Imaging the airways has always been a difficult task. Since the introduction of high resolution computed tomography a lot has been achieved in this area, specially in the visualization of the small airways. With the fine details provided by this technique, morphological changes related to the bronchioles can now be detected in a way hitherto impossible. This study was aimed at the description of the CT scan signs of airway disease that were present in a group of 36 patients suffering from chronic respiratory symptoms of cough and great amount of sputum production (bronchial suppuration) attending the outpatient clinics of the Pulmonary Disease Service of the State University of Campinas School of Medicine. Among these patients, 12 were diagnosed as having cystic fibrosis, and 24, other diseases with chronic sputum production. The authors looked for the direct signs of airway disease, such as thickening of the wall and dilatation of the lumen of large airways and these same abnormalities, appearing as micronodules at the center of the lobule and branching linear opacities, or a combination of the two (the so-called "tree in bud" pattern), when the disease is predominantly located in the small airways, in the films obtained from all the patients. The indirect signs of small airway disease, like mosaic perfusion and air-trapping, were also analyzed. Imaging of the airways has come of age with the use of high-resolution computed tomography and there is little doubt that this technique is now the most sensitive radiographic method for imaging the small airways, this previously hidden area of the lungs.

Keywords: Computed tomography. High resolution computed tomography. Airway diseases. Bronchiolar diseases. Bronchiectasis.

Neuromuscular diseases affect alveolar air exchange and therefore cause chronic respiratory failure. The onset of respiratory failure can be acute, as in traumas, or progressive (slow or rapid), as in amyotrophic lateral sclerosis, muscular dystrophies, diseases of the myoneural junction, etc. Respiratory muscle impairment also affects cough efficiency and, according to the current knowledge regarding the type of treatment available in Brazil to these patients, it can be said that the high rates of morbidity and mortality in these individuals are more often related to the fact that they cough inefficiently rather than to the fact that they ventilate poorly. In this review, with the objective of presenting the options of devices available to support and substitute for natural ventilation in patients with neuromuscular diseases, we have compiled a brief history of the evolution of orthopedic braces and prostheses used to aid respiration since the end of the 19th century. In addition, we highlight the elements that are fundamental to the diagnosis of alveolar hypoventilation and of failure of the protective cough mechanism: taking of a clinical history; determination of peak cough flow; measurement of maximal inspiratory and expiratory pressures; spirometry in two positions (sitting and supine); pulse oximetry; capnography; and polysomnography. Furthermore, the threshold values available in the literature for the use of nocturnal ventilatory support and for the extension of this support through the daytime period are presented. Moreover, the maneuvers used to increase cough efficiency, as well as the proper timing of their introduction, are discussed.

Keywords: Respiratory insufficiency/diagnosis; Chronic disease; Respiratory insufficiency/therapy;

In cases of recent asthma in which clinical control with the usual treatment (corticosteroids and bronchodilator) is unsatisfactory, it is important to consider other diagnoses, such as congestive heart failure, gastroesophageal reflux or other forms of airway obstruction. We report the case of a female patient with mucoepidermoid carcinoma of the trachea mimicking asthma. The patient presented cough and wheezing, as well as abnormal spirometry results with an obstructive pattern that was responsive to bronchodilators. One year later, the patient presented clinical and spirometric worsening. The chest X-ray revealed no abnormalities. A CT scan showed a vegetative lesion obstructing the tracheal lumen and located 1 cm from the carina. Fiberoptic bronchoscopy showed a finding similar to a bronchial carcinoid tumor. The anatomopathological diagnosis made after surgical resection was low-grade mucoepidermoid carcinoma, without lymph node involvement. Although the flow-volume curve was not suggestive of upper airway obstruction, the spirometry performed after the surgery showed a significant reduction in the degree of obstruction and greater reversibility after bronchodilator use. There was no evidence of recurrence of the disease or of the symptoms after a two-year follow-up period.

Keywords: Bronchial hyperreactivity; Carcinoma, mucoepidermoid; Trachea; Asthma; Lung diseases, obstructive.

Eosinophilia-myalgia syndrome was described in 1989 in patients who presented progressive and incapacitating myalgia and eosinophilia in blood, fluids and secretions. Most patients report previous L-tryptophan intake. Respiratory manifestations are found in up to 80% of the cases, occasionally as the only manifestation. Treatment includes drug discontinuation and administration of corticosteroids. Here, we describe the case of a 61-year-old female admitted with acute respiratory failure after using L-tryptophan, hydroxytryptophan and other drugs. The patient presented eosinophilia, together with elevated eosinophil counts in the bronchoalveolar lavage and pleural effusion. After discontinuation of the drugs previously used, corticosteroids were administered, resulting in clinical and radiological improvement within just a few days.

Keywords: Respiratory insufficiency; Tryptophan; Eosinophilia-myalgia syndrome.

Objective: To determine the probability of oxygen desaturation in healthy individuals undergoing the incremental shuttle walk test (ISWT). Methods: We enrolled 83 healthy subjects: 55 males (including 1 smoker) and 28 females. We determined pre-ISWT FEV1, FEV6, HR and SpO2, as well as post-ISWT HR and SpO2. Results: Mean values overall were as follows: age, 35.05 ± 12.53 years; body mass index, 24.30 ± 3.47 kg/m2; resting HR, 75.12 ± 12.48 bpm; resting SpO2, 97.96 ± 1.02%; FEV1, 3.75 ± 0.81 L; FEV6, 4.45 ± 0.87 L; FEV1/FEV6 ratio, 0.83 ± 0.08 (no restriction or obstruction); incremental shuttle walk distance, 958.30 ± 146.32 m; post-ISWT HR, 162.41 ± 18.24 bpm; and post-ISWT SpO2, 96.27 ± 2.21%. In 11 subjects, post-ISWT SpO2 was higher than was pre-ISWT SpO2. In 17 subjects, there was a 4% decrease in SpO2 after the ISWT. There were no statistically significant differences between the groups with and without post-ISWT oxygen desaturation in terms of age, gender, FEV1, FEV6, FEV1/FEV6, pre-ISWT SpO2, incremental shuttle walk distance, HR, or percentage of maximal HR. In the individuals with post-ISWT oxygen desaturation, the body mass index was higher (p = 0.01) and post-ISWT SpO2 was lower (p = 0.0001). Conclusions: Healthy individuals can present oxygen desaturation after the ISWT. Using the ISWT to predict subtle respiratory abnormalities can be misleading. In healthy subjects, oxygen desaturation is common after the ISWT, as it is during any intense physical activity.

Keywords: Heart function tests; Respiratory function tests; Body mass index; Oximetry

Abstract Objective: To determine the levels of alpha-1 antitrypsin (AAT) and the presence of S and Z alleles in patients with chronic respiratory symptoms. Methods: Patients with chronic cough and dyspnea were submitted to clinical evaluation, pulmonary function tests, high-resolution computed tomography, nephelometric determination of AAT and determination of S and Z alleles by polymerase chain reaction. Smoking and AAT levels were considered the dependent variables. Results: Of the 89 patients included in the study, 44 were female. The mean age was 51.3 ± 18.2 years. The S and Z alleles were detected in 33.3% and 5.7%, respectively, and the gene frequency was 0.16 and 0.028, respectively. Two patients were SZ heterozygotes (AAT levels ≤ 89 mg/dL). The patients were divided into groups based on AAT level: ≤ 89 mg/­dL (deficiency, no group); 90-140 mg/dL (intermediate, Group 1, n = 30); and ≥ 141 mg/dL (normal, Group 2, n = 57). The frequency of smokers was the same in both groups, although tobacco intake was greater in Group 2. The S allele was present in 13 and 14 patients in Groups 1 and 2, respectively, whereas the Z allele was present in 2 and 1 patient in the same groups. There was no difference in the results of pulmonary function tests or in the frequency of bronchiectasis or emphysema between the two groups. Spirometric values and AAT levels were similar in smokers and nonsmokers. Bronchiectasis was more common in nonsmokers, and emphysema was more common in smokers. Conclusions: Thirty patients presented AAT levels lower than the mean values found in patients with the MM or MS genotype, and this fact could not be explained by an increased frequency of S and Z alleles.

Keywords: Alpha 1-antitrypsin; Emphysema: Lung diseases; Alleles.

Pulmonary thromboembolism is a common condition. Its diagnosis usually requires pulmonary scintigraphy, computed angiotomography, pulmonary arteriography and, in order to rule out other diagnoses, the measurement of D-dimer levels. Due to the fact that these diagnostic methods are not available in most Brazilian hospitals, the validation of other diagnostic techniques is of fundamental importance. We describe a case of a woman with chronic pulmonary hypertension who experienced a pulmonary thromboembolism event. Pulmonary scintigraphy, computed angiotomography and pulmonary arteriography were used in the diagnosis. The D-dimer test result was positive. Volumetric capnography was performed at admission and after treatment. The values obtained were compared with the imaging test results.

Keywords: Thromboembolism; Hypertension, pulmonary; Capnography; Schistosomiasis.

We report the case of a patient with severe dyspnea upon reclining. Lung disease, neuromuscular disorders and heart disease were ruled out. However, during the course of the investigation, bilateral diaphragmatic paresis was discovered. A key sign leading to the diagnosis was evidence of paradoxical respiration in the dorsal decubitus position. When the patient was moved from the orthostatic position to the dorsal decubitus position, oxygenation and forced vital capacity worsened. The orthostatic fluoroscopy was normal. Maximal inspiratory pressure was severely reduced. The responses to transcutaneous electric stimulation of the diaphragm were normal. However, electric stimulation of the phrenic nerve produced no response, leading to the diagnosis of bilateral diaphragmatic paresis.

Keywords: Paresis; Respiratory insufficiency; Diaphragm; Respiration