Splendors and miseries of expired CO2 measurement in the suspicion of pulmonary embolism

Capnography has been studied for decades as a potential diagnostic tool for suspected pulmonary embolism. Despite technological refinements and its combination with other non-invasive instruments, no evidence to date allows recommending the use of expired carbon dioxide measurement as a rule-out test for pulmonary embolism without additional radiological testing. Further investigations are, however, still warranted

Patient Assessments of the Most Important Medical Decision During a Hospitalization

Background: How medical decisions are made in real-life situations is largely unexplored. We explored patients' perceptions of decision-making during a hospitalization and examined the conformity of the decision process with expert recommendations. Objective: To describe the conformity of the decision-making process with current expert opinion and examine the associations between various aspects of the decision-making process and a global assessment of the decision. Methods: Mail survey of patients discharged from a teaching hospital in Geneva, Switzerland. Patients identified the main medical decision during their stay, and rated the decision process (11-item "decision process score”) and their satisfaction with the decision (five-item "decision satisfaction score”). Both scores were scaled between 0 (worst) and 100 (best). Participants: The survey had 1467 respondents. Main Results: In total 862 (58.8%) of 1467 respondents reported having made a medical decision while in the hospital. The decision process score (mean 78.5, SD 21.5) and the decision satisfaction score (mean 86.5, SD 20.4) were moderately correlated (r = 0.62). Men, healthier patients, patients discharged from the department of surgery, and those who reported sharing the decision with their doctor gave the highest ratings on both scales. Five process variables were independently associated with high satisfaction with the decision: the doctor explained all possible treatments and examinations, the patient was aware of risks at the time of the decision, the doctor's explanations were easy to understand, the patient was involved in the decision as much as desired or more, and the patient was not pressured into the decision. Conclusions: A majority of patients discharged from a general hospital were able to identify and rate a medical decision. Recommended features of the process of medical decision-making were associated with greater satisfaction with the decisio

Tutor Training, Evaluation Criteria and Teaching Environment Influence Students' Ratings of Tutor Feedback in Problem-Based Learning

Aim: In a problem-based learning (PBL) curriculum, tutor's feedback skills are important. However, evaluation studies often show that students rate many tutors as ineffective in providing feedback. We explored whether this is related: (a) to tutors' skills, and hence a teaching intervention might improve their performance; (b) to the formulation of the evaluation item, hence a more specific wording might help students better recognize a feedback when received; (c) to PBL teaching environment, and hence the tutors' teaching unit might influence students' ratings. Methods: Students rated 126 tutors of 13 one-month teaching units over three consecutive years on their ability of providing feedback. We assessed how (a) a teaching intervention given between years 1 and 2, (b) a rewording of the evaluation item which took place in year 3, and (c) the tutors' teaching unit, influenced students' ratings. Results: The ratings of tutors considered as effective by students at year 1 improved after the teaching intervention, while those of unsatisfactory tutors did not progress. However the ratings of the latter increased after reformulation of the evaluation item. This increase varied across teaching units. Discussion: Students' ratings of tutors' ability to give feedback seem to vary in function of the tutors'␣training, of the formulation of the evaluation item, and of the tutors' teaching environment. These variables should be considered for setting up effective strategies in faculty developmen

Systemic thrombolytic therapy for acute pulmonary embolism: a systematic review and meta-analysis

Aim Thrombolytic therapy induces faster clot dissolution than anticoagulation in patients with acute pulmonary embolism (PE) but is associated with an increased risk of haemorrhage. We reviewed the risks and benefits of thrombolytic therapy in the management of patients with acute PE. Methods and results We systematically reviewed randomized controlled studies comparing systemic thrombolytic therapy plus anticoagulation with anticoagulation alone in patients with acute PE. Fifteen trials involving 2057 patients were included in our meta-analysis. Compared with heparin, thrombolytic therapy was associated with a significant reduction of overall mortality (OR; 0.59, 95% CI: 0.36-0.96). This reduction was not statistically significant after exclusion of studies including high-risk PE (OR; 0.64, 95% CI: 0.35-1.17). Thrombolytic therapy was associated with a significant reduction in the combined endpoint of death or treatment escalation (OR: 0.34, 95% CI: 0.22-0.53), PE-related mortality (OR: 0.29; 95% CI: 0.14-0.60) and PE recurrence (OR: 0.50; 95% CI: 0.27-0.94). Major haemorrhage (OR; 2.91, 95% CI: 1.95-4.36) and fatal or intracranial bleeding (OR: 3.18, 95% CI: 1.25-8.11) were significantly more frequent among patients receiving thrombolysis. Conclusions Thrombolytic therapy reduces total mortality, PE recurrence, and PE-related mortality in patients with acute PE. The decrease in overall mortality is, however, not significant in haemodynamically stable patients with acute PE. Thrombolytic therapy is associated with an increase of major and fatal or intracranial haemorrhag

Effect of Screening for Methicillin-Resistant Staphylococcus aureus Carriage by Polymerase Chain Reaction on the Duration of Unnecessary Preemptive Contact Isolation

A high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage at hospital readmission among previous MRSA carriers warrants screening and preemptive isolation precautions. The replacement of culture on chromogenic agar with rapid quantitative polymerase chain reaction for readmission screening reduces the number of unnecessary preemptive isolation-days by 54% (from 6.88 to 3.14 isolation-days) and related costs by 45% (from US$113.2 to US$62.1) for patients who test negative for MRS

CLASSIFYING HEARTRATE BY CHANGE DETECTION AND WAVELET METHODS FOR EMERGENCY PHYSICIANS

10 pages.Heart Rate Variability (HRV) carries a wealth of information about the physiological state and the behaviour of a living subject. Indeed, the heart rate variation is intrinsically linked to the autonomic nervous system: the Parasympathetic and Sympathetic systems. Thus, any imbalance in these two opposite systems results in a variation of the cardiac frequency modulation. It is also recognized that this alternation between equilibrium and disequilibrium (frequency variability) is an indicator of well being and good health. In other words, decreased heart rate variability is always linked to stress, fatigue and decreased physical performances. The aim of this work is to exploit the heart rate signals to detect situations of stress in different populations: emergency physicians, sportsmen, animal behaviours, etc...This paper introduces a methodological framework for the detection of stress and eventually well being. Our contribution is based on first extracting high and low frequencies energies which are linked to the Parasympathetic and Sympathetic systems. We then detect change points on these energies using the Filtered Derivative with p-value (FDpV) method. Finally, we develop a typology of cardiac activity by distinguishing homogeneous groups or state profiles having a characteristic similarity. We apply our methodology on a real dataset corresponding to an emergency doctor

Targeting intracellular, multi-drug resistant Staphylococcus aureus with guanidinium polymers by elucidating the structure-activity relationship

Intracellular persistence of bacteria represents a clinical challenge as bacteria can thrive in an environment protected from antibiotics and immune responses. Novel targeting strategies are critical in tackling antibiotic resistant infections. Synthetic antimicrobial peptides (SAMPs) are interesting candidates as they exhibit a very high antimicrobial activity. We first compared the activity of a library of ammonium and guanidinium polymers with different sequences (statistical, tetrablock and diblock) synthesized by RAFT polymerization against methicillin-resistant S. aureus (MRSA) and methicillin-sensitive strains (MSSA). As the guanidinium SAMPs were the most potent, they were used to treat intracellular S. aureus in keratinocytes. The diblock structure was the most active, reducing the amount of intracellular MSSA and MRSA by two-fold. We present here a potential treatment for intracellular, multi-drug resistant bacteria, using a simple and scalable strategy

Brief report: Beyond clinical experience: Features of data collection and interpretation that contribute to diagnostic accuracy

BACKGROUND: Clinical experience, features of data collection process, or both, affect diagnostic accuracy, but their respective role is unclear. OBJECTIVE, DESIGN: Prospective, observational study, to determine the respective contribution of clinical experience and data collection features to diagnostic accuracy. METHODS: Six Internists, 6 second year internal medicine residents, and 6 senior medical students worked up the same 7 cases with a standardized patient. Each encounter was audiotaped and immediately assessed by the subjects who indicated the reasons underlying their data collection. We analyzed the encounters according to diagnostic accuracy, information collected, organ systems explored, diagnoses evaluated, and final decisions made, and we determined predictors of diagnostic accuracy by logistic regression models. RESULTS: Several features significantly predicted diagnostic accuracy after correction for clinical experience: early exploration of correct diagnosis (odds ratio [OR] 24.35) or of relevant diagnostic hypotheses (OR 2.22) to frame clinical data collection, larger number of diagnostic hypotheses evaluated (OR 1.08), and collection of relevant clinical data (OR 1.19). CONCLUSION: Some features of data collection and interpretation are related to diagnostic accuracy beyond clinical experience and should be explicitly included in clinical training and modeled by clinical teachers. Thoroughness in data collection should not be considered a privileged way to diagnostic succes

The type VII secretion system protects Staphylococcus aureus against antimicrobial host fatty acids

The Staphylococcus aureus type VII secretion system (T7SS) exports several proteins that are pivotal for bacterial virulence. The mechanisms underlying T7SS-mediated staphylococcal survival during infection nevertheless remain unclear. Here we report that S. aureus lacking T7SS components are more susceptible to host-derived antimicrobial fatty acids. Unsaturated fatty acids such as linoleic acid (LA) elicited an increased inhibition of S. aureus mutants lacking T7SS effectors EsxC, EsxA and EsxB, or the membrane-bound ATPase EssC, compared to the wild-type (WT). T7SS mutants generated in different S. aureus strain backgrounds also displayed an increased sensitivity to LA. Analysis of bacterial membrane lipid profiles revealed that the esxC mutant was less able to incorporate LA into its membrane phospholipids. Although the ability to bind labelled LA did not differ between the WT and mutant strains, LA induced more cell membrane damage in the T7SS mutants compared to the WT. Furthermore, proteomic analyses of WT and mutant cell fractions revealed that, in addition to compromising membranes, T7SS defects induce oxidative stress and hamper their response to LA challenge. Thus, our findings indicate that T7SS contribute to maintaining S. aureus membrane integrity and homeostasis when bacteria encounter antimicrobial fatty acids