RESUMEN
OBJECTIVE: To collect all published cases up to January 2019 of pulmonary alveolar microlithiasis (PAM) in patients age 5 years and under and to compare their characteristics with those of the 1022 cases in the most recent all-age cohort published in 2015. STUDY DESIGN: We identified 28 cases of PAM worldwide in children age 5 years and under, accounting for only 2%-3% of all cases. RESULTS: Children seem more frequently symptomatic, notably with more cough and severe acute respiratory failure, but had no reported extrapulmonary manifestation. Children with PAM evidenced less typical radiologic findings, with frequent ground glass opacities not reported in adult cases and milder calcifications as less frequent, smaller, and mainly restricted to the lower lobes. CONCLUSIONS: PAM remains an uncommon diagnosis in young children, as symptoms and radiologic findings are less specific. Physicians should be aware to look for calcifications in chest computed tomography at mediastinal window and avoid elution of the bronchoalveolar lavage to find microliths. Collecting longitudinal data through an international registry would help in characterizing PAM to predict disease progression and plan lung transplantation.
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Calcinosis/epidemiología , Enfermedades Genéticas Congénitas/epidemiología , Enfermedades Pulmonares/epidemiología , Alveolos Pulmonares/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Lavado Broncoalveolar , Calcinosis/diagnóstico , Preescolar , Estudios de Seguimiento , Enfermedades Genéticas Congénitas/diagnóstico , Humanos , Lactante , Enfermedades Pulmonares/diagnóstico , Masculino , Radiografía TorácicaRESUMEN
Alveolar stresses are fundamental to enable the respiration process in mammalians and have recently gained increasing attention due to their mechanobiological role in the pathogenesis and development of respiratory diseases. Despite the fundamental physiological role of stresses in the alveolar wall, the determination of alveolar stresses remains challenging, and our current knowledge is largely drawn from 2D studies that idealize the alveolar septal wall as a spring or a planar continuum. Here we study the 3D stress distribution in alveolar walls of normal lungs by combining ex-vivo micro-computed tomography and 3D finite-element analysis. Our results show that alveolar walls are subject to a fully 3D state of stresses rather than to a pure axial stress state. To understand the contributions of the different components and deformation modes, we decompose the stress tensor field into hydrostatic and deviatoric components, which are associated with isotropic and distortional stresses, respectively. Stress concentrations arise in localized regions of the alveolar microstructure, with magnitudes that can be up to 27 times the applied alveolar pressure. Interestingly, we show that the stress amplification factor strongly depends on the level of alveolar pressure, i.e, stresses do not scale proportional to the applied alveolar pressure. In addition, we show that 2D techniques to assess alveolar stresses consistently overestimate the stress magnitude in alveolar walls, particularly for lungs under high transpulmonary pressure. These findings take particular relevance in the study of stress-induced remodeling of the emphysematous lung and in ventilator-induced lung injury, where the relation between transpulmonary pressure and alveolar wall stress is key to understand mechanotransduction processes in pneumocytes.
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Presión , Alveolos Pulmonares/fisiología , Estrés Mecánico , Animales , Presión Hidrostática , Masculino , Modelos Biológicos , Alveolos Pulmonares/diagnóstico por imagen , Ratas Sprague-Dawley , Microtomografía por Rayos XAsunto(s)
Endoscopía/métodos , Microscopía Confocal/métodos , Lesiones Precancerosas/diagnóstico por imagen , Lesiones Precancerosas/patología , Neoplasias del Sistema Respiratorio/diagnóstico por imagen , Neoplasias del Sistema Respiratorio/patología , Elastina , Humanos , Estudios Prospectivos , Alveolos Pulmonares/diagnóstico por imagen , Alveolos Pulmonares/patología , Reproducibilidad de los ResultadosRESUMEN
The lung acinus is the most distal portion of the airway responsible for the gas exchange. The normal acini are not visible on conventional computed tomography (CT), but the advent of micro-CT improved the understanding of the microarchitecture of healthy acini. The comprehension of the acinar architecture is pivotal for the understanding of CT findings of diseases that involve the acini. Centriacinar emphysema, for example, presents as round areas of low attenuation due to the destruction of the most central acini with compensatory enlargement of proximal acini due to alveolar wall destruction. In pulmonary fibrosis, intralobular septal fibrosis manifests as acinar wall thickening with an overlap of acinar collapse and compensatory dilation of surrounding acini constituting the cystic disease typical of the usual interstitial pneumonia pattern. This is a state-of-the-art review to describe the acinar structure from the micro-CT perspective and display how the comprehension of the acinar structure can aid in the interpretation of its microarchitecture disruption on conventional CT.
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Pulmón/diagnóstico por imagen , Alveolos Pulmonares/diagnóstico por imagen , Enfisema Pulmonar/diagnóstico por imagen , Fibrosis Pulmonar/diagnóstico por imagen , Tuberculosis Pulmonar/diagnóstico por imagen , Humanos , Tomografía Computarizada por Rayos X , Microtomografía por Rayos XAsunto(s)
Humanos , Lesiones Precancerosas/patología , Lesiones Precancerosas/diagnóstico por imagen , Neoplasias del Sistema Respiratorio/patología , Neoplasias del Sistema Respiratorio/diagnóstico por imagen , Microscopía Confocal/métodos , Endoscopía/métodos , Alveolos Pulmonares/patología , Alveolos Pulmonares/diagnóstico por imagen , Estudios Prospectivos , Reproducibilidad de los Resultados , ElastinaRESUMEN
OBJECTIVE: To evaluate prevalence, clinical manifestations, laboratory abnormalities and treatment in a multicenter cohort study including 847 childhood-onset systemic lupus erythematosus (cSLE) patients with and without diffuse alveolar hemorrhage (DAH), as well as concomitant parameters of severity. METHODS: DAH was defined as the presence of at least three respiratory symptoms/signs associated with diffuse interstitial/alveolar infiltrates on chest x-ray or high-resolution computer tomography and sudden drop in hemoglobin levels. Statistical analysis was performed using Bonferroni correction (p < 0.0022). RESULTS: DAH was observed in 19/847 (2.2%) cSLE patients. Cough/dyspnea/tachycardia/hypoxemia occurred in all cSLE patients with DAH. Concomitant parameters of severity observed were: mechanical ventilation in 14/19 (74%), hemoptysis 12/19 (63%), macrophage activation syndrome 2/19 (10%) and death 9/19 (47%). Further analysis of cSLE patients at DAH diagnosis compared to 76 cSLE control patients without DAH with same disease duration [3 (1-151) vs. 4 (1-151) months, p = 0.335], showed higher frequencies of constitutional involvement (74% vs. 10%, p < 0.0001), serositis (63% vs. 6%, p < 0.0001) and sepsis (53% vs. 9%, p < 0.0001) in the DAH group. The median of disease activity score(SLEDAI-2 K) was significantly higher in cSLE patients with DAH [18 (5-40) vs. 6 (0-44), p < 0.0001]. The frequencies of thrombocytopenia (53% vs. 12%, p < 0.0001), intravenous methylprednisolone (95% vs. 16%, p < 0.0001) and intravenous cyclophosphamide (47% vs. 8%, p < 0.0001) were also significantly higher in DAH patients. CONCLUSIONS: This was the first study to demonstrate that DAH, although not a disease activity score descriptor, occurred in the context of significant moderate/severe cSLE flare. Importantly, we identified that this condition was associated with serious disease flare complicated by sepsis with high mortality rate.
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Hemorragia/etiología , Enfermedades Pulmonares/etiología , Lupus Eritematoso Sistémico/complicaciones , Alveolos Pulmonares , Edad de Inicio , Niño , Ciclofosfamida/uso terapéutico , Glucocorticoides/uso terapéutico , Hemoglobina A/análisis , Hemoptisis/etiología , Hemorragia/sangre , Hemorragia/diagnóstico por imagen , Humanos , Enfermedades Pulmonares/sangre , Enfermedades Pulmonares/diagnóstico por imagen , Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/tratamiento farmacológico , Activación de Macrófagos , Metilprednisolona/uso terapéutico , Alveolos Pulmonares/diagnóstico por imagen , Respiración Artificial/estadística & datos numéricos , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Evaluación de Síntomas/métodos , Brote de los Síntomas , Trombocitopenia/etiologíaRESUMEN
BACKGROUND: There is debate whether pressure transmission within the lungs and alveolar collapse follow a hydrostatic pattern or the compression exerted by the weight of the heart and the diaphragm causes collapse localized in the areas adjacent to these structures. The second hypothesis proposes the existence of a cephalocaudal gradient in alveolar collapse. We aimed to define whether or not lung density and collapse follow a 'liquid-like' pattern with homogeneous isogravitational layers along the cephalocaudal axis in acute respiratory distress syndrome lungs. METHODS: Acute respiratory distress syndrome patients were submitted to full lung computed tomography scans at positive end-expiratory pressure (PEEP) zero (before) and 25 cmH2 O after a maximum-recruitment maneuver. PEEP was then decreased by 2 cmH2 O every 4 min, and a semi-complete scan performed at the end of each PEEP step. RESULTS: Lung densities were homogeneous within each lung layer. Lung density increased along the ventrodorsal axis toward the dorsal region (ß = 0.49, P < 0.001), while there was no increase, but rather a slight decrease, toward the diaphragm along the cephalocaudal axis and toward the heart. Higher PEEP attenuated density gradients. At PEEP 18 cmH2 O, dependent lung regions started to collapse massively, while best compliance was only reached at a lower PEEP. CONCLUSIONS: We could not detect cephalocaudal gradients in lung densities or in alveolar collapse. Likely, external pressures applied on the lung by the chest wall, organs, and effusions are transmitted throughout the lung in a hydrostatic pattern with homogeneous consequences at each isogravitational layer. A single cross-sectional image of the lung could fully represent the heterogeneous mechanical properties of dependent and non-dependent lung regions.
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Pulmón/diagnóstico por imagen , Pulmón/fisiopatología , Síndrome de Dificultad Respiratoria/diagnóstico por imagen , Síndrome de Dificultad Respiratoria/fisiopatología , Tomografía Computarizada por Rayos X/métodos , Adolescente , Adulto , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Respiración con Presión Positiva , Alveolos Pulmonares/diagnóstico por imagen , Alveolos Pulmonares/fisiopatología , Posición Supina/fisiología , Adulto JovenRESUMEN
OBJECTIVE: The aim of this study was to evaluate the high-resolution computed tomographic (HRCT) findings from patients with leptospirosis and diffuse alveolar hemorrhage (DAH). MATERIALS AND METHODS: We retrospectively reviewed HRCT findings from 16 patients diagnosed as having leptospirosis causing DAH. The patient sample was composed of 13 men and 3 women aged 22 to 53 years (mean age, 34.5 years). Diagnosis was established with confirmation of leptospirosis infection by serologic microagglutination test. Histopathological study was performed in 8 patients. Two chest radiologists analyzed the HRCT images and reached decisions by consensus. RESULTS: The predominant HRCT findings were ground-glass opacities and airspace nodules (both n = 12, 75%), ground-glass nodules (n = 9, 56.25%), consolidations (n = 7, 43.75%), "crazy-paving" pattern (n = 3, 18.75%), and interlobular septal thickening without ground-glass opacity (n = 3, 18.75%). Bilateral pleural effusion was an associated finding in 2 (12.5%) patients. Analysis of the axial distribution of the lesions revealed diffuse distribution in 11 (68.75%) patients and peripheral lung zone predominance in 5 (31.25%) patients. Abnormalities were bilateral in all 16 (100%) patients. Analysis of the craniocaudal distribution of the lesions revealed lower zone predominance in 9 (56.25%) patients, diffuse distribution in 5 (31.25%) patients, middle zone predominance in 1 (6.25%) patient, and upper zone predominance in 1 (6.25%) patient. CONCLUSIONS: The most frequent HRCT findings in patients with leptospirosis causing DAH were ground-glass opacities, airspace nodules, ground-glass nodules, and consolidations. The lesions showed symmetrical distribution with lower zone predominance in most cases.
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Hemorragia/diagnóstico por imagen , Leptospirosis/diagnóstico por imagen , Enfermedades Pulmonares/diagnóstico por imagen , Alveolos Pulmonares/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Diagnóstico Diferencial , Femenino , Hemorragia/complicaciones , Hemorragia/microbiología , Humanos , Leptospirosis/complicaciones , Pulmón/diagnóstico por imagen , Pulmón/microbiología , Enfermedades Pulmonares/complicaciones , Enfermedades Pulmonares/microbiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto JovenRESUMEN
Coronary thrombolysis is used as a strategy for coronary reperfusion for acute myocardial infarction. Bleeding is the main complication described. Although most of these events occur at sites of vascular access and are mild, in some cases gastrointestinal, retroperitoneal, genitourinary, lung and central nervous system bleeding may occur. These episodes are usually serious and sometimes fatal. The following report describes the case of a patient who received thrombolytic therapy with streptokinase as a treatment for myocardial infarction. Subsequently he developed acute respiratory failure, bilateral pulmonary infiltrates and fall of hematocrit compatible with diagnosis of alveolar hemorrhage.
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Hemorragia/inducido químicamente , Enfermedades Pulmonares/inducido químicamente , Terapia Trombolítica/efectos adversos , Adulto , Humanos , Enfermedades Pulmonares/diagnóstico por imagen , Masculino , Infarto del Miocardio/terapia , Alveolos Pulmonares/diagnóstico por imagen , RadiografíaAsunto(s)
Inmunocompetencia/inmunología , Enfermedades Pulmonares Intersticiales/inmunología , Enfermedades Pulmonares Intersticiales/patología , Linfocitos/patología , Células Plasmáticas/patología , Biopsia , Femenino , Humanos , Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Linfocitos/inmunología , Persona de Mediana Edad , Células Plasmáticas/inmunología , Alveolos Pulmonares/diagnóstico por imagen , Alveolos Pulmonares/inmunología , Alveolos Pulmonares/patología , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: In hypersensitivity pneumonitis (HP), survival can be predicted on the basis of the severity of fibrosis in surgical lung biopsy, but few data are available on the influence of clinical, functional, tomographic and histologic findings on prognosis. OBJECTIVES: To describe the impact on survival of clinical data, histological patterns, and HRCT findings in subacute/chronic HP. METHODS: A retrospective analysis of 103 patients diagnosed with HP submitted to surgical lung biopsy. Chronic HP was characterized by HRCT findings indicative of fibrosis (n=76). RESULTS: The most relevant exposures were to molds and birds. Lung biopsies revealed typical HP with granulomas in 46 patients, bronchiolocentric interstitial pneumonia in 27, and non-specific interstitial pneumonia (NSIP) in 16. By univariate analysis, several findings were predictors of mortality: older age, male sex, velcro crackles, higher FEV(1)/FVC ratio, lower oxygen saturation during exercise, and absence of mosaic pattern/air trapping and presence of fibrosis on HRCT. By multivariate analysis, remained significant: age (p=0.007), oxygen saturation during exercise (p=0.003), and mosaic pattern/air trapping on HRCT (p=0.004). Patients with NSIP had a greater survival than did those with typical histology and those with bronchiolocentric pneumonia (p=0.033). CONCLUSIONS: A wide range of histological features are found in HP. Typical findings are seen in 45% of cases. Other common patterns are NSIP and centriacinar lesions. Survival is better in patients with NSIP and worse in those with older age, desaturation during exercise, and absence of mosaic pattern/air trapping on HRCT.
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Alveolitis Alérgica Extrínseca , Alveolos Pulmonares , Adolescente , Adulto , Anciano , Alveolitis Alérgica Extrínseca/diagnóstico por imagen , Alveolitis Alérgica Extrínseca/mortalidad , Alveolitis Alérgica Extrínseca/patología , Biopsia , Brasil/epidemiología , Enfermedad Crónica , Femenino , Hongos , Humanos , Enfermedades Pulmonares Intersticiales/diagnóstico , Enfermedades Pulmonares Intersticiales/mortalidad , Masculino , Persona de Mediana Edad , Pronóstico , Alveolos Pulmonares/diagnóstico por imagen , Alveolos Pulmonares/patología , Estudios Retrospectivos , Factores de Riesgo , Análisis de Supervivencia , Tomografía Computarizada por Rayos X/métodos , Adulto JovenRESUMEN
OBJECTIVE: Behcet's syndrome, or Behcet's disease (BD), is a multisystem pathology, and survival is related to pulmonary involvement. However, it appears that different treatments correlate with different prognoses. The aim of this study was to evaluate clinical and tomographic evolution, as well as the survival, of patients with BD-related pulmonary involvement. METHODS: A retrospective review of our experience with pulmonary manifestations in patients with BD treated at our institution between January 1, 1988 and April 30, 2006. The clinical, radiological, treatment and survival data were obtained from medical charts. RESULTS: We identified 9 patients with BD-related pulmonary involvement. The mean age was 34 +/- 11.5 years, and 7 of the patients were male. The radiological findings were as follows: pulmonary artery aneurysm (PAA) in 8 patients; pulmonary embolism in 3 (translating to an incidence of 5.11 cases/100 patient-years); alveolar hemorrhage in one; and pulmonary hypertension in one. The treatment consisted of immunosuppression with prednisone plus chlorambucil (or cyclophosphamide or mycophenolate mofetil) in all patients, with partial or complete resolution of the PAAs. One patient with a PAA and pulmonary hypertension also received sildenafil and warfarin, with good clinical and tomographic response (the first report in the English literature). In our sample, the mean duration of the follow-up period was 6.52 years. The three-year survival rate was 88.8%, as was the five-year survival rate. CONCLUSIONS: Patients with BD-related pulmonary involvement can present good survival with immunosuppressive therapy, and BD should be borne in mind as a possible cause of pulmonary hypertension and alveolar hemorrhage.
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Aneurisma/etiología , Síndrome de Behçet/complicaciones , Hipertensión Pulmonar/etiología , Arteria Pulmonar , Embolia Pulmonar/etiología , Adulto , Aneurisma/diagnóstico por imagen , Antiinflamatorios/uso terapéutico , Síndrome de Behçet/diagnóstico por imagen , Síndrome de Behçet/tratamiento farmacológico , Clorambucilo/uso terapéutico , Femenino , Hemorragia/diagnóstico por imagen , Humanos , Hipertensión Pulmonar/diagnóstico por imagen , Inmunosupresores/uso terapéutico , Masculino , Persona de Mediana Edad , Prednisona/uso terapéutico , Alveolos Pulmonares/diagnóstico por imagen , Arteria Pulmonar/diagnóstico por imagen , Embolia Pulmonar/diagnóstico por imagen , Radiografía , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
OBJECTIVE: To present the high-resolution computed tomography (HRCT) findings of pulmonary alveolar microlithiasis. METHODS: The HRCT scans of 10 adult patients (seven females and three males; mean age, 38.7 years) were retrospectively analyzed. The films were studied independently by two radiologists. RESULTS: The most common tomographic findings were ground-glass attenuation and linear subpleural calcifications, which were seen in 90% of the patients. Other relevant findings were small parenchymal nodules, calcification along the interlobular septa, nodular cissures, subpleural nodules, subpleural cysts, dense consolidations, and a mosaic pattern of attenuation. CONCLUSIONS: The HRCT findings presented by individuals with pulmonary alveolar microlithiasis are distinct. In most cases, such findings can form the basis of the diagnosis, eliminating the need to perform a lung biopsy.
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Calcinosis/diagnóstico por imagen , Litiasis/diagnóstico por imagen , Enfermedades Pulmonares/diagnóstico por imagen , Alveolos Pulmonares/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Quistes/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
CONTEXT AND OBJECTIVE: Many children with acute lower respiratory tract infections (ALRI) present to the emergency ward with concurrent wheezing. A chest x-ray is often requested to rule out pneumonia. We assessed inter-observer agreement in interpreting x-rays on such children. DESIGNS AND SETTING: Prospective consecutive case study at Instituto de Salud del Niño, Lima, Peru. METHODS: Chest x-rays were obtained from eligible children younger than two years old with ALRI and concurrent wheezing who were seen in the emergency ward of a nationwide pediatric referral hospital. The x-rays were read independently by three different pediatric residents who were aware only that the children had a respiratory infection. All the children had received inhaled beta-adrenergic agonists before undergoing chest x-rays. Lobar and complicated pneumonia cases were excluded from the study. RESULTS: Two hundred x-rays were read. The overall kappa index was 0.2. The highest individual kappa values for specific x-ray findings ranged from 0.26 to 0.34 for rib horizontalization and from 0.14 to 0.31 for alveolar infiltrate. Inter-observer variation was intermediate for alveolar infiltrate (kappa 0.14 to 0.21) and for air bronchogram (kappa 0.13 to 0.23). Reinforcement of the bronchovascular network (kappa 0.10 to 0.16) and air trapping (kappa 0.05 to 0.20) had the lowest agreement. CONCLUSIONS: There was poor inter-observer agreement for chest x-ray interpretation on children with ALRI and concurrent wheezing seen at the emergency ward. This may preclude reliable diagnosing of pneumonia in settings where residents make management decisions regarding sick children. The effects of training on inter-observer variation need further studies.
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Ruidos Respiratorios/diagnóstico , Infecciones del Sistema Respiratorio/diagnóstico por imagen , Enfermedad Aguda , Bronquiolitis/diagnóstico por imagen , Estudios Transversales , Interpretación Estadística de Datos , Servicio de Urgencia en Hospital , Humanos , Lactante , Internado y Residencia , Variaciones Dependientes del Observador , Pediatría , Neumonía/diagnóstico por imagen , Estudios Prospectivos , Alveolos Pulmonares/diagnóstico por imagen , Radiografía , Costillas/diagnóstico por imagenRESUMEN
Pulmonary alveolar microlithiasis (PAM) is an uncommon chronic disease characterized by calcifications within the alveoli and a paucity of symptoms in contrast to the imaging findings. We present a 59-year-old woman with a 4-year history of shortness of breath on exertion. Lung auscultation revealed random wheezes and fine and coarse crackles. Pulmonary function tests showed a restrictive pattern. The chest radiograph demonstrated a bilateral symmetric micronodular pattern. High resolution CT scan revealed diffuse ground-glass attenuation with superimposed septal thickening ("crazy-paving" pattern). The patient underwent a lung biopsy, which confirmed the diagnosis of PAM. Our case demonstrates that PAM needs to be considerate in the differential diagnosis of lung lesions that present with crazy-paving pattern on the high resolution CT.
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Cálculos/diagnóstico por imagen , Enfermedades Pulmonares/diagnóstico por imagen , Alveolos Pulmonares/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Enfermedad Crónica , Femenino , Humanos , Persona de Mediana EdadRESUMEN
To determine the prognostic factors for leptospirosis, we conducted a retrospective study of data collected in the emergency department of our hospital between 1989 and 1993. Sixty-eight patients, for whom the diagnosis of leptospirosis was based on pertinent clinical and epidemiological data and positive serology, were included in this study. Fifty-six patients (82%) were discharged from the hospital, and 12 (18%) died. Multivariate logistic regression demonstrated that five factors were independently associated with mortality: dyspnea (odds ratio [OR], 11.7; 95% confidence interval [CI], 2.8-48.5; P < .05), oliguria (OR, 9; CI, 2.1-37.9; P < .05); white blood cell count, >12,900/mm3 (OR, 2.5; CI, 1.8-3.5; P < or = .01), repolarization abnormalities on electrocardiograms (OR, 5.9; CI, 1.4-24.8; P < or = .01), and alveolar infiltrates on chest radiographs (OR, 7.3; CI, 1.7-31.7; P < or = .01). Identification of these factors on admission might provide useful selection criteria for patients who need early transfer to the intensive care unit.
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Leptospirosis/mortalidad , Adulto , Anciano , Estudios de Cohortes , Cuidados Críticos , Disnea/fisiopatología , Electrocardiografía , Servicios Médicos de Urgencia , Femenino , Humanos , Leptospirosis/diagnóstico , Leptospirosis/fisiopatología , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oliguria/fisiopatología , Pronóstico , Alveolos Pulmonares/diagnóstico por imagen , Radiografía , Estudios Retrospectivos , Indias Occidentales/epidemiologíaRESUMEN
Age is known to reduce the efficacy of body organs and systems, even in the absence of disease. The alveolar-capillary clearance (ACC) rate is representative of the alveolar-capillary barrier's functional state. We studied 29 healthy non-smokers, who were selected after clinical and radiographic evaluation. The patients were divided into three groups based on age: Group I, < or = 30 years (n = 10); Group II, 31-55 years (n = 9); Group III, > or = 56 years (n = 10). Each patient inhaled 750 MBq 99Tcm-diethylenetriamine pentaacetate (99Tcm-DTPA) aerosol generated by a Venticis nebulizer (particles with a mean diameter of 1.1 microns) for 5 min. Forty frames of 30 s duration each were acquired and the ACC rates for the right and left lungs determined using a computer program. The mean ACC rates for the three groups were as follows: Group I, 1.31% min-1; Group II, 1.08% min-1; Group III, 0.76% min-1. The differences between Groups I and III (P < 0.001) and Groups II and III (P = 0.03) were shown to be significant. There was no significant difference between Groups I and II. Possible explanations for an age-related reduction in ACC rates include a reduction in the internal alveolar surface, the closure of the small airways, a reduction in the lung blood capillaries and a reduction in cardiac output. We conclude that there appears to be an age-related reduction in ACC rates in healthy non-smokers, even in the absence of clinically and radiographically detectable lung disease. However, larger studies are required.