Significant and safe reduction of propofol sedation dose for geriatric population undergoing pacemaker implantation: randomized clinical trial.

OBJECTIVE: A previous multidisciplinary pilot study based on computer simulations for the geriatric population showed that a dose of 0.5 mg/kg/h of propofol could sedate patients older than 65 for pacemaker implantation. The present study validates that the pacemaker implantation can be done in the elderly using 0.5-1 mg/kg/h of propofol with hemodynamic stability. METHODS: 66 patients from 65 to 88 years old scheduled for pacemaker implantation were randomly assigned one of three doses of propofol. The first group received 2 mg/kg/h of propofol (P2) that is within normal range of the sedation dose. The second group received 1 mg/kg/h (P1) dose and the third group received the dose of 0.5 mg/kg/h (P0.5) according to the simulation-predicted dose for geriatric populations. RESULTS: All patients kept MAP between 76 and 85 mmHg, with no hypotension episodes in any of the groups; therefore, they were all hemodynamically stable during the procedure. BIS was between 80 and 65 during the pacemaker implantation for the three groups, BIS of group P2 was significantly lower than the other groups. BIS in groups P1 and P0.5 was within the appropriated range for moderate sedation. Brice was positive for auditory recalls only when there was arousing noise in the operating room. CONCLUSIONS: Moderate sedation, adequate for pacemaker implantation, can be achieved infusing 0.5-1 mg/kg/h of propofol in elderly patients when the patient has proper analgesia management at the device implantation site. The second important condition is to avoid unnecessary and alerting auditory and mechanical stimuli in the operating room, so that the patient will remain calm.

Surgical Resolution of Patients With Hypertrophy of Papillary Muscles in Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy encompasses a broad spectrum of muscular diseases that involve not only the interventricular septum and the left ventricular outflow tract but also the papillary muscles and the mitral valve apparatus. This article presents the successful surgical treatment of two patients with generalized hypertrophic cardiomyopathy with hypertrophy of the papillary muscles without severe septal hypertrophy: one with a history of unsuccessful chemical ablation and coronary disease following an interventional event, and another young patient without a history of chronic degenerative diseases who developed hypertrophic cardiomyopathy during her third pregnancy. Both patients with left ventricular outflow tract gradients greater than 55 mmHg and those who underwent surgical treatment had a gradient of less than 10 mmHg.

Minimally-Invasive and Efficient Method to Accurately Fit the Bergman Minimal Model to Diabetes Type 2.

Introduction: Diabetes mellitus is a global burden that is expected to grow 25 % by 2030. This will increase the need for prevention, diagnosis and treatment of diabetes. Animal and individualized in silico models will allow understanding and compensation for inter and intra-individual differences in treatment and management strategies for diabetic patients. The method presented here can advance the concept of personalized medicine. Methods: Twenty experiments were performed with Sprague-Dawley rats with streptozotocin induced experimental diabetes in which the insulin-glucose response curve was recorded over 60-100 min using only an insulin pump and a percutaneous glucose sensor. The information was used to fit the five-parameter Bergman Minimal Model to the experimental results using a genetic algorithm with a root-mean-squared optimization rule. Results: The Bergman Minimal Model parameters were estimated with high accuracy, low prediction bias, and low average root-mean-squared error of 15.27 mg/dl glucose. Conclusions: This study demonstrates a simple method to accurately parameterize the Bergman Minimal Model. We used Sprague-Dawley rats since their physiology is close to that of humans. The parameters can be used to objectively characterize the physiological severity of diabetes. In this way, planned treatments can compensate for natural variations of conditions both inter and intra patients. Changes in parameters indicate the patient's diabetic condition using values of glucose effectiveness ( S G = p 1 ) and insulin sensitivity ( S I = p 3 / p 2 ). Quantifying the diabetic patient's condition is consistent with the trend toward personalized medicine. Parameter values can also be used to explain atypical research results of other studies and increase understanding of diabetes.

Accurate diagnosis of sepsis using a neural network: Pilot study using routine clinical variables.

BACKGROUND AND OBJECTIVES: Sepsis is a severe infection that increases mortality risk and is one if the main causes of death in intensive care units. Accurate detection is key to successful interventions, but diagnosis of sepsis is complicated because the initial signs and symptoms are not specific. Biomarkers that have been proposed have low specificity and sensitivity, are expensive, and not available in every hospital. In this study, we propose the use of artificial intelligence in the form of a neural network to diagnose sepsis using only common laboratory tests and vital signs that are routine and widely available. METHODS: A retrospective, cross sectional cohort of 113 patients from an intensive care unit, each with 48 routinely evaluated vital signs and biochemical parameters was used to train, validate and test a neural network with 48 inputs, 10 neurons in a single hidden layer and one output. The sensitivity and specificity of the neural network as a point sampled diagnostic test was calculated. RESULTS: All but one case were correctly diagnosed by the neural network, with 91% sensitivity and 100% specificity in the validation data set, and 100% sensitivity and specificity in the test data set. CONCLUSIONS: The designed neural network system can identify patients with sepsis, with minimal resources using standard laboratory tests widely available in most health care facilities. This should reduce the burden on the medical staff of a difficult diagnosis and should improve outcomes for patients with sepsis.

Unexpected Pregnancy during Treatment of Multidrug-resistant Tuberculosis.

Several drugs used in the treatment of multidrug-resistant tuberculosis (MDR-TB) have been reported as teratogenic. Treatment of such cases during gestation is disputable. Some experts favor the termination of pregnancy, whereas others suggest reducing the dose of teratogenic drugs or even suspending the regimen during pregnancy. There have been no clinical trials on the subject, but case reports and case series show excellent outcomes for children exposed during pregnancy to second-line agents, indicating that aggressive management of gestational MDR-TB may benefit not only the mother but also the fetus. We present a case of pregnancy in a teenager while she was under treatment for MDR-TB and continued with full treatment and nevertheless delivered a healthy child.

Tromboelastografía para cirugía general / Thromboelastography for general surgery

Resumen: Las pruebas convencionales de coagulación evalúan el tiempo en que los factores de coagulación se activan en el plasma sanguíneo, el cual carece de componentes celulares, como enzimas y plaquetas que intervienen en el desarrollo de la hemostasia. La tromboelastografía (TEG) realiza un análisis in vitro de la relación entre plaquetas, enzimas, fibrinógeno y otros elementos de la coagulación de manera integral; por lo que se utiliza con mayor frecuencia en cirugías cardíacas, trasplantes y cirugías de malformaciones arteriovenosas, donde la pérdida sanguínea esperada es mayor a 40% del volumen sanguíneo circulante. La inclusión de la TEG en la valoración preanestésica permite evaluar la actividad plaquetaria en los pacientes que utilizan antiagregantes, como clopidogrel o ácido acetilsalicílico, a través del mapeo plaquetario (Platelet Mapping®). Cuando se presenta hemorragia en el período transanestésico, la TEG permite identificar de manera específica el tipo de tratamiento necesario para mejorar la coagulación o la transfusión de elementos formes de la sangre. La TEG permite realizar protocolos más sofisticados de terapia transfusional, lo que implica una disminución de las complicaciones asociadas con la politransfusión y, por ende, la disminución de costos, por lo que estos beneficios justifican el uso rutinario de la TEG para cualquier cirugía general.

Abstract: Conventional coagulation tests evaluate the time in which the coagulation factors are activated in the blood plasma, which lacks cellular components such as enzymes and platelets that are involved in the development of hemostasis. Thromboelastography (TEG) performs an in vitro analysis of the relationship between platelets, enzymes, fibrinogen, and other coagulation elements in an integral way; reason why it is used more frequently in cardiac surgeries, transplants, and surgeries of arteriovenous malformations, where the expected blood loss is greater than 40% of the circulating blood volume. The inclusion of TEG in the pre-anesthetic evaluation allows evaluating platelet activity in patients who use antiplatelets therapy, such as clopidogrel or acetylsalicylic acid, through platelet mapping (Platelet Mapping®). When bleeding occurs in the trans-anesthetic period, TEG specifically identifies the type of treatment necessary to improve coagulation or transfusion of formed blood elements. The TEG allows more sophisticated transfusion therapy protocols to be carried out, which implies a decrease in complications associated with polytransfusion and a reduction in costs, so these benefits justify the routine use of TEG for any general surgery.

Clinical testing of propofol geriatic dose for sedation designed via in silico trial.

The geriatric population shows significant physiological changes due to aging and the multiple co-morbidities that they often present. Conventionally the propofol sedation dose for patients older than 65 years is 80% of the adult dose. We performed an in silico trial for elderly population and the results showed that the necessary simulated dose of propofol was lower than the conventional dose; therefore, a clinical trial was implemented to test three different propofol doses, two of them lower than the conventional dose, during a pacemaker implantation. The clinical trial showed that there was no clinical difference between the effects of the doses. A BIS monitor was used to measure the level of sedation, which proved to be adequate and well maintained by all patients. All the patients maintained an acceptable level of sedation, measured by a BIS monitor. Since propofol has some dose-dependent secondary effects, the use of lower doses, especially the ones designed for this age group, helps to avoid them.

[Utility of a pneumatic system to transport erythrocyte concentrates: pilot study]. / Utilidad de un sistema neumático para trasladar concentrados eritrocitarios. Estudio piloto.

BACKGROUND: The transport systems of erythrocyte concentrates should be safe and modern. In this paper we analyzed the safety of one pneumatic system to transport erythrocyte concentrates from blood transfusion service to post-surgical therapy service. METHODS: We analyzed 50 erythrocyte concentrates; a sample of 1.5 mL of blood was drawn previously and after delivering the concentrated erythrocyte. The samples were placed in glass tubes to measure temperature, hemoglobin, hematocrit and extracellular potassium concentration. The average and range as univariate analysis and the Mann-Whitney U test as a bivariate analysis were done for statistical analysis. RESULTS: Statistical differences were not observed in the parameters measured. The temperature was not modified by the pneumatic delivery system. The data indicated no significant differences (p > 0.05) pre and post delivered samples in temperature, hemoglobin concentration, hematocrit level or extracellular potassium concentration. The estimated travel time for each sample was 22.88 seconds. CONCLUSIONS: The transport of erythrocyte concentrates through pneumatic delivery system did not change temperature conditions according to the current regulation. Indeed, the data did not show evidence that the cellular suspension underwent a spontaneous cellular lysis by sending erythrocyte concentrates through a pneumatic delivery system.

INTRODUCCIÓN: los sistemas de transporte de componentes eritrocitarios deben ser seguros y modernos. En este trabajo se analiza la seguridad de un sistema neumático como medio de transporte de concentrados eritrocitarios del servicio de transfusiones al servicio de la terapia posquirúrgica. MÉTODOS: se estudiaron las muestras piloto de 50 concentrados eritrocitarios, previa homogeneización del tubo con pinza rotatoria. Se obtuvieron 1.5 mL de la muestra antes de enviar el concentrado eritrocitario por el sistema neumático y 1.5 mL después de su llegada a su destino. Las muestras fueron colocadas en tubos de cristal para su análisis. También se analizaron la concentración de hemoglobina, el nivel de hematócrito y la concentración de potasio extracelular. RESULTADOS: la información obtenida indicó que no hubo diferencias estadísticamente significativas (p > 0.05) al comparar los valores pre o posentrega respecto a la temperatura, la concentración de hemoglobina, el nivel de hematócrito ni la concentración extracelular de potasio. La estimación del tiempo de transporte a través del sistema neumático fue de 22.88 segundos. CONCLUSIONES: el envío de concentrados eritrocitarios mediante el sistema neumático no produjo cambios en las condiciones óptimas de temperatura indicadas en la normatividad vigente. Tampoco existió evidencia de que la suspensión celular enviada sufriera lisis celular espontánea debido al traslado de los componentes sanguíneos.

High-order sliding-mode control for anesthesia.

Depth of anesthesia can be indirectly measured by Bispectral Index (BIS), therefore it is possible to administer propofol in a closed loop to maintain the optimal level of anesthesia while minimizing the dose to improve the postanesthesia recovery. High-Order Sliding-Mode control can be used to individualize drug dosing. In this study, the controller is tested with four in silico patients.

Puerperio de corta estancia hospitalaria / Short hospital stay puerperium

En el Hospital General de la Ciudad de México se realizó un estudio observacional de cohorte, prospectivo, de embarazadas y sus productos, catalogados como de bajo riesgo, divididos en corta estancia, cuya alta hospitalaria fue antes de 12 horas posparto (n 67) y grupo de estancia habitual, es decir, con 24 horas o más de internamiento (n 240). Se revisaron a los diez días del nacimiento con búsqueda intencionada de complicaciones. No hubo diferencias en la presentación de hemorragia uterina anormal, infección urinaria ni endometritis. Se presentó una mayor frecuencia de tromboflebitis en el grupo de corta estancia (13.4 vs 3.75 por ciento), estadística y clínicamente significativa (RR 3.58, IC 95 por ciento 1.48-8.67, P=0.003). Se trata de explicar este hallazgo y la manera de prevenirlo y se concluye que en mujeres embarazadas y productos catalogados como de bajo riesgo es factible el alta hospitalaria antes de las 12 horas posparto sin deterioro en su evolución