ABSTRACT
The ability of the ancient Egyptians to preserve the human body through embalming has not only fascinated people since antiquity, but also has always raised the question of how this outstanding chemical and ritual process was practically achieved. Here we integrate archaeological, philological and organic residue analyses, shedding new light on the practice and economy of embalming in ancient Egypt. We analysed the organic contents of 31 ceramic vessels recovered from a 26th Dynasty embalming workshop at Saqqara1,2. These vessels were labelled according to their content and/or use, enabling us to correlate organic substances with their Egyptian names and specific embalming practices. We identified specific mixtures of fragrant or antiseptic oils, tars and resins that were used to embalm the head and treat the wrappings using gas chromatography-mass spectrometry analyses. Our study of the Saqqara workshop extends interpretations from a micro-level analysis highlighting the socio-economic status of a tomb owner3-7 to macro-level interpretations of the society. The identification of non-local organic substances enables the reconstruction of trade networks that provided ancient Egyptian embalmers with the substances required for mummification. This extensive demand for foreign products promoted trade both within the Mediterranean8-10 (for example, Pistacia and conifer by-products) and with tropical forest regions (for example, dammar and elemi). Additionally, we show that at Saqqara, antiu and sefet-well known from ancient texts and usually translated as 'myrrh' or 'incense'11-13 and 'a sacred oil'13,14-refer to a coniferous oils-or-tars-based mixture and an unguent with plant additives, respectively.
Subject(s)
Embalming , Mummies , Humans , Egypt, Ancient , Embalming/economics , Embalming/history , Embalming/methods , Gas Chromatography-Mass Spectrometry , History, Ancient , Mummies/history , Resins, Plant/analysis , Resins, Plant/history , Ceramics/chemistry , Ceramics/history , Tars/analysis , Tars/history , Plant Oils/analysis , Plant Oils/history , Mediterranean Region , Tropical Climate , Forests , Tracheophyta/chemistry , Commerce/historyABSTRACT
OBJECTIVES: To develop the use of Thiel soft embalmed human cadavers (TeC) in open radical cystectomy (ORC) training for the first time, to investigate the effect of cadaveric training on surgical trainees' technical skills/performance and to determine how trainees perceive the use of cadaveric workshops. METHODS: A 3-day hands-on workshop was organised. Ten trainees performed ORC on five TeC, supervised by five experts. Feedback from trainees and mentors was evaluated on a five-point Likert scale. All procedures were completed in a fully equipped surgical environment and complied with the principles outlined in the Declaration of Helsinki. RESULTS: The workshop participants evaluated the anatomical and manipulation characteristics of the TeC as similar to real-life conditions. The colour and consistency of the urethra and ureter differed little from those in live patients. The trainees stated that the TeC were beneficial for learning the stages of ORC and urinary diversion (UD), while their self-confidence increased. In terms of realism, all steps of radical cystectomy (RC) were rated 4 out of 5 or higher on the Likert scale by both trainees and faculty. CONCLUSIONS: The use of TeC for RC und UD was perceived as favourable by trainees and faculty. The TeC demonstrated a surprising ability to mimic real-life anatomy and represent a new and effective surgical training tool.
Subject(s)
Cadaver , Cystectomy , Embalming , Humans , Cystectomy/education , Pilot Projects , Embalming/methods , Clinical Competence , Male , FemaleABSTRACT
Estimation of the exposure temperature of skeletal remains can be done by means of colourimetry and a previously published decision model for the colourimetric data, resulting in clusters that represent a range of exposure temperature. The method was based on thermally altered freshly burned human skeletal remains. However, in practice the origin or pre-burning condition of (possibly fragmentary) burned remains can be unknown. Further, in order to use the colourimetric analysis, and accompanying decision model, it is important to have a reference or test set. Fresh human material is not available for this purpose in all countries. Hence, the classification accuracy of the decision model was tested for, in some countries more readily available substitutes for fresh bone; embalmed human bone and non-human bone. The model yielded high accuracies for these sample materials, making it possible to create a reference or test set from fresh non-human and embalmed human bone as substitute for human, and also to use the decision model for these deviating samples in practice.
Subject(s)
Bone and Bones , Colorimetry , Humans , Colorimetry/methods , Animals , Embalming/methods , Body Remains , Temperature , Burns , FiresSubject(s)
Embalming , Mummies , Archaeology , Egypt, Ancient , History, Ancient , Mummies/history , Embalming/history , Embalming/methods , HumansABSTRACT
Black organic coatings and ritual deposits on ancient Egyptian coffins and cartonnage cases are important and understudied sources of evidence about the rituals of funerary practice. Sometimes, the coatings were applied extensively over the surface of the coffin, resembling paint; in other cases, they were poured over the mummy case or wrapped body, presumably as part of a funerary ritual. For this study, multiple samples of black coatings and ritual liquids were taken from 20 Egyptian funerary items dating to a specific time period (c. 943 to 716 BC). Multiple sampling from each object enabled several comparisons to be made: the variability of the black coating within one application, the variability between two applications on one object, and the variability from object to object. All samples were analyzed for lipids using gas chromatography-mass spectrometry (GC-MS), and 51 samples from across the 20 items were further analyzed for the presence of bitumen using solid phase separation followed by selected ion monitoring GC-MS. The majority of the black substances were found to comprise a complex mixture of organic materials, including bitumen from the Dead Sea, conifer resin, and Pistacia resin, providing evidence for a continuation in international trade between Egypt and the eastern Mediterranean after the Late Bronze Age. Both the coating and the anointing liquid are very similar to mummification balms, pointing to parallels with Egyptian embalming rituals and raising questions about the practical aspects of Egyptian funerary practice.
Subject(s)
Embalming , Lipids/isolation & purification , Mummies/history , Resins, Plant/isolation & purification , Egypt, Ancient , Funeral Homes/history , Gas Chromatography-Mass Spectrometry , History, Ancient , Humans , Hydrocarbons/chemistry , Hydrocarbons/isolation & purification , Lipids/chemistry , Pistacia/chemistry , Resins, Plant/chemistryABSTRACT
BACKGROUND: Standard training for ultrasound-guided cyst needle aspiration is currently performed on live patients during residency. This practice presents risk of iatrogenic injury to patients and provides a high-stress learning environment for medical trainees. Simulation training using synthetic cysts in a formalin-embalmed cadaver model may allow for realistic, practical, and effective training free from patient risk. METHODS: Thirty first-year medical students viewed an orientation video, then attended a skills workshop to perform cyst needle aspiration in formalin-embalmed cadaver tissue under ultrasound guidance. Participants were randomly assigned to one of three ultrasound-trained instructor-types which included a medical student, clinical anatomist, or an ultrasound fellowship trained emergency medicine physician. After training, participants underwent a 5-min skills test to assess their ability to drain a synthetic cyst independently. Pre- and post-training self-confidence surveys were administered. RESULTS: Ultrasound images of synthetic cysts in formalin-embalmed tissue were clear and realistic in appearance, and sonographic needle visualization was excellent. Participants took an average of 161.5 s and 1.9 attempts to complete the procedure. Two of the 30 participants could not complete the procedure within the time limit. Participants' self-reported confidence with respect to all aspects of the procedure significantly increased post-training. Mean confidence scores rose from 1.2 (95% CI 0.96 to 1.39) to 4.4 (95% CI 4.09 to 4.53) (P < 0.0001) Procedure time, number of attempts, performance scores, and self-confidence outcomes were not significantly affected by instructor type. CONCLUSIONS: The use of synthetic cysts in formalin-embalmed cadaveric tissue is feasible, realistic, and efficacious for the teaching of ultrasound-guided needle aspiration to novice medical trainees. This simulation training method can be delivered effectively by multiple instructor types and may allow medical trainees to increase their tactical skill and self-confidence prior to performing ultrasound-guided cyst needle aspiration on live patients.
Subject(s)
Cadaver , Clinical Competence , Simulation Training , Humans , Formaldehyde , Students, Medical , Embalming , Ultrasonography, Interventional , Male , Education, Medical, Undergraduate/methods , FemaleABSTRACT
OBJECTIVES: This study aims to compare the efficacy of remote versus in-person training strategies to teach ultrasound guided knee arthrocentesis using formalin embalmed cadavers. METHODS: 30 first-year medical student participants were randomly assigned to remote or in-person training groups. Pre- and post- training surveys were used to evaluate participant's self-confidence in their ability to perform the procedure. Participants were asked to watch a 30-minute training video and then attend a skills training workshop. The workshops consisted of 20 min of hands-on instruction followed by a skills assessment. RESULTS: Following training, participant self-confidence increased significantly across all survey items in both groups (p = 0.0001). No significant changes in participant self-confidence were detected between the groups. Skills and knowledge-related metrics did not differ significantly between the groups with the exception of the "knowledge of instruments" variable. CONCLUSIONS: Our data suggests that remote ultrasound-guided procedure training, although logistically complex, is a viable alternative to traditional in-person learning techniques even for a notoriously hands on skill like ultrasound guided knee arthrocentesis. Novice first-year medical student operators in the remote-training group were able to significantly increase their confidence and demonstrate competency in a manner statistically indistinguishable from those trained in-person. These results support the pedagogical validity of using remote training to teach ultrasound guided procedures which could have implications in rural and global health initiatives where educational resources are more limited.
Subject(s)
Arthrocentesis , Cadaver , Clinical Competence , Embalming , Humans , Arthrocentesis/education , Ultrasonography, Interventional , Formaldehyde , Knee Joint/diagnostic imaging , Education, Medical, Undergraduate/methods , Education, Distance , Students, Medical , Male , FemaleABSTRACT
BACKGROUND: Novel interfascial plane blocks like PEricapsular Nerve Group (PENG) and SupraInguinal Fascia Iliaca (SIFI) blocks are effective for management of hip fracture pain. We compared the difference in the distribution of the dye injected and nerves stained by the addition of the SIFI block to the PENG block. METHODS: A total of 24 designated dye injections were performed in eight soft-embalmed cadavers. Under ultrasound guidance 20 ml green ink injected bilaterally in PENG block and 30 ml methylene blue dye was injected in the SIFI block on the right side. The cadavers were dissected 24 h later to assess the extent of dye spread. RESULTS: Extensive spread of dyes was seen on both side of iliacus muscle on the right side, but blue dye was not visible medial to the psoas tendon. The subcostal and iliohypogastric nerves were stained green in the infra-inguinal region. On the left side (PENG alone), the anterior division of the obturator, femoral and saphenous nerve (7/8) and iliohypogastric nerves (3/8) were stained in the infrainguinal region. In the suprainguinal region, the femoral nerve (5/8), accessory obturator nerve (3/8), lateral femoral cutaneous (1/8) and nerve to rectus femoris (4/8) were stained. The main obturator nerve trunk was spared with both injections while its anterior branch and accessory obturator nerve were stained with the PENG injection. CONCLUSION: The study findings indicate that combined PENG + SIFI injections lead to an extensive craniocaudal and longitudinal spread along the iliacus muscle. We perceive that the combination of these two injections will have a superior clinical outcome.
Subject(s)
Cadaver , Coloring Agents , Fascia , Nerve Block , Ultrasonography, Interventional , Humans , Nerve Block/methods , Ultrasonography, Interventional/methods , Coloring Agents/administration & dosage , Fascia/diagnostic imaging , Fascia/drug effects , Male , Female , Aged , Embalming/methods , Aged, 80 and over , Methylene Blue/administration & dosageABSTRACT
PURPOSE: Fresh-frozen specimen availability and cost may be a barrier for initiation of biomechanical studies where soft tissue is used in a construct with other medical devices. The impact of soft tissue preservation method on the outcomes of biomechanical studies in the specific case of graft-suture constructs is relatively unexplored. This study aimed to observe peak loads and failure modes in biomechanical testing of fresh-frozen (FF) versus formalin embalmed (FE) quadriceps tendon (QT) graft-suture constructs for soft tissue fixation in ACLR and assess suitability of FE QT graft constructs for load-to-fail testing. METHODS: Twenty QT grafts were harvested from human cadaver specimens. Ten grafts came from fresh-frozen donors and 10 from embalmed donors. All grafts were prepared with the modified Prusik knot using a braided composite suture and subjected to tensile loading. Comparisons between the biomechanical properties of the graft-suture constructs were made with unpaired t tests with α = 0.05. RESULTS: FE and FF constructs displayed similar peak loads and failure modes. FF constructs had greater elongation after pre-tensioning than FE (7.3 vs. 5.5 mm, p = 0.02) and greater elongation after cyclic loading than FE constructs (17.5 vs. 10.5 mm, p = 0.01). Hysteresis was greater for FF constructs at the 50th, 100th, 150th, and 200th cycle (p = 0.02, p = 0.07, p < 0.001, p = 0.004, respectively). FE constructs were stiffer than fresh-frozen (103 vs. 84 N/mm, p < 0.001). CONCLUSION: FE constructs were significantly stiffer but displayed similar peak load and failure mode to FF which was reflective of the strength of the suture material. FE grafts can offer an alternative to FF grafts in graft-suture constructs for biomechanical studies where load at failure and knot security and strength is of main interest.
Subject(s)
Cadaver , Formaldehyde , Tendons , Tensile Strength , Humans , Biomechanical Phenomena , Tendons/transplantation , Quadriceps Muscle/physiology , Sutures , Embalming/methods , Suture Techniques , Cryopreservation/methods , Materials Testing , Weight-Bearing , Male , FixativesABSTRACT
While body decompensation is mainly facilitated by bacteria, investigating the antimicrobial properties of body preservation methods is still a neglected research area. We performed microbiological sampling for potentially pathogenic bacteria species of brain, lung, liver, colon, and subcutis samples obtained from bodies perfused with embalming solutions of variable composition with emphasis on variable formaldehyde concentrations. We, thereby, identified spore-forming aerobic and anaerobic bacteria mainly in the samples obtained from the colon of ethanol- and lower-concentrated formaldehyde formulation embalmed bodies. Moreover, we could identify Enterococcus species in bodies preserved with the latter method. Tissue samples of the subcutis remained sterile. Long-term incubation of special mycobacteria growth indicator tubes revealed no growth of mycobacteria in all 60 samples analyzed. Overall, we show survival of bacterial genera known to be especially environmentally resistant but also include potentially pathogenic members. Knowledge of bactericidal capacities of embalming solutions are therefore critical to assess risk and apply appropriate disinfection routines while working with human bodies. Moreover, new formulations to reduce potentially toxic substances for embalming needs to be evaluated regarding their bactericidal capacities.
Subject(s)
Anti-Infective Agents , Embalming , Humans , Embalming/methods , Cadaver , Formaldehyde , Bacteria , Anti-Bacterial AgentsABSTRACT
To create anatomical educational materials that can be viewed in three dimensions using stereo photographs and photogrammetry, multiple photographs must be taken from different directions. In this process, shadows and reflections from different positions in each photograph are undesirable for creating three-dimensional (3D) anatomy educational materials. Although a ring flash eliminates shadows, allowing light to enter from all directions, reflections cannot be eliminated. In particular, Thiel-embalmed cadavers, which are widely used in clinical anatomy, are highly wet and exhibit strong specular highlights. In this study, a straight polarization filter was attached to a handheld camera lens and ring flash, and shooting was performed using cross-polarization photography. Consequently, even in Thiel-embalmed cadavers, the details lost due to the effects of reflections and shadows can be recovered, and good results can be obtained when taking stereo photos or creating a 3D model using photogrammetry.
Subject(s)
Photogrammetry , Photography , Humans , Cadaver , Embalming/methodsABSTRACT
Human cadavers used for surgical training are embalmed using various methods to facilitate tissue storage and longevity while preserving the natural characteristics required to achieve high fidelity functional task alignment. However, there are no standardized means to evaluate the suitability of embalming solutions for this purpose. The McMaster Embalming Scale (MES) was developed to assess the extent to which embalming solutions allow tissues to achieve physical and functional correspondence to clinical contexts. The MES follows a five-point Likert scale format and evaluates the effect of embalming solutions on tissue utility in seven domains. This study aims to determine the reliability and validity of the MES by presenting it to users after performing surgical skills on tissues embalmed using various solutions. A pilot study of the MES was conducted using porcine material. Surgical residents of all levels and faculty were recruited via the Surgical Foundations program at McMaster University. Porcine tissue was unembalmed (fresh- frozen) or embalmed using one of seven solutions identified in the literature. Participants were blinded to the embalming method as they completed four surgical skills on the tissue. After each performance, participants evaluated their experience using the MES. Internal consistency was evaluated using Cronbach's alpha. Domain to total correlations and a g-study were also conducted. Formalin-fixed tissue achieved the lowest average scores, while fresh frozen tissue achieved the highest. Tissues preserved using Surgical Reality Fluid (Trinity Fluids, LLC, Harsens Island, MI) achieved the highest scores among embalmed tissues. The Cronbach's alpha scores varied between 0.85 and 0.92, indicating a random sample of new raters would offer similar ratings using the MES. All domains except odor were positively correlated. The g-study indicated that the MES is able to differentiate between embalming solutions, but an individual rater's preference for certain tissue qualities also contributes to the variance in scores captured. This study evaluated the psychometric characteristics of the MES. Future steps to this investigation include validating the MES on human cadavers.
Subject(s)
Embalming , Formaldehyde , Humans , Animals , Swine , Embalming/methods , Pilot Projects , Reproducibility of Results , CadaverABSTRACT
Scientific examination of the heart of Blessed Pauline Jaricot-a French missionary figure-was carried out in 2022. As tandem mass spectrometry proteotyping has proven to be valuable to obtain the broad taxonomic repertoire of a given sample without any a priori information, we aimed at exploring the conditions of preservation of the relics and possible conditions of death. Metaproteomics and high-resolution microtomography imaging approaches were combined. A dataset comprising 6731 high-resolution MS/MS spectra was acquired and 968 of these spectra could be assigned to specific peptidic biomolecules. Based on the taxonomical information encompassed by the identified peptide sequences, 5 phyla were identified amongst eukaryota (94% of the biomass): Ascomycota (55%), with the species Aspergillus versicolor, Trichophyton mentagrophytes and Aspergillus glaucus, corresponding to expected cadaverous fungal flora; Chordata (42%), represented by a unique species, Homo sapiens; Streptophyta (3%); and Arthropoda (traces). Bacteria (6% of the biomass) were poorly represented. No trace of embalming substance could be retrieved, nor any pathogens. Imaging evidenced no heart defect nor embalming traces. No evidence that was inconsistent with natural and spontaneous conservation could be retrieved. This study prefigures the power of modern molecular techniques such as paleoproteotyping coupled to microtomography to gain insight into historical relics.
Subject(s)
Embalming , Heart Defects, Congenital , Humans , Embalming/methods , Tandem Mass Spectrometry , Heart , BacteriaABSTRACT
THE AIM OF THE STUDY: Is to establish the possibility of studying the vitreous body of the eye from embalmed corpses using the spin probe method to develop diagnostic criteria for the prescription of death coming. The article presents data showing the possibility of diagnosing the prescription of death coming by the method of spin probes with the examination of the vitreous body of the eye from embalmed corpses. A total of 510 spectra obtained during incubation of the 1-oxyl-4-oxo-2.2.6.6-tetramethyl-piperidin spin probe in the vitreous body were studied. Measurements of each of the 6 objects were carried out daily for 10 days after embalming. The prospects of studying the vitreous body by spin probes in embalmed corpses for the development of diagnostic criteria for the prescription of death coming up to 4 days from the moment of embalming have been established.
Subject(s)
Embalming , Prescriptions , Humans , Embalming/methods , CadaverABSTRACT
PURPOSE: Thiel embalming followed by freezing in the desired position and acquiring CTâ¯+ MRI scans is expected to be the ideal approach to obtain accurate, enhanced CT data for delineation guideline development. The effect of Thiel embalming and freezing on MRI image quality is not known. This study evaluates the above-described process to obtain enhanced CT datasets, focusing on the integration of MRI data obtained from frozen, Thiel-embalmed specimens. METHODS: Three Thiel-embalmed specimens were frozen in prone crawl position and MRI scanning protocols were evaluated based on contrast detail and structural conformity between 3D renderings from corresponding structures, segmented on corresponding MRI and CT scans. The measurement error of the dataset registration procedure was also assessed. RESULTS: Scanning protocol T1 VIBE FS enabled swift differentiation of soft tissues based on contrast detail, even allowing a fully detailed segmentation of the brachial plexus. Structural conformity between the reconstructed structures on CT and MRI was excellent, with nerves and blood vessels imported into the CT scan never intersecting with the bones. The mean measurement error for the image registration procedure was consistently in the submillimeter range (range 0.77-0.94â¯mm). CONCLUSION: Based on the excellent MRI image quality and the submillimeter error margin, the procedure of scanning frozen Thiel-embalmed specimens in the treatment position to obtain enhanced CT scans is recommended. The procedure can be used to support the postulation of delineation guidelines, or for training deep learning algorithms, considering automated segmentations.
Subject(s)
Embalming , Magnetic Resonance Imaging , Cadaver , Embalming/methods , Humans , Magnetic Resonance Imaging/methods , Tomography, X-Ray ComputedABSTRACT
It is extremely rare for table salt to be used to preserve a dead body in criminal cases. In the case presented here, after the death of his 85-year-old mother, a son kept her body preserved in table salt for about 2 years to extort social benefits (pension). Before her death, the woman had been hospitalised twice due to chronic diseases. The case has been examined by the multi-disciplinary team. The unusual conditions in which the corpse was stored influenced its good condition (close to mummification), with limited colonisation of the corpse by necrophagous insects and insects involved in soft tissue biolysis (i.e. selected Diptera or Coleoptera). The use of table salt inhibited the growth of most fungi which would normally be present on a corpse stored in ambient conditions, and the corpse's surface was colonised by halophilic fungus (Scopulariopsis brevicaulis).
Subject(s)
Coleoptera , Diptera , Aged, 80 and over , Animals , Cadaver , Embalming , Female , Humans , Sodium Chloride, DietaryABSTRACT
Within the discipline of anatomical education, the use of donated human cadavers in laboratory-based learning activities is often described as the 'gold standard' resource for supporting student understanding of anatomy. Due to both historical and educational factors, cadaveric dissection has traditionally been the approach against which other anatomy learning modalities and resources have been judged. To prepare human donors for teaching purposes, bodies must be embalmed with fixative agents to preserve the tissues. Embalmed cadavers can then be dissected by students or can be prosected or plastinated to produce teaching resources. Here, we describe the history of cadaveric preservation in anatomy education and review the practical strengths and limitations of current approaches for the embalming of human bodies. Furthermore, we investigate the pedagogic benefits of a range of established modern embalming techniques. We describe relevant cadaveric attributes and their impacts on learning, including the importance of colour, texture, smell, and joint mobility. We also explore the emotional and humanistic elements of the use of human donors in anatomy education, and the relative impact of these factors when alternative types of embalming process are performed. Based on these underpinnings, we provide a technical description of our modern Newcastle-WhitWell embalming process. In doing so, we aim to inform anatomy educators and technical staff seeking to embalm human donors rapidly and safely and at reduced costs, while enhancing visual and haptic tissue characteristics. We propose that our technique has logistical and pedagogic implications, both for the development of embalming techniques and for student visualisation and learning.
Subject(s)
Dissection , Embalming , Cadaver , Fixatives , Humans , Range of Motion, ArticularABSTRACT
In 1992, Walter Thiel described and embalming method that rendered "lifelike" tissues. Over the last 30 years, the Thiel method has been introduced worldwide for medical training and scientific purposes. This review examines research which can be linked to the use of Thiel embalming. A systematic review was performed to identify articles published in the following categories: research content, disciplines involved, sources and quantities of tissues deployed, and changes in research scope related to changes in the chemical composition of Thiel embalming. Four-hundred twenty-four publications were included. A number of adaptations to the original Thiel protocol were found, aiming to provide suitable tissue-substitutes in the development of emerging medical technologies or procedures. Musculoskeletal surgery, anesthesia and intensive care were the most common disciplines that used Thiel embalmed tissues for research. Anatomy and biomechanics played a lesser role. An increase over time was observed in research outputs related to the Thiel method, while the number of specimens used per study decreased. The main centers using Thiel embalming were in Graz, Dundee, Sapporo, Bern, Zurich and Ghent, which jointly accounted for more than 54% of all research conducted using this method. Following three decades of use, the Thiel method has evolved into being a well-established embalming technique for research purposes. Its future is challenged by the demanding requirements on both technical facilities and personnel, limitations of certain chemicals for use as fixatives, costs, and questions as to how "lifelike" the embalmed-tissues are from an objective standpoint, all of which warrants future investigations.
Subject(s)
Biomedical Research , Embalming , Biomechanical Phenomena , Cadaver , Embalming/methods , Fixatives , HumansABSTRACT
PURPOSE: Forceful needle-nerve contact and high subepineural pressures and are recognised causes of nerve damage. Pressure and force measurements are necessary to inform the mechanisms of nerve injury, build virtual simulator environments and provide operator feedback during simulation training. However, the range of pressures and forces encountered at tissue layers during targeted needle insertion and fluid injection are not known. METHODS: We built a needle that recorded in-line pressure during fluid injection and continuously measured force at the needle tip. Two anaesthetists were randomised to insert a 21 g block needle at 48 nerve sites on both sides of 3 soft embalmed Thiel cadavers. Our objective was to measure pressure and force during the course of targeted nerve injection at epimysium, in perineural tissue, on epineurium and during subepineural injection. At each interface, we infused a 0.5 ml bolus of embalming solution at a rate of 12 ml min-1 and recorded the pressure response. Force was measured continuously in the background throughout the procedure. RESULTS: Pressure was greater at epineurium and within subepineurium than perineural tissue, geometric ratio (95% CI) 4.7 (3.0-7.3) kPa and 3.8 (2.5-5.7) kPa, respectively, both P < 0.0001. Force on nerve contact and on nerve penetration was greater than force in perineural tissue, geometric ratios (95% CI) 3.0 (1.9-4.7) N and 3.6 (2.2-7.5) N, respectively, both P < 0.0001. On nerve contact, 1 in 6 insertions were ≥ 5 N CONCLUSIONS: Despite valid infusion pressures, anaesthetists exerted excessive force on nerves.
Subject(s)
Embalming , Nerve Block , Cadaver , Embalming/methods , Humans , Needles , Nerve Block/methods , Ultrasonography, Interventional/methodsABSTRACT
Biochemical investigations were carried out on the embalmed head of Nebiri (Museo Egizio, Turin; S-5109)-an 18th Dynasty Ancient Egyptian dignitary-and on the canopic jar containing his lungs (Museo Egizio, Turin; S. 5111/02) with the aim of characterizing the organ's (lung) specific paleo-proteins and of identifying the compounds used in his embalming "recipe". The application of a functionalized film method allowed us to perform a non-invasive sampling. Paleo-proteomics confirmed the presence of lung tissue-specific proteins (organ specific) as well as the presence of proteins linked to severe inflammation. Paleoproteomics and paleometabolomics further allowed the identification of the main components of Nebiri's embalming recipe: animal fats and glue, balms, essential oils, aromatic plants, heated Pistacia, and coniferous resins. Both the use of Pistacia and coniferous resins in an early 18th Dynasty individual confirm Nebiri's high social status. The technique applied offers a targeted approach to the chemical characterization of human tissues, embalming compounds, and organic materials layering in pottery. The ability of the functionalized film method to harvest all types of compounds, from macromolecules (i.e., proteins) to small molecules (i.e., organic acids) opens a new path in the study of ancient material culture; furthermore, it allows to perform untargeted analysis, which is necessary when no a priori information is available.