Segmentation and grid generation for numerical simulations of vad connections with patient-specific data

Objectives: We are interested in the numerical simulation of the anastomotic region comprised between outflow canula of LVAD and the aorta. Segmenta¬tion, geometry reconstruction and grid generation from patient-specific data remain an issue because of the variable quality of DICOM images, in particular CT-scan (e.g. metallic noise of the device, non-aortic contrast phase). We pro¬pose a general framework to overcome this problem and create suitable grids for numerical simulations.Methods: Preliminary treatment of images is performed by reducing the level window and enhancing the contrast of the greyscale image using contrast-limited adaptive histogram equalization. A gradient anisotropic diffusion filter is applied to reduce the noise. Then, watershed segmentation algorithms and mathematical morphology filters allow reconstructing the patient geometry. This is done using the InsightToolKit library (www.itk.org). Finally the Vascular Model¬ing ToolKit (www.vmtk.org) and gmsh (www.geuz.org/gmsh) are used to create the meshes for the fluid (blood) and structure (arterial wall, outflow canula) and to a priori identify the boundary layers. The method is tested on five different patients with left ventricular assistance and who underwent a CT-scan exam.Results: This method produced good results in four patients. The anastomosis area is recovered and the generated grids are suitable for numerical simulations. In one patient the method failed to produce a good segmentation because of the small dimension of the aortic arch with respect to the image resolution.Conclusions: The described framework allows the use of data that could not be otherwise segmented by standard automatic segmentation tools. In particular the computational grids that have been generated are suitable for simulations that take into account fluid-structure interactions. Finally the presented method features a good reproducibility and fast application.

Adaptation of AHRQ patient safety indicators for use in ICD-10 administrative data by an international consortium.

Objective: The Agency for Healthcare Research and Quality (AHRQ) developed Patient Safety Indicators (PSIs) for use with ICD-9-CM data. Many countries have adopted ICD-10 for coding hospital diagnoses. We conducted this study to develop an internationally harmonized ICD-10 coding algorithm for the AHRQ PSIs. Methods: The AHRQ PSI Version 2.1 has been translated into ICD-10-AM (Australian Modification), and PSI Version 3.0a has been independently translated into ICD-10-GM (German Modification). We converted these two country-specific coding algorithms into ICD-10-WHO (World Health Organization version) and combined them to form one master list. Members of an international expert panel-including physicians, professional medical coders, disease classification specialists, health services researchers, epidemiologists, and users of the PSI-independently evaluated this master list and rated each code as either "include," "exclude," or "uncertain," following the AHRQ PSI definitions. After summarizing the independent rating results, we held a face-to-face meeting to discuss codes for which there was no unanimous consensus and newly proposed codes. A modified Delphi method was employed to generate a final ICD-10 WHO coding list. Results: Of 20 PSIs, 15 that were based mainly on diagnosis codes were selected for translation. At the meeting, panelists discussed 794 codes for which consensus had not been achieved and 2,541 additional codes that were proposed by individual panelists for consideration prior to the meeting. Three documents were generated: a PSI ICD-10-WHO version-coding list, a list of issues for consideration on certain AHRQ PSIs and ICD-9-CM codes, and a recommendation to WHO to improve specification of some disease classifications. Conclusion: An ICD-10-WHO PSI coding list has been developed and structured in a manner similar to the AHRQ manual. Although face validity of the list has been ensured through a rigorous expert panel assessment, its true validity and applicability should be assessed internationally.

Hyperlactatémie et acidose lactique chez le patient critique [Hyperlactatemia and lactic acidosis in the critically ill patient].

Hyperlactatemia is associated with an ominous prognosis in critical illness and must be rapidly detected. Lactate is produced by glycolysis through reduction of pyruvate, itself oxidized in the mitochondria. It is transported to the liver and converted to glucose through gluconeogenesis (Cori's cycle). Hyperlactatemia can result from excessive production or reduced clearance. Excess production can occur in aerobic conditions, following an increase in pyruvate generation, or in anaerobic conditions, due to impaired pyruvate oxidation. Reduced lactate clearance occurs as a result of liver hypoperfusion or hepatic failure. Lactate/pyruvate ratio, as well as the concomitant existence of metabolic acidosis (lactic acidosis), help distinguish the different mechanisms leading to hyperlactatemia, which are reviewed in detail in this article.

Adaptation au codage CIM-10 de 15 indicateurs de la sécurité des patients proposés par l'Agence étasunienne pour la recherche et la qualité des soins de santé (AHRQ) [ICD-10 adaptation of 15 Agency for Healthcare Research and Quality patient safety indicators].

BACKGROUND: In the United States, the Agency for Healthcare Research and Quality (AHRQ) has developed 20 Patient Safety Indicators (PSIs) to measure the occurrence of hospital adverse events from medico-administrative data coded according to the ninth revision of the international classification of disease (ICD-9-CM). The adaptation of these PSIs to the WHO version of ICD-10 was carried out by an international consortium. METHODS: Two independent teams transcoded ICD-9-CM diagnosis codes proposed by the AHRQ into ICD-10-WHO. Using a Delphi process, experts from six countries evaluated each code independently, stating whether it was "included", "excluded" or "uncertain". During a two-day meeting, the experts then discussed the codes that had not obtained a consensus, and the additional codes proposed. RESULTS: Fifteen PSIs were adapted. Among the 2569 proposed diagnosis codes, 1775 were unanimously adopted straightaway. The 794 remaining codes and 2541 additional codes were discussed. Three documents were prepared: (1) a list of ICD-10-WHO codes for the 15 adapted PSIs; (2) recommendations to the AHRQ for the improvement of the nosological frame and the coding of PSI with ICD-9-CM; (3) recommendations to the WHO to improve ICD-10. CONCLUSIONS: This work allows international comparisons of PSIs among the countries using ICD-10. Nevertheless, these PSIs must still be evaluated further before being broadly used.

Optimizing patient-ventilator synchrony during invasive ventilator assist in children and infants remains a difficult task.

OBJECTIVES: To document and compare the prevalence of asynchrony events during invasive-assisted mechanical ventilation in pressure support mode and in neurally adjusted ventilatory assist in children. DESIGN: Prospective, randomized, and crossover study. SETTING: Pediatric and Neonatal Intensive Care Unit, University Hospital of Geneva, Switzerland. PATIENTS: Intubated and mechanically ventilated children, between 4 weeks and 5 years old. INTERVENTIONS: Two consecutive ventilation periods (pressure support and neurally adjusted ventilatory assist) were applied in random order. During pressure support, three levels of expiratory trigger setting were compared: expiratory trigger setting as set by the clinician in charge (PSinit), followed by a 10% (in absolute values) increase and decrease of the clinician's expiratory trigger setting. The pressure support session with the least number of asynchrony events was defined as PSbest. Therefore, three periods were compared: PSinit, PSbest, and neurally adjusted ventilatory assist. Asynchrony events, trigger delay, and inspiratory time in excess were quantified for each of them. MEASUREMENTS AND MAIN RESULTS: Data from 19 children were analyzed. Main asynchrony events during PSinit were autotriggering (3.6 events/min [0.7-8.2]), ineffective efforts (1.2/min [0.6-5]), and premature cycling (3.5/min [1.3-4.9]). Their number was significantly reduced with PSbest: autotriggering 1.6/min (0.2-4.9), ineffective efforts 0.7/min (0-2.6), and premature cycling 2/min (0.1-3.1), p < 0.005 for each comparison. The median asynchrony index (total number of asynchronies/triggered and not triggered breaths ×100) was significantly different between PSinit and PSbest: 37.3% [19-47%] and 29% [24-43%], respectively, p < 0.005). With neurally adjusted ventilatory assist, all types of asynchrony events except double-triggering and inspiratory time in excess were significantly reduced resulting in an asynchrony index of 3.8% (2.4-15%) (p < 0.005 compared to PSbest). CONCLUSIONS: Asynchrony events are frequent during pressure support in children despite adjusting the cycling off criteria. Neurally adjusted ventilatory assist allowed for an almost ten-fold reduction in asynchrony events. Further studies should determine the clinical impact of these findings.

Fusion telomérique de deux chromosomes X par leurs bras courts chez une patiente présentant un syndrome de Turner atypique. [Telomeric fusion of the short arms of both X chromosomes in a patient presenting an atypical Turner syndrome.]

A case of atypical Turner's syndrome with unusual karyotype is reported. The chromosome complements of the patient, studied with different banding techniques, is 45,XO/46,X,dic(X)(Xqter leads to p22::p22 leads to qter). In the literature 8 similar cases have been reported. Short stature and amenorrhea are the most constant findings. The mechanisms by which the observed chromosomal "rearrangement" can be produced are briefly discussed.

A dramatic lung cancer course in a patient with a rare EGFR germline mutation exon 21 V843I: Is EGFR TKI resistance predictable?

We report on the medical history of a Caucasian smoker woman diagnosed with a stage IV NSCLC adenocarcinoma, characterized by a rare epidermal growth factor receptor (EGFR) point mutation in exon 21 codon 843 (p.V843I/c.2527G>A/COSMIC ID 85894). This genetic alteration revealed to be germline, after its presence was demonstrated in chondroblasts from the bone biopsy. While it is the first description of germline V843I mutation without concomitant additional known EGFR activating mutation, we modeled the EGFR ATP catalytic domain in complex with ATP, gefitinib and erlotinib using computer-aided approaches to estimate possible changes in affinity upon the V843I mutation.

Can neurally adjusted ventilatory assist (NAVA) improve patient-ventilator interaction? A preliminary study

INTRODUCTION. NAVA is a new spontaneous-assisted ventilatory mode based on thedetection of diaphragmatic electrical activity (Eadi) and its feedback to adjust ventilatorsettings. NAVA uses the Eadi, an expression of the respiratory center's activity, to initiatepressurization, set the level of pressure support and cycle the ventilator into exhalation.Therefore, NAVA should theoretically allow near-perfect synchronization between the patientand the ventilator. However there are few data documenting these effects in intensive carepatients.OBJECTIVES. To determine whether NAVA can improve patient-ventilator synchronycompared to standard pressure support (PS) in intubated intensive care patients.METHODS. Comparative study of patient-ventilator interaction during PS with cliniciandetermined ventilator settings and NAVA with NAVA gain (proportionality factor betweenEadi and the amount of delivered inspiratory pressure) set as to obtain the same peak airwaypressure as the total pressure obtained in PS. A 20 min continuous recording with eachventilatory mode was performed allowing determination of trigger delay (Td), patient neuralinspiratory time (Tin), duration of pressurization by the ventilator (Tiv), excess durationof pressurization (Ti excess = Tiv - Tin/Tin 9 100) and number of asynchrony events byminute: non-triggering breaths, auto-triggering, double triggering, premature and delayedcycling.Results are given in mean ± SD. p is considered significant if\0.05.RESULTS. Preliminary results (mean ± SD): five patients (age 75 ± 12 years, 1 M/4F,BMI 25.7 ± 4.1 kg m-2), two pts with COPD, 1 with restrictive disease, initial settings: PS14.6 ± 1.7 cm H2O, PEEP 6.4 ± 1.5 cm H2O, NAVA gain 2.8 ± 1.3PS NAVA % reduction NAVAversus PSTd (ms) 210.4 ± 63.0 51.8 ± 12.1* 74.5 ± 5.0Ti excess (%) 12.9 ± 19.6 2.2 ± 0.6 70.8 ± 37.8n asynchrony/minute 7.6 ± 6.4 4.1 ± 3.7* 47.5 ± 17.0Respiratory rate (min-1) 16.8 ± 2.6 20.4 ± 4.7 NA* p\0.05CONCLUSION. Compared to standard PS, NAVA improves patient ventilator interaction byreducing Td and the overall incidence of asynchrony events. There is also a strong trend inreducing delayed cycling. This ongoing trial should provide evidence that NAVA can indeedimprove patient-ventilator synchrony in intubated patients undergoing PS.REFERENCE(S). 1. Sinderby C, Navalesi P et al (1995) Neural control of mechanicalventilation in respiratory failure. Nat Med 5(12):1433-1436.2. Colombo D, Cammarota G et al (2008) Physiologic response to varying levels of pressuresupport and neurally adjusted ventilator assist in patients with acute respiratory failure.Intensive Care Med 34(11):2010-2018.

Particularités de la prise en charge des infections chez le patient neutropénique [Special feature in the handling of infectious in neutropenic patients]

Les progrès continus des connaissances réalisés dans le domaine de l'oncohématologie depuis quelques décennies ont permis une amélioration considérable du pronostic de la plupart des formes de cancer. Toutefois, la morbidité et la mortalité attribuables aux infections apparaissent actuellement comme les principaux facteurs limitant l'agressivité des traitements de la maladie cancéreuse, et un meilleur contrôle de ces dernières est devenu l'un des éléments essentiels de la prise en charge de ce type de patients. Une recherche clinique intense a permis d'en identifier les grands principes qui sont exposés dans cet article. Un algorithme thérapeutique susceptible de guider le clinicien face au développement d'un état fébrile, toujours suspect d'infection chez le patient cancéreux neutropénique, est ensuite proposé.

Traitement chirurgical de la diplopie secondaire à l'orbitopathie dysthyroïdienne [Surgical treatment of diplopia in Graves' orbitopathy]

BACKGROUND: The correction of oculomotor disorder in Grave's disease is applied on pathological extraocular muscles. Based on the global muscular restriction (bilateral forced duction test) and angular measurements, we have used a non-adjustable technique. PATIENTS AND METHODS: We performed a retrospective analysis of 21 patients (23 operations) with thyroid-associated orbitopathy operated for persisting diplopia. The angles of deviation in the 9 diagnostic directions of gaze and the field of binocular vision were measured with the Harm's tangent scale before and after surgery. Sixteen patients were operated only on vertical muscles. The mean follow-up was 45 months. RESULTS: 76 % of the patients (95 % confidence interval [CI], 58-94 %) obtained a large and centred field of binocular vision without prisms. 14 % (95 % CI, 0-29 %) had binocular vision with the use of prisms. Diplopia persisted in one patient despite 3 operations. Taking into consideration the interventions done before the patient was referred to us, the reintervention rate was 13 % (95 % CI, 0-28 %). CONCLUSIONS: A binocular field of vision can be successfully restored in the majority of patients with Graves' orbitopathy, using a non-adjustable surgical technique.

Instances d'aliénation: portrait du patient tiraillé 1. Individu et contexte [Instances of alienation: portrait of the torn patient. I. Individual and context].

While the past decades were marked by an increased interest for the existential situation of man suffering from disease, the mechanisms alienating the patient from himself and from his context have been poorly investigated. These mechanisms, though operating in a dynamic interaction, will be discussed here sequentially. The first part of this article focuses on individual mechanisms of alienation emerging from the relationship the patient establishes with his body and psyche and on those related to his relational context. The aim is not to comprehensively describe these phenomena, but to discuss--based on clinical vignettes--some examples and their implications. The second part of the article describes some mechanisms of alienation that are incorporated in the medical apparatus and the dominant discourses.

Droits du patient: ce que le nouveau Code civil va modifier dans les soins aux enfants [Patients' rights: what the new swiss civil code will change in the health care of children].

Recent progress in medicine allow to provide treatment, to cure or to extend the lifespan of people that would have not survived before. Doctors and healthcare providers have become indispensable actors in Western societies. This is particularly true for children's health issues. With the new information technologies, knowledge is now available to everyone, which enables patients to dialog on an equal footing with the physician. Nowadays, therapeutic choices are discussed and negotiated. The new tensions caused by this relationship between therapist and patient have created the need for new regulations. The Swiss Confederation has modified its Civil Code with the objective of a better protection of vulnerable individuals. This article summarizes the consequences of the new regulations with regard to the care and treatment provided to children.

Tetrasomy 8 in a patient with acute nonlymphocytic leukemia: a metaphase and interphase study with fluorescence in situ hybridization.

Tetrasomy 8 constitutes a relatively rare recurring chromosome defect in myeloid disorders. The patient reported here, a 71-year-old man, presented with tetrasomy 8 as the sole chromosome abnormality associated with an acute nonlymphocytic leukemia of the M2 type. He failed to respond to chemotherapy and died one year after diagnosis. Following conventional cytogenetics and fluorescence in situ hybridization (FISH) with a centromeric probe specific for chromosome 8, tetrasomy 8 was detected in 61% of the metaphases analyzed and trisomy 8 in 39%. FISH analysis of interphase nuclei confirmed the existence of tetrasomic (35%) and trisomic cells (56%) and revealed a number of cells with two chromosomes 8 (8%). This normal population may represent lymphocytes or myeloid cells that escaped conventional analysis due to their inability to divide or to the small number of metaphases available. The relatively higher proportion of tetrasomic cells in metaphase compared with interphase may be attributed to a proliferative advantage of tetrasomic cells in vitro or to the longer duration of their cell cycle. The simultaneous presence of trisomic and tetrasomic cells confirms the hypothesis of a clonal relationship between trisomy 8 and tetrasomy 8. Our case brings further evidence to the specificity of tetrasomy 8 to myeloid disorders and to the association of this chromosome abnormality with a relatively poor prognosis. However, new patients must be studied to further delineate this cytogenetic entity.