Polynomial deformations of the Heisenberg algebra are studied in detail. Natural realizations of them are given by the higher order susy partners of the harmonic oscillator for even order polynomials. Here, it is shown that the susy partners of the radial oscillator play a similar role when the order of the polynomial is odd. Indeed, it will be proved that the general systems ruled by such a kind of algebras, in the quadratic and cubic cases, involve Painlevé transcendents of type IV and V, respectively.

BACKGROUND: Laboratory studies suggest applying positive pressure without endotracheal suction during cuff deflation and extubation. Although some studies reported better physiological outcomes (e.g. arterial blood gases) with this technique, the safety of positive pressure extubation technique has not been well studied. The aim of this study was to determine the safety of the positive-pressure extubation technique compared with the traditional extubation technique in terms of incidence of complications. METHODS: Adult subjects who were critically ill and on invasive mechanical ventilation who met extubation criteria were included. The subjects were randomly assigned to positive-pressure extubation (n ‫؍‬ 120) or to traditional extubation (n ‫؍‬ 120). Sequential tests for noninferiority and, when appropriate, for superiority were performed. Positive pressure was considered noninferior if the upper limit of the CI for the absolute risk difference did not exceed a threshold of 15% in favor of the traditional group, both in per protocol and intentionto-treat analyses. A P value of <.05 was considered significant. RESULTS: A total of 236 subjects were included in the primary analysis (per protocol) (119 in the positive-pressure group and 117 in the traditional group). The incidence of overall major and minor complications, pneumonia, extubation failure, and reintubation was lower in the positive-pressure group than in the traditional group, with statistical significance for noninferiority both in the per protocol (P < .001) and intention-to-treat (P < .001) analyses. The lower incidence of major complications found in the positive-pressure group reached statistical significance for the superiority comparison, both in per protocol (P ‫؍‬ .03) and intention-to-treat (P ‫؍‬ .049) analyses. No statistically significant differences were found in the superiority comparison for overall complications, minor complications, pneumonia, extubation failure, and reintubation. CONCLUSIONS: Positive pressure was safe and noninferior to traditional extubation methods. Furthermore, positive pressure has shown to be superior in terms of a lower incidence of major complications. (ClinicalTrials.gov registration NCT03174509.

La ventilación mecánica invasiva (VMI) es una terapia de soporte vital que no está exenta de complicaciones, como la disfunción diafragmática inducida por la ventilación mecánica, que se caracteriza por atrofia y debilidad de dicho musculo. El interés en esta patología parece estar basado en la asociación encontrada con resultados clínicos negativos. La prevalencia oscila entre 29 y 80%, probablemente debido a la variabilidad entre los diferentes métodos diagnósticos y el momento de la evaluación. El patrón de oro continúa siendo la presión negativa transdiafragmática generada por la estimulación bilateral de los nervios frénicos, aunque por la falta de practicidad, se comenzó a utilizar la ecografía diafragmática. Si bien cuenta con varias modalidades, no todas tienen análisis de correlación con el patrón de oro. Otra problemática surge al momento de analizar la asociación independiente entre la patología y la VMI, ya que los factores confusores no son sencillos de aislar.

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Background: Cardiac surgery with extracorporeal circulation (ECC) requires the administration of anticoagulant drugs to maintain ACT ranges 400–600 seconds, which requires exhaustive coagulation monitoring for which various point-of-care devices are available. However, there is variability between them, so we aimed to compare the values in ACT measurement. Methods: Simultaneous ACT measurements were performed with the Hemochron Response®, Hemostasis Management System Plus® (HMS Plus®) and Hemochron Signature® systems. Results: A total of 255 simultaneous measurements were taken, the mean and standard deviation (SD) of each device were: Hemochron Signature® 361.1 seconds (SD: 156.9), HMS Plus® 412.8 seconds (SD: 180.9) and Hemochron Response® 422.8 seconds (SD: 187.9), being these differences statistically significant (Fridman’s test p < 0.01). For comparisons the Bland–Altman method was used, resulting the Hemochron Response® has 61.7 seconds higher mean values than the Hemochron Signature®, the Hemochron Response® 10 seconds higher than the HMS Plus® and the HMS Plus® 51.7 seconds higher than the Hemochron Signature®. Conclusion: The differences found in comparisons are considered to be clinically relevant, which is why it is considered important to make the variability of the different monitoring systems known and to take them into account for optimal control of this parameter and its clinical repercussions.