Caracterización clínica y tomográfica de pacientes hospitalizados con COVID-19 / Clinical and tomographic characterization of patients hospitalized with COVID-19

OBJETIVO: Realizar una caracterización clínica y por imágenes a pacientes hospitalizados por COVID-19 y analizar si existen predictores de riesgo asociados con una mayor gravedad. MÉTODO: Estudio observacional, retrospectivo. Se incluyeron pacientes hospitalizados con COVID-19, entre abril y julio de 2020. Se registraron datos demográficos, comorbilidades, exámenes de laboratorio, tipo de compromiso en tomografía computada (TC) de tórax, terapias recibidas y tipo de soporte respiratorio. En el análisis estadístico para identificar factores de riesgo se utilizó test χ2 de Pearson o test de Fisher para comparar variables categóricas y test de Mann-Whitney para comparar variables continuas. RESULTADOS: Se analizaron 164 pacientes. La mediana de edad fue de 57 años (rango 21 a 89). 111 pacientes (68%) de género masculino y mediana de 7 días de síntomas previo al ingreso (rango 1 a 23). 68 pacientes (41%) tienen obesidad (significativamente mayor en pacientes < 60 años, p = 0,026), 56 (34%) hipertensión arterial (HTA) y 43 (26%) diabetes. El patrón predominante en la TC de ingreso fue de vidrio esmerilado (VE) con "crazy paving" (35%) y luego VE puro (28%). Como indicador de gravedad se tomó en cuenta el tipo de soporte ventilatorio requerido: 51 pacientes (31%) requieren soporte ventilatorio no invasivo (cánula nasal de alto flujo o VMNI) y 19 (11%) ventilación invasiva (VMI). Las variables predictoras de gravedad, estadísticamente significativas, fueron: HTA (p = 0,001), Diabetes Mellitus (p = 0,001) y Obesidad. (p = 0,002). CONCLUSIONES: Los pacientes hospitalizados por COVID 19 con mayor riesgo de evolución tórpida, del punto de vista respiratorio, fueron los pacientes obesos, hipertensos y diabéticos.

OBJECTIVE: To perform a clinical and imaging characterization in patients hospitalized for COVID-19 and to analyze whether there are risk predictors associated with greater severity of the condition. METHOD: Observational, retrospective study. Patients hospitalized with COVID-19 were included between April and July 2020. Demographic data, comorbidities, laboratory tests, tomographic pattern in thorax tomography (TC), therapies received, and type of respiratory support were recorded. In the statistical analysis to identify risk factors, we used Pearson's χ2 test or Fisher's test to compare categorical variables and Mann-Whitney test to compare continuous variables. RESULTS: 164 patients were analyzed. Median age was 57 years (21 to 89). 111 patients (68%) were male and a median of 7 days of symptoms prior to admission (1 to 23). 68 patients (41%) have obesity (significantly higher in patients < 60 years, p = 0.026), 56 (34%) arterial hypertension (HT) and 43 (26%) with diabetes mellitus. The predominant pattern in the admission CT scan was ground glass opacity (GGO) with "crazy paving" (35%) and then pure GGO (28%). Type of ventilatory support required was considered as an indicator of severity. 51 patients (31%) require non-invasive ventilatory support (high-flow nasal cannula or NIMV) and 19 (11%) invasive ventilation (IMV). The statistically significant predictor variables of severity were HT (p = 0.001), Diabetes Mellitus (p = 0.001) and Obesity. (p = 0.002). CONCLUSIONS: Patients hospitalized for COVID 19 with the highest risk of respiratory torpid evolution were obese, hypertensive and diabetic patients

Ecuaciones de referencia para informe de espirometrías. ¿Será tiempo de adoptar las ecuaciones de la Global Initiative for Lung Function? / Reference equations for spirometry values. Should be time for adopting the Global Lung Function Initiative equations?

Las guías ATS/ERS recomiendan utilizar valores de referencia nacionales para la interpretación de la espirometría. En 2014 se publicaron valores de referencia en población general chilena adulta, que difieren de los de Knudson actualmente en uso. Sin embargo, la mayoría de los laboratorios de función pulmonar siguen utilizando estas últimas ecuaciones. En 2012 se publicaron las ecuaciones multi-étnicas de la Global Lung Function Initiative (GLI) a fin de estandarizar mundialmente la interpretación de los exámenes de función pulmonar Nuestro objetivo fue comparar la concordancia de los informes espirométricos utilizando las ecuaciones más usadas en Chile versus las GLI. Métodos: Se comparó la concordancia en interpretación del patrón espirométrico (normal, obstructivo y restrictivo) y el grado de alteración, entre GLI con Gutiérrez 2014, con Knudson, y con NHANES III según las recomendaciones de la Sociedad Chilena de Enfermedades Respiratorias, a través del coeficiente de concordancia Kappa (K). Se estudiaron 315 sujetos mayores de 40 años (55% mujeres, edad: 59,3 ± 9,2 años), fumadores o ex fumadores, sanos o con EPOC, sometidos a una espirometría con broncodilatador como parte de un reconocimiento respiratorio. Se graficaron las diferencias utilizando el método de Bland-Altman. Resultados: La concordancia para patrón entre GLI con Gutiérrez 2014, con Knudson y con NHANES III fue buena (K = 0,73; 0,71 y 0,77 respectivamente), al igual que para patrón y grado de alteración (K = 0,68; 0,67 y 0,76 respectivamente). Conclusiones: Encontramos una buena concordancia entre las ecuaciones más usadas en Chile y las de GLI, en una muestra que incluyó adultos, fumadores, ex fumadores sanos y enfermos.

ATS/ERS recommend the use of national reference values for the interpretation of spirometry. Reference values were published (2014) in general adult Chilean population, which are different from those of Knudson currently in use. However, most pulmonary function laboratories continue to use these latter equations. Multi-ethnic Global Lung Function Initiative (GLI) equations were published (2012) in order to standardize the interpretation of pulmonary function tests worldwide. Our objective was to evaluate the agreement in the spirometric reports between the most used equations in Chile with those from GLI. Methods: We compared the agreement in the interpretation of the spirometric pattern (normal, obstructive and restrictive) and the degree of alteration between GLI with Gutiérrez 2014, with Knudson and with NHANES III according to recommendations of the Chilean Society of Respiratory Diseases, through the Kappa concordance coefficient (K). The sample correspond to 315 adults over 40 years of age (55% women, 59.3 ± 9.2 years-old), smokers or ex-smokers, healthy or with COPD, who underwent spirometry with a bronchodilator as part of a respiratory check-up. Differences were plotted using the Bland-Altman method. Results: agreement for pattern between GLI with Gutiérrez 2014, with Knudson and with NHANES III was good (K = 0.73, 0.71 and 0.77 respectively) and also was good for the pattern and degree of alteration (K = 0.68, 0.67 and 0.76 respectively). Conclusions: We found a good agreement between the equations most used in Chile and those from the GLI, for a sample that includes subjects with and without lung disease, smokers and ex-smokers.

Cáncer pulmonar: prevención y pesquisa precoz / Lung cancer: screening and prevention

El cáncer pulmonar es el más mortal de todos los cánceres. Debido a que la gran mayoría de los cánceres pulmonares son causados por el hábito de fumar, su erradicación es la mejor estrategia de prevención primaria. El diagnóstico del cáncer pulmonar en etapas tempranas mejora significativamente su pronóstico, por lo que ésta es la mejor estrategia de prevención secundaria. Recientemente se ha reportado que un programa de pesquisa de cáncer pulmonar con escáner de tórax (TAC) reduce la mortalidad por cáncer. El objetivo de esta revisión es, en primer lugar, apelar a la evidencia en cuanto al rendimiento de los programas de pesquisa de cáncer pulmonar en poblaciones de alto riesgo, y en segundo lugar, analizar las distintas estrategias que tiene un médico cuando se enfrenta a un paciente a quien se le ha encontrado incidentalmente un nódulo pulmonar.

Lung cancer is a deadly disease. Since this cancer is closely related to tobacco smoke, the best way to avoid this disease is smoking prevention. Unfortunately smoking is a worldwide epidemic and in Chile its prevalence is not decreasing. The second best strategy is an early detection. For the first time there is a report showing that screening with the use of low dose CT reduces mortality from lung cancer. The prognosis is much better in early stages. The purpose of this publication is to review the evidence about screening of lung cancer, and to analyze the different strategies to deal, in the general practice, with a finding of a lung nodule.

Diagnóstico precoz de enfermedades pulmonares por tabaquismo / Early diagnose of smoking lung diseases

El tabaquismo es una epidemia y en Chile la prevalencia no ha disminuido. Entre las causas más importantes de muerte por tabaquismo están el cáncer pulmonar y la enfermedad pulmonar obstructiva crónica (EPOC). La erradicación del tabaquismo es la mejor estrategia de prevención de estas enfermedades. La segunda estrategia es la detección precoz de ellas. Sin embargo la EPOC está sub diagnosticada en todo el mundo. No está claro si la solución es hacer más espirometrías en población de riesgo. Es posible que otros métodos diagnósticos como la tomografía axial computada de tórax (TAC) y la difusión pulmonar, puedan mejorar la capacidad de diagnóstico precoz de esta enfermedad. El cáncer pulmonar es el más mortal de los cánceres. El diagnóstico en etapas tempranas mejora significativamente su pronóstico. Hay varios estudios en curso que evalúan el beneficio de hacer pesquisa de cáncer pulmonar con TAC

Cigarette smoking is worldwide epidemic and in Chile its prevalence is not decreasing. Lung cancer and COPD are important causes of smoking related mortality. Primary prevention of smoking is the best way to avoid these diseases. The second best strategy is an early detection of them. However COPD is under diagnosed all over the world and it is not clear if the solution is doing spirometry in risk population. CT scan of the chest and DLCO could increase the early diagnose. Lung cancer is a deadly disease. Its prognosis is much better in early stages. Currently there are some studies in progress evaluating the benefit of doing screening for lung cancer with CT of the chest

[Distal intestinal obstruction syndrome: report of two cases with cystic fibrosis]. / Síndrome de obstrucción intestinal distal en pacientes adultos con fibrosis quística: Casos clínicos.

Distal Intestinal Obstruction Syndrome (DIOS) has a 16% incidence among patients with Cystic Fibrosis (CF). It is characterized by an intestinal obstruction secondary to fecal impaction in distal ileum or cecum. We report two adult patients with DIOS. A female with CF and subjected to lung transplantation at the age of 13 years old. Five years later, she consulted for an intestinal obstruction. She was treated conservatively with a good clinical evolution. She had a new episode of DIOS eight months later that was also treated conservatively. A 31 year-old mole, subjected to bilateral lung transplantation nine years before, that was admitted to the hospital for a bronchiolitis. Three days after admission he started with an intestinal obstruction that was diagnosed as a DIOS. He was managed conservatively with a good clinical response.

Síndrome de obstrucción intestinal distal en pacientes adultos con fibrosis quística: Casos clínicos / Distal intestinal obstruction syndrome: Report of two cases with cystic fibrosis

Distal Intestinal Obstruction Syndrome (DIOS) has a 16 percent incidence among patients with Cystic Fibrosis (CF). It is characterized by an intestinal obstruction secondary to fecal impaction in distal ileum or cecum. We report two adult patients with DIOS. A female with CF and subjected to lung transplantation at the age of 13 years old. Five years later, she consulted for an intestinal obstruction. She was treated conservatively with a good clinical evolution. She had a new episode of DIOS eight months later that was also treated conservatively. A 31 year-old mole, subjected to bilateral lung transplantation nine years before, that was admitted to the hospital for a bronchiolitis. Three days after admission he started with an intestinal obstruction that was diagnosed as a DIOS. He was managed conservatively with a good clinical response.

Silicosis y trasplante pulmonar / Lung transplantation in silicosis

Silicosis is a prevalent disease in Chile, a developing miner country. Scarce information about lung transplantation as an alternative for treating severe silicosis is available. Objective: To describe the time and way of exposure to silica and the clinical characteristics of silicotic patients subjected to lung transplantation at Clinica Las Condes, Santiago. Patients and Methods: From 38 patients subjected to lung transplantation between 1999 and 2006, four of them were transplanted because of severe silicosis. Ldiopathic pulmonary fibrosis was the predominant underlying disease (55 percent) of these 38 patients. Results: The four silicotic patients were transplanted at an age ranging from 34 to 65 years old. Their period of exposure ranged between 5 and 30 years and symptoms become evident after 4 to 30 years of exposure. Two patients were miners, another one was a quartz grinding worker and the fourth of them was a polisher of dental prothesis, The surgery was complex because of distortion in pulmonary anatomy. The hospital length of stay was longer in silicotics as compared with non-silicotic patients with lung transplant (41 versus 21 days, p < 0.10; c²). The long-term clinical course has been satisfactory. Association with tuberculosis has not been shown in any of these patients, Conclusions: Lung transplant is an alternative in patients with severe silicosis. Pulmonary anatomy is distorted in these patients determining more perioperatory morbidity than in non-silicotic patients.

La silicosis es una enfermedad prevalente en Chile, que es un país minero y en desarrollo. Existe escasa bibliografía sobre trasplante pulmonar, como alternativa de tratamiento en silicosis avanzada. Objetivo: Describir el tiempo y forma de exposición a la sílice y las características clínicas de enfermos silicóticos tratados con trasplante pulmonar en la Clínica Las Condes de Santiago. Pacientes y Métodos: De un total de 38 pacientes en los que se practicó trasplante pulmonar entre 1999 y 2006, cuatro de ellos fueron trasplantados por padecer de silicosis avanzada. En estos 38 enfermos la fibrosis pulmonar idiopática fue la enfermedad subyacente predominante (55 por ciento). Resultados: Los 4 pacientes silicóticos fueron trasplantados a una edad que fluctuó entre 34 y 65 años. Su período de exposición varió entre 5 y 30 años y sus síntomas comenzaron a manifestarse 4 a 30 años después de iniciada la exposición. Dos pacientes eran mineros, otro trabajó en la molienda de cuarzo y el 4° enfermo fue pulidor de prótesis dentales. La cirugía fue compleja debido a la distorsión de la anatomía pulmonar de estos enfermos. La estadía hospitalaria fue más prolongada en los trasplantados silicóticos que en los no silicóticos (41 versus 21 días, p < 0,10; c²). La evolución clínica a largo plazo ha sido satisfactoria, no demostrándose asociación con tuberculosis. Conclusiones: El trasplante pulmonar es una alternativa de tratamiento en pacientes con silicosis avanzada. La anatomía de estos pacientes está alterada, lo cual determina mayor morbilidadperi-operatoria que en trasplantes pulmonares en pacientes no silicóticos.

Embolia pulmonar / Pulmonary embolism

La embolia pulmonar es la causa más frecuente de muerte de las cirugías electivas, y una complicación que presentan muchos pacientes hospitalizados por patologías cardíacas, respiratorias y oncológicas. Muchos de estos casos se pueden prevenir en forma efectiva y sencilla, reduciendo su morbilidad y mortalidad, por lo que se considera a la embolia pulmonar como la causa más frecuente de muertes hospitalarias prevenibles. A pesar de ello, en todo el mundo, un alto porcentaje de los pacientes que tiene indicación de profilaxis no la reciben. Por otra parte, el tratamiento de la embolia pulmonar reduce la mortalidad desde 30 por ciento a cifras entre 2 a 8 por ciento. Sin embargo, sólo un 50 por ciento de los pacientes con embolia pulmonar se diagnostican a tiempo. En este capítulo revisaremos nuevos conceptos en profilaxis, diagnóstico y tratamiento de esta enfermedad.

Estudio multicéntrico de factores pronósticos en adultos hospitalizados por neumonía adquirida en la comunidad / Prognostic factors and outcome of community-acquired pneumonia in hospitalized adult patients

Background: Severity assessment of community-acquired pneumonia (CAP) patients allows the clinician to decide the place of management and guide empirical antimicrobial treatment. Aim: To assess admission prognostic factors and outcome of CAP in immunocompetent adult patients hospitalized in 21 medical centers in Chile. Material and methods: Prospective evaluation of non immunocompromised adults with CAP admitted to 21 Chilean hospitals between July and August, 1999. All patients were assessed on admission and followed until discharge or death. Results: During the study period, 1,194 patients (aged 68±17 years, 573 males) were evaluated. Seventy two percent had an underlying disease (especially chronic cardiovascular, neurological, respiratory diseases and diabetes mellitus), and 90 percent were treated with ß-lactamic agents (especially a third generation cephalosporin or penicillin). Mean hospital length of stay was 11±9 days, 10 percent were admitted to Intermediate Care or Intensive Care Units (ICU), 6 percent were mechanically ventilated and in-hospital mortality was 15.7 percent. Admission prognostic factors associated with hospital mortality were: advanced age, male gender, presence of comorbidity (chronic cardiovascular, renal, neurological and hepatic disease), undernutrition, suspicion of aspiration, altered mental status, low blood pressure, tachypnea, absence of fever, high blood urea nitrogen, multilobar radiographic pulmonary infiltrates, high risk categories from Chilean Respiratory Diseases Society Consensus, admission to Intermediate Care Units or ICU, and mechanical ventilation. In the multivariate analysis, prognostic factors associated with high hospital mortality were: mental confusion, high blood urea nitrogen, multilobar pneumonia, presence of comorbidity and absence of fever on admission. Conclusions: These results validate in Chile, findings from foreign studies.

[Etiology and prognostics factors of community-acquired pneumonia among adults patients admitted to a regional hospital in Chile]. / Etiología y factores pronósticos de la neumonía adquirida en la comunidad en el adulto hospitalizado, Puerto Montt, Chile.

BACKGROUND: Community-acquired pneumonia (CAP) is a common and serious illness in Chile. AIM: To evaluate the etiology, severity, prognostic factors and blood culture yield of CAP requiring hospitalization in Puerto Montt in Southern, Chile. PATIENTS AND METHODS: All non immunocompromised adults with CAP admitted at Puerto Montt Hospital during one year, were prospectively studied. Clinical and radiological assessment was done in all patients. Blood and sputum cultures were obtained and serology for atypical agents was determined. RESULTS: We studied 200 patients, aged 63+/-19 years (109 males). The prognostic factors associated with mortality were an age over 65 years, an altered mental status, shock and acute renal failure. Etiology was demonstrated in 29% of patients. The most frequent pathogens were Streptococcus pneumoniae (40.7%), Haemophilus influenzae (23.7%) and Chlamydia pneumoniae (16.9%). Mixed infections were found in 17%. Fifteen atypical pathogens were identified in 12 patients. Of these only two received a specific treatment but no one died and their length hospital stay was similar than in the rest of the patients. Overall, blood cultures were positive in 12.5% of patients, but among alcoholics, 58% were positive. In only one percent of cases, positive cultures motivated therapeutic changes among clinicians. Eight percent of S pneumoniae strains were penicillin resistant. CONCLUSIONS: Atypical agents were a common cause of CAP in this group of patients, but their pathogenic role and treatment requirements are debatable. Focusing blood cultures on specific groups could improve their yield. The rate of Penicillin resistance for S pneumoniae was.

Etiologíay factores pronósticos de la neumonía adquirida en la comunidad en el adulto hospitalizado, Puerto Montt, Chile / Etiology and prognostics factors of community-acquired pneumonia among adults patients admitted to a regional hospital in Chile

Background: Community-acquired pneumonia (CAP) is a common and serious illness in Chile. Aim: To evaluate the etiology, severity, prognostic factors and blood culture yield of CAP requiring hospitalization in Puerto Montt in Southern, Chile. Patients and methods: All non immunocompromised adults with CAP admitted at Puerto Montt Hospital during one year, were prospectively studied. Clinical and radiological assessment was done in all patients. Blood and sputum cultures were obtained and serology for atypical agents was determined. Results: We studied 200 patients, aged 63±19 years (109 males). The prognostic factors associated with mortality were an age over 65 years, an altered mental status, shock and acute renal failure. Etiology was demonstrated in 29% of patients. The most frequent pathogens were Streptococcus pneumoniae (40.7%), Haemophilus influenzae (23.7%) and Chlamydia pneumoniae (16.9%). Mixed infections were found in 17%. Fifteen atypical pathogens were identified in 12 patients. Of these only two received a specific treatment but no one died and their length hospital stay was similar than in the rest of the patients. Overall, blood cultures were positive in 12.5% of patients, but among alcoholics, 58% were positive. In only one percent of cases, positive cultures motivated therapeutic changes among clinicians. Eight percent of S pneumoniae strains were penicillin resistant. Conclusions: Atypical agents were a common cause of CAP in this group of patients, but their pathogenic role and treatment requirements are debatable. Focusing blood cultures on specific groups could improve their yield. The rate of Penicillin resistance for S pneumoniae was low.

[Prognostic factors and outcome of community-acquired pneumonia in hospitalized adult patients]. / Estudio multicéntrico de factores pronósticos en adultos hospitalizados por neumonía adquirida en la comunidad.

BACKGROUND: Severity assessment of community-acquired pneumonia (CAP) patients allows the clinician to decide the place of management and guide empirical antimicrobial treatment. AIM: To assess admission prognostic factors and outcome of CAP in immunocompetent adult patients hospitalized in 21 medical centers in Chile. MATERIAL AND METHODS: Prospective evaluation of non immunocompromised adults with CAP admitted to 21 Chilean hospitals between July and August, 1999. All patients were assessed on admission and followed until discharge or death. RESULTS: During the study period, 1,194 patients (aged 68+/-17 years, 573 males) were evaluated. Seventy two percent had an underlying disease (especially chronic cardiovascular, neurological, respiratory diseases and diabetes mellitus), and 90% were treated with beta-lactamic agents (especially a third generation cephalosporin or penicillin). Mean hospital length of stay was 11+/-9 days, 10% were admitted to Intermediate Care or Intensive Care Units (ICU), 6% were mechanically ventilated and in-hospital mortality was 15.7%. Admission prognostic factors associated with hospital mortality were: advanced age, male gender, presence of comorbidity (chronic cardiovascular, renal, neurological and hepatic disease), undernutrition, suspicion of aspiration, altered mental status, low blood pressure, tachypnea, absence of fever, high blood urea nitrogen, multilobar radiographic pulmonary infiltrates, high risk categories from Chilean Respiratory Diseases Society Consensus, admission to Intermediate Care Units or ICU, and mechanical ventilation. In the multivariate analysis, prognostic factors associated with high hospital mortality were: mental confusion, high blood urea nitrogen, multilobar pneumonia, presence of comorbidity and absence of fever on admission. CONCLUSIONS: These results validate in Chile, findings from foreign studies.

[Clinical and radiological diagnosis of community-acquired pneumonia in adults]. / Diagnóstico clínico-radiológico de la neumonía del adulto adquirida en la comunidad.

Community acquired pneumonia in adults is an acute disease characterized by worsening in general conditions, fever, chills, cough, mucopurulent sputum and dyspnea; associated with tachycardia, tachypnea, fever and focal signs in pulmonary examination. The probability of pneumonia in a patient with acute respiratory symptoms depends on the disease prevalence in the environment where it is acquired and on clinical features. It is estimated that pneumonia prevalence is 3-5% in patients with respiratory disease seen in outpatient facilities. Clinical diagnosis of pneumonia without radiological confirmation lacks specificity because clinical presentation (history and physical examination) does not allow to differentiate pneumonia from other acute respiratory diseases (upper respiratory infections, bronchitis, influenza). Diagnosis must be based in clinical-radiological findings: clinical history and physical examination suggest the presence of pulmonary infection but accurate diagnosis is established when chest X ray confirms the existence of pulmonary infiltrates. Clinical findings and chest X ray do not permit to predict with certainty the etiology of pulmonary infection. Radiology is useful to confirm clinical suspicion, it establishes pneumonia location, its extension and severity; furthermore, it allows differentiation between pneumonia and other diseases, to detect possible complications, and may be useful in follow up of high risk patients. The resolution of radiological infiltrates often ensues several weeks or months after clinical recovery, especially in the elderly and in multilobar pneumonia cared for in intensive care units.

Diagnóstico clínico-radiológico de la neumonía del adulto adquirida en la comunidad / Clinical andradiiological diagnosis of community-acquired pneumonia in adults

Community acquired pneumonia in adults is an acute disease characterized by worsening in general conditions, fever, chills, cough, mucopurulent sputum and dyspnea; associated with tachycardia, tachypnea, fever and focal signs in pulmonary examination. The probability of pneumonia in a patient with acute respiratory symptoms depends on the disease prevalence in the environment where it is acquired and on clinical features. It is estimated that pneumonia prevalence is 3-5% in patients with respiratory disease seen in outpatient facilities. Clinical diagnosis of pneumonia without radiological confirmation lacks specificity because clinical presentation (history and physical examination) does not allow to differentiate pneumonia from other acute respiratory diseases (upper respiratory infections, bronchitis, influenza). Diagnosis must be based in clinical-radiological findings: clinical history and physical examination suggest the presence of pulmonary infection but accurate diagnosis is established when chest X ray confirms the existence of pulmonary infiltrates. Clinical findings and chest X ray do not permit to predict with certainty the etiology of pulmonary infection. Radiology is useful to confirm clinical suspicion, it establishes pneumonia location, its extension and severity; furthermore, it allows differentiation between pneumonia and other diseases, to detect possible complications, and may be useful in follow up of high risk patients. The resolution of radiological infiltrates often ensues several weeks or months after clinical recovery, especially in the elderly and in multilobar pneumonia cared for in intensive care units.

La neumonía del adulto adquirida en la comunidad es un cuadro de evolución aguda, caracterizado por compromiso del estado general, fiebre, calofríos, tos, expectoración mucopurulenta y dificultad respiratoria; asociado en el examen físico a taquicardia, taquipnea, fiebre y signos focales en el examen pulmonar. La probabilidad que un paciente con síntomas respiratorios agudos tenga una neumonía depende de la prevalencia de la enfermedad en el ambiente donde se presenta y de las manifestaciones clínicas del enfermo. Se estima que la prevalencia de neumonía en los servicios de atención ambulatoria corresponde a 3-5% de las consultas por patología respiratoria. El diagnóstico clínico de neumonía sin confirmación radiográfica carece de precisión ya que el cuadro clínico (historia y examen físico) no permite diferenciar con certeza al paciente con neumonía de otras condiciones respiratorias agudas (infecciones de la vía aérea superior, bronquitis, influenza). El diagnóstico de neumonía es clínico-radiográfico: la historia y examen físico sugieren la presencia de una infección pulmonar, pero el diagnóstico de certeza se establece cuando se confirma la presencia de infiltrados pulmonares en la radiografía de tórax. El cuadro clínico y los hallazgos de la radiografía de tórax no permiten predecir con certeza el agente etiológico de la infección pulmonar. La radiografía de tórax permite confirmar el diagnóstico clínico, establecer su localización, extensión y gravedad; además permite diferenciar la neumonía de otras patologías, detectar posibles complicaciones, y puede ser útil en el seguimiento de los pacientes de alto riesgo. La resolución de los infiltrados radiográficos a menudo ocurre varias semanas o meses después de la mejoría clínica, especialmente en el anciano y en la neumonía multilobar manejada en la UCI.