Insuficiencia ovárica primaria en adolescentes: revisión de la literatura a propósito de un caso clínico / Primary ovarian insufficiency in adolescents: review of the literature regarding a clinical case

El objetivo de este manuscrito es realizar una revisión y actualización de la literatura de la insuficiencia ovárica primaria (IOP) en población adolescente, a partir del diagnóstico, manejo y seguimiento de un caso clínico. La insuficiencia ovárica primaria se define como la menopausia en una mujer antes de los 40 años, acompañada de amenorrea, hipogonadismo hipergonadotrópico e infertilidad. Su prevalencia varía entre 1 a 2%, y en mujeres menores de 20 años su prevalencia es un caso de cada 10,000. Aunque se sabe que muchas afecciones pueden llevar a una IOP, la más común es la causa idiopática. La presentación clínica es diversa, y varios trastornos diferentes pueden también, llevar a esta condición. CASO CLÍNICO: Se presenta el caso de una adolescente de 17 años, previamente sana, con historia de amenorrea secundaria, no embarazada, con examen físico general y ginecológico normal. Se solicita estudio analítico complementario resultando con niveles de hormona folículo estimulante (FHS), estradiol (E2) y hormona antimülleriana (AMH) compatibles con una insuficiencia ovárica como la observada en la posmenopausia. Se inicia terapia hormonal (TH) clásica con estradiol y progesterona, siendo posteriormente reemplazada por anticoncepción hormonal combinada (AHC) oral, coincidente con el inicio de vida sexual, con respuesta favorable y sangrados regulares. La IOP tiene graves consecuencias para la salud incluyendo trastornos psicológicos como angustia, síntomas depresivos o depresión, infertilidad, osteoporosis, trastornos autoinmunes, cardiopatía isquémica, y un mayor riesgo de mortalidad. La enfermedad de Hashimoto es el trastorno autoinmune más frecuente asociado a la IOP. Su tratamiento y diagnóstico deben establecerse de forma precoz para evitar consecuencias a largo plazo. La terapia con estrógenos es la base del tratamiento para eliminar los síntomas de la deficiencia de estrógenos, además de evitar las consecuencias futuras del hipogonadismo no tratado. También el manejo debe incluir los siguientes dominios: fertilidad y anticoncepción, salud ósea, problemas cardiovasculares, función psicosexual, psicológica y neurológica, informando a los familiares y a la paciente sobre la dimensión real de la IOP y la necesidad de tratamiento multidisciplinario en muchos casos. CONCLUSIÓN: El caso presentado, pese a ser infrecuente, permite abordar de manera sistematizada el diagnostico de IOP y evaluar alternativas de manejo plausibles para evitar graves consecuencias en la salud, así como conocer respuesta clínica y de satisfacción de la adolescente.

The objective of this manuscript is to review and update the literature on primary ovarian insufficiency (POI) in an adolescent population, based on the diagnosis, management and follow-up of a clinical case. Primary ovarian insufficiency is defined as menopause in a woman before the age of 40, accompanied by amenorrhea, hypergonadotropic hypogonadism, and infertility. Its prevalence varies between 1 to 2%, and in women under 20 years of age its prevalence is one case in every 10,000. Although it is known that many conditions can lead to POI, the most common is the idiopathic cause. The clinical presentation is diverse, and several different disorders can also lead to this condition. CLINICAL CASE: The case of a 17-year-old adolescent, previously healthy, with a history of secondary amenorrhea, not pregnant, with a normal general physical and gynecological examination is presented. A complementary analytical study is requested, resulting in levels of follicle stimulating hormone (FHS), estradiol (E2) and anti-müllerian hormone (AMH) compatible with ovarian insufficiency such as that observed in postmenopause. Classic hormonal therapy (HT) with estradiol and progesterone was started, later being replaced by combined hormonal contraception (CHC), coinciding with the beginning of sexual life, with a favorable response and regular bleeding. POI has serious health consequences including psychological disorders such as distress, depressive symptoms or depression, infertility, osteoporosis, autoimmune disorders, ischemic heart disease, and an increased risk of mortality. Hashimoto's disease is the most common autoimmune disorder associated with POI. Its treatment and diagnosis must be established early to avoid long-term consequences. Estrogen therapy is the mainstay of treatment to eliminate the symptoms of estrogen deficiency, in addition to avoiding the future consequences of untreated hypogonadism. Management should also include the following domains: fertility and contraception, bone health, cardiovascular problems, psychosexual, psychological and neurological function, informing family members and the patient about the real dimension of POI and the need for multidisciplinary treatment in many cases. CONCLUSION: The case, although infrequent, allows a systematic approach to the diagnosis of POI and evaluate plausible management alternatives to avoid serious health consequences, as well as to know the clinical response and satisfaction of the adolescent.

Corrección del intercambio gaseoso utilizando ventilación no invasiva guiada por manometría esofágica en un paciente con síndrome de obesidad e hipoventilación. Reporte de un caso / Correction of the exchange gaseous using ventilation non-invasive guided by esophageal manometry in a patient with syndrome obesity and hypoventilation. Report of a case

Se comunica el caso de un hombre de 68 años, obeso mórbido, con antecedentes de síndrome de apneas del sueño, que ingresa en la Unidad de Terapia Intensiva con insuficiencia respiratoria aguda hipercápnica y es tratado con ventilación mecánica no invasiva. Pese a una buena adaptación a la interfaz, el menor valor de la PaCO2 fue de 68 mmHg. Se decide colocar un balón esofágico con el objetivo de determinar en qué medida el componente toracoabdominal estaba afectando el esfuerzo de músculos inspiratorios y el intercambio gaseoso. Luego de la medición, los valores de presión positiva al final de la espiración se incrementaron, y se obtuvo una presión transpulmonar telespiratoria cercana a 0 cmH2O y una mejoría en el valor de la PaCO2. El paciente no tuvo ninguna complicación asociada a la titulación con manometría esofágica y fue dado de alta de la Terapia Intensiva, a las 72 horas (AU)

We report the case of a 68-year-old morbidly obese man, with a history of sleep apnea syndrome, who is admitted to the Intensive Care Unit with hypercapnic acute respiratory failure and is treated with non-invasive mechanical ventilation. Despite a good adaptation to the interface, the lowest value of PaCO2 was 68 mmHg. An esophageal balloon was inserted in order to determine to what extent the thoracoabdominal component was affecting inspiratory muscle effort and gas exchange. After the measurement, positive end-expiratory pressure values were increased, and a transpulmonary end-expiratory pressure close to 0 cmH2O was obtained and PaCO2 value was improved. The patient did not have any complication associated with the titration with esophageal manometry and he was discharged from Intensive Care Unit 72 hours later(AU)

Echocardiographic and biochemical analysis of cardiac function and injury among female amateur runners post-marathon.

BACKGROUND: Numerous studies with male amateur runners have determined negative changes in their cardiac function/of their myocard following long endurance loads. This study aims to examine such potential changes in women, specifically, after running a marathon. METHODS: A total of 18 female amateur runners (39.5 ± 10.5 years) were examined before (T1), immediately after (T2) and 24 h post-marathon (T3). An echocardiography was performed using Tissue Doppler (TD) imaging. In addition, the concentration of cardiac troponin T (cTnT) and the activity of the myocardial muscle creatine kinase (CK-MB) were determined at T1 and T2. RESULTS: The echocardiographic parameters revealed impairment of the diastolic function, without, however, documenting a diastolic dysfunction (in accordance with the classification of Nagueh (J Am Soc Echocardiogr, 22:107-33, 2009)). The ratio of blood flow velocity through the mitral valve during early versus late diastole (MV E/A ratio), for example, decreased. The values measured at T3 were similar to those measured at T1. The ratio of early transmitral diastolic filling velocity and of the transmitral diastolic filling velocity by TD imaging (MV E/E') did not indicate any change from T1 to T2, but a significant increase at T3 (in comparison with T1). The systolic function (measured by the left ventricular ejection fraction) did not change significantly. The cTnT concentration and CK-MB activity were significantly higher in T2 than in T1. CONCLUSION: The data collected does not provide any solid evidence of pathological changes in the cardiac function of female amateur runners post-marathon, although the lab values indicate a strongly increased myocardial stimulation.

Influencia de las modificaciones epigenéticasocasionadas por el consumo de cigarrillos en relación con la disminución del hueso alveolar-revisión de la literatura / Epigenetic influence of changes caused by cigarette consumption in relation to the bone reduction alveolar-literature review

La epigenética hoy en día constituye uno de los temas de mayor interés en el campo científico, debido a la relación que se ha encontrado con cambios fenotípicos, siendo la metilación del ADN y la desacetilación de las histonas los principales eventos que la caracterizan. A su vez, se ha evidenciado en una amplia gama de patologías. Es por esto, que los factores que inducen estos cambios epigenéticos pueden ser ambientales (como el cigarrillo) o hereditarios. Hay que destacar que entre las alteraciones en las que se ha visto involucrada a la epigenética se encuentra disminución en la cantidad y calidad del hueso en el complejo maxilar-mandíbula, los cuales, a su vez son considerados parámetros de vital importancia en tratamientos odontológicos rehabilitadores. El objetivo de la presente investigación realizar una revisión a la literatura actualizada con el propósito de describir la influencia de las modificaciones epigenéticas ocasionadas por el consumo de cigarrillos y su asociación con la resorción ósea alveolar.

In the present time, the epigenetics is one of the topics with most interest on the scientific field, due to the relationship that has been found with phenotypic changes, been epigenetic´s main event the DNA methylation and the Histone acetylation, that at the same time have been evidenced on a great quantity of pathologies. Because of this, the epigenetics changes are induced by environmental (like smoking) and hereditary factors. Is worth to mention, that among the alterations on which the epigenetic has been related is found the decrease en the quality and quantity of the bone on the maxillary-mandibular complex, which are also consider important parameters for successful dental rehabilitators treatments. A current bibliographic revision was made with the purpose of describe the influence of epigenetic´s modifications involved on the smoking in relationships with the of the alveolar bone loss.

Influence of glycemic status and physical fitness on oxidative stress and the peroxiredoxin system in the erythrocytes of non-insulin-dependent type 2 diabetic men.

UNLABELLED: Oxidative stress plays a leading role in the progression of diabetic secondary complications, e.g., of cardio-vascular illnesses. Physical activity has been shown to delay and even prevent the progression of type 2 diabetes by improving the antioxidative capacity and thereby decreasing systemic oxidative stress. Peroxiredoxins (PRDX) are important antioxidative components that are highly abundant in erythrocytes. The present study examines the influence of glycemic control and physical fitness on oxidative stress and the peroxiredoxin system in the erythrocytes of non-insulin-dependent type 2 diabetic men ( N=22, years=61 ± 10) at rest. Oxidative stress was measured by immunohistochemical stainings for 8-iso-prostaglandin-F2α (8-Iso-PGF) and the overoxidized form of peroxiredoxins (PRDX-SO (2-3)). Peroxiredoxin isoforms PRDX1 and PRDX2 were also quantified immunohistochemically. Physical fitness was determined during the WHO-step test. Regression analyses showed a positive relationship between 8-Iso-PGF plotted against HbA (1c) (hyperbolic curve (y=a+b/x), R (2)=0.346, P=0.013), a positive relationship between 8-Iso-PGF plotted against fasting glucose (hyperbolic curve (y=a+b/x), R (2)=0.440, P=0.003), as well as positive relationships between PRDX2 plotted against VO (2 peak) (S-curve (y=e(a+b/x)), R(2)=0.259, P=0.018) and between PRDX2 plotted against the workload corresponding to the 4 mmol/l blood lactate concentration (hyperbolic curve (y=a+b/x), R(2)=0.203, P=0.041). Further significant relationships were not found. CONCLUSIONS: Poor glycemic control may increase oxidative stress in the erythrocytes of type 2 diabetic men. Good physical fitness seems to be associated with increased peroxiredoxin contents. Therefore, it can be speculated that physical training can contribute to the improvement of the erythrocyte peroxiredoxin system to counteract free radicals in type 2 diabetic patients.

Consenso argentino de ventilación no invasiva / Argentine consensus of non-invasive ventilation

Non-invasive ventilation (NIV) is nowadays increasingly used. The significant decrease in tracheal intubation related complications makes it particularly attractive in patients with moderately acute respiratory failure (ARF) who still have some degree of respiratory autonomy. It has also been used to support patients with chronic respiratory failure. However, final outcomes are variable according to the conditions which determined its application. This Consensus was performed in order to review the evidence supporting the use of positive pressure NIV. The patho-physiological background of NIV and the equipment required technology are described. Available evidence clearly suggests benefits of NIV in acute exacerbation of chronic obstructive pulmonary disease (COPD) and in cardiogenic pulmonary edema (Recommendation A). When considering ARF in the setting of acute respiratory distress syndrome results are uncertain, unless dealing with immunosupressed patients (Recommendation B). Positive results are also shown in weaning of mechanical ventilation (MV), particularly regarding acute exacerbation of COPD patients (Recommendation A). An improved quality of life in chronic respiratory failure and a longer survival in restrictive disorders has also been shown (Recommendation B) while its benefit in stable COPD patients is still controversial (Recommendation C). NIV should be performed according to pre-established standards. A revision of NIV related complications is performed and the cost-benefit comparison with invasive MV is also considered.

La ventilación no invasiva (VNI) ha alcanzado notable difusión en los últimos años. El ahorro delas complicaciones causadas por la intubación traqueal la hace especialmente atractiva en pacientesque presentan insuficiencia respiratoria aguda (IRA) no muy grave y que conservan cierta autonomía respiratoria.También se han descripto efectos terapéuticos en pacientes con insuficiencia respiratoria crónica de etiologías diversas. No obstante, los resultados obtenidos son variables según las circunstancias que motivan su aplicación. A fin de revisar la evidencia a favor de su uso se elaboró este Consenso referido particularmente a la VNI a presión positiva. Se describen su fundamento fisiopatológico, esencial para su correcta aplicación, y elequipamiento necesario para implementarla. La evidencia existente en la literatura establece definida utilidad de la VNI en la exacerbación de la EPOC y en el edema agudo de pulmón cardiogénico (Recomendación A).Su beneficio es aún incierto en pacientes con IRA secundaria a síndrome de dificultad respiratoria aguda, salvoen el subgrupo de pacientes inmunosuprimidos (Recomendación B). Los resultados son también favorablesen la desvinculación de la asistencia respiratoria mecánica (ARM), especialmente en pacientes ventilados por exacerbación de EPOC (Recomendación A). En la insuficiencia respiratoria crónica se ha hallado mejoría en la calidad de vida y mayor sobrevida en pacientes con enfermedades restrictivas (Recomendación B), mientrasque existe aún controversia sobre su utilidad en pacientes con EPOC estable (Recomendación C). La VNI debeser aplicada con estándares de cuidados que son establecidos. Se revisan las eventuales complicaciones derivadasde su uso y el beneficio costo-efectividad ahorrando recursos de mayor complejidad y disminuyendolos riesgos que implica la ARM invasiva.

[The PreFord Study. A prospective cohort study to evaluate the risk of a cardiovascular event (overall-collective) as well as a prospective, randomized, controlled, multicentre clinical intervention study (high-risk-collective) on primary prevention of cardiovascular diseases in the Ford Motor Company employees in Germany]. / Die PräFord-Studie. Prospektive Kohortenstudie zur Bewertung des Risikos für ein kardiovaskuläres Akutereignis (Gesamtkollektiv) sowie eine prospektive, randomisierte, kontrollierte, multizentrische klinische Interventionsstudie (Hochrisikoteilkollektiv) in der Primärprävention von Herz-Kreislauferkrankungen bei Mitarbeitern der Firma Ford in Deutschland.

The PreFord Study is a multicenter prospective cohort study to evaluate guideline based risk management on primary prevention of cardiovascular diseases. Furthermore a randomised controlled trial (RCT) will be designed to analyse the effect of a special intervention program. 40,000 employees of the Ford Motor Company, Visteon Company and Deutz Company in Germany will be included, monitored for ten years and the following primary endpoints will be investigated: 1. evaluation and comparison of established and newly developed risk-scores, 2. the relative impact of single and combined cardiovascular risk factors on cardiovascular diseases, 3. the influence of a novel occupationally integrated ambulant rehabilitation program in combination with a guideline oriented optimal drug therapy within a high risk group on the primary endpoint: risk reduction by, 4. the influence of this intervention on secondary endpoints: death, myocardial infarction and stroke, combined appearance of angina pectoris and hospitalisation, occurrence of cerebral circulatory disorder and hospitalisation, occurrence of peripheral occlusive arterial disease and hospitalisation and single cardiovascular risk factors and cost-benefit-analysis. Beginning with an cross sectional study there will be a systemic screening of cardiovascular risk profiles, of anthropometric data and different lifestyle-factors. Based on these data participants will be differentiated into three risk-groups according to the risk score of the European Society of Cardiology (risk of a lethal primary acute cardiovascular event: I < or = 1%; II > 1-< 5% and III > or = 5%). In the following longitudinal study different strategies will be applied: Group I: low risk (< 0.5% per year): repetition of the investigation after five and ten years. Group II: middle risk, (0.6% to 1.4% per year), repetition of the investigation every two years, instruction of the patients general practitioner (GP) with respect to a risk factor oriented and evidence based treatment. Group III: high risk, (> 1.5% per year or >15% within the next 10 years) will be randomised into two interventional groups. The first one, the intervention-group "PreFord" will perform an occupational integrated rehabilitation program (2,5-3 hours twice a week, for 15 weeks according to the BAR guidelines) with a following engagement in heart-groups and an annual repetition of the check-ups. The second group, the "classic" intervention-group will be treated evidence based in cooperation with their GP. As a result of this long term interventional study efficient, area wide implementable and economically feasible prevention concepts with special regards to operational healthcare will be developed and evaluated. Core elements will be exercise- and lifestyle-oriented concepts as well as guideline-based pharmacotherapy.

Eficacia y tolerancia de cefepima en infecciones adquiridas en la comunidad / Effectiveness and tolerance of cefepima in infections acquired in the community

Se evaluó la eficacia y tolerancia de cefepima, una cefalosporina de cuarta generación, en infecciones adquiridas en la comunidad siguiendo un diseño abierto y no controlado en cuatro hospitales en Lima, Perú. Entre mayo y noviembre de 1997, se tuvo 31 pacientes: 10 con infecciones de la piel y tejidos blandos, 16 con infecciones del tracto urinario alto y 5 con neumonía lobar. Se obtuvo la cura clínica en todos los pacientes con infecciones del tracto urinario y neumonía lobar; y en 8 pacientes con infecciones de la piel y tejidos blandos. Todos los pacientes lograron cura bacteriológica. Cefepima fue bien tolerada. Concluimos que cefepima es una alternativa en el manejo de las infecciones adquiridas en la comunidad.

Utilidad del nomograma hemodilucional (ZNa+-ZK+) en terapia intensiva / Utility of hemodilutional nomogram (ZNañZK+) in Intensive Care

Se evaluó la distribución de los valores ZNa + - ZK + dentro del nomograma en pacientes internados en un área crítica, para determinar la tendencia de ciertas patologías en asociarse con cambios hidroelectrolíticos plasmáticos y su eventual valor pronóstico. Se consideraron 2.000 egresos consecutivos, seleccionándose en cada enfermo el valor ZNa+ - ZK+ que se ubicó durante su internación, en la zona más alejada al área de normalidad. Se dividió el nomograma en áreas y sub-áreas, permitiendo diferenciar un grupo normal (N) de otro patológico (P) y dentro de éste último, una zona donde la dilución es responsable de los cambios del soluto, de otras con alteración primaria de un o ambos iones. Se evaluó la incidencia de pacientes con ubicación en nivel patológico y su relación con índices pronósticos, porcentual de fallecimientos y patología correspondiente a cada zona del nomograma. Los resultados mostraron que el grupo (P) representó el 17 por ciento del total. La mortalidad fue del 38 por ciento para el (P) y del 17 por ciento para el grupo (N) (pó0.000). La evaluación por zonas mostró: (A -dilucional) representa el 41 por ciento de los valores (P), con mortalidad del 28 por ciento y predominio en ACV, postoperatorios y patología cardiológica; (B -ZNa + disminuido y ZK + aumentado) con 34 por ciento de los valores (P) mortalidad del 50 por ciento y asociado a sepsis, shock, patología renal y respiratoria; (C - ZNa + -ZK+ descendidos) frecuencia 7.8 por ciento de los (P), mortalidad 26 por ciento y presente en postoperatorios y patología respiratoria; (D - ZNa+ aumentado y ZK+ disminuido) frecuencia del 11.5 por ciento de los (P), mortalidad 35 por ciento se presenta en ACV, postoperatorios y patología cardiorespiratoria; (E - ZNa+-ZK+ elevados) frecuencia 5,4 por ciento de los (P), mortalidad 63 por ciento y se observa en postoperatorios, patología respiratoria, renal y bacteriemias. La mortalidad no mostró significación cuando se la relacionó con el grado de dispersión del valor ZNa+ -ZK+ con respecto al centro del nomograma. Se concluye que el empleo del nomograma en un área de cuidados intensivos resulta de utilidad, permitiendo objetivar y determinar si los cambios plasmáticos del sodio y potasio responden a causas dilucionales y de acuerdo a su ubicación en sus diferentes zonas, orientar el diagnóstico, pronóstico y eventual conducta terapeútica

Evaluation of bronchodilator response in patients with airway obstruction.

The aim of this study was to define the most useful index of expressing bronchodilator response and to distinguish between asthma and COPD. A prospective study was carried out of bronchodilator response in 142 asthmatics and 58 COPD patients in a university hospital. Reversibility was expressed as: 1. absolute change (delta abs); 2. % of initial (delta %init); 3. % of predicted (delta %pred) and 4. % of maximum possible response (delta %max). Dependence on forced expirations volume in 1 sec (FEV1) as % of predicted and sensitivity and specificity for diagnosis of asthma were established. A relationship between delta abs and initial FEV1 was not found in asthma (delta abs vs. % initial FEV1. r = 0.07) or COPD (r = 0.02). delta %pred did not show a correlation in asthma (r = 0.10) or COPD (r = 0.06). delta %init was dependent on the baseline value in asthma (r = 0.38, P < or = 0.001) but not in COPD (r = 0.18, P = n.s.). delta max was dependent in both. The combination of best sensitivity and specificity to separate asthma and COPD was obtained with delta abs (70.4 or 70.6%). The worst specificity for asthma diagnosis was obtained with delta %init (50%). The best likelihood ratios were obtained with delta abs and delta %pred and the worst likelihood ratio with delta %init. delta %init is not recommended as an index for differential diagnosis between asthma and COPD; 2) delta %init overscores bronchodilator response in patients with low FEV1. The independence of each bronchodilator response index should be verified in clinical trials for each selected sample.

Assessment of respiratory function: influence of spirometry reference values and normality criteria selection.

The purpose of this study was to determine the impact upon classification of patients of the choice of reference equation and the criterion defining the lower limit of the normal range in clinical practice. One thousand consecutive spirometries were checked to calculate the predicted values [forced vital capacity (FVC) and forced expiratory volume in sec (FEV1)] in accordance with the equations by Morris, Cherniack, Crapo, Knudson and the Economic Community for Coal and Steel (ECCS). We quantified the difference between the predicted values obtained for each individual and each equation, determined the percentage of individuals whose classification might have changed from normal to abnormal when using a different equation and defined the lower limit of the normal range in accordance with the determination of 1. the 90% confidence interval or 2. 80% of predicted, comparing their differences. The greatest differences found were between the values given by Morris and Crapo's equations for male FEV1, between Morris and Cherniak for female FEV1 and male FVC and between Morris and Knudson for female FVC. Using 80% of predicted value for female FEV1, up to 35% of tests changed their classification from 'normal' to 'abnormal' upon changing the equation used. A high percentage of tests showed a lower limit of normal defined by the confidence interval under 80% and 70% of predicted value. This study emphasizes the importance of choosing the appropriate reference equation. We do not consider it acceptable to use a fixed percentage of the predicted value as the lower limit of normal because of the great number of patients found to be inappropriately classified.

Nomograma hemodilucional (Z Na+ - Z K+) / Model for diagnosis of dilution-induced hyponatremia. The dilutional zone

Se propone un método para el diagnóstico de las hiponatremias dilucionales basado en un modelo que presenta gráficamente los valors estándar Z de las concentraciones de sodio y potasio sanguíneo. Del modelo se obtiene que ante variaciones en el contenido hídrico del plasma la natremia y la kalemia cambian en forma proporcional, desplazándose sobre una recta en el gráfico. La pendiente de la recta obtenida a partir del modelo fue comparada con las correspondientes a plasma y sangre entera (n=6) luego de un aporte creciente de solución dextrosada al 5 por ciento en agua en volúmenes equivalentes al 5,10,15,20 por ciento de la muestra. En ellas se determinó además el contenido de uremia, glucemia, sodio, potasio, gases en sangre y estado ácido-base. La pendiente del modelo resultó de 0,20, obteniéndose para el plasma 0,16 más menos 0,03 y para la sangre entera 0,10 más menos 0,03. En este último caso, las diferencias significativas con el modelo se justificaron por procesos globulares, asociados al metabolismo y a cambios en la osmolaridad. Se concluye pues que el modelo abarca dentro de la "zona dilucional" al comportamiento de la sangre entera y el plasma, siendo representativo de los efectos dilucionales. La experiencia clínica muestra asimismo el desplazamiento de los valores (Z Na+ - Z k+) sobre la zona dilucional en concordancia con el balance hídrico, y permite a la vez verificr su alejamiento cuando los cambios iónicos son determinados por causas no dilucionales que, sin llegar a ser un factor pronóstico, reflejan la evolución de la enfermedad

[Non-invasive mechanical ventilation as treatment for severe pneumonia in an HIV positive patient]. / Ventilacion mecanica no invasiva como tratamiento de la neumonia severa en un paciente con serologia HIV positiva.

A 27 year-old HIV+ patient was admitted to the hospital for probable Pneumocystis carinii pneumonia (PCP). He was severely dyspneic, with respiratory rate of 44 x min and accessory respiratory muscle contraction. The alveolar-arterial quotient was 0.35. Ventilation by BiPAP was applied during 12 hours. After BiPAP a/AO2 was O.42, with amelioration of dyspnea, decrease of respiratory rate (25 x min) and without using of accessory respiratory muscles. No complications occurred. At the end of hospital stay a/AO2 was 0.68. CPAP application but not BiPAP has been reported in PCP. Our patient showed evident improvement after BiPAP, suggesting that this method of ventilation is useful and should be incorporated to the routine management of these patients.

[Immediate postoperative respiratory complications after coronary surgery]. / Complicaciones respiratorias en el postoperatorio inmediato de la cirugía coronaria.

The influence of anesthesia, surgical procedure and special conditions of open-heart surgery upon respiratory function alterations is analyzed. Hypoxemia (present even in non-complicated open heart surgery) can be due to alveolar hypoventilation, ventilation-perfusion mismatch or shunt. The origin of atelectasias (present in 50-92% of patients) and pleural effusion (42-87%) is discussed. Phrenic nerve damage is usually secondary to thermal injury. Other less common complications are discussed. The influence of age, smoking and previous pulmonary diseases on respiratory complications is analyzed. Respiratory care after heart surgery (as time and requisites of extubations) and results of different methods (CPAP, PEEP, incentive inspirometry) are reviewed.

Anormalidades urinarias en pacientes adultos infectados por VIH / Urinary abnormalities in adult patients infected with HIV

Objetivo: determinar la frecuencia de anormalidades urinarias en pacientes adultos infectados con el virus de la inmunodeficiencia humana (VIH) y los factores de riesgo asociados. Metodología: se examinaron muestras de primera orina matutina de 61 pacientes seropositivos (Western-Blot) atendidos en el consultorio externo del Instituto de Medicina Tropical Alexander von Humboldt entre Noviembre 1993 y Diciembre de 1994. Se determinó: osmolalidad, pH, examen bioquímico por tira reactiva, proteinuria en 24 horas (para pacientes con albuminuria>1+) y sedimento urinario. Resultados: La edad promedio fue de 32.4 + 8.1 años, 58 por ciento eran homosexuales, no hubieron adictos a drogas endovenosas y sólo un paciente era de raza negra. El 84 por ciento tenía SIDA al momento del estudio. Se encontró por lo menos una alteración en el 27.9 por ciento de los pacientes. El porcentaje de pacientes con incapacidad de concentración urinaria fue de 16.0 por ciento y de acidosis tubular renal 13.3 por ciento. Ningún paciente presentó proteinuria significativa, 3.3 por ciento presentó hematuria glomerular y 4.9 por ciento hematuria no glomerular. En ningún paciente se encontró glucosuria y se detectó leucocituria sólo en 3.3 por ciento de ellos. No se encontró ninguna relación significativa entre variables clínicas y las alteraciones urinarias. Conclusión: la frecuencia de alteraciones urinarias asociadas a daño túbulo intersticial fue de 29.7 por ciento. La ausencia de proteinuria significativa obedece probablemente al escaso porcentaje de pacientes de raza negra y de adictos endovenosos.

[Non-invasive mechanical ventilation in intensive care]. / Ventilación mecánica no invasiva en terapia intensiva.

Non-invasive mechanical ventilation is useful in order to delay or avoid endotracheal intubation. Continuous positive airway pressure (CPAP) is helpful for patients with decreased lung compliance, airways obstruction due to vocal cord paralysis or tracheobronchomalacia, presence of auto-PEEP (positive end-expiratory pressure) and as a weaning method. Non-invasive intermittent positive pressure ventilation (IPPV) is not very different from conventional mechanical ventilation except for the absence of an endotracheal tube. It is specially useful in patients with neuromuscular diseases or central hypoventilation. It has been also helpful for patients with decrease of lung compliance or COPD and as a weaning procedure. It may be applied with or without PEEP and by means of a bi-level IPPV system. All of these methods require cooperative patients and by means of a bi-level IPPV system. All of these methods require cooperative patients and they do not allow an adequate management of increased respiratory secretions. Non-invasive mechanical ventilation has the advantages of not showing complications associated to endotraqueal intubation and may be performed by means of less expensive equipment.

Bilateral diaphragmatic paralysis after mediastinal radiotherapy.

A 35-year-old man presented bilateral phrenic paralysis 7 months after radio-therapy for treatment of Hodgkin's lymphoma. Diaphragmatic dysfunction appeared after complete lymphoma remission and 4 months after chemotherapy discontinuation. There were no other potential causes. Idiopathic diaphragmatic paralysis was unlikely because it is usually unilateral. Radiation-induced neuropathy is well documented in other nerves as the brachial plexus. The timing, the applied dose and the location of the nerve within the radiation field are suggestive of radiation-induced phrenic nerve damage. Partial recovery was achieved after 4 years' follow-up.