Learning inequality during Covid-19: Evidence from secondary schools in Colombia.

During 2020, the Covid-19 pandemic unleashed a socioeconomic crisis in most countries, as well as strict restrictions on mobility and social distancing were implemented. The pandemic brought a severe socioeconomic shock -decreasing economic activity- and forced policy responses that affected the education sector -notably school closures-. There is scarce evidence on the implications of the pandemic and its socioeconomic consequences on learning inequality, particularly in the Latin-American context. The aim of this paper is to measure the change in learning inequality during the years of the pandemic (2020-2021) in Colombia. To measure learning inequality, we use the results of a standardize exam taken by all upper secondary education graduates in the country. To capture inequality, we use secondary-level students' characteristics, their households, and schools' characteristics. Our econometric results suggest an increase in learning inequality between 48% and 372% depending on the dimension studied, except for gender where learning inequality decreased. Moreover, through dynamic specifications, we determine that for all the analyzed dimensions the 2020-2021 period represents a change in the trend of learning inequality as in the periods prior to the pandemic inequality gaps decreased or, at least, remained constant. We conclude with concrete and immediate policy recommendations to target the learning processes of vulnerable students and bridge learning gaps.

Comparing long-term educational effects of two early childhood health interventions.

We compare the educational effects of two medical protocols that mitigate long-term consequences of prematurity or low birth weight. The two protocols are Traditional Care (TC), which uses incubators, and Kangaroo Mother Care (KMC) which replaces incubators for 24-hour skin-to-skin contact between newborns and caregivers. We concentrate on educational outcomes addressing contradictory results in previous contributions. We use a randomized controlled trial implemented in 1993 that randomly assigned children to either TC or KMC. OLS results suggest that KMC children spent more time in preschool, had fewer temporary school absences, and showed lower math test scores. Both groups observed similar effects on high-school graduation and language test scores. We correct for attrition, small sample, and multiple outcomes. Effects on preschool attendance and school absenteeism are robust, particularly for more vulnerable infants (birth weight ≤ 1,800 g). The other effects lose statistical significance due to multiple outcome testing or attrition corrections.

Exercise Capacity, Ventilatory Response, and Gas Exchange in COPD Patients With Mild to Severe Obstruction Residing at High Altitude.

BACKGROUND: Exercise intolerance, desaturation, and dyspnea are common features in patients with chronic obstructive pulmonary disease (COPD). At altitude, the barometric pressure (BP) decreases, and therefore the inspired oxygen pressure and the partial pressure of arterial oxygen (PaO2) also decrease in healthy subjects and even more in patients with COPD. Most of the studies evaluating ventilation and arterial blood gas (ABG) during exercise in COPD patients have been conducted at sea level and in small populations of people ascending to high altitudes. Our objective was to compare exercise capacity, gas exchange, ventilatory alterations, and symptoms in COPD patients at the altitude of Bogotá (2,640 m), of all degrees of severity. METHODS: Measurement during a cardiopulmonary exercise test of oxygen consumption (VO2), minute ventilation (VE), tidal volume (VT), heart rate (HR), ventilatory equivalents of CO2 (VE/VCO2), inspiratory capacity (IC), end-tidal carbon dioxide tension (PETCO2), and ABG. For the comparison of the variables between the control subjects and the patients according to the GOLD stages, the non-parametric Kruskal-Wallis test or the one-way analysis of variance test was used. RESULTS: Eighty-one controls and 525 patients with COPD aged 67.5 ± 9.1 years were included. Compared with controls, COPD patients had lower VO2 and VE (p < 0.001) and higher VE/VCO2 (p = 0.001), A-aPO2, and V D /V T (p < 0.001). In COPD patients, PaO2 and saturation decreased, and delta IC (p = 0.004) and VT/IC increased (p = 0.002). These alterations were also seen in mild COPD and progressed with increasing severity of the obstruction. CONCLUSION: The main findings of this study in COPD patients residing at high altitude were a progressive decrease in exercise capacity, increased dyspnea, dynamic hyperinflation, restrictive mechanical constraints, and gas exchange abnormalities during exercise, across GOLD stages 1-4. In patients with mild COPD, there were also lower exercise capacity and gas exchange alterations, with significant differences from controls. Compared with studies at sea level, because of the lower inspired oxygen pressure and the compensatory increase in ventilation, hypoxemia at rest and during exercise was more severe; PaCO2 and PETCO2 were lower; and VE/VO2 was higher.

Arterial blood gases and ventilation at rest by age and sex in an adult Andean population resident at high altitude.

PURPOSE: Arterial blood gases (ABG) are influenced by the altitude above sea level, age and sex. Most studies have been conducted at sea level and in small populations ascending to or residents at very high altitudes. Our objective was to evaluate the ventilation and ABG by age and sex in an Andean population resident at high altitude (2640 m). METHODS: Analytical cross-sectional study was done in healthy volunteers. ABG and minute ventilation (VE) were measured. T test and ANOVA for differences by sex and age, and Pearson test for correlations between age, VE and ABG were performed. RESULTS: We included 374 adults, 55% women from 18 to 83 years and hemoglobin of 15.7 ± 1.6 g/dl. There was a significant decrease in PaO2 and SaO2 and an increase in P(A - a)O2 with age (p < 0.001). Unlike men, with age women had a significant increase in PaCO2 and a higher decrease in PaO2. The correlations between age, the decrease in PaO2 and the increase in PaCO2 were greater in women than in men. The VE adjusted to body surface area decreased with age, but this correlation was significantly higher in women. CONCLUSIONS: In this study, with a considerable number of healthy adults living at high altitude (2640 m), we established the physiological impact of altitude, aging and gender in ABG. The PaO2 and PaCO2 were significantly lower and the hemoglobin values slightly higher than described at sea level. In addition to PaO2 decline with age, there was an age-related increase in PaCO2 in women, associated with a greater reduction of VE.

Twenty-year Follow-up of Kangaroo Mother Care Versus Traditional Care.

BACKGROUND AND OBJECTIVES: Kangaroo mother care (KMC) is a multifaceted intervention for preterm and low birth weight infants and their parents. Short- and mid-term benefits of KMC on survival, neurodevelopment, breastfeeding, and the quality of mother-infant bonding were documented in a randomized controlled trial (RCT) conducted in Colombia from 1993 to 1996. The aim of the present study was to evaluate the persistence of these results in young adulthood. METHODS: From 2012 to 2014, a total of 494 (69%) of the 716 participants of the original RCT known to be alive were identified; 441 (62% of the participants in the original RCT) were re-enrolled, and results for the 264 participants weighing ≤1800 g at birth were analyzed. The KMC and control groups were compared for health status and neurologic, cognitive, and social functioning with the use of neuroimaging, neurophysiological, and behavioral tests. RESULTS: The effects of KMC at 1 year on IQ and home environment were still present 20 years later in the most fragile individuals, and KMC parents were more protective and nurturing, reflected by reduced school absenteeism and reduced hyperactivity, aggressiveness, externalization, and socio-deviant conduct of young adults. Neuroimaging showed larger volume of the left caudate nucleus in the KMC group. CONCLUSIONS: This study indicates that KMC had significant, long-lasting social and behavioral protective effects 20 years after the intervention. Coverage with this efficient and scientifically based health care intervention should be extended to the 18 million infants born each year who are candidates for the method.

Prevalence, risk factors and underdiagnosis of asthma and wheezing in adults 40 years and older: A population-based study.

OBJECTIVE: There are differences in the prevalence and risk factors of asthma around the world. The epidemiological situation of adults 40 years and older is not well established. Our aim was to determine the prevalence, underdiagnosis and risk factors of asthma and wheezing in adults in Colombia. METHODS: A cross-sectional, population-based study including 5539 subjects from 40 to 93 years selected by a probabilistic sampling technique in five cities was conducted. MEASUREMENTS: respiratory symptoms and risk factors questionnaire and spirometry. DEFINITIONS: (a) Wheezing: Affirmative answer to the question "have you ever had two or more attacks of "wheezes" causing you to feel short of breath?" (b) Asthma: Wheezing definition and FEV1/FVC post-bronchodilator ≥ 70%. (c) Underdiagnosis: Asthma definition without a physician-diagnosis. Logistic regression was used for exploring risk factors. RESULTS: Prevalence of asthma was 9.0% (95% CI: 8.3-9.8) and wheezing 11.9% (95% CI: 11.0-12.8). Asthma underdiagnosis was 69.9% and increased to 79.0% in subjects 64 years or older. The risk factors related to asthma and/or wheezing were: living in Bogota or Medellin, female gender, first degree relative with asthma, respiratory disease before 16 years of age, obesity, no education, indoor wood smoke exposure and occupational exposure to dust particles, gases or fumes. CONCLUSION: We described the epidemiologic situation of asthma in adults 40 years and older in Colombia. In addition to some recognized risk factors, our data supports the association of indoor wood smoke and occupational exposures with asthma and wheezing. Underdiagnosis of asthma in adults was high, particularly in older subjects.

Sobrevida de pacientes con fibrosis pulmonar idiopática a la altura de Bogotá (2640 m) / Survival of patients with idiopathic pulmonary fibrosis at the altitude of Bogota (2640 m)

Resumen Introducción: la sobrevida promedio de pacientes con fibrosis pulmonar idiopática (FPI) anivel del mar es de dos a tres años. Desconocemos su comportamiento en Bogotá, ciudad situadaa gran altura (2640 metros), donde hay mayor hipoxemia, factor asociado en la literatura con malpronóstico. El objetivo del estudio es describir, en una cohorte de pacientes con FPI, la sobreviday las características clínicas y funcionales en el momento del diagnóstico. Material y métodos: pacientes con diagnóstico de FPI confirmado por biopsia o por criteriosclínicos, radiológicos y funcionales. Se utilizó el análisis de sobrevida de Kaplan Meier y la prueba log rank. Resultados: cuarenta pacientes, 50% mujeres, con edad de 59.1±13 años y biopsia en52.5%. Al diagnóstico, PaO2: 48.5±11.2 mmHg, CVF: 61.5±16.8 %, CPT: 66.1±11.7 %, D LCO: 39.5±12.4%. La sobrevida desde el diagnóstico fue 42 meses (IC 95% 25.3-58.7 meses) ydesde el inicio de los síntomas 50 meses (IC 95% 40.3-59.7 meses). No hubo diferencias enla sobrevida por sexo, historia de tabaquismo, forma de diagnóstico (biopsia o no biopsia),variables gasométricas y de función pulmonar. Hubo una menor sobrevida en mayores de 60años (23 vs. 72 meses, p=0.03). Conclusiones: la sobrevida de pacientes con FPI en Bogotá con hipoxemia significativa aldiagnóstico, fue similar a la descrita en estudios a nivel del mar. La edad mayor de 60 años se relacionó con mal pronóstico. (Acta Med Colomb 2014; 39: 15-20).

Abstract Introduction: the mean survival of patients with idiopathic pulmonary fibrosis (IPF) at sea level is two to three years. We don't know its behavior in Bogotá, a city at high altitude (2640 meters), where there is greater hypoxemia, factor associated in the literature with poor prognosis. The objective of the study is to describe, in a cohort of patients with IPF survival and clinical and functional characteristics at the time of diagnosis. Methods: patients diagnosed with IPF confirmed by biopsy or by clinical, radiological and functional criteria. Survival analysis of Kaplan Meier and log rank test was utilized. Results: forty patients , 50% women with age 59.1 ± 13 years. 52.5% had biopsy . At diagnosis, PaO2: 48.5 ± 11.2 mmHg, FVC: 61.5 ± 16.8%, CPT: 66.1 ± 11.7%, DLCO: 39.5 ± 12.4%. Survival from diagnosis was 42 months (95% CI 25.3-58.7 months) and from the onset of symptoms 50 months (95% CI 40.3-59.7 months). There was no difference in survival by sex, smoking history, form of diagnosis (biopsy or not biopsy), blood gas and pulmonary function variables. There was a lower survival in patients older than 60 years (23 vs. 72 months, p = 0.03). Conclusions: the survival of patients with IPF in Bogota with significant hypoxemia at diagnosis was similar to that described in studies at sea level. Age older than 60 years was associated with poor prognosis. (Acta Med Colomb 2014; 39: 15-20).

Exercise endurance in chronic obstructive pulmonary disease patients at an altitude of 2640 meters breathing air and oxygen (FIO2 28% and 35%): a randomized crossover trial.

BACKGROUND: At Bogota's altitude (2640 m), the lower barometric pressure (560 mmHg) causes severe hypoxemia in COPD patients, limiting their exercise capacity. The aim was to compare the effects of breathing oxygen on exercise tolerance. METHODS: In a blind, crossover clinical study, 29 COPD patients (FEV1 42.9 ± 11.9%) breathed room air (RA) or oxygen (FIO2 28% and 35%) during three treadmill exercise tests at 70% of their maximal capacity in a randomized order. Endurance time (ET), inspiratory capacity (IC), arterial blood gases and lactate were compared. RESULTS: At the end of the exercise breathing RA, the ET was 9.7 ± 4.2 min, the PaO2 46.5 ± 8.2 mmHg, the lactate increased and the IC decreased. The oxygen significantly increased the ET (p < 0.001), without differences between 28% (16.4 ± 6.8 min) and 35% (17.6 ± 7.0 min) (p = 0.22). Breathing oxygen, there was an increase in the PaO2 and SaO2, higher with FIO2 35%, and a decrease in the lactate level. At "isotime" (ET at RA), with oxygen, the SpO2, the oxygen pulse and the IC were higher and the heart rate lower than breathing RA (p < 0.05). CONCLUSION: Oxygen administration for COPD patients in Bogotá significantly increased ET by decreased respiratory load, improved cardiovascular performance and oxygen transport. The higher increases of the PaO2 and SaO2 with 35% FIO2 did not represent a significant advantage in the ET. This finding has important logistic and economic implications for oxygen use in rehabilitation programs of COPD patients at the altitude of Bogotá and similar altitudes.

Bronchial hyperresponsiveness in women with chronic obstructive pulmonary disease related to wood smoke.

PURPOSE: Chronic obstructive pulmonary disease (COPD) related to wood smoke exposure is characterized by important inflammation of the central and peripheral airways without significant emphysema. The objective of this study is to describe the bronchial hyperresponsiveness (BHR) level in women with COPD related to wood smoke exposure and to compare it with the BHR in women with COPD related to tobacco smoking. MATERIALS AND METHODS: TWO GROUPS OF WOMEN WITH STABLE COPD WERE STUDIED: (1) wood smoke exposed (WS-COPD); and (2) tobacco smoke exposed (TS-COPD). A methacholine challenge test (MCT) was performed in all patients according to American Thoracic Society criteria. BHR levels were compared using the methacholine concentration, which caused a 20% fall in the FEV1 (PC20). RESULTS: Thirty-one patients, 19 with WS-COPD and 12 with TS-COPD, were included. There were no significant differences between the groups in baseline FVC, FEV1, IC, FEF25-75, and FEF25-75/FVC. All 31 patients had a positive MCT (PC20<16 mg/mL) and the fall in the FEV1 and IC was similar in both groups. The severity of BHR was significantly higher in the WS-COPD patients (PC20: 0.39 mg/mL) than in the TS-COPD patients (PC20: 1.24 mg/mL) (P=0.028). The presence of cough, phlegm, and dyspnea during the test were similar in both groups. CONCLUSION: We found moderate to severe BHR in women with WS-COPD, which was more severe than in the TS-COPD women with similar age and airflow obstruction. This paper suggests that the structural and inflammatory changes induced by the chronic exposure to wood smoke, described in other studies, can explain the differences with TS-COPD patients. Future studies may clarify our understanding of the impact of BHR on COPD physiopathology, phenotypes, and treatment strategies.

Inadequate glucose control in type 2 diabetes is associated with impaired lung function and systemic inflammation: a cross-sectional study.

BACKGROUND: Inadequate glucose control may be simultaneously associated with inflammation and decreased lung function in type 2 diabetes. We evaluated if lung function is worse in patients with inadequate glucose control, and if inflammatory markers are simultaneously increased in these subjects. METHODS: Subjects were selected at the Colombian Diabetes Association Center in Bogotá. Pulmonary function tests were performed and mean residual values were obtained for forced expiratory volume (FEV1), forced vital capacity (FVC) and FEV1/FVC, with predicted values based on those derived by Hankinson et al. for Mexican-Americans. Multiple least-squares regression was used to adjust for differences in known determinants of lung function. We measured blood levels of glycosylated hemoglobin (HBA1c), interleukin 6 (IL-6), tumor necrosis factor (TNF-alpha), fibrinogen, ferritin, and C-reactive protein (C-RP). RESULTS: 495 diabetic patients were studied, out of which 352 had inadequate control (HBA1c > 7%). After adjusting for known determinants of lung function, those with inadequate control had lower FEV1 (-75.4 mL, IC95%: -92, -59; P < 0.0001) and FVC (-121 mL, IC95%: -134, -108; P < 0,0001) mean residuals, and higher FEV1/FVC (0.013%, IC95%: 0.009, 0.018, P < 0.0001) residuals than those with adequate control, as well as increased levels of all inflammatory markers (P < 0.05), with the exception of IL-6. CONCLUSIONS: Subjects with type 2 diabetes and inadequate control had lower FVC and FEV1 than predicted and than those of subjects with adequate control. It is postulated that poorer pulmonary function may be associated with increased levels of inflammatory mediators.

Diabetes mellitus tipo 2 y deterioro de la función pulmonar / Diabetes mellitus type 2 and deterioration of pulmonary function

Introducción: un aspecto poco estudiado de la diabetes mellitus tipo 2 (DM 2), es su posible asociación con alteraciones de la función pulmonar. Estudios recientes han mostrado niveles mayores de marcadores de inflamación sistémica de bajo nivel en pacientes con DM 2, lo que también podría afectar la función pulmonar. El objetivo de este estudio fue determinar si la función pulmonar de personas con DM 2 es diferente de la función pulmonar de un grupo control sin DM.Población y método: se realizó un estudio observacional transversal, comunitario, en diabéticos y en controles sanos, apareados por estratos de edad y sexo. Los controles fueron vecinos de cada diabético, del mismo sexo y grupo de edad, sin DM. La muestra de diabéticos se seleccionó de la población de pacientes que consultan a la Asociación Colombiana de Diabetes (ACD) en Bogotá. Se comprobó el estatus de diabético y de control sano mediante las pruebas de glucemia en ayunas y glucemia poscarga de glucosa. Se realizaron curvas de flujo volumen tanto para los diabéticos como para los controles, y de acuerdo con los valores de referencia obtenido por Hankinson para mexicoamericanos se obtuvieron valores residuales promedios (observado – esperado) para VEF1, CVF y relación VEF1/CVF. Mediante regresión lineal múltiple se ajustó por diferencias en determinantes conocidos de la función pulmonar (edad, sexo, talla, tabaquismo, exposición a humo de leña)...

Biomass fuels and respiratory diseases: a review of the evidence.

Globally, about 50% of all households and 90% of rural households use solid fuels (coal and biomass) as the main domestic source of energy, thus exposing approximately 50% of the world population-close to 3 billion people-to the harmful effects of these combustion products. There is strong evidence that acute respiratory infections in children and chronic obstructive pulmonary disease in women are associated with indoor biomass smoke. Lung cancer in women has been clearly associated with household coal use. Other conditions such as chronic obstructive pulmonary disease in men and tuberculosis could be also associated but evidence is scarce. According to estimates of the World Health Organization, more than 1.6 million deaths and over 38.5 million disability-adjusted life-years can be attributable to indoor smoke from solid fuels affecting mainly children and women. Interventions to suppress or reduce indoor exposure include behavior changes, improvements of household ventilation, improvements of stoves, and, outstandingly, transitions to better and cleaner fuels. These changes face personal and local beliefs and economic and sociocultural conditions. In addition, selection of fuels should consider cost, sustainability, and protection of the environment. Consequently, complex solutions need to be locally adapted, and involve the commitment and active participation of governments, scientific societies, nongovernmental organizations, and the general community.

Prevalence of COPD in five Colombian cities situated at low, medium, and high altitude (PREPOCOL study).

BACKGROUND: The prevalence of COPD in Colombia is unknown. This study aimed to investigate COPD prevalence in five Colombian cities and measure the association between COPD and altitude. METHODS: A cross-sectional design and a random, multistage, cluster-sampling strategy were used to provide representative samples of adults aged >or= 40 years. Each participant was interviewed (validated Spanish version of the Ferris Respiratory Questionnaire) and performed spirometry before and after 200 microg of inhaled salbutamol, using a portable spirometer according to American Thoracic Society recommendations. COPD definitions were as follows: (1) spirometric: fixed ratio (primary definition): FEV1/FVC < 70% after bronchodilator; (2) medical: a diagnosis of chronic bronchitis, emphysema, or COPD made by a physician; (3) clinical: cough and phlegm >or= 3 months every year during >or= 2 consecutive years (chronic bronchitis). Analysis was performed using statistical software. RESULTS: A total of 5,539 orsubjects were included. The overall COPD prevalence using the primary definition (spirometric) was 8.9%, ranging from 6.2% in Barranquilla to 13.5% in Medellín. The prevalence measured by the spirometric definition was higher than medical (2.8%) and clinical (3.2%) definitions. After the logistic regression analysis, the factors related with COPD were age >or= 60 years, male gender, history of tuberculosis, smoking, wood smoke exposure >or= 10 years, and very low education level. There was a nonsignificant tendency toward larger prevalence with higher altitude. CONCLUSION: COPD is an important health burden in Colombia. Additional studies are needed to establish the real influence of altitude on COPD prevalence.

Enfermedad pulmonar obstructiva crónica (EPOC) por humo de leña en mujeres / Chronic obstructive pulmonary disease (COPD) produced by woodsmoke in women

Objetivo: comparar las características clínicas, radiológicas y funcionales de mujeres con enfermedad pulmonar por exposición al humo de leña con las de mujeres con enfermedad pulmonar obstructiva crónica (EPOC) por cigarrillo en Bogotá, Colombia (2640 m).Material y métodos: estudio observacional analítico de corte transversal en mujeres con exposición crónica a humo de leña o a cigarrillo. Se realizó evaluación clínica, radiografía del tórax, espirometría, volúmenes pulmonares, difusión de monóxido de carbono (DLCO) y gases arteriales.Resultados: se incluyeron 139 mujeres, 86 con exposición a humo de leña y 53 a cigarrillo. La enfermedad por leña se caracterizó clínicamente por tos, expectoración y disnea; en la radiografía del tórax por infiltrados peribronquiales, atelectasias (28.6porcentaje), principalmente del lóbulo medio e hipertensión pulmonar (33.7porcentaje) y en la gasimetría arterial por hipoxemia (47.2±7 mmHg) e hipercapnia (34.5±5 mmHg) que aumentaron con la severidad de la obstrucción. Las pruebas de función pulmonar mostraron alteración obstructiva con hiperinflación, disminución de la DLCO menos severa que en la EPOC por cigarrillo, en la cual hubo disminución de la relación DLCO/volumen alveolar que no se observó en las mujeres expuestas a humo de leña. La correlación entre la disminución del volumen espiratorio forzado en el primer segundo (VEF1) y la disminución de la DLCO fue mayor en la EPOC por cigarrillo (p <0.001, r = 0.60).Conclusión: las mujeres expuestas al humo de leña desarrollan enfermedad pulmonar obstructiva con características clínicas y radiológicas de bronquitis crónica e hipertensión pulmonar. La hipoxemia y la hipercapnia son características, principalmente al aumentar la obstrucción y el comportamiento de la difusión sugiere la ausencia de enfisema significativo.

Generacion de valores de referencia para la evaluacion de la espirometria: Estudio en una poblacion colombiana / Spirometric reference values

Objetivo: derivar valores de referencia para Colombia de los parámetros espirométricos (CVF, VEF1, VEF1/CV, y FEF) más utilizados en la evaluación funcional del sistema respiratorio. Diseño: análisis secundario de datos generados en un estudio observacional analítico de corte transversal, que obtuvo información sobre antecedentes familiares y personales de síntomas o enfermedades pulmonares, en muestra probabilística de 4.224 personas de ambos sexos, a quienes se les realizó curvas de flujo volumen. Lugar: cinco municipios del Valle del Cauca. Pacientes: 1558 niños entre 9 y 18 años y 1150 adultos entre 19 y 65 años, libres de alteración pulmonar determinada por encuesta (Ferris B., 1978). Mediciones: 2708 curvas de flujo volumen realizadas de acuerdo con recomendaciones de la Sociedad Torácia Americana (ATS). Resultados: de la población general, 63,8 por ciento fueron mujeres. Entre la población adulta, 19,5 por ciento hombres. La población infantil se distribuyó homogéneamente entre ambos sexos. La descripción gráfica de los datos permitió establecer puntos de corte para la edad en 18 años para mujeres y 20 años para hombres. Se generaron ecuaciones de predicción para cuatro variables espirométricas considerando talla y edad como factores predictores para cada sexo y grupo de edad definido. Estas ecuaciones permiten el cálculo de valores de referencia y obtención del límite inferior de normalidad de cada parámetro estudiado. Conclusiones: los modelos obtenidos para VEF1 y CVF mostraron el mayor ajuste y precisión. La mayor variabilidad observada en los hombres, hace que se requiera, en estudios posteriores, mayor tamaño de muestra para predecir los parámetros de curvas de flujo volumen con una mejor precisión. Los valores de referencia generados, muestran similitud en la tendencia con los obtenidos por otros autores, pero cuantitativamente son diferentes. Estas ecuaciones deben ser validadas en poblaciones similares a aquélla de donde fueron derivadas.

Linfoma de Hodgkin primario de pulmón

Presentamos el caso de una mujer de 75 años, con artritis reumatoidea y síndrome de Sjogren, quien presenta un cuadro clínico de un año de evolución de disnea progresiva hasta el reposo acompañada de tos no productiva. La radiografía y la TAC del tórax mostraron infiltrado interticial bilateral micronodular e infiltrado de ocupación alveolar bibasal, sin la presencia de adenomegalias. Se realizó biopsia pulmonar abierta que fue demostrativa de enfermedades de Hodgkin asociada a cambios de pulmón reumatoideo (neumonia intersticial usual, UPI). No se encontró compromiso linfomatoso extratorácico en los estudios de extensión. Se discute la presentación clínica, radiológica y los hallazgos histológicos de esta infrecuente expresión de la enfermedad de Hodgkin