Current status of nuclear cardiology practice in Latin America and the Caribbean, in the era of multimodality cardiac imaging approach: 2022 update.

Cardiovascular diseases (CVDs) are the leading cause of mortality in Latin America and the Caribbean (LAC), with the risk in men being slightly higher than in women. The coronavirus disease 2019 (COVID-19) pandemic caused a significant reduction in the number of cardiac diagnostic procedures globally and in particular in LAC. Nuclear cardiology is available in the region, but there is variability in terms of existing technology, radiopharmaceuticals, and human resources. In the region, there are 2385 single photon emission computed tomography (SPECT) and 315 PET scanners, Argentina and Brazil have the largest number. There is an increasing number of new technologies such as cadmium-zinc-telluride (CZT) cardiac-dedicated gamma cameras, SPECT/computed tomography (CT), and PET/CT. All countries performed myocardial perfusion imaging studies, mainly gated-SPECT; the rest are multi-gated acquisition, mainly for cardiac toxicity; detection of viability; rest gated SPECT in patients with dilated cardiomyopathy, and bone-avid tracer cardiac scintigraphy for transthyretin cardiac amyloidosis diagnosis. Regarding other non-nuclear cardiac imaging modalities, Argentina, Colombia, and Chile have the highest ratio of CT scanners, while Brazil, Argentina, and Chile show the highest ratio of MRI scanners. The development of nuclear cardiology and other advanced imaging modalities is challenged by the high cost of equipment, lack of equipment maintenance and service, insufficient-specific training both for imaging specialists and referring clinicians, and lack of awareness of cardiologists or other referring physicians on the clinical applications of nuclear cardiology. Another important aspect to consider is the necessity of implementing cardiac imaging multimodality training. A joint work of nuclear medicine specialists, radiologists, cardiologists, and clinicians, in general, is mandatory to achieve this goal. National, regional, and international cooperation including support from scientific professional societies such as the American Society of Nuclear Cardiology and Latin American Association of Biology and Nuclear Medicine Societies, cardiological societies, and organizations such as the International Atomic Energy Agency, and Pan American Health Organization, as well as government commitment are key factors in the overall efforts to tackle the burden of cardiovascular diseases in the region.

[Comparative study of the effect of two analgesic techniques in postoperative pain control in pediatric surgery]. / Estudio comparativo de dos técnicas analgésicas en el postoperatorio de Cirugía Pediátrica.

OBJECTIVE: The study purpose was to evaluate the analgesic efficacy of the association of paracetamol + metamizol versus tramadol in pediatric surgery. METHODS: A prospective, randomized and double-blinded study of 60 patients between 3 and 8 years, undergoing abdominal surgery in the ambulatory unit. Patients were divided into 2 groups who received paracetamol plus metamizol (Group I) or tramadol (Group II), prior to the end of the procedure. The anesthetic technique in all cases consisted of general anesthesia balanced. The study compared the pain intensity according to the Wong-Baker scale, the need of rescue analgesia, and the side effects every hour in the postoperative period. The statistical analysis was performed using the chi-square test and T-Student test. RESULTS: The analgesia time for Group I was 202 ± 25 minutes and 215 ± 17 minutes for Group II without statistical significance. There was no significant differences (p= 0.233) in the pain scores; only 3 children in the first group had more than 4 points on the Wong-Baker scale versus 5 children in the tramadol group. The overall side effects were significantly higher (p< 0.05) in Group II, 5 patients presented vomiting compared to no child in Group I. The average dose of morphine chloride was 0.6 ± 0.2 mg. CONCLUSIONS: Both techniques provide adequate pain control in the postoperative period of abdominal ambulatory surgery in pediatric patients. However, children treated with tramadol presented a greater number of side effects compared to the NSAIDs group.

OBJETIVO: Evaluar la eficacia analgésica de la asociación paracetamol + metamizol frente a tramadol en Cirugía Pediátrica. MATERIAL Y METODOS: Se realiza un estudio prospectivo, randomizado y a doble ciego, se seleccionaron 60 pacientes de entre 3 y 8 años programados para cirugía abdominal ambulatoria, divididos en 2 grupos, al grupo I se les administró paracetamol y metamizol intravenosos y al grupo II tramadol intravenoso, previos a la finalización de la intervención. La técnica anestésica consistió en anestesia general balanceada. Se valoró en el periodo postoperatorio la intensidad del dolor según la escala de Wong-Baker, la necesidad de analgesia de rescate y los efectos indeseables. El análisis estadístico se realizó mediante el test de Chi-cuadrado y la t-Student. RESULTADOS: El tiempo de analgesia para el grupo I fue de 202 ± 25 minutos y para el grupo II 215 ± 17 minutos sin significación estadística. Solo 3 niños en el grupo I presentaron valores superiores a 4 en la escala de Wong-Baker y 5 en el grupo II sin diferencias significativas (p= 0,233). En el grupo II presentaron vómitos 5 pacientes frente a ningún niño en el grupo I con diferencias estadísticamente significativas (p< 0,05). La dosis media de cloruro mórfico fue de 0,6 ± 0,2 mg. CONCLUSIONES: Ambas técnicas proporcionan una analgesia adecuada en el postoperatorio de la cirugía abdominal ambulatoria. Destaca un mayor número de efectos secundarios en el grupo del tramadol frente al grupo de los AINEs.

[Adherence to the treatment of pre surgical nasoalveolar molding in cleft lip and palate]. / Adherencia al tratamiento de moldeado nasoalveolar en pacientes con fisura labiopalatina.

OBJECTIVES: The nasoalveolar molding device (NAM) designed to decrease the size of the defect and improve nasal asymmetry, facilitates surgical intervention improving the results. However, family involvement is highly necessary due to the fact that the treatment herein referred is long and tedious. The aim of this study is to determine adherence to treatment and possible variables that can determine their rejection. MATERIALS AND METHODS: Patients treated with NAM over the last 6 years (64 patients). Retrospective data collection and telephone surveys. 5 groups established depending on its respective adherence to the treatment (from rejection of the treatment to good adherence to it). Several aspects are herein analyzed related to the caregiver, the patient and the social background (degree of education, number of caregivers, distance to the hospital, etc.). Through the SPSS program, a descriptive study was carried out, analyzing the variables using chi2 with Fisher's exact correction. RESULTS: 46 surveys were completed (32 boys and 14 girls), 63% were unilateral, 91% had a cleft palate. Adherence to the treatment was good by 80%, and only 6% rejected the treatment. The adherence was significantly higher, if they had contacted with other families of patients (P < 0.01) and a higher tendency of abandonment of treatment in other nationalities than the Spanish one, although without significant differences. CONCLUSIONS: Adherence to treatment is very good in general, and we can not significantly determine the variables that can condition the rejection of treatment, but contacting with family members of patients or associations of patients makes the adherence greater.

OBJETIVOS: El dispositivo de moldeamiento nasoalveolar (NAM), diseñado para aproximar los segmentos fisurados y mejorar la asimetría nasal, facilita la intervención quirúrgica mejorando los resultados. Sin embargo, necesita gran colaboración por parte de la familia por ser largo, y a veces, tedioso. El objetivo de este trabajo es determinar la adherencia al tratamiento y las posibles variables que puedan determinar su rechazo. MATERIAL Y METODOS: Pacientes tratados con NAM en los últimos 6 años (64 pacientes). Recogida de datos retrospectiva (historias) y encuesta telefónica. Clasificación en 5 grupos según el seguimiento del tratamiento (rechazo del tratamiento hasta un cumplimiento correcto del tratamiento). Analizamos factores relacionados con el cuidador, el paciente y el contexto social (nivel de estudios, número de cuidadores, distancia al hospital, etc.). Mediante el programa SPSS se realizó un estudio descriptivo, analizando las variables mediante chi2 con corrección exacta de Fisher. RESULTADOS: Se completaron las 46 encuestas (32 niños y 14 niñas), el 63% fueron unilaterales, el 91% con fisura palatina. El cumplimiento terapéutico fue bueno en el 80%, y solo el 7% rechazaron el tratamiento. La adherencia fue mayor, de forma significativa, si habían contactado con otras familias de pacientes (P< 0,01) y tendencia a mayor abandono en otras nacionalidades distinta a la española, aunque sin significación estadística. CONCLUSIONES: El cumplimiento terapéutico de estos pacientes es bueno de forma general, y no podemos determinar de forma significativa las variables que pueden condicionar el rechazo al tratamiento, pero si, que el contacto con familiares de afectados o asociaciones de pacientes hacen que la adherencia sea mayor.

Gastric ischemia due to critical stenosis of the celiac trunk.

Gastric ischemia (GI) results from diffuse or localized vascular insufficiency caused by different aetiologies such as systemic hypotension, vasculitis, disseminated thromboembolism and celiac or mesenteric stenosis. We present a case of gastric ischemia due to critical stenosis of the celiac artery treated using endovascular therapy. The celiac artery is the first major branch of the abdominal aorta and provides some of the blood supply to the stomach through the left gastric artery and other organs like the spleen (splenic artery branch) and the liver. Although the collateral blood supply to the stomach is protective, systemic hypotension or occlusion of the main arteries, as in the case of our patient, may result in gastric ischemia. The stent placement is an alternative to surgery in patients with high comorbidity and with good outcomes. The clinical awareness of this syndrome will allow gastroenterologists and radiologists to appropriately diagnose and manage affected patients.

Phenotype and natural history of elderly onset inflammatory bowel disease: a multicentre, case-control study.

BACKGROUND: Onset during old age has been reported in upto 10% of total cases of inflammatory bowel disease (IBD). AIM: To evaluate phenotypic characteristics and the use of therapeutic resources in patients with elderly onset IBD. METHODS: Case-control study including all those patients diagnosed with IBD over the age of 60 years since 2000 who were followed-up for >12 months, identified from the IBD databases. Elderly onset cases were compared with IBD patients aged 18 to 40 years at diagnosis, matched by year of diagnosis, gender and type of IBD (adult-onset). RESULTS: One thousand three hundred and seventy-four elderly onset and 1374 adult-onset cases were included (62% ulcerative colitis (UC), 38% Crohn's disease (CD)). Among UC patients, elderly onset cases had a lower proportion of extensive disease (33% vs 39%; P < 0.0001). In CD, elderly onset cases showed an increased rate of stenosing pattern (24% vs 13%; P < 0.0001) and exclusive colonic location (28% vs 16%; P < 0.0001), whereas penetrating pattern (12% vs 19%; P < 0.0001) was significantly less frequent. Regarding the use of therapeutic resources, there was a significantly lower use of corticosteroids (P < 0.0001), immunosuppressants (P < 0.0001) and anti-TNFs agents (P < 0.0001) in elderly onset cases. Regarding surgery, we found a significantly higher surgery rate among elderly onset UC cases (8.3% vs 5.1%; P < 0.009). Finally, elderly onset cases were characterised by a higher rate of hospitalisations (66% vs 49%; P < 0.0001) and neoplasms (14% vs 0.5%; P < 0.0001). CONCLUSIONS: Elderly onset IBD shows specific characteristics and they are managed differently, with a lower use of immunosuppressants and a higher rate of surgery in UC.

Evidence-based guides in tracheostomy use in critical patients

Objetivos: Proporcionar guías de traqueostomía para el paciente crítico, basadas en la evidencia científica disponible, y facilitar la identificación de áreas en las cuales se requieren mayores estudios. Métodos: Un grupo de trabajo formado con representantes de 10 países pertenecientes a la Federación Panamericana e Ibérica de Sociedades de Medicina Crítica y Terapia Intensiva y a la Latin American Critical Care Trial Investigators Network(LACCTIN) desarrollaron estas recomendaciones basadas en el sistema Grading of Recommendations Assessment, Development and Evaluation (GRADE). Resultados: El grupo identificó 23 preguntas relevantes entre las 87 preguntas planteadas inicialmente. En la búsqueda inicial de la literatura se identificaron 333 estudios, de los cuales se escogieron un total de 226. El equipo de trabajo generó un total de 19 recomendaciones: 10 positivas (1B = 3, 2C = 3, 2D = 4) y 9 negativas (1B = 8, 2C = 1). En 6 ocasiones no se pudieron establecer recomendaciones. Conclusión: La traqueostomía percutánea se asocia a menor riesgo de infecciones en comparación con la traqueostomía quirúrgica. La traqueostomía precoz solo parece reducir la duración de la ventilación mecánica pero no la incidencia de neumonía, la duración de la estancia hospitalaria o la mortalidad a largo plazo. La evidencia no apoya el uso de broncoscopia de forma rutinaria ni el uso de máscara laríngea durante el procedimiento. Finalmente, el entrenamiento adecuado previo es tanto o más importante que la técnica utilizada para disminuir las complicaciones.(AU)

OBJECTIVES: Provide evidence based guidelines for tracheostomy in critically ill adult patients and identify areas needing further research. METHODS: A task force composed of representatives of 10 member countries of the Pan-American and Iberic Federation of Societies of Critical and Intensive Therapy Medicine and of the Latin American Critical Care Trial Investigators Network developed recommendations based on the Grading of Recommendations Assessment, Development and Evaluation system. RESULTS: The group identified 23 relevant questions among 87 issues that were initially identified. In the initial search, 333 relevant publications were identified of which 226 publications were chosen. The task force generated a total of 19 recommendations: 10 positive (1B=3, 2C=3, 2D=4) and 9 negative (1B=8, 2C=1). A recommendation was not possible in six questions. CONCLUSION: Percutaneous techniques are associated with a lower risk of infections compared to surgical tracheostomy. Early tracheostomy only seems to reduce the duration of ventilator use but not the incidence of pneumonia, the length of stay, or the long-term mortality rate. The evidence does not support the use of routine bronchoscopy guidance or laryngeal masks during the procedure. Finally, proper prior training is as important or even a more significant factor in reducing complications than the technique used.(AU)

Evidence-based guides in tracheostomy use in critical patients. / Guías basadas en la evidencia para el uso de traqueostomía en el paciente crítico.

OBJECTIVES: Provide evidence based guidelines for tracheostomy in critically ill adult patients and identify areas needing further research. METHODS: A task force composed of representatives of 10 member countries of the Pan-American and Iberic Federation of Societies of Critical and Intensive Therapy Medicine and of the Latin American Critical Care Trial Investigators Network developed recommendations based on the Grading of Recommendations Assessment, Development and Evaluation system. RESULTS: The group identified 23 relevant questions among 87 issues that were initially identified. In the initial search, 333 relevant publications were identified of which 226 publications were chosen. The task force generated a total of 19 recommendations: 10 positive (1B=3, 2C=3, 2D=4) and 9 negative (1B=8, 2C=1). A recommendation was not possible in six questions. CONCLUSION: Percutaneous techniques are associated with a lower risk of infections compared to surgical tracheostomy. Early tracheostomy only seems to reduce the duration of ventilator use but not the incidence of pneumonia, the length of stay, or the long-term mortality rate. The evidence does not support the use of routine bronchoscopy guidance or laryngeal masks during the procedure. Finally, proper prior training is as important or even a more significant factor in reducing complications than the technique used.

Evolution After Anti-TNF Discontinuation in Patients With Inflammatory Bowel Disease: A Multicenter Long-Term Follow-Up Study.

OBJECTIVES: The aims of this study were to assess the risk of relapse after discontinuation of anti-tumor necrosis factor (anti-TNF) drugs in patients with inflammatory bowel disease (IBD), to identify the factors associated with relapse, and to evaluate the overcome after retreatment with the same anti-TNF in those who relapsed. METHODS: This was a retrospective, observational, multicenter study. IBD patients who had been treated with anti-TNFs and in whom these drugs were discontinued after clinical remission was achieved were included. RESULTS: A total of 1,055 patients were included. The incidence rate of relapse was 19% and 17% per patient-year in Crohn's disease and ulcerative colitis patients, respectively. In both Crohn's disease and ulcerative colitis patients in deep remission, the incidence rate of relapse was 19% per patient-year. The treatment with adalimumab vs. infliximab (hazard ratio (HR)=1.29; 95% confidence interval (CI)=1.01-1.66), elective discontinuation of anti-TNFs (HR=1.90; 95% CI=1.07-3.37) or discontinuation because of adverse events (HR=2.33; 95% CI=1.27-2.02) vs. a top-down strategy, colonic localization (HR=1.51; 95% CI=1.13-2.02) vs. ileal, and stricturing behavior (HR=1.5; 95% CI=1.09-2.05) vs. inflammatory were associated with a higher risk of relapse in Crohn's disease patients, whereas treatment with immunomodulators after discontinuation (HR=0.67; 95% CI=0.51-0.87) and age (HR=0.98; 95% CI=0.97-0.99) were protective factors. None of the factors were predictive in ulcerative colitis patients. Retreatment of relapse with the same anti-TNF was effective (80% responded) and safe. CONCLUSIONS: The incidence rate of inflammatory bowel disease relapse after anti-TNF discontinuation is relevant. Some predictive factors of relapse after anti-TNF withdrawal have been identified. Retreatment with the same anti-TNF drug was effective and safe.

[Hepatocellular carcinoma in Navarre: study of characteristics and evolution in clinical practice]. / El hepatocarcinoma en la Comunidad Foral de Navarra: estudio de características y evolución en la práctica clínica habitual.

BACKGROUND: Hepatocellular carcinoma generally arises in a cirrhotic liver. The aim of screening is to improve survival. The aims of our study are to determine the characteristics and evolution of hepatocellular carcinoma and the effect of screening on survival, in clinical practice in Navarre. METHODS: Prospective and retrospective study of 111 patients diagnosed with hepatocellular carcinoma in public hospitals in Navarre between January 2009 and January 2015. Epidemiological, clinical, analytical, radiological characteristics, tumour staging, treatment and evolution were analyzed. Survival was compared between patients subjected to screening and those not. RESULTS: Mean age was 67 years. The patients (84.7%) were mainly male and 85.6% had cirrhosis. The most frequent aetiology was alcohol consumption (40.7%). 62.2% were diagnosed in early stages, 15.3% in intermediate and 22.5 % in advanced or terminal stages. 4.5% received transplants, 21.6% received surgical resection, 23.4% were treated with abla-tion techniques, 10.8 % with chemoembolization, 5.4% with radiembolization, 2.7% with embolization, 13.5 % with sorafenib and 18% symptomatically. Only 32 patients (28.8%) were subjected to screening. No statistical differences were found in survival depending on surveillance (32 month versus 34; p = 0.971). CONCLUSIONS: In Navarre, hepatocellular carcinoma generally appears against a background of cirrhosis, and alcohol is the most frequent aetiology. Hepatocellular carcinoma is diagnosed most frequently in early stages and out of screening practi-ces. Screening was not associated to better survival.

Rational application of adenosine deaminase activity in cerebrospinal fluid for the diagnosis of tuberculous meningitis.

PURPOSE: Tuberculous meningitis (TBM) is one of the most serious and difficult to diagnose manifestations of TB. An ADA value >9.5 IU/L has great sensitivity and specificity. However, all available studies have been conducted in areas of high endemicity, so we sought to determine the accuracy of ADA in a low endemicity area. METHODS: This retrospective study included 190 patients (105 men) who had ADA tested in CSF for some reason. Patients were classified as probable/certain TBM or non-TBM based on clinical and Thwaite's criteria. Optimal ADA cutoff was established by ROC curves and a predictive algorithm based on ADA and other CSF biochemical parameters was generated. RESULTS: Eleven patients were classified as probable/certain TBM. In a low endemicity area, the best ADA cutoff was 11.5 IU/L with 91 % sensitivity and 77.7 % specificity. We also developed a predictive algorithm based on the combination of ADA (>11.5 IU/L), glucose (<65 mg/dL) and leukocytes (≥13.5 cell/mm(3)) with increased accuracy (Se: 91 % Sp: 88 %). CONCLUSIONS: Optimal ADA cutoff value in areas of low TB endemicity is higher than previously reported. Our algorithm is more accurate than ADA activity alone with better sensitivity and specificity than previously reported algorithms.

Behavior of ambient concentrations of natural radionuclides (7)Be, (210)Pb, (40)K in the Mediterranean coastal city of Málaga (Spain).

During a 4-year period (January 2009-December 2012), the (7)Be, (210)Pb, and (40)K activity concentrations in airborne particulate matter were weekly determined at the Málaga (Spain) located in the southern Iberian Peninsula. Totally 209 polypropylene filters were analyzed in the mentioned period. In 100% of the filters, (7)Be and (40)K activity concentrations were detected while (210)Pb activity concentration was detected in 96% of the filters. The results from individual measurements of (7)Be, (210)Pb, and (40)K concentrations were analyzed to derive the statistical estimates characterizing the distributions. Principal components analysis (PCA) was applied to the datasets and the results of the study reveal that aerosol behavior is represented by two principal components which explain 73.2% of total variance. Components PC1 and PC2 respectively explain 46.0 and 27.2% of total variance. PC1 was related positively to dust content, (7)Be and (40)K concentrations and negatively to sunspot numbers. In contrast, PC2 was related positively to temperature and (210)Pb activity and negatively to precipitation and relative humidity. The (7)Be levels showed a significant correlation with sunspot numbers due to the cosmogenic origin. (40)K activities showed a good correlation with dust deposition in filters mainly because it was transported to the air as resuspended particle from the soil. An inverse relationship was observed between the (210)Pb concentrations and monthly rainfall, indicating washout of atmospheric aerosols carrying these radionuclides and a pronounced positive correlation with the average monthly temperature of air.

Posttraumatic pericardial cyst.

Pericardial cysts are uncommon lesions usually found incidentally upon the radiologic investigation of some other condition. The aetiology can be both congenital and acquired (post inflammatory processes, infection or even posttraumatic). They are the most common benign tumour of the pericardium but there is still a difficulty in the differential diagnosis because even clinical or analytically are not different from some other benign or malignant lesions. Further image studies are required to complete the study of these lesions. Even the majority are asymptomatic (>50%), the localization and relation to adjacent structures lead the role of the clinical manifestations (persistent cough, dyspnoea, chest pain...). We present the case of a man with oppressive chest pain after 2 weeks of thoracic traumatism with an abnormal radiological image in the chest X-ray.

Safety of thiopurines and anti-TNF-α drugs during pregnancy in patients with inflammatory bowel disease.

OBJECTIVES: The safety of thiopurines and anti-tumor necrosis factor-α (TNF-α) drugs during pregnancy remains controversial, as the experience with these drugs in this situation is limited. Our aim is to assess the safety of thiopurines and anti-TNF-α drugs for the treatment of inflammatory bowel disease (IBD) during pregnancy. METHODS: Retrospective, multicenter study in IBD patients. Pregnancies were classified according to the therapeutic regimens during pregnancy or during the 3 months before the conception: non-exposed group, pregnancies exposed to thiopurines alone (group A), and pregnancies exposed to anti-TNF-α drugs (group B). An unfavorable Global Pregnancy Outcome (GPO) was considered if pregnancy developed with obstetric complications in the mother and in the newborn. RESULTS: A total of 187 pregnancies in the group A, 66 pregnancies in the group B, and 318 pregnancies in the non-exposed group were included. The rate of unfavorable GPO was different among the three groups (31.8% in non-exposed group, 21.9% in group A, and 34.8% in group B), being lower in pregnancies under thiopurines than among non-exposed (P = 0.01). The rate of pregnancy complications was similar among the three groups (27.7% in non-exposed, 20.9% in group A, and 30.3% in group B). The rate of neonatal complications was different among the three groups (23.3% in non-exposed group, 13.9% in group A, and 21.2% in group B), being lower in pregnancies under thiopurines than among non-exposed (P = 0.01). In the multivariate analysis, the treatment with thiopurines (odds ratio = 0.6; 95% confidence interval = 0.4-0.9, P = 0.02) was the only predictor of favorable GPO, whereas maternal age >35 years at conception was the only predictor of unfavorable GPO. The treatment with anti-TNF-α drugs was not associated with an unfavorable GPO. CONCLUSION: The treatment with thiopurines and anti-TNF-α drugs does not seem to increase the risk of complications during pregnancy and does seem to be safe for the newborn.

Ventilación asistida por presión vs. ventilación mandatoria intermitente sincronizada: efectos hemodinámicos en pacientes críticos / Pressure support ventilation vs. synchronized intermittent mandatory ventilation hemodynamic effects on critically ill patients

Introducción: en los últimos años han aparecido varias publicaciones acerca de los efectos hemodinámicos de la ventilación asistida por presión (VAP). Ningún estudio ha comparado los efectos fisiológicos de la VAP con los de la ventilación mandatoria intermitente sincronizada (VMIS) en el mismo paciente. Objetivo: establecer si existe diferencia en los efectos hemodinámicos de la VAP y de la VMIS en cuidado intensivo. Diseño: experimento clínico cruzado (aleatorizado-controlado). Pacientes y métodos: de junio de 1993 a mayo de 1995, 31 pacientes ingresaron al estudio. Fueron sometidos a ventilación mecánica por ventilación asistida (VAC) o VMIS de manera no premeditada, durante la fase de estabilización. Antes del destete del ventilador, aleatoriamente, se asignaron a VAP o VMIS por 2 horas, tomándose medidas hemodinámicas. Luego permanecieron en VAC 1 hora y seguidamente se sometieron por 2 horas al método contrario al usado en las primeras 2. Se mantuvo VC de 10 cc/kg, FIO2 de 40% y PEEP de 4. Las variables estudiadas fueron frecuencia cardíaca, frecuencia respiratoria, tensión arterial, diuresis, presión ven osa central, presión capilar pulmonar, índice cardíaco, aporte de O2, consumo de oxígeno, resistencias vasculares sistémicas y pulmonares, SaO2, SvO2 y distensibilidad. Los resultados obtenidos son presentados en 2 subgrupos según la enfermedad: Grupo 1: respuesta inflamatoria sistémica (SDRIS) y Grupo 11: falla cardíaca severa. El análisis estadístico fue hecho con promedios, desviación estándar y prueba T de student. Resultados: no hubo diferencias significativas entre los 31 pacientes. Tampoco al dividirlos en SDRIS y falla cardíaca, salvo que estos últimos pacientes tuvieron mejor índice cardíaco con VAP que con VMIS. Ventilatoriamente fue evidente una mejor distensibilidad en todos los grupos con VAP. Conclusión: la VAP puede considerarse como método de elección para pacientes con falla cardíaca severa que requieran ventilación mecánica.

The role of cellular plasticity in cancer development.

It has traditionally been accepted that, in the process of cellular differentiation, developmental options are progressively restricted until commitment to a specific fate is established and then only terminal differentiation along this lineage is possible. Although this is usually the case in normal physiological development, the latest experimental evidences indicate that the differentiated state of mature cells is not always as stable and durable as it was thought to be. In fact, recently, a hidden plasticity has been revealed in differentiated cells which allows them to deviate to other cell types that might be, functionally, very far away in other developmental pathways. This plasticity has biological significance since it is necessary for normal development to occur, but it also makes possible the emergence of aberrant lineages when interferences with the normal transcriptional and epigenetic mechanisms in charge of maintaining cellular identity do appear. Cancer is one of the possible outcomes of this aberrant reprogramming. The plasticity of the initial cell suffering the first oncogenic alteration plays an essential role in cancer development, since only if this cell possesses enough plasticity a tumoral reprogramming will be possible and a full-blown tumor will develop. Also, plasticity makes it possible for differentiated cells to acquire cancer stem cell properties in the presence of the appropriate oncogenic insults. In this review we discuss the role of cellular plasticity in the normal development of adult tissues and how cellular susceptibility to reprogramming plays an essential part in cancer development.

[Viability of colonoscopy without analgesia and conscious sedation]. / Viabilidad de la colonoscopia sin analgesia y sedación consciente.

AIM: To study the need for analgesia and sedation before colonoscopy. PATIENTS AND STUDY DESIGN: Fifty consecutive outpatients were randomly assigned to receive meperidine (0.7 mg/kg) or midazolam (0-035 mg/kg) intravenously (n = 25) or to receive no medication (n = 25) before colonoscopy. Oxygen saturation (SaO2) and heart rate were monitored. Mean blood pressure (MBP) was recorded before and after endoscopy. Patients in the group receiving no medication who experienced marked abdominal pain received sedation and analgesia similar to the premedicated group. Twenty-four hours after the procedure, the patients evaluated the degree of abdominal pain experienced during colonoscopy on a scale from 0 to 9. RESULTS: Complete colonoscopy was performed in 92% of the patients. No significant changes in heart rate were registered in either group. However, in the premedicated group mean blood pressure fell significantly (97.6 +/- 2.6 vs. 89.5 +/- 2.7 mmHg) before and after colonoscopy, respectively (p < 0.05). Nine patients experienced clinically relevant oxygen desaturation (SaO2 > 90%). Of these, five were from the premedicated group and four were from the group receiving no medication. In two patients, both from the premedicated group, the decrease in SaO2 was severe (SaO2 < 85%). The degree of abdominal pain was similar in both groups: 3.64_0.47 (premedicated) vs. 3.92 +/- 0.5 (non-medicated). In the non-medicated group, two patients required analgesia and sedation to complete the colonoscopy and 20 (80%) preferred not to receive sedation in future colonoscopies. CONCLUSIONS: Colonoscopy may be well tolerated without systematic administration of sedation and analgesia, which could be administered selectively.

Idiopathic portal hypertension and angiosarcoma associated with arsenical salts therapy.

We describe a 60-year-old man with idiopathic portal hypertension and hepatic angiosarcoma. The patient had taken an arsenical preparation for the treatment of psoriasis for 10 years. Five cases of this association have been reported previously; in one only, exposure to arsenical salts was present.

[Chylous ascites in cirrhotic and non-cirrhotic patients]. / Ascitis quilosa en pacientes cirróticos y no cirróticos.

Chylous ascites is an accumulation of lymph in the abdominal cavity. The diagnosis is established when the concentration of triglycerides in plasma is greater than in ascitic fluid over a level of 200 mg/dl. The clinical and biochemical characteristics of 22 patients with chylous ascites (11 cirrhotics and 11 non cirrhotics) were studied in order to assess differences between patients with and without hepatic cirrhosis. The cirrhotic patients with chylous ascites showed lower protein (1.3 +/- 0.74 mg/dl, p = 0.002) and cholesterol concentration (46.0 +/- 45.2 mg/dl, p = 0.02) in ascitic fluid than non cirrhotic patients (3.1 +/- 1.09 mg/dl, and 100.85 +/- 41.7 mg/dl, respectively). In addition, the cellularity in the ascitic fluid was also lower in cirrhotic patients (209.09 +/- 113.96 cel/mm3) versus (831.8 +/- 945.08 cel/mm3; p < 0.05). Four patients (18.18%) presented high adenosine deaminase levels (ADA) in the ascitic fluid in the absence of tuberculous peritonitis. The authors conclude that the biochemical differences observed in the ascitic fluid of the cirrhotic patients with chylous ascites may be explained by a dilutional mechanism due to the combination of "clear" ascites secondary to portal hypertension and chylous ascites. Furthermore, chylous ascites could be the cause of an elevation in ADA in the absence of tuberculous peritonitis.

Value of endothelin in cellular rejection after liver transplantation.

Endothelin-1 is a vasoconstrictor peptide released by the vascular endothelium by various chemical and mechanical factors. Cellular rejection is one of the most common complications following orthotopic liver transplantation, endotheliitis being its most specific and consistent histological feature. To assess the role of endothelin in cellular hepatic rejection, we studied 21 cirrhotic patients undergoing elective liver transplantation. These patients were divided in two groups: Group I comprised 10 patients without cellular rejection, and Group II comprised 11 patients with cellular rejection. Endothelin was measured on day 7 after transplantation, on the day of liver biopsy, and after treatment for rejection. We found a significant increase in the plasma endothelin levels in the early postoperative period in the patients with moderate or severe cellular rejection compared with the non-rejection group. It remained significantly elevated until the clinical diagnosis of rejection was made. This value returned to baseline with successful treatment. So, the monitorization of this peptide may be of help in the diagnosis of rejection, its severity, and the evaluation of its resolution.