Assuntos
Embolia Aérea , Embolia Pulmonar , Humanos , Doença Iatrogênica , Embolia Pulmonar/etiologiaRESUMO
BACKGROUND: Lung cancer is the second most common cancer in both men and women. Mediastinal lymph node involvement in these patients, determined by imaging tests, indicates prognosis and modifies therapeutic attitude. PURPOSE: The aim of this study was to analyze the diagnostic capacity of magnetic resonance imaging (MRI) in the study of the mediastinum in comparison with conventional tests (computed tomography [CT] and positron-emission tomography [PET] or PET/CT scans), taking histology as the gold standard. MATERIALS AND METHODS: An observational study was conducted on 16 patients with suspicion of primary lung cancer (June 2016 through December 2018). We studied their demographic characteristics and used CT, PET, or PET/CT scans and MRI (diffusion-weighted imaging-MRI sequence) to examine mediastinal disease and compare MRIs diagnostic yield and percentage agreement to that of conventional tests. RESULTS: As compared to CT and PET scanning, MRI displayed a very low sensitivity and a specificity of 90 and 88%, respectively; positive predictive value was 0.67 (both) and negative predictive value (NPV) was 0.28 and 0.22, respectively. MRI showed a high degree of agreement in lymph node diagnosis when compared with histology (91.2%; P = 0.001): specificity in this case was high (E = 0.94), as was the NPV (NPV = 0.97). CONCLUSIONS: The results of this study would appear to indicate that MRI could play a relevant role in mediastinal staging of lung cancer. More prospective, multicenter studies are, however, needed to be able to draw up firm recommendations about the role of MRI and its place in lung cancer staging.
Assuntos
Neoplasias Pulmonares/fisiopatologia , Linfonodos/patologia , Linfadenopatia/patologia , Imageamento por Ressonância Magnética/métodos , Doenças do Mediastino/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Idoso , Seguimentos , Humanos , Linfadenopatia/diagnóstico por imagem , Metástase Linfática , Masculino , Doenças do Mediastino/diagnóstico por imagem , Valor Preditivo dos Testes , PrognósticoRESUMO
Introduction: Lung cancer is a major health problem. Mediastinal staging performed with the aid of imaging techniques is essential for appropriate disease treatment and prognosis. Accordingly, this study aimed to ascertain the usefulness of positron emission tomography (PET) in mediastinal staging, establish the best maximum standardized uptake value (SUVmax) cutoff point, compare its usefulness to that of computed tomography (CT), and determine the influence of histological tumour subtype. Methods: We conducted a retrospective study across a period of 3 years on 128 patients with suspicion of lung cancer and analyzed their demographic and radiological characteristics using CT and PET to perform the mediastinal examination. Histology was regarded as the gold standard. Results: PET displayed a high sensitivity (95%) and negative predictive value (NPV) (92%), outperforming CT (89% and 85%, respectively). Percentage agreement with histology was also higher (0.207 and 0.241 for CT and PET, respectively; p < 0.001). Taking an SUVmax value of 0.5 as that which would ensure greatest diagnostic accuracy, S and NPV were 100%, though percentage agreement did not increase (0.189; p < 0.001). PET discriminatory power was not affected by histological tumour subtype. Conclusions: The results of our study indicate that PET might be a useful test for examination of the mediastinum in lung cancer patients. Its high NPV suggests that the absence of mediastinal uptake could be used to proceed to surgical treatment without the need for further tests or examinations. Nevertheless, studies directly aimed to answer this specific question are needed.
Assuntos
Neoplasias Pulmonares , Linfadenopatia , Mediastino/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Idoso , Biópsia/métodos , Biópsia/estatística & dados numéricos , Pesquisa Comparativa da Efetividade , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/cirurgia , Linfadenopatia/diagnóstico , Linfadenopatia/patologia , Metástase Linfática/diagnóstico por imagem , Masculino , Estadiamento de Neoplasias , Seleção de Pacientes , Tomografia por Emissão de Pósitrons/métodos , Tomografia por Emissão de Pósitrons/estatística & dados numéricos , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Espanha/epidemiologia , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/estatística & dados numéricosRESUMO
INTRODUCTION: The aim of this study is to assess the diagnostic value of the magnetic resonance imaging (MRI) in differentiating metastasic from non-metastatic lymph nodes in NSCLC patients compared with computed tomography (CT) and fluorodeoxyglucose (FDG) - positron emission tomography (PET) or both combined. METHODS: Twenty-three studies (19 studies and 4 meta-analysis) with sample size ranging between 22 and 250 patients were included in this analysis. MRI, regardless of the sequence obtained, where used for the evaluation of N-staging of NSCLC. Histopathology results and clinical or imaging follow-up were used as the reference standard. Studies were excluded if the sample size was less than 20 cases, if less than 10 lymph nodes assessment were presented or studies where standard reference was not used. Papers not reporting sufficient data were also excluded. RESULTS: As compared to CT and PET, MRI demonstrated a higher sensitivity, specificity and diagnostic accuracy in the diagnosis of metastatic or non-metastatic lymph nodes in N-staging in NSCLC patients. No study considered MRI inferior than conventional techniques (CT, PET or PET/CT). Other outstanding results of this review are fewer false positives with MRI in comparison with PET, their superiority over PET/CT to detect non-resectable lung cancer, to diagnosing infiltration of adjacent structures or brain metastasis and detecting small nodules. CONCLUSION: MRI has shown at least similar or better results in diagnostic accuracy to differentiate metastatic from non-metastatic mediastinal lymph nodes. This suggests that MRI could play a significant role in mediastinal NSCLC staging.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Imageamento por Ressonância Magnética , Estadiamento de Neoplasias/métodos , Carcinoma Pulmonar de Células não Pequenas/patologia , Diagnóstico Diferencial , Humanos , Neoplasias Pulmonares/patologia , Linfonodos/patologia , Metástase Linfática/diagnóstico por imagem , Metástase Linfática/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Estudos Prospectivos , Estudos Retrospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios XRESUMO
Incidence of musculoskeletal disorders (MSDs) is high among health care workers (HCWs). To determine whether MSDs are associated with preexisting anxiety and/or depression, a case-control study was carried out in female HCWs (56 cases/55 controls). Cases were HCWs with a first-time clinical diagnosis of MSD within the previous 2 years. Occupation, workplace, work shift, direct patient assistance, and anxiety/depression scores (Goldberg scale) were assessed. Increased risk of incident MSDs (multivariate logistic regression) was found in workers with preexisting anxiety/depression compared to those without (OR 5.01; 95% CI 2.20-12.05; p < .01). Other significant risk factors were direct patient assistance (OR 2.59; 95% CI 1.03-6.92; p = .04) and morning work shift (OR 2.47; 95% CI 0.99-6.48; p = .05). Preexisting anxiety/depression was associated with incident MSDs in HCWs, adjusting for occupational exposure risk factors.
Assuntos
Ansiedade/epidemiologia , Depressão/epidemiologia , Pessoal de Saúde , Doenças Musculoesqueléticas/epidemiologia , Doenças Profissionais/epidemiologia , Adulto , Ansiedade/psicologia , Estudos de Casos e Controles , Depressão/psicologia , Feminino , Pessoal de Saúde/estatística & dados numéricos , Humanos , Incidência , Pessoa de Meia-Idade , Doenças Musculoesqueléticas/etiologia , Doenças Profissionais/etiologia , Fatores de Risco , Espanha/epidemiologia , Adulto JovemRESUMO
Influenza vaccination recommendations are traditionally met with low compliance by healthcare workers (HCWs). The aim of this study is to analyze influenza vaccination among HCWs following a vaccination strategy characterized by an increased effort to maximize the hospital vaccination rate. For this, 2009-2010 seasonal and pandemic influenza vaccination rates among 2739 HCWs at a tertiary university hospital were evaluated. The seasonal influenza vaccination rate was 26.7% (48.3% increase vs. 2008-2009, p=0.0000), and 14.8% in the case of pandemic influenza. HCWs with direct patient contact showed similar seasonal (25.7%) and pandemic (15.4%) influenza vaccination rates compared to the overall rates. Physician vaccination displayed the highest rate, showing significant differences vs. total rate (38.3%, p=0.0007 for seasonal, and 32.2%, p=0.0000 for pandemic influenza). The areas in which the vaccination strategy was most active reflected a significant increase (32.6%, p=0.0056 for seasonal, and 25.2%, p=0.0000 for pandemic influenza). It therefore appears that more active campaigns might increase influenza vaccination among HCWs.
Assuntos
Pessoal de Saúde/estatística & dados numéricos , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Vacinação/estatística & dados numéricos , Hospitais Universitários/estatística & dados numéricos , Humanos , Programas de Imunização , Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana/epidemiologia , Estudos Retrospectivos , Espanha/epidemiologiaRESUMO
The aim of this study was to compare the central inspiratory drive (P(0.1)) response to hypoxia and hypercapnia between different age groups of elderly, nonsmoker, healthy subjects and young healthy controls. A random sample, proportionally stratified by age (65-69, 70-74, 75-79 and 80-84 yrs) from a sample of nonsmoker elderly subjects representative of a general population and 47 healthy subjects aged 20-40 were selected. Arterial blood gas, lung volumes, diffusing capacity, maximal respiratory pressure and oxygen uptake measurements were performed. Breathing pattern and mouth occlusion pressure, as well as P(0.1) responses to hyperoxic progressive hypercapnia and isocapnic progressive hypoxia were evaluated. The elderly subjects had lower P0.1 responses to hypoxia (0.017+/-0.006 vs. 0.031+/-0.008 kPa/%, P<0.001) and hypercapnia (0.042+/-0.018 vs. 0.051+/-0.030 kPa/mmHg, P=0.047) than the young healthy controls. Hypoxic sensitivity gradually decreased as age increased to 70-74 and remained unchanged from 75 years of age onward. CO(2) threshold was lower in the elderly groups than in young healthy controls. Lung volumes, inspiratory muscle strength and baseline metabolic rate were the principal determinants of hypoxic sensitivity. In summary, during old age, a progressive decline in hypoxic sensitivity and a decrease in the CO(2) threshold are experienced. These alterations remain stable from the age of 75 onward.
Assuntos
Envelhecimento/fisiologia , Dióxido de Carbono/sangue , Células Quimiorreceptoras/fisiologia , Inalação/fisiologia , Oxigênio/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Volume Expiratório Forçado/fisiologia , Humanos , Masculino , Capacidade Vital/fisiologiaRESUMO
Together with inflammation and subsequent remodeling of airways, an imbalance between oxidative and anti-oxidative agents is generated during the development of numerous pulmonary diseases. This process seems to be involved in both the pathogenesis and chronification of asthma, chronic obstructive pulmonary disease (COPD), SOAS, interstitial lung diseases and cystic fibrosis. Reactive oxygen species including superoxide anion, hidroxyl radicals and hydrogen peroxide (H2O2) are synthetised as a response of inflammatory cells and are responsible of the oxidation of nucleic acids, proteins and membrane lipids, leading to cell damage and enhanced inflammation. Until recently, it was difficult to quantify the airway production of reactive oxidative species (ROS). In fact, it has been only in the last few years when it has been possible to determine indirectly the levels of ROS in expired air and in tissue of asthmatic patients. The analysis of exhaled air is a single, reproducible and non-invasive technique which is useful in the study of volatile and non-volatile gases generated in different conditions. The determination of exhaled nitric oxide and carbon monoxide (CO) has a great usefulness in the assessment of asthma. Nitric oxide seems to be closely related to the physiopathology of asthma and COPD. In fact, it is correlated with the levels of sputum eosinophils and with the response to the treatment with steroids. Yet a correlation with the degree of airflow obstruction and the seriousness of the process has not been found. Exhaled CO is another indirect marker of inflammation and it is increased in asthma, COPD, cystic fibrosis and bronchectases. Even though numerous studies have shown its usefulness as a marker of inflammation and in the response to corticosteroids, its clinical application has limitations. In particular, it is not a specific and exclusive marker of oxidative stress and its levels are highly influenced by tobacco smoke. On the other hand, the association between exhaled CO and FEV1 is not clear and no relationship has been proved so far with the improvement of pulmonary function after steroid therapy and with the decrease of maximum expiratory flow at relapses. In this Review, we describe the advances in the knowledge of oxidative stress as a decisive factor in the pathogenesis of prevalent pulmonary diseases, as well as the methods allowing its analysis and monitoring.
Assuntos
Estresse Oxidativo/fisiologia , Transtornos Respiratórios/metabolismo , Biomarcadores/análise , Testes Respiratórios , Monóxido de Carbono/análise , Monóxido de Carbono/metabolismo , Humanos , Óxido Nítrico/análise , Óxido Nítrico/metabolismo , Transtornos Respiratórios/diagnósticoRESUMO
AIMS: We tested the hypothesis that: (i) obstructive sleep apnoea (OSA) by itself originates pulmonary hypertension (PH); and (ii) the application of continuous positive airway pressure (CPAP) can reduce pulmonary pressure. METHODS AND RESULTS: In this randomized and cross-over trial, 23 middle-aged OSA (apnoea-hypopnoea index, 44.1 +/- 29.3 h(-1)) and otherwise healthy patients and 10 control subjects were included. OSA patients randomly received either sham or effective CPAP for 12 weeks. Echocardiographic parameters, blood pressure recordings, and urinary catecholamine levels were obtained at baseline and after both treatment modalities. At baseline, OSA patients had higher pulmonary artery systolic pressure than control subjects (29.8 +/- 8.8 vs. 23.4 +/- 4.1 mmHg, respectively, P = 0.036). Ten out of 23 patients [43%, (95% CI: 23-64%)] and none of the control subjects had PH at baseline (P = 0.012). Two patients were removed from the study because of inadequate CPAP compliance. Effective CPAP induced a significant reduction in the values for pulmonary systolic pressure (from 28.9 +/- 8.6 to 24.0 +/- 5.8 mmHg, P < 0.0001). The reduction was greatest in patients with either PH or left ventricular diastolic dysfunction at baseline. CONCLUSION: Severe OSA is independently associated with PH in direct relationship with disease severity and presence of diastolic dysfunction. Application of CPAP reduces pulmonary systolic pressure levels.
Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Hipertensão Pulmonar/terapia , Apneia Obstrutiva do Sono/terapia , Pressão Sanguínea/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Ecocardiografia , Feminino , Volume Expiratório Forçado/fisiologia , Humanos , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/fisiopatologia , Capacidade Vital/fisiologiaRESUMO
AIMS: To evaluate cardiac response to exercise in middle-aged normotensive obstructive sleep apnoea-hypoapnoea syndrome (OSAHS) adults with normal resting left ventricular systolic function and to test the hypothesis that nasal continuous positive airway pressure (CPAP) therapy might improve cardiac performance during exercise. METHODS AND RESULTS: We performed a prospective, randomized, double-blind, placebo-controlled, cross-over clinical trial including 31 consecutive newly diagnosed OSAHS patients and 15 healthy subjects. Cardiopulmonary exercise testing with cardiac output measurement, blood pressure (BP) recordings, and urinary excretion of catecholamine levels were obtained at baseline and after 3 months on both effective and sham CPAP. OSAHS subjects had higher systolic and mean nocturnal BP and higher nocturnal levels of catecholamines. In contrast, they had lower increments in cardiac output (Qt) and in stroke volume (SV) in response to exercise than control subjects. CPAP therapy was associated with highly significant improvements in all the indices of left ventricular systolic performance response during exercise, whereas with sham CPAP, all of them remained unchanged. CONCLUSION: OSAHS patients with normal resting left ventricular systolic function and no hypertension had a worse cardiac response to exercise than healthy subjects. In these patients, 3 months of CPAP improved both Qt and SV responses to exercise.
Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Exercício Físico/fisiologia , Apneia Obstrutiva do Sono/terapia , Análise de Variância , Baixo Débito Cardíaco , Estudos Cross-Over , Método Duplo-Cego , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Apneia Obstrutiva do Sono/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/terapiaRESUMO
BACKGROUND: The purpose of this study was to determine the role of obstructive sleep apnea syndrome (OSAS) as an independent risk factor for the development of left ventricular diastolic abnormalities. Moreover, we tested the hypothesis that nasal continuous positive airway pressure (nCPAP) improves such alterations in OSAS patients by eliminating apneic events. METHODS AND RESULTS: In this prospective, randomized, placebo-controlled, double-blind crossover study, 27 consecutive newly diagnosed middle-aged OSAS men with neither controllable factors nor conditions affecting left ventricular diastolic function and 15 healthy control subjects were selected. OSAS patients were randomized to 12 weeks on sham nCPAP and 12 weeks on effective nCPAP application. Echocardiographic parameters, blood pressure recordings, and urinary catecholamine levels were obtained at baseline and after both treatment modalities. At baseline, an abnormal left ventricular filling pattern was present in 15 of the 27 OSAS patients and only in 3 of the 15 control subjects (P=0.020). Impaired relaxation was by far the most common abnormal pattern in both groups (11 and 3 patients, respectively). In OSAS patients, 12 weeks on effective nCPAP induced a significant increase in E/A ratio (P<0.01), as well as reductions in mitral deceleration (P<0.01) and isovolumic relaxation (P<0.05) times. CONCLUSIONS: OSAS can affect left ventricular diastolic function independently of other possible factors. Chronic application of nCPAP could avoid the progression of diastolic abnormalities, and indeed, it might reverse these alterations, at least in the initial stages before severe structural changes can be developed.
Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Diástole , Apneia Obstrutiva do Sono/fisiopatologia , Apneia Obstrutiva do Sono/terapia , Função Ventricular Esquerda , Adulto , Idoso , Pressão Sanguínea , Estudos Cross-Over , Método Duplo-Cego , Ecocardiografia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Disfunção Ventricular Esquerda/terapiaRESUMO
STUDY OBJECTIVES: To compare the frequency of daytime and nocturnal cardiac arrhythmias and ST-segment depression episodes among patients with obstructive sleep apnea-hypopnea syndrome (OSAHS), snoring subjects, and healthy subjects, and to analyze the relationship between the cardiac disturbances, sleep characteristics, and sympathetic tone in patients with OSAHS. PATIENTS AND INTERVENTIONS: Twenty-one consecutive patients with OSAHS, 12 snorers without hypersomnolence, and 15 healthy subjects were selected. Polysomnography, 24-h Holter ECG recording, and urinary catecholamine determination were simultaneously performed on all subjects. RESULTS: Patients with OSAHS had more daytime and nocturnal episodes of sinus and supraventricular arrhythmias and couplets than the snoring and control groups. Moreover, nocturnal ST-segment depression episodes were more frequent in the OSAHS group than in control subjects (0.565 +/- 0.826/h vs 0 +/- 0/h [mean +/- SD]). In patients with OSAHS, arousal index and daytime epinephrine levels were related to daytime and nocturnal ST-segment depression episodes, whereas minimum arterial oxygen saturation was related to nocturnal sinus bradycardia and supraventricular tachycardia. Epinephrine and norepinephrine urinary concentrations correlated with sinus and supraventricular arrhythmias. CONCLUSIONS: Patients with OSAHS have a higher frequency of cardiac rhythm disturbances and ST-segment depression episodes than snoring and control subjects. Moreover, ST-segment changes are related to sympathetic tone and sleep fragmentation, whereas most of the rhythm disturbances in patients with OSAHS are associated with sleep fragmentation, nocturnal hypoxemia, and sympathetic tone.
Assuntos
Arritmias Cardíacas/epidemiologia , Apneia Obstrutiva do Sono/epidemiologia , Ronco/epidemiologia , Nível de Alerta , Arritmia Sinusal/epidemiologia , Arritmias Cardíacas/sangue , Pressão Sanguínea , Catecolaminas/sangue , Eletrocardiografia Ambulatorial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Apneia Obstrutiva do Sono/sangueRESUMO
BACKGROUND: The strength of the association between obstructive sleep apnea-hypopnea syndrome (OSAHS) and systemic hypertension could be affected by methodologic problems in the definition of hypertension. STUDY OBJECTIVES: To determine the frequency of white coat hypertension (WCH) in patients with OSAHS, and to analyze the characteristics of patients with OSASH and WCH. PATIENTS AND INTERVENTIONS: Ninety-nine consecutive patients with OSAHS and 20 healthy control subjects were included into the study. Twenty-four-hour ambulatory BP monitoring (ABPM) and urinary catecholamines were determined simultaneously with the polysomnographic study. Arterial blood gases and lung volumes were also measured. RESULTS: Office hypertension was diagnosed in 45 patients, while the control group included 54 normotensive patients with OSAHS. After ABPM, hypertension was confirmed in 30 patients with OSAHS and office hypertension. WCH was diagnosed in the remaining 15 patients (33%). Patients with WCH presented higher values of sleep onset latency and wake after sleep onset than normotensive and sustained hypertensive patients. No other differences in sleep parameters, function tests, or urinary catecholamines were found between the OSAHS groups. CONCLUSION: The results indicate that WCH is a frequent phenomenon in patients with OSAHS, and that it is not predictable by clinical variables.
Assuntos
Hipertensão/diagnóstico , Visita a Consultório Médico , Apneia Obstrutiva do Sono/fisiopatologia , Ansiedade/fisiopatologia , Monitorização Ambulatorial da Pressão Arterial , Catecolaminas/urina , Feminino , Humanos , Hipertensão/etiologia , Hipertensão/psicologia , Masculino , Pessoa de Meia-Idade , Polissonografia , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/diagnósticoRESUMO
The study objectives were to analyze the changes in exhaled carbon monoxide (COex) induced by histamine provocation challenge in asthmatic patients and to evaluate the relationship between COex and airway sensitivity and reactivity. Levels of COex were measured in 105 nonsmoking mildly asthmatic subjects before and after histamine provocation challenge. Dose-response curves were characterized by their sensitivity (PD20) and reactivity. Dose-response slope (DRS), continuous index of responsiveness (CIR), and bronchial reactivity index (BRI) were determined as reactivity indices. Bronchial challenge was positive for 47 subjects and negative for 58. The COex levels rose significantly after bronchial challenge in the positive response group (4.49 +/- 0.4 vs. 5.74 +/- 0.57 ppm, p = 0.025) and in the negative response group (2.84 +/- 0.25 vs. 4.00 +/- 0.41 ppm, p = 0.000). An inverse relation between basal COex and PD20 was found (r = -0.318, p = 0.030). In all subjects, a proportional direct relationship between COex and DRS (r = 0.214, p = 0.015), CIR (r = 0.401, p = 0.000), and BRI (r = 0.208, p = 0.012) was observed. On stepwise multiple linear regression analysis, COex only significantly correlated with CIR (multiple r2 = 0.174, p = 0.000). In conclusion, exhaled CO determination is a noninvasive inflammatory marker of the respiratory tract, which shows an acceptable association with airway hyperresponsiveness.
Assuntos
Asma/diagnóstico , Hiper-Reatividade Brônquica/diagnóstico , Testes de Provocação Brônquica/métodos , Monóxido de Carbono/análise , Adulto , Asma/fisiopatologia , Testes Respiratórios , Hiper-Reatividade Brônquica/induzido quimicamente , Feminino , Histamina/efeitos adversos , Humanos , Masculino , EspirometriaRESUMO
Mean inspiratory pressure (Pi), estimated from the occlusion pressure at the mouth and the inspiratory time, is useful as a noninvasive estimate of respiratory muscle effort during spontaneous breathing in normal subjects and patients with chronic obstructive pulmonary disease. The aim of this study was to compare the Pi with respect to mean esophageal pressure (Pes) in patients with restrictive disorders. Eleven healthy volunteers, 12 patients with chest wall disease, 14 patients with usual interstitial pneumonia, and 17 patients with neuromuscular diseases were studied. Pi, Pes, and mean transdiaphragmatic pressure were simultaneously measured. Tension-time indexes of diaphragm (TTdi) and inspiratory muscles (TTmu) were also determined. In neuromuscular patients, significant correlations were found between Pi and Pes, Pi and transdiaphragmatic pressure, and TTmu and TTdi. A moderate agreement between Pi and Pes and between TTmu and TTdi was found. No significant correlation between these parameters was found in the other patient groups. These findings suggest that Pi is a good surrogate for the invasive measurement of respiratory muscle effort during spontaneous breathing in neuromuscular patients.