Failure Analysis in Multiple TKA Revisions—Periprosthetic Infections Remain Surgeons’ Nemesis

Background: The aim of this study was to categorize reasons for failure and to analyze the survivorship of multiple total knee arthroplasty (TKA) revisions. Methods: The study retrospectively evaluated all multiple TKA revisions performed between 2005 and 2015 at the authors’ institutions. Sixty-three patients (35 female, 28 male, age 64 ± 10 years, follow-up 55 ± 36 months) underwent a total of 157 re-revision TKA surgeries (range 2–5). The revision indications were divided up into main diagnoses. Survivorship was evaluated by mixed model analysis. Results: The main overall reason for re-revision was periprosthetic joint infection (PJI) (48%), followed by instability (12%), polyethylene wear (11%), malpositioning (8%), and aseptic loosening (8%). Survivorship shortened with an increasing number of revision surgeries (p = 0.003). While PJI was in 38% of all cases, the reason for the first revision, incidence increased constantly with the number of revisions (48% at second revision, 55% at third revision, 86% at fourth revision, and 100% at fifth revision, p = 0.022). If periprosthetic infection caused the first revision, patients showed an average of two more septic revisions at follow-up than patients with an aseptic first revision indication (p < 0.001). In 36% of cases, the reason for follow-up surgery in case of periprosthetic infection was again PJI. Conclusion: The probability of survival of the implanted knee arthroplasty is significantly reduced with each subsequent revision. Periprosthetic infection is the main cause of multiple revisions.

Pulmonary Embolism in Patients with COVID-19

Infection with the novel severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) and the resulting syndrome, COVID-19, have been associated with inflammation and a prothrombotic state, with increases in fibrin, fibrinogen, fibrin degradation products and D-dimers. In some studies, elevations in these markers have been associated with worse clinical outcomes. Several studies have demonstrated a high prevalence of venous thromboembolism (VTE), and pulmonary embolism (PE), particularly in patients admitted to the intensive care unit (ICU), even in those receiving prophylactic anticoagulation. The high rate of thrombosis in COVID-19 is driven by at least two interrelated processes: a hypercoagulable state responsible for large-vessel thrombosis and thromboembolism and direct vascular and endothelial injury responsible for in situ microvascular thrombosis. The presence of PE and pulmonary thrombosis may explain why hypoxemia is out of proportion to impairment in lung compliance in some patients with COVID-19 pneumonia. Diagnosing PE in patients with COVID-19 pneumonia may be challenging, because the two pathologies share many signs and symptoms. It has been demonstrated that the administration of prophylactic anticoagulation within 24 h of admission in patients with COVID-19 was associated with decreased mortality when compared with no prophylactic anticoagulation. Given the antithrombotic, anti-inflammatory and possibly antiviral properties of heparins, it has been hypothesized that anticoagulation with heparin administered at doses higher than conventionally used for venous thromboprophylaxis may improve outcomes. In non-critically ill patients hospitalized with COVID-19, therapeutic-dose anticoagulants with heparin (most commonly, low-molecular-weight heparin) increased the probability of survival until hospital discharge with a reduced need for ICU-level organ support at 21 days as compared with usual-care thromboprophylaxis. In Critically ill patients with confirmed COVID-19, therapeutic-dose anticoagulation did not increase the probability of survival to hospital discharge or the number of days free of cardiovascular o respiratory organ support and had a 95% probability of being inferior to usual-care pharmacologic thromboprophylaxis. Currently, randomized trials evaluating the use of tissue plasminogen activator and Tenecteplase in patients with COVID-19 ARDS are underway.

Sperm Storage Costs Determine Survival and Immunocompetence in Newly Mated Queens of the Leaf-Cutting Ant Atta colombica

In the leaf-cutting ant Atta colombica, queens receive ejaculates from multiple males during one single mating event early in their lives. A queen’s fertility and fitness therefore depend on maximizing the number of sperm cells she can store and maintain inside her spermatheca. Previous studies implied significant physiological mating costs, either originating from energetic investments maximizing sperm survival, or from resolving sexual conflicts to terminate male-driven incapacitation of rival sperm via serine proteases found in seminal fluid. Here we conducted an artificial insemination experiment, which allowed us to distinguish between the effects of sperm and seminal fluid within the queen’s sexual tract on her survival and immunocompetence. We found significantly higher mortality in queens that we had inseminated with sperm, independently of whether seminal fluid was present or not. Additionally, after receiving sperm, heavier queens had a higher probability of survival compared to lightweight queens, and immunocompetence decreased disproportionally for queens that had lost weight during the experiment. These findings indicate that queens pay significant physiological costs for maintaining and storing sperm shortly after mating. On the other hand, the presence of seminal fluid within the queens’ sexual tract neither affected their survival nor their immunocompetence. This suggests that the energetic costs that queens incur shortly after mating are primarily due to investments in sperm maintenance and not costs of terminating conflicts between competing ejaculates. This outcome is consistent with the idea that sexually selected traits in social insects with permanent castes can evolve only when they do not affect survival or life-time fitness of queens in any significant way.

Who should get the scarce ICU bed? The US public’s view on triage in the time of COVID-19

ObjectiveTo determine the relative importance members of the US public place on different patient attributes in triage decisions about who should receive the last available intensive care unit (ICU) bed.MethodsA discrete choice experiment was conducted with a nationally representative sample of 2000 respondents from the YouGov internet panel of US households. Respondents chose which of three hypothetical patients with COVID-19 should receive an ICU bed if only one were available. The three patients differed in age, gender, Alzheimer’s-like disability and probability of survival if the patient received the ICU bed. An experimental design varied the values of the four attributes of the three hypothetical patients with COVID-19 that a respondent saw in four choice tasks.ResultsThe most important patient attribute to respondents was the probability the patient survives COVID-19 if they get the ICU bed (OR CI: 4.41 to 6.91). There was heterogeneity among different age groups of respondents about how much age of the patient mattered. Respondents under 30 years of age were more likely to choose young patients and old patients, and less likely to select patients aged 40–60 years old. For respondents in the age group 30–49 years old, as the age of the patient declined, their preference for saving the patient declined modestly in a linear fashion.ConclusionsRespondents favoured giving the last ICU bed available to the patient with the highest probability of surviving COVID-19. Public opinion suggests a simple guideline for physician choices based on likelihood of survival as opposed to the number of life-years saved. There was heterogeneity among respondents of different age groups for allocating the last ICU bed, as well as to the importance of the patient having an Alzheimer’s-like disability (where religion of the respondent is important) and the gender of the patient (where the gender and racial identity are important).

Toxic epidermal necrolysis associated with anticonvulsants

Background and Objetives: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are considered as a continuum of the same process. TEN or Lyell Syndrome is the most severe form. Both entities involve an acute mucocutaneous blistering reaction associated with systemic inflammation. Materials and Methods: We present a case of a young woman who developed TEN following concomitant treatment with valproate, lamotrigine, and phenobarbital. Despite the extensive mucocutaneous detachment (over 90%), prognostic evaluation was favorable (SCORTEN score 2; probability of survival 88%), and this patient evolved satisfactorily. Five days after admission, valproate was reinitiated without any subsequent adverse reaction. Results: Causality evaluation identified both lamotrigine and phenobarbital as “very probable” (ALDEN score = 6) causes and valproate as “very unlikely” (ALDEN score = 0) cause of TEN. Conclusions: SJS and TEN are true life-threatening medical emergencies. This case emphasizes the importance of early diagnosis and treatment, including the discontinuation of the causative agent, which can be lifesaving.

An Integrated Deep Learning and Belief Rule Base Intelligent System to Predict Survival of COVID-19 Patient under Uncertainty

The novel Coronavirus-induced disease COVID-19 is the biggest threat to human health at the present time, and due to the transmission ability of this virus via its conveyor, it is spreading rapidly in almost every corner of the globe. The unification of medical and IT experts is required to bring this outbreak under control. In this research, an integration of both data and knowledge-driven approaches in a single framework is proposed to assess the survival probability of a COVID-19 patient. Several neural networks pre-trained models: Xception, InceptionResNetV2, and VGG Net, are trained on X-ray images of COVID-19 patients to distinguish between critical and non-critical patients. This prediction result, along with eight other significant risk factors associated with COVID-19 patients, is analyzed with a knowledge-driven belief rule-based expert system which forms a probability of survival for that particular patient. The reliability of the proposed integrated system has been tested by using real patient data and compared with expert opinion, where the performance of the system is found promising.

Microbiota composition in the lower respiratory tract is associated with severity in patients with acute respiratory distress by influenza

Several factors are associated with the severity of the respiratory disease caused by the influenza virus. Although viral factors are one of the most studied, in recent years the role of the microbiota and co-infections in severe and fatal outcomes has been recognized. However, most of the work has focused on the microbiota of the upper respiratory tract (URT), hindering potential insights from the lower respiratory tract (LRT) that may help to understand the role of the microbiota in Influenza disease. In this work, we characterized the microbiota of the LRT of patients with Influenza A using 16S rRNA sequencing. We tested if patients with different outcomes (deceased/recovered), use of antibiotics, and different days of symptoms onset differ in their microbial community composition. We found striking differences in the diversity and composition of the microbiota depending on the days of symptoms onset and with mortality of the studied patients. We detected a high abundance of opportunistic pathogens such as Enterococcus, Granulicatella, and Staphylococcus in patients either deceased or with antibiotic treatment. Also, we found that antibiotic treatment deeply perturbs the microbial communities in the LRT and affect the probability of survival in Influenza A patients. Altogether, the loss of microbial diversity could, in turn, generate a disequilibrium in the community, potentially compromising the immune response increasing viral infectivity, promoting the growth of potentially pathogenic bacteria that, together with altered biochemical parameters, can be leading to severe forms of the disease. Overall, the present study gives one of the first characterizations of the diversity and composition of microbial communities in the LRT of Influenza patients and its relationship with clinical variables and disease severity.

Prevalence of Lung Metastases among 19,321 Metastatic Colorectal Cancer Patients in Eight Countries of Europe and Asia

Background: Colorectal cancer is one of the most common malignancies in the Western world, and is responsible for about 10% of annual cancer-related deaths. Especially for UICC stage IV, the probability of survival is significantly reduced. Little is known about risk factors for specific metastatic patterns of colorectal cancer that may also influence patients’ overall survival. Methods: We used data from the IQVIA oncology dynamics (OD) database to determine the prevalence of pulmonary metastases in 19,321 patients with UICC stage IV colorectal cancer in eight European and Asian countries. Results: In total, 6132 of 19,321 (31.7%) study patients had lung metastases, with a higher prevalence among patients with rectal (37.5%) than colon (30.1%) cancer. When compared to China as the country with the lowest lung metastases prevalence, the odds for lung metastases were highest in UK (OR: 2.02, 95%CI: 1.80–2.28), followed by Italy (OR: 1.86, 95%CI: 1.52–2.27), Spain (OR: 1.85, 95%CI: 1.64–2.09), and Germany (OR: 1.47, 95%CI: 1.26–1.71). Conclusion: The prevalence of pulmonary metastases in UICC stage IV colorectal cancer varies widely among the different analyzed countries. Although the present data are purely descriptive, a possible combination of ethnic, environmental, and health care system-associated differences could be discussed as the underlying cause. Further studies are needed to investigate the reasons for differences in the prevalence of lung metastases.