace de la moelle osseuse pour des perfusions est une alternative efficace, le point d’insertion tibial étant la norme. OBJECTIFS : Cette étude a été menée afin d’établir une méthode de perfusion intra-osseuse rapide qui pourrait être une alternative à la voie tibiale chez les nouveau-nés lors de situations d’urgence. METHODE : Un échantillon de 30 cadavres néonatals a été disséqué pour explorer une alternative possible au point d’insertion tibial. L’aiguille a été insérée dans la partie supéro-externe de l’humérus. Le point de perfusion de l’aiguille a ensuite été disséqué afin de déterminer d’éventuels dommages musculaires et neurovasculaires qui auraient pu se produire lors de l’administration de cette procédure, la plus grande préoccupation étant l’artère circonflexe humérale postérieure et le nerf axillaire sortant de l’espace quadrangulaire. La distance entre le point d’insertion de l’aiguille a été mesurée par rapport au tissu mou et à des repères osseux. RESULTATS : L’intervalle de confiance à 95% calculé montre que l’aiguille peut être insérée en toute sécurité dans le tissu intra-osseux au niveau du tubercule majeur de l’humérus à 9.5 mm – 11.1 mm de l’acromion. Ceci représente environ la largeur d’un petit doigt à partir de l’articulation acromio-claviculaire. CONCLUSION : Sur le plan anatomique, on suggère le point décrit afin d’offrir un point d’accès alternatif sûr pour la perfusion d’urgence chez les nouveau-nés et les nourrissons gravement hypovolémiques, sans risque de dommage aux structures anatomiques.http://www.phcfm.orgam201

The value of Tuffier’s line for neonatal neuraxial procedures

The spine of L4 usually lies on a line drawn between the highest points of the iliac crests (Tuffier’s line) in adults. Although its accuracy has been questioned, it is still commonly used to identify the spinous process of the 4th lumbar vertebra before performing lumbar neuraxial procedures. In children, this line is said to cross the midline at the level of L5. A literature search revealed that the description this surface anatomical line is vague in neonates. The aims of this study were to determine the vertebral level of Tuffier’s line, as well as its distance from the apex of the sacrococcygeal membrane (ASM), in 39 neonatal cadavers in both a prone and flexed position. It was found that when flexed, Tuffier’s line shifted from the level of L4/L5 (prone position) to the upper third of L5. The mean distance from the ASM to Tuffier’s line was 23.64mm when prone and 25.47mm when flexed, constituting a statistically significant increase in the distance (p=0.0061). Therefore, in the absence of advanced imaging modalities, Tuffier’s line provides practitioners with a simple method of determining a level caudal to the termination of the spinal cord, at approximately the L4/L5 in a prone neonate and the upper margins of L5 when flexed.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-2353hb201

Degenerative trends of the palmaris longus muscle in a South African population

The literature reports that the palmaris longus muscle (PL) is only found in mammals in which the forelimbs are weight-bearing extremities. It is suggested that the function of this muscle has been taken over by the other flexors in the forearm. Terms used in the literature to describe the diminishing of this muscle include retrogressive or phylogenetic degenerative trends. The aims of this study were to determine the prevalence of PL in a South African population and whether a phylogenetic degenerative trend for the PL exists. To determine the prevalence of the PL, five groups, representing different age intervals (Years 0–20, 21–40, 41–60, 61–80, and 81–99) were used. A sample of 706 participants of various ages was randomly selected. Statistical analysis included comparisons of the prevalence of the muscle between males and females and left and right sides, using a student t-test. A Chi-squared test was used to determine a possible phylogenetic degenerative trend of PL within the five groups. The sample yielded a bilateral absence of the PL in 11.9% of the cases. The muscle was unilaterally absent on the left side in 7.65% and 6.94% on the right side. The Chi-squared tests revealed a P-value of 0.27 for the left arm and 0.39 for the right arm. No obvious trend could be established for the phylogenetic degeneration of the PL in this study. It would appear that the PL muscle should not be considered as a phylogenetically degenerating muscle in a South African population.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-2353hb201

Descriptive study of the differences in the level of the conus medullaris in four different age groups

In performing neuraxial procedures, knowledge of the location of the conus medullaris in patients of all ages is important. The aim of this study was to determine the location of conus medullaris in a sample of newborn/infant cadavers and sagittal MRIs of children, adolescents and young adults. MATERIALS AND METHODS: The subjects of both the samples were subdivided into four developmental stages. No statistical difference was seen between the three older age groups (p>0.05). A significant difference was evident when the newborn/infant stage was compared with the other, older stages (p<0.001 for all comparisons). RESULTS: In the newborn/infant group the spinal cord terminated most frequently at the level of L2/L3 (16%). In the childhood stage, the spinal cord terminated at the levels of T12/L1 and the lower third of L1 (21%). In the adolescent population, it was most often found at the level of the middle third of L1 and L1/L2 (19%). Finally, in the young adult group, the spinal cord terminated at the level of L1/L2 (25%). This study confirmed the different level of spinal cord termination between newborns/infants less than one year old and subjects older than one year. In this sample the conus medullaris was not found caudal to the L3 vertebral body, which is more cranial than the prescribed level of needle insertion recommended for lumbar neuraxial procedures. CONCLUSION: It is recommended that the exact level of spinal cord termination should be determined prior to attempting lumbar neuraxial procedures in newborns or infants.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-23532016-07-31hb201

Revisiting the anatomy of the ilio-inguinal/iliohypogastric nerve block

BACKGROUND : The ilio-inguinal/iliohypogastric nerve block (INB) is one of the most common peripheral nerve block techniques in pediatric anesthesia, which is largely due to the introduction of ultrasound (US) guidance. Despite the benefits of US guidance, the absence of an US machine should not deter the provider from performing INB, considering that many institutions, especially in developing countries, cannot afford to provide ultrasound machines in their anesthesiology departments. The aim of this study was to revisit the anatomical position of the ilio-inguinal and iliohypogastric nerves in relation to the anterior superior iliac spine (ASIS), in a large sample of neonatal cadavers, and compare the results with a similar group in a previously published US-guided study. METHODS : With Ethics Committee approval, the ilio-inguinal and iliohypogastric nerves were carefully dissected in 54 neonatal cadavers. RESULTS : In the total sample, the ilio-inguinal nerve was found to be 2.2 1.2 mm from the ASIS, on a line connecting the ASIS to the umbilicus. The iliohypogastric nerve was on average 3.8 1.3 mm from the ASIS. For the entire sample, the optimal needle insertion site was 3.00 mm from the ASIS. Although there is a strong correlation between the needle insertion point and the weight of the neonate, this will only ‘fit’ for 60%of the population. CONCLUSION : The linear regression formula; needle insertion distance (mm) = 0.6 9 weight + 1.8 can be used as a guideline for the position of the ilio-inguinal and iliohypogastric nerves.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1460-9592hb201

Clinical anatomy of the maxillary nerve block in pediatric patients

BACKGROUND : Anatomical landmarks in children are mostly extrapolated from studies in adults. Despite this, complex regional anesthetic procedures are frequently performed on pediatric patients. Sophisticated imaging techniques are available but the exact position, course and/or relationships of the structures are best understood with appropriate anatomical dissections. Maxillary nerve blocks are being used for peri-operative analgesia after cleft palate repair in infants. However, the best approach for blocking the maxillary nerve in pediatric patients has yet to be established. OBJECTIVE : To determine the best approach for blocking the maxillary nerve within the pterygopalatine fossa. METHODS : In an attempt to define an optimal approach for maxillary nerve block in this age group three approaches were simulated and compared on 10 dried pediatric skulls as well as 30 dissected pediatric cadavers. The needle course, including depth and angles, to block the maxillary nerve, as it exits the skull at the foramen rotundum within the pterygopalatine fossa, was measured and compared. Two groups were studied: Group 1 consisted of skulls and cadavers of neonates (0–28 days after birth) and Group 2 consisted of skulls and cadavers from 28 days to 1 year after birth. RESULTS : No statistically significant difference (P > 0.05) was found between the left and right side of each skull or cadaver. Only technique B, the suprazygomatic approach from the frontozygomatic angle towards the pterygopalatine fossa, exhibited no statistical significance (P > 0.05) when other measurements made on the skulls and cadavers were compared. Technique A, a suprazygomatic approach from the midpoint on the lateral border of the orbit, as well as technique C, an infrazygomatic approach with an entry at a point on a vertical line extending along the lateral orbit wall, showed statistical significant differences when measurements of the skulls and cadavers were compared. CONCLUSIONS : On the basis of these findings technique B produces the most consistent data for age groups 1 and 2 and supports the clinical findings recently reported.National Research Foundation (NRF)http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1460-95922015-07-30hb201

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo