Ajuste a la ventilación mecánica guiado por curvas presión-volumen de flujo lento en pacientes con síndrome de distress respiratorio agudo e injuria pulmonar aguda / Mechanical ventilatory parameters guided by the low flow pressure-volume curve in patients with acute lung injury/acute respiratory distress syndrome

Background: Mechanical ventilation may contribute to lung injury and then enhance systemic inflammation. Optimal ventilatory parameters such as tidal volume (V T) and positive end expiratory pressure (PEEP) can be determined using different methods. Low flow pressure volume (P/V-LF) curve is a useful tool to assess the respiratory system mechanics and set ventilatory parameters. Aim: To set V T and PEEP according P/V-LF curve analysis and evaluate its effects on gas exchange and hemodynamic parameters. Materials and methods: Twenty seven patients underwent P/V-LF within the first 72 hours of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). P/V-LF curves were obtained from the ventilator and both lower and upper inflexion points determined. Gas exchange and hemodynamic parameters were measured before and after modifying ventilator settings guided by P/V-LF curves. Results: Ventilatory parameters set according P/V-LF curve, led to a rise of PEEP and reduction of V T: 11.6±2.8 to 14.1±2.1 cm H2O, and 9.7±2.4 to 8.8±2.2 mL/kg (p <0.01). Arterial to inspired oxygen fraction ratio increased from 158.0±66 to 188.5±68.5 (p <0.01), and oxygenation index was reduced, 13.7±8.2 to 12.3±7.2 (p <0.05). Cardiac output and oxygen delivery index (IDO2) were not modified. Demographic data, gas exchange improvement and respiratory system mechanics showed no significant difference between patients with extra-pulmonary and pulmonary ALI/ARDS. There was no evidence of significant adverse events related with this technique. Conclusion: P/V-LF curves information allowed us to adjust ventilatory parameters and optimize gas exchange without detrimental effects on oxygen delivery in mechanically ventilated ALI/ARDS patients.

Tromboembolismo pulmonar: el valor de la clínica / Pulmonary embolism: the importance of clinical evaluation

El tromboembolismo pulmonar constituye un problema clínico frecuente; sus síntomas y signos son inespecíficos y los exámenes habitualmente utilizados para su diagnóstico son a menudo poco sensibles y específicos. La Angiografía Pulmonar es el Gold Standard, no obstante es de escasa disponibilidad en nuestro medio, de alto costo, constituye un método invasivo no exento de complicaciones y de difícil interpretación en algunas oportunidades. La tomografía helicoidal de tórax es una técnica nueva, de mayor accesibilidad, cuyo desarrollo tecnológico ha permitido lograr mejorías en su sensibilidad y especificidad diagnósticas y consecuentemente un cambio en nuestras decisiones terapéuticas. Presentamos el caso de un paciente con trombosis venosa de las extremidades inferiores y un cuadro clínico compatible con alta probabilidad para tromboembolismo pulmonar. Hubo desarrollo de infiltrados pulmonares bilaterales asociados a derrame pleural en ausencia de fiebre y leucocitosis. Se inició terapia anticoagulante con lo cual hubo mejoría clínica del cuadro. Sin embargo, la realización de una tomografía helicoidal de tórax no demostró presencia de émbolos en la vasculatura pulmonar. Es por ello que debemos ser cautos en el momento de tomar decisiones clínicas basadas en un solo test diagnóstico, sin importar cuan eficiente este sea

Prescripción de la vacuna anti influenza por médicos institucionales y estudiantes de especialidades médicas en un hospital docente / Influenza vaccine prescription by faculties and medical fellows in an universitary hospital

A study was designed aimed to know rates of influenza vaccine prescriptions among medical staff personnel and postgraduate medical student in a tertiary care teaching hospital. Data was collected by a questionnaire asking forprevious year prescription, age of patients seen at the outpatient clinic, years of professional experience and other potential factors that may influence its use. A total of 103 physicians were consulted, including 14.8 percent of 452 staff physicians and 16.3 percent of 220 postgraduate medical students. Forty percent of the requested doctors indicated influenza vaccine during 1999. This rate was quite similar among doctors that work seeing older persons at outpatient clinics (43.5 percent). Rates were similar among staff doctors and postgraduate medical students. Prescription of the vaccine was more frequently declared among physicians working at the Internal Medicine Department although differences with other services were not significant. Thirty percent of the vaccine indications were temporarily inadequate and used after the reasonable time-frame before the influenza season. Influenza vaccine is an underprescribed preventive strategy

Enteritis y colitis por radioterapia / Enteritis and colitis due to radiation

Desde fines del siglo XIX, con la utilización de los rayos X, aparecieron las primeras descripciones de lesiones ocasionadas por la radiación abdominal y pelviana. Luego, en la segunda mitad del siglo XX se perfeccionaron los equipos de radiación que se utilizaron en el tratamiento del cáncer. Desde esa fecha, se multiplicaron los pacientes con afección actínica de algún segmento del tubo digestivo. La radiación produce en el intestino: a) lesiones agudas en las primeras semanas, generalmente autolimitadas, que habitualmente no requieren manejo específico y b) lesiones crónicas que aparecen entre 6 meses a 2 años y se caracterizan por dolor abdominal, diarrea y sangrado digestivo, junto con las complicaciones como fístulas, estenosis y perforación, que son subsidiarias de terapias de elevada complejidad y morbimortalidad. Entre los métodos diagnósticos se incluye la colonoscopía, que muestra lesiones en la mucosa intestinal tanto en la fase aguda como en la crónica, con edema, granularidad, friabilidad, lesiones vasculares telangiectásicas y eventualmente ulceraciones o estenosis con pérdida de pliegues y haustras. La radiología contrastada con bario muestra dilatación de asas, edema de la mucosa, pérdida de haustras o pliegues, estenosis y fístula o perforación en la fase más crónica. La tomografía axial computada proporciona ayuda en la pesquisa de complicaciones como abscesos o perforación y en el diagnóstico diferencial de carcinoma versus lesión actínica. Las medidas terapéuticas incluyen apoyo nutricional y sintomático en fase aguda. En la fase crónica, a lo anterior se agregan terapias endoscópicas como aplicación de formalina tópica, coagulación con plasma argón o argón láser. Finalmente, frente a complicaciones como estenosis, fístula o perforación, se plantea el tratamiento quirúrgico

Angioplastía en infarto agudo de miocardio: resultado inicial y seguimiento alejado / Angioplasty in acute myocardial infarction: early and late results

Background: The usefulness of angioplasty in the first hours of an acute myocardial infarction is widely demonstrated. However, its long term effects are less well known. Aim: To report the effects of coronary angioplasty on early and late outcome of patients with acute myocardial infarction. Patients and methods: A non-randomized, consecutive and retrospective analysis of the hospital and late outcome of 70 patients, aged 35 to 85 years, subjected to coronary angioplasty during an acute myocardial infarction. Patients were followed during 12 to 60 months. Results: Angioplasty was performed 5.3 ñ 5 hours after the initial symptoms. Anterior descendent artery was occluded in 63 percent of patients with a 99.5 percent luminal occlusion and TIMI 0-1 anterograde flow. An angiographic success was achieved in 83 percent of procedures with a residual stenosis of 32.3 percent. Recurrent ischemia was observed in 6 percent of patients, that were treated with a new revascularization procedure. Thirteen percent of patients died, all due to cardiogenic shock. Severe ventricular failure and failure of revascularization influenced mortality. During the first year of follow up there was a 3.3 percent mortality and 3.3 percent of patients required a new revascularization procedure. Eighty percent of patients were asymptomatic and event-free. Conclusion: Angioplasty was a useful therapeutic procedure in this group of patients