Beck’s Tetrad? Adding POCUS To The Clinical Exam For Pericardial Tamponade Improves Diagnostic Accuracy In Obstructive Shock

Beck’s Tetrad? Adding POCUS To The Clinical Exam For Pericardial Tamponade Improves Diagnostic Accuracy In Obstructive Shock Cody Wiench, MD Providence Portland Medical Center – Portland, OR Additional Authors: Benjamin Pedroja, MD Introduction: Obstructive shock due to tamponade is an important, but rare, cause for sudden cardiovascular collapse. Accurate treatment requires prompt (and correct) diagnosis. Bedside echocardiogram can provide rapid and accurate diagnosis, however the physical exam can provide important clues to consider tamponade. In patients with conditions that predispose them to pericardial disease, such as SLE, one must have a high index of suspicion for tamponade when patients suddenly de-compensate. Case Presentation: A 27-year old woman with a history of SLE on chronic immunosuppression, pulmonary hypertension and chronic pain presents to the Emergency Department with subjective fevers to 40C, diaphoresis and sudden onset back pain. Vitals in the ED were impressive for heart rate of 106, blood pressure of 92/67, respiration rate of 10. Labs and imaging were unremarkable. Pt admitted to hospital for potential sepsis of unclear cause in an immunosuppressed patient and was started on vancomycin and piperacillin-tazobactam. On day 5 of hospitalization, a rapid response was called due to sudden onset of heart rate to 150, respiration rate to 24, blood pressures of 80s/50s and severe chest pain. Physical exam at that time was notable for muffled heart sounds and pulsus paradoxus. Bedside ultrasound demonstrated a large pericardial effusion resulting in cardiac tamponade. Emergent pericardial fluid drainage was preformed, draining 70 cc of fibrinous, bloody fluid. After procedure, the patient had rapid normalization of hemodynamics. Pericardial fluid analysis was performed, but nonspecific. It is thought that the effusion was secondary to SLE, and the patient was discharged to home in stable condition. Discussion: Cardiac involvement in SLE is thought to occur in more than 50% of SLE patients, however tamponade is much rarer with an estimated incidence of \u3c1% in a review series. Tamponade portends a poor prognosis in SLE patients. During acute cardiovascular collapse in SLE, one much have a rapid approach to evaluating for tamponade. Pulsus paradoxus is one of those maneuvers; in one prospective study, it was found in 2/3 of patients with tamponade. Unfortunately, patients presenting with the classical “Beck’s Triad” (hypotension, distended neck veins and distant heart sounds) is uncommon; in once study of ultrasound-confirmed tamponade, Beck’s Triad was present in 0% of patients. Fortunately, there are key findings on POCUS exam that, in conjunction with the physical exam, can lead to rapid and accurate diagnosis of tamponade, for instance the absence of a dilated IVC can exclude tamponade with 97% sensitivity.https://digitalcommons.psjhealth.org/ppmc_internal/1006/thumbnail.jp

Conservation implications of limited genetic diversity and population structure in Tasmanian devils ( Sarcophilus harrisii )

Tasmanian devils face a combination of threats to persistence, including Devil Facial Tumor Disease (DFTD), an epidemic transmissible cancer. We used RAD sequencing to investigate genome-wide patterns of genetic diversity and geographic population structure. Consistent with previous results, we found very low genetic diversity in the species as a whole, and we detected two broad genetic clusters occupying the northwestern portion of the range, and the central and eastern portions. However, these two groups overlap across a broad geographic area, and differentiation between them is modest ( = 0.1081). Our results refine the geographic extent of the zone of mixed ancestry and substructure within it, potentially informing management of genetic variation that existed in pre-diseased populations of the species. DFTD has spread across both genetic clusters, but recent evidence points to a genomic response to selection imposed by DFTD. Any allelic variation for resistance to DFTD may be able to spread across the devil population under selection by DFTD, and/or be present as standing variation in both genetic regions

Rapid evolutionary response to a transmissible cancer in Tasmanian devils

Although cancer rarely acts as an infectious disease, a recently emerged transmissible cancer in Tasmanian devils ( Sarcophilus harrisii ) is virtually 100% fatal. Devil facial tumour disease (DFTD) has swept across nearly the entire species' range, resulting in localized declines exceeding 90% and an overall species decline of more than 80% in less than 20 years. Despite epidemiological models that predict extinction, populations in long-diseased sites persist. Here we report rare genomic evidence of a rapid, parallel evolutionary response to strong selection imposed by a wildlife disease. We identify two genomic regions that contain genes related to immune function or cancer risk in humans that exhibit concordant signatures of selection across three populations. DFTD spreads between hosts by suppressing and evading the immune system, and our results suggest that hosts are evolving immune-modulated resistance that could aid in species persistence in the face of this devastating disease. A recently emerged infectious cancer has caused the near extinction of the Tasmanian devil, but some populations persist. Here, Epstein et al . provide evidence for possible resistance via rapid evolution in two genomic regions that contain cancer-related immune response genes

Genotype calls from Stacks for Tasmanian devil RAD-seq

This VCF file contains raw genotype calls produced by Stacks as described in Epstein et al. 2016. Very briefly, the genotyping workflow was quality control -> PCR de-duplication (for paired-end samples) -> Alignment to reference -> Filter out MAPQ < 40 -> Stacks

Large‐effect loci affect survival in Tasmanian devils (Sarcophilus harrisii) infected with a transmissible cancer

Identifying the genetic architecture of complex phenotypes is a central goal of modern biology, particularly for disease-related traits. Genome-wide association methods are a classical approach for identifying the genomic basis of variation in disease phenotypes, but such analyses are particularly challenging in natural populations due to sample size difficulties. Extensive mark-recapture data, strong linkage disequilibrium and a lethal transmissible cancer make the Tasmanian devil (Sarcophilus harrisii) an ideal model for such an association study. We used a RAD-capture approach to genotype 624 devils at ~16,000 loci and then used association analyses to assess the heritability of three cancer-related phenotypes: infection case-control (where cases were infected devils and controls were devils that were never infected), age of first infection and survival following infection. The SNP array explained much of the phenotypic variance for female survival (&gt;80%) and female case-control (&gt;61%). We found that a few large-effect SNPs explained much of the variance for female survival (~5 SNPs explained &gt;61% of the total variance), whereas more SNPs (~56) of smaller effect explained less of the variance for female case-control (~23% of the total variance). By contrast, these same SNPs did not account for a significant proportion of phenotypic variance in males, suggesting that the genetic bases of these traits and/or selection differ across sexes. Loci involved with cell adhesion and cell-cycle regulation underlay trait variation, suggesting that the devil immune system is rapidly evolving to recognize and potentially suppress cancer growth through these pathways. Overall, our study provided necessary data for genomics-based conservation and management in Tasmanian devils

Conservation implications of limited genetic diversity and population structure in Tasmanian devils (Sarcophilus harrisii)

Tasmanian devils face a combination of threats to persistence, including Devil Facial Tumor Disease (DFTD), an epidemic transmissible cancer. We used RAD sequencing to investigate genome-wide patterns of genetic diversity and geographic population structure. Consistent with previous results, we found very low genetic diversity in the species as a whole, and we detected two broad genetic clusters occupying the northwestern portion of the range, and the central and eastern portions. However, these two groups overlap across a broad geographic area, and differentiation between them is modest ( = 0.1081). Our results refine the geographic extent of the zone of mixed ancestry and substructure within it, potentially informing management of genetic variation that existed in pre-diseased populations of the species. DFTD has spread across both genetic clusters, but recent evidence points to a genomic response to selection imposed by DFTD. Any allelic variation for resistance to DFTD may be able to spread across the devil population under selection by DFTD, and/or be present as standing variation in both genetic regions