Intravenous lipid emulsion interference in coagulation testing: an ex vivo analysis.

INTRODUCTION: Intravenous lipid emulsion is used in the rescue treatment of certain poisonings. A complication is interference with laboratory analyses. The aim of this study was to determine the impact of intravenous lipid emulsion on routine laboratory analysis of coagulation parameters ex vivo and determine if any of the analytical techniques remain reliable. METHODS: Samples were obtained from 19 healthy volunteers and divided in triplicate. One sample served as a control, and the other two were diluted to simulate the treatment of an average adult with Intralipid® 20 per cent Fresenius Kabi 100 mL (dilution-1) or 500 mL (dilution-2). Coagulation tests performed were prothrombin time, activated prothrombin time, D-dimer concentration and fibrinogen. Coagulation testing was performed by three techniques. Test-1 was performed on a Sysmex CN6000 analyzer. Test-2 was performed with a manual mechanical endpoint method using the semi-automated Stago KC4 Delta. Test-3 involved high-speed centrifugation before repeat testing on the Sysmex CN6000 analyzer. RESULTS: For test-1, only nine (47 per cent) samples in dilution-1 could be analyzed for coagulation tests, and no coagulation tests could be analyzed for dilution-2 because of lipaemia. For test-2 and test-3, all samples could be analyzed, and all results of both testing methods fell within the limits of the laboratory reference range. DISCUSSION: Difficulties in laboratory analysis of patients having received intravenous lipid emulsion are due to multiple factors. Most automated coagulation analyzers use optical measurements, which can be unreliable in the presence of a high intravenous lipid concentration. By altering the lipaemia in the testing solution using high-speed centrifugation or by using manual mechanical endpoint detection, we were able to obtain reliable results. These findings are limited by the use of an ex vivo method and healthy volunteers. CONCLUSIONS: This ex vivo model confirms that Intralipid® interferes with routine coagulation studies. It is important that clinicians are aware and inform their laboratories of its administration.

Probing the neurocardiac circuit in trauma and posttraumatic stress.

The neurocardiac circuit is integral to physiological regulation of threat and trauma-related responses. However, few direct investigations of brain-behavior associations with replicable physiological markers of PTSD have been conducted. The current study probed the neurocardiac circuit by examining associations among its core regions in the brain (e.g., insula, hypothalamus) and the periphery (heart rate [HR], high frequency heart rate variability [HF-HRV], and blood pressure [BP]). We sought to characterize these associations and to determine whether there were differences by PTSD status. Participants were N = 315 (64.1 % female) trauma-exposed adults enrolled from emergency departments as part of the prospective AURORA study. Participants completed a deep phenotyping session (e.g., fear conditioning, magnetic resonance imaging) two weeks after emergency department admission. Voxelwise analyses revealed several significant interactions between PTSD severity 8-weeks posttrauma and psychophysiological recordings on hypothalamic connectivity to the prefrontal cortex (PFC), insula, superior temporal sulcus, and temporoparietaloccipital junction. Among those with PTSD, diastolic BP was directly correlated with right insula-hypothalamic connectivity, whereas the reverse was found for those without PTSD. PTSD status moderated the association between systolic BP, HR, and HF-HRV and hypothalamic connectivity in the same direction. While preliminary, our findings may suggest that individuals with higher PTSD severity exhibit compensatory neural mechanisms to down-regulate autonomic imbalance. Additional study is warranted to determine how underlying mechanisms (e.g., inflammation) may disrupt the neurocardiac circuit and increase cardiometabolic disease risk in PTSD.

An Internet Snapshot Survey Assessing the sale of Synthetic Cannabinoid Receptor Agonists for use with Electronic Vaping Devices.

INTRODUCTION: Synthetic cannabinoid receptor agonists (SCRAs) are associated with significant toxicity and are increasingly used in electronic vaping devices. We assessed the availability of SCRA vaping products to UK purchasers on the surface web. METHODS: An internet snapshot survey was performed between October 2022 and January 2023 on 'google.com' using the search terms "buy c-liquid vape", "buy herbal incense vape liquid", "buy cannabis vape liquid", "buy hashish vape liquid", "buy K2 vape liquid". RESULTS: 62 websites selling 128 SCRA vaping brands were identified. Most were purportedly based in the USA (41 websites, 66%) and most sold other controlled substances. Purchase incentives offered included discreet packaging (38, 61%), discounts for bulk purchase (34, 55%) and tracked delivery (30, 48%). Many websites stated SCRA products were: not for human consumption (41, 66%), for research purposes only (15, 24%), or legal (28, 45%). Websites sold a median (IQR) of 16 (7-25) SCRA vaping brands. Almost all were bottles of vaping liquid (1220/1225, 99.6%). The most common bottle size was 5mL (60%), the median (IQR) total volume of SCRA liquid per sale was 50mL (10-200mL). Median (IQR) price was £3.39/mL (£2.01/mL- £5.29/mL). Price decreased with increasing volume purchased (£6.58/mL for ≤ 5mL, £1.60/mL for > 200mL). CONCLUSION: SCRA vaping products are easily obtainable online, in both small and bulk quantities. Information provided to purchasers on safety and legality is lacking or misleading. Further studies are needed to confirm the chemistry of these products. Policymakers should consider steps to limit the potential harm caused by the purchase and use of these products.

Clinical effects of cannabis compared to synthetic cannabinoid receptor agonists (SCRAs): a retrospective cohort study of presentations with acute toxicity to European hospitals between 2013 and 2020.

INTRODUCTION: Cannabis is the most common recreational drug worldwide and synthetic cannabinoid receptor agonists are currently the largest group of new psychoactive substances. The aim of this study was to compare the clinical features and outcomes of lone acute cannabis toxicity with lone acute synthetic cannabinoid receptor agonist toxicity in a large series of presentations to European emergency departments between 2013-2020. METHODS: Self-reported drug exposure, clinical, and outcome data were extracted from the European Drug Emergencies Network Plus which is a surveillance network that records data on drug-related emergency department presentations to 36 centres in 24 European countries. Cannabis exposure was considered the control in all analyses. To compare the lone cannabis and lone synthetic cannabinoid receptor agonist groups, univariate analysis using chi squared testing was used for categorical variables and non-parametric Mann-Whitney U- testing for continuous variables. Statistical significance was defined as a P value of < 0.05. RESULTS: Between 2013-2020 there were 54,314 drug related presentations of which 2,657 were lone cannabis exposures and 503 lone synthetic cannabinoid receptor agonist exposures. Synthetic cannabinoid receptor agonist presentations had statistically significantly higher rates of drowsiness, coma, agitation, seizures and bradycardia at the time of presentation. Cannabis presentations were significantly more likely to have palpitations, chest pain, hypertension, tachycardia, anxiety, vomiting and headache. DISCUSSION: Emergency department presentations involving lone synthetic cannabinoid receptor agonist exposures were more likely to have neuropsychiatric features and be admitted to a psychiatric ward, and lone cannabis exposures were more likely to have cardiovascular features. Previous studies have shown variability in the acute toxicity of synthetic cannabinoid receptor agonists compared with cannabis but there is little comparative data available on lone exposures. There is limited direct comparison in the current literature between lone synthetic cannabinoid receptor agonist and lone cannabis exposure, with only two previous poison centre series and two clinical series. Whilst this study is limited by self-report being used to identify the drug(s) involved in the presentations, previous studies have demonstrated that self-report is reliable in emergency department presentations with acute drug toxicity. CONCLUSION: This study directly compares presentations with acute drug toxicity related to the lone use of cannabis or synthetic cannabinoid receptor agonists. It supports previous findings of increased neuropsychiatric toxicity from synthetic cannabinoid receptor agonists compared to cannabis and provides further data on cardiovascular toxicity in lone cannabis use.

Patient Comments and Patient Experience Ratings Are Strongly Correlated With Emergency Department Wait Times.

BACKGROUND AND OBJECTIVES: Hospitals and clinicians increasingly are reimbursed based on quality of care through financial incentives tied to value-based purchasing. Patient-centered care, measured through patient experience surveys, is a key component of many quality incentive programs. We hypothesize that operational aspects such as wait times are an important element of emergency department (ED) patient experience. The objectives of this paper are to determine (1) the association between ED wait times and patient experience and (2) whether patient comments show awareness of wait times. METHODS: This is a cross-sectional observational study from January 1, 2019, to December 31, 2020, across 16 EDs within a regional health care system. Patient and operations data were obtained as secondary data through internal sources and merged with primary patient experience data from our data analytics team. Dependent variables are (1) the association between ED wait times in minutes and patient experience ratings and (2) the association between wait times in minutes and patient comments including the term wait (yes/no). Patients rated their "likelihood to recommend (LTR) an ED" on a 0 to 10 scale (categories: "Promoter" = 9-10, "Neutral" = 7-8, or "Detractor" = 0-6). Our aggregate experience rating, or Net Promoter Score (NPS), is calculated by the following formula for each distinct wait time (rounded to the nearest minute): NPS = 100* (# promoters - # detractors)/(# promoters + # neutrals + # detractors). Independent variables for patient age and gender and triage acuity, were included as potential confounders. We performed a mixed-effect multivariate ordinal logistic regression for the rating category as a function of 30 minutes waited. We also performed a logistic regression for the percentage of patients commenting on the wait as a function of 30 minutes waited. Standard errors are adjusted for clustering between the 16 ED sites. RESULTS: A total of 50 833 unique participants completed an experience survey, representing a response rate of 8.1%. Of these respondents, 28.1% included comments, with 10.9% using the term "wait." The odds ratio for association of a 30-minute wait with LTR category is 0.83 [0.81, 0.84]. As wait times increase, the odds of commenting on the wait increase by 1.49 [1.46, 1.53]. We show policy-relevant bubble plot visualizations of these two relationships. CONCLUSIONS: Patients were less likely to give a positive patient experience rating as wait times increased, and this was reflected in their comments. Improving on the factors contributing to ED wait times is essential to meeting health care systems' quality initiatives.

Intensive longitudinal assessment following index trauma to predict development of PTSD using machine learning.

There are significant challenges to identifying which individuals require intervention following exposure to trauma, and a need for strategies to identify and provide individuals at risk for developing PTSD with timely interventions. The present study seeks to identify a minimal set of trauma-related symptoms, assessed during the weeks following traumatic exposure, that can accurately predict PTSD. Participants were 2185 adults (Mean age=36.4 years; 64% women; 50% Black) presenting for emergency care following traumatic exposure. Participants received a 'flash survey' with 6-8 varying symptoms (from a pool of 26 trauma symptoms) several times per week for eight weeks following the trauma exposure (each symptom assessed ∼6 times). Features (mean, sd, last, worst, peak-end scores) from the repeatedly assessed symptoms were included as candidate variables in a CART machine learning analysis to develop a pragmatic predictive algorithm. PTSD (PCL-5 ≥38) was present for 669 (31%) participants at the 8-week follow-up. A classification tree with three splits, based on mean scores of nervousness, rehashing, and fatigue, predicted PTSD with an Area Under the Curve of 0.836. Findings suggest feasibility for a 3-item assessment protocol, delivered once per week, following traumatic exposure to assess and potentially facilitate follow-up care for those at risk.

Joint RCEM and NPIS best practice guideline: assessment and management of acute opioid toxicity in adults in the emergency department.

The Royal College of Emergency Medicine Toxicology Special Interest Group in collaboration with the UK National Poisons Information Service and the Clinical Toxicology Department at Guy's and St Thomas' NHS Foundation Trust has produced guidance to support clinicians working in the ED with the assessment and management of adults with acute opioid toxicity.Considerations regarding identification of acute opioid toxicity are discussed and recommendations regarding treatment options and secondary prevention are made. There is a focus on making recommendations on the best available evidence.

Sex-dependent differences in vulnerability to early risk factors for posttraumatic stress disorder: results from the AURORA study.

BACKGROUND: Knowledge of sex differences in risk factors for posttraumatic stress disorder (PTSD) can contribute to the development of refined preventive interventions. Therefore, the aim of this study was to examine if women and men differ in their vulnerability to risk factors for PTSD. METHODS: As part of the longitudinal AURORA study, 2924 patients seeking emergency department (ED) treatment in the acute aftermath of trauma provided self-report assessments of pre- peri- and post-traumatic risk factors, as well as 3-month PTSD severity. We systematically examined sex-dependent effects of 16 risk factors that have previously been hypothesized to show different associations with PTSD severity in women and men. RESULTS: Women reported higher PTSD severity at 3-months post-trauma. Z-score comparisons indicated that for five of the 16 examined risk factors the association with 3-month PTSD severity was stronger in men than in women. In multivariable models, interaction effects with sex were observed for pre-traumatic anxiety symptoms, and acute dissociative symptoms; both showed stronger associations with PTSD in men than in women. Subgroup analyses suggested trauma type-conditional effects. CONCLUSIONS: Our findings indicate mechanisms to which men might be particularly vulnerable, demonstrating that known PTSD risk factors might behave differently in women and men. Analyses did not identify any risk factors to which women were more vulnerable than men, pointing toward further mechanisms to explain women's higher PTSD risk. Our study illustrates the need for a more systematic examination of sex differences in contributors to PTSD severity after trauma, which may inform refined preventive interventions.

Photochemistry of Ru(II) Triazole Complexes with 6-Membered Chelate Ligands: Detection and Reactivity of Ligand-Loss Intermediates.

Photochemical ligand release from metal complexes may be exploited in the development of novel photoactivated chemotherapy agents for the treatment of cancer and other diseases. Highly intriguing photochemical behavior is reported for two ruthenium(II) complexes bearing conformationally flexible 1,2,3-triazole-based ligands incorporating a methylene spacer to form 6-membered chelate rings. [Ru(bpy)2(pictz)]2+ (1) and [Ru(bpy)2(btzm)]2+ (2) (bpy = 2,2'-bipyridyl; pictz = 1-(picolyl)-4-phenyl-1,2,3-triazole; btzm = bis(4-phenyl-1,2,3-triazol-4-yl)methane) exhibit coordination by the triazole ring through the less basic N2 atom as a consequence of chelation and readily undergo photochemical release of the pictz and btzm ligands (ϕ = 0.079 and 0.091, respectively) in acetonitrile solution to form cis-[Ru(bpy)2(NCMe)2]2+ (3) in both cases. Ligand-loss intermediates of the form [Ru(bpy)2(κ1-pictz or κ1-btzm)(NCCD3)]2+ are detected by 1H NMR spectroscopy and mass spectrometry. Photolysis of 1 yields three ligand-loss intermediates with monodentate pictz ligands, two of which form through simple decoordination of either the pyridine or triazole donor with subsequent solvent coordination (4-tz(N2) and 4-py, respectively). The third intermediate, shown to be able to form photochemically directly from 1, arises through linkage isomerism in which the monodentate pictz ligand is coordinated by the triazole N3 atom (4-tz(N3)) with a comparable ligand-loss intermediate with an N3-bound κ1-btzm ligand also observed for 2.

A Near-Infrared Luminescent Cr(III) N-Heterocyclic Carbene Complex.

Photoluminescent coordination complexes of Cr(III) are of interest as near-infrared spin-flip emitters. Here, we explore the preparation, electrochemistry, and photophysical properties of the first two examples of homoleptic N-heterocyclic carbene complexes of Cr(III), featuring 2,6-bis(imidazolyl)pyridine (ImPyIm) and 2-imidazolylpyridine (ImPy) ligands. The complex [Cr(ImPy)3]3+ displays luminescence at 803 nm on the microsecond time scale (13.7 µs) from a spin-flip doublet excited state, which transient absorption spectroscopy reveals to be populated within several picoseconds following photoexcitation. Conversely, [Cr(ImPyIm)2]3+ is nonemissive and has a ca. 500 ps excited-state lifetime.

Microvascular Muscle vs. Fascio-Cutaneous Free Flaps for Reconstruction of Plantar Load-Bearing Foot Defects-An International Survey.

Background: The reconstruction of plantar load-bearing foot defects faces many plastic surgeons with a major challenge. The optimal patient- and defect-oriented reconstructive strategy must be selected. Methods: To analyze the current trends and recommendations in reconstruction of plantar load-bearing foot defects, we conducted an international survey among plastic surgeons querying them about their recommendations and experiences. Results: The survey revealed that the most common strategies for reconstruction of the foot sole are locoregional and microvascular free flaps, emphasizing the relevance of plastic surgery. Among microvascular free flaps, muscle and fascio-cutaneous free flaps are by far the most frequently used. The target qualities of the reconstructed tissue to be considered are manifold, with adherence being the most frequently mentioned. We observed a noteworthy correlation between the utilization of muscle flaps and a preference for adherence. In addition, we identified a substantial correlation between the usage of fascio-cutaneous free flaps and further target qualities, such as good skin quality and sensitivity. Conclusions: Our findings provide insights into the clinical reality and highlight important aspects that must be considered in reconstruction of the weight-bearing areas of the foot providing support in the selection of the appropriate therapy.

Mortality and mortality disparities among people with epilepsy in the United States, 2011-2021.

Studies on epilepsy mortality in the United States are limited. We used the National Vital Statistics System Multiple Cause of Death data to investigate mortality rates and trends during 2011-2021 for epilepsy (defined by the International Classification of Diseases, 10th Revision, codes G40.0-G40.9) as an underlying, contributing, or any cause of death (i.e., either an underlying or contributing cause) for U.S. residents. We also examined epilepsy as an underlying or contributing cause of death by selected sociodemographic characteristics to assess mortality rate changes and disparities in subpopulations. During 2011-2021, the overall age-standardized mortality rates for epilepsy as an underlying (39 % of all deaths) or contributing (61 % of all deaths) cause of death increased 83.6 % (from 2.9 per million to 6.4 per million population) as underlying cause and 144.1 % (from 3.3 per million to 11.0 per million population) as contributing cause (P < 0.001 for both based on annual percent changes). Compared to 2011-2015, in 2016-2020 mortality rates with epilepsy as an underlying or contributing cause of death were higher overall and in nearly all subgroups. Overall, mortality rates with epilepsy as an underlying or contributing cause of death were higher in older age groups, among males than females, among non-Hispanic Black or non-Hispanic American Indian/Alaska Native persons than non-Hispanic White persons, among those living in the West and Midwest than those living in the Northeast, and in nonmetro counties compared to urban regions. Results identify priority subgroups for intervention to reduce mortality in people with epilepsy and eliminate mortality disparity.

Sex Differences in Response Inhibition-Related Neural Predictors of Posttraumatic Stress Disorder in Civilians With Recent Trauma.

BACKGROUND: Females are more likely to develop posttraumatic stress disorder (PTSD) than males. Impaired inhibition has been identified as a mechanism for PTSD development, but studies on potential sex differences in this neurobiological mechanism and how it relates to PTSD severity and progression are relatively rare. Here, we examined sex differences in neural activation during response inhibition and PTSD following recent trauma. METHODS: Participants (n = 205, 138 female sex assigned at birth) were recruited from emergency departments within 72 hours of a traumatic event. PTSD symptoms were assessed 2 weeks and 6 months posttrauma. A Go/NoGo task was performed 2 weeks posttrauma in a 3T magnetic resonance imaging scanner to measure neural activity during response inhibition in the ventromedial prefrontal cortex, right inferior frontal gyrus, and bilateral hippocampus. General linear models were used to examine the interaction effect of sex on the relationship between our regions of interest and the whole brain, PTSD symptoms at 6 months, and symptom progression between 2 weeks and 6 months. RESULTS: Lower response inhibition-related ventromedial prefrontal cortex activation 2 weeks posttrauma predicted more PTSD symptoms at 6 months in females but not in males, while greater response inhibition-related right inferior frontal gyrus activation predicted lower PTSD symptom progression in males but not females. Whole-brain interaction effects were observed in the medial temporal gyrus and left precentral gyrus. CONCLUSIONS: There are sex differences in the relationship between inhibition-related brain activation and PTSD symptom severity and progression. These findings suggest that sex differences should be assessed in future PTSD studies and reveal potential targets for sex-specific interventions.

Post-traumatic stress and future substance use outcomes: leveraging antecedent factors to stratify risk.

Background: Post-traumatic stress disorder (PTSD) and substance use (tobacco, alcohol, and cannabis) are highly comorbid. Many factors affect this relationship, including sociodemographic and psychosocial characteristics, other prior traumas, and physical health. However, few prior studies have investigated this prospectively, examining new substance use and the extent to which a wide range of factors may modify the relationship to PTSD. Methods: The Advancing Understanding of RecOvery afteR traumA (AURORA) study is a prospective cohort of adults presenting at emergency departments (N = 2,943). Participants self-reported PTSD symptoms and the frequency and quantity of tobacco, alcohol, and cannabis use at six total timepoints. We assessed the associations of PTSD and future substance use, lagged by one timepoint, using the Poisson generalized estimating equations. We also stratified by incident and prevalent substance use and generated causal forests to identify the most important effect modifiers of this relationship out of 128 potential variables. Results: At baseline, 37.3% (N = 1,099) of participants reported likely PTSD. PTSD was associated with tobacco frequency (incidence rate ratio (IRR): 1.003, 95% CI: 1.00, 1.01, p = 0.02) and quantity (IRR: 1.01, 95% CI: 1.001, 1.01, p = 0.01), and alcohol frequency (IRR: 1.002, 95% CI: 1.00, 1.004, p = 0.03) and quantity (IRR: 1.003, 95% CI: 1.001, 1.01, p = 0.001), but not with cannabis use. There were slight differences in incident compared to prevalent tobacco frequency and quantity of use; prevalent tobacco frequency and quantity were associated with PTSD symptoms, while incident tobacco frequency and quantity were not. Using causal forests, lifetime worst use of cigarettes, overall self-rated physical health, and prior childhood trauma were major moderators of the relationship between PTSD symptoms and the three substances investigated. Conclusion: PTSD symptoms were highly associated with tobacco and alcohol use, while the association with prospective cannabis use is not clear. Findings suggest that understanding the different risk stratification that occurs can aid in tailoring interventions to populations at greatest risk to best mitigate the comorbidity between PTSD symptoms and future substance use outcomes. We demonstrate that this is particularly salient for tobacco use and, to some extent, alcohol use, while cannabis is less likely to be impacted by PTSD symptoms across the strata.

Correction: Neonatal blood lead concentration predicts medium term lead-related outcomes in children ≤5 years old with congenital lead poisoning: A retrospective cohort study in Northern Nigeria.

[This corrects the article DOI: 10.1371/journal.pgph.0001644.].

Critical role of water conditions in the responses of autumn phenology of marsh wetlands to climate change on the Tibetan Plateau.

The Tibetan Plateau, housing 20% of China's wetlands, plays a vital role in the regional carbon cycle. Examining the phenological dynamics of wetland vegetation in response to climate change is crucial for understanding its impact on the ecosystem. Despite this importance, the specific effects of climate change on wetland vegetation phenology in this region remain uncertain. In this study, we investigated the influence of climate change on the end of the growing season (EOS) of marsh wetland vegetation across the Tibetan Plateau, utilizing satellite-derived Normalized Difference Vegetation Index (NDVI) data and observational climate data. We observed that the regionally averaged EOS of marsh vegetation across the Tibetan Plateau was significantly (p < .05) delayed by 4.10 days/decade from 2001 to 2020. Warming preseason temperatures were found to be the primary driver behind the delay in the EOS of marsh vegetation, whereas preseason cumulative precipitation showed no significant impact. Interestingly, the responses of EOS to climate change varied spatially across the plateau, indicating a regulatory role for hydrological conditions in marsh phenology. In the humid and cold central regions, preseason daytime warming significantly delayed the EOS. However, areas with lower soil moisture exhibited a weaker or reversed delay effect, suggesting complex interplays between temperature, soil moisture, and EOS. Notably, in the arid southwestern regions of the plateau, increased preseason rainfall directly delayed the EOS, while higher daytime temperatures advanced it. Our results emphasize the critical role of hydrological conditions, specifically soil moisture, in shaping marsh EOS responses in different regions. Our findings underscore the need to incorporate hydrological factors into terrestrial ecosystem models, particularly in cold and dry regions, for accurate predictions of marsh vegetation phenological responses to climate change. This understanding is vital for informed conservation and management strategies in the face of current and future climate challenges.

Dual-energy CT applications in musculoskeletal disorders.

Dual-energy CT (DECT) is an exciting application in CT technology conferring many advantages over conventional single-energy CT at no additional with comparable radiation dose to the patient. Various emerging and increasingly established clinical DECT applications in musculoskeletal (MSK) imaging such as bone marrow oedema detection, metal artefact reduction, monosodium urate analysis, and collagen analysis for ligamentous, meniscal, and disc injuries are made possible through its advanced DECT post-processing capabilities. These provide superior information on tissue composition, artefact reduction and image optimization. Newer DECT applications to evaluate fat fraction for sarcopenia, Rho/Z application for soft tissue calcification differentiation, 3D rendering, and AI integration are being assessed for future use. In this article, we will discuss the established and developing applications of DECT in the setting of MSK radiology as well as the basic principles of DECT which facilitate them.

The Role of Density in Achieving Volume and Weight Symmetry in Breast Reconstruction.

BACKGROUND: Knowledge of tissue and implant density is crucial in obtaining both volume and weight symmetry in unilateral breast reconstruction. Therefore, the aim of this study was to determine and compare the density of abdominal and breast tissue specimens as well as of 5th generation breast implants. METHODS: Thirty-one breast tissue and 30 abdominal tissue specimens from 61 patients undergoing either mammaplasty or abdominoplasty as well as five different 5th generation breast implants were examined. Density (g/mL) was calculated by applying the water displacement method. RESULTS: The mean specimen density was 0.94 ± 0.02 g/mL for breast tissue and 0.94 ± 0.02 g/mL for abdominal tissue, showing no significant difference (p = 0.230). Breast tissue density significantly (p = 0.04) decreased with age, while abdominal tissue did not. A regression equation to calculate the density of breast tissue corrected for age (breast density [g/mL] = 0.975-0.0007 * age) is provided. Breast tissue density was not related to body mass index, past pregnancy, or a history of breastfeeding. The breast implants had a density ranging from 0.76 to 1.03 g/mL which differed significantly from breast tissue density (-0.19 g/mL [-19.8%] to +0.09 g/mL [+9.58%]; p ≤ 0.001). CONCLUSION: Our results support the suitability of abdominal-based perforator flaps in achieving both volume and weight symmetry in unilateral autologous breast reconstruction. Abdominal flap volume can be derived one-to-one from mastectomy weight. Further, given significant brand-dependent density differences, the potential to impose weight disbalances when performing unilateral implant-based reconstructions of large breasts should be considered.