Efectos de la injuria renal isquémica aguda en la disfunción extrarenal: estudio experimental aleatorizado / Acute kidney injury and extrarenal organ dysfunction: a randomized experimental study

Introducción: La insuficiencia renal aguda (IRA) es una enfermedad grave y causante de disfunciones de órganos distantes que incrementan su mortalidad. Objetivo: Identificar disfunción hemodinámica y respiratoria gatillada por IRA en un modelo pediátrico animal de isquemia-reperfusión renal. Método: Doce cerdos anestesiados (11,9 +/- 1,0 kg). En seis animales se indujo lesión renal bilateral por isquemia-reperfusión: 45 min de isquemia y 240 min de reperfusión, mientras que los seis animales restantes fueron grupo control. En condiciones basales y posterior a lesión renal se realizó monitorización hemodinámica convencional y termodilución transpulmonar. Paralelamente se midió gasometría arterial y análisis de mecánica pulmonar. Resultados: Hubo un incremento de la precarga volumétrica en 29 por ciento (221 +/- 22 ml/m² vs 286 +/- 16 ml/m², p = 0,04) y de la presión arterial media en 58 por ciento (71 +/- 6 mmHg vs 112 +/- 17 mmHg, p = 0,04) respecto a controles, sin cambios en frecuencia cardíaca, presión venosa central ni gasto cardíaco. Además ocurrió un aumento del agua extravascular pulmonar en 86 por ciento (7,6 +/- 0,6 ml/kg vs 14,1 +/- 1,4 ml/kg, p = 0,02), sin cambios en intercambio gaseoso ni mecánica pulmonar. Simultáneamente hubo un leve deterioro de la creatinina sérica (1,12 +/- 0,07 mg/dL vs 1,45 +/- 0,10 mg/dL, p = 0,03). Discusión: En este modelo experimental se pudo apreciar el desarrollo temprano de disfunción hemodinámica y pulmonar. Se evidenció un aumento de la precarga volumétrica y de la presión arterial, asociado a un incremento substancial del agua extravascular pulmonar. Creemos que es fundamental monitorizar de forma seriada la función hemodinámica y respiratoria en sujetos con una lesión renal aguda, aún sin una IRA urémica.

Background: Acute kidney injury (AKI) is a serious disease that can cause distant organ injuries and is associated with high mortality rates. Objective: To identify the hemodynamic and respiratory dysfunction triggered by AKI, in an animal model of renal ischemia-reperfusion. Method: Twelve anesthetized juvenile pigs (11.9 +/- 1.0 kg). Six animals underwent ischemia/reperfusion-induced AKI: 45 min of ischemia and 240 minutes of reperfusion, while the remaining six animals were the control group. In basal conditions and after AKI, a conventional hemodynamic monitoring and transpulmonary thermodilution were performed. At the same time, arterial blood gases and lung mechanics were measured. Results: There was a 29 percent increase in volumetric preload (221 +/- 22 ml/m² vs 286 +/- 16 ml/m², p = 0.04) and a 58 percent mean arterial pressure increase (71 +/- 6 mmHg vs 112 +/- 17 mmHg, p = 0.04) compared to controls, without changes in heart rate, central venous pressure and cardiac output. In addition, an increase of 86 percent in extravascular lung water (7.6 +/- 0.6 ml/kg vs 14.1 +/- 1.4 ml/ kg, p = 0.02) was reported, without changes in gas exchange and lung mechanics. Simultaneously, a slight increase in serum creatinine (1.12 +/- 0.07 mg/dl vs 1.45 +/- 0.10 mg/dl, p = 0.03) was described. Discussion: An early development of hemodynamic and pulmonary dysfunction was observed in this experimental reperfusion model. An increase in volumetric preload and blood pressure associated with a substantial increase in the extravascular lung water were also reported. It is essential serially monitor the hemodynamic and respiratory functions in AKI, including nonuremic subjects.

Falla hepática fulminante por virus Epstein Barr: rol de los corticoides: caso clínico / Epstein Barr virus and acute liver failure: role of steroids: clinical case

La falla hepática fulminante (FHF) debida a Virus Epstein Barr (VEB) es poco frecuente en inmunocompetentes. La utilidad de los esteroides en este cuadro no ha sido definida y permanece muy controversial. Objetivo: Reportar el caso de una paciente con mononucleosis infecciosa por VEB que presenta FHF y es tratada con corticoides. Caso clínico: Escolar con cuadro de 2 sem de síntomas respiratorios altos, fiebre, adenopatías, con ictericia y orina oscura. Bilirrubina total: 9; B. Directa: 6,3; Fosfatasas Alcalinas: 523; GOT: 7.527; GPT: 6.537; Protrombina (PT): 17 por ciento INR: 4,7; Amonio 510 y glicemia 33. Ecografía abdominal hígado normal y esplenomegalia. Monotest Positivo. Se transfirió a centro de trasplante hepático (TH). Laboratorio de ingreso PT 21 por ciento; bilirrubina en 9,8; GOT 2717; GPT 3716 y amonio 177. EEG con enlentecimiento difuso compatible con encefalopatía grado 1. IgM VEB positiva, descartándose otras etiologías. Se activó para TH por FHF y mientras se administró Metilprednisolona por 5 días. Evolucionó con normalización de las pruebas hepáticas y mejoría clínica. Conclusión: En este caso el uso de esteroides se asoció a una rápida y favorable respuesta tanto clínica como de laboratorio sin presentar efectos secundarios negativos. Al igual que en otras presentaciones de infección grave por VEB, debiera considerarse el uso de esteroides en FHF por VEB.

Acute liver failure (ALF) due to Epstein Barr Virus (EBV) is rare in immunocompetent patients. The role of steroids in this case is not well defined and remains controversial. Case report: 7 years old female presenting with unspecific respiratory symptoms for 2 weeks, fever, lymphadenopathy, jaundice and dark brown urine. Total bilirubin: 9 and direct: 6.3, alkaline phosphatases: 523; AST: 7.527, ALT: 6.537; Prothrombin (PT): 17 percent, INR: 4.7; ammonium 510 and glucose 33. Abdominal ultrasound: normal liver and splenomegaly. Monotest Positive. She was transferred to a liver transplant centre (LT). Lab results at admission: PT 21 percent, bilirubin 9.8, AST 2717, ALT 3.716 and ammonium 177. EEG with diffuse and slowing conductivity consistent with encephalopathy. Positive IgM EBV, other aetiologies were ruled out. She was activated for LT due to ALF and while in waiting list methylprednisolone was administered for 5 days. She evolved with normalization of liver tests and clinical improvement. Conclusion: In this case the use of steroids was associated with a rapid and favourable clinical and laboratory response without negative side effects. As in other presentations of serious infection by EBV, should consider the use of steroids in ALF due to EBV.

Acompañamiento del enfermo: Una experiencia de aprendizaje sobre el significado de la enfermedad / Accompanying a patient as an experience to learn the meaning of disease

Background: Due to technical advances and progressive specialization, patient physician relationship evolved from being based on confidence and comprehension to be impersonal and contractual. Aim: To evaluate the change produced in medical students' concept of the meaning of disease, after living an experience of accompanying a patient and their family environment. Material and methods: We used a qualitative research methodology based on participative-action to evaluate an educational method in which a group of third year medical students accompanied a previously selected chronic patient during two months. We performed two focal groups, one previous to the experience and the second one a month later. Additionally, every student wrote a personal narration of the experience. We compared the students' perception of the meaning of disease for the patients and their relatives, before and after the experience. Results: The students confirmed their previous conception about chronic disease, but they also discovered the ways in which some patients and their families overcome their ¡imitations. They pointed out their belief that the physician's comprehension of the meaning of disease for the patient and the family, a need to practice a good medicine and that this knowledge change the physician-patient relationship. Conclusions: This experience was an effective way of ¡earning the meaning of disease, which might be a part of medical student' training, with the corresponding adjustments and changes.

Conflicto de intereses en la práctica clínica: Análisis ético de algunas relaciones con la industria / Conflicts of interest in clinical practice: Ethical analysis of some relationships with the pharmaceutical industry

Sometimes, the prescription practice of physicians can be influenced by factors that are not related to scientific evidence due to the appearance of several conflicts of interest. These conflicts cause social concern and have prompted actions to regulate the ethics of individual and corporative activities related to healthcare. We analyzed the ethical problems involved in the physician-industry relationship. For this purpose, we considered as the main actors related to this problem, the pharmaceutical industry and their marketing strategies, medical doctors and the independence and objectivity that should guide prescriptions and, finally, patients and their right to receive prescriptions based on scientific evidence. From the point of view of the Bioethics principles, Beneficence would not be respected when gifts or other donations received from the industry affect doctor's independence. Non Maleficence principle could be jeopardized if there is an increased risk of treatment failure and finally Justice could be altered if there is a cost increase for either patients or health institutions. As a conclusion, we consider that the presence of conflicts of interest in the relationship of physicians with the pharmaceutical industry is an important ethical problem. In consequence, this group endorses the recommendations of the Chilean Association of Medical Scientific Societies and advices to include ethical guidelines on this topic in the curriculum of medical schools.