Knowledge of the structure and function of pulmonary circulation has evolved considerably in the last few decades. The use of non-invasive imaging techniques to assess the anatomy and function of the pulmonary vessels and heart has taken on added importance with the recent advent of novel therapies. Imaging findings not only constitute a diagnostic tool but have also proven to be essential for prognosis and treatment follow-up. This article reviews the myriad of imaging methods currently available for the assessment of pulmonary circulation, from the simple chest X-ray to techniques that are more complex and promising, such as electrical impedance tomography.

Keywords: Pulmonary circulation; Diagnostic imaging; Hypertension, pulmonary.

Nitric oxide (NO) is an endogenous vasoactive compound that contributes to pulmonary vascular homeostasis and is produced by three nitric oxide synthase (NOS) isoforms-neuronal NOS (nNOS); inducible NOS (iNOS); and endothelial NOS (eNOS)-all three of which are present in the lung. Studies using pharmacological inhibitors or knockout mice have shown that eNOS-derived NO plays an important role in modulating pulmonary vascular tone and attenuating pulmonary hypertension. However, studies focusing on the role of iNOS have shown that this isoform contributes to the pathophysiology of acute lung injury and acute respiratory distress syndrome. This review aimed at outlining the role played by NO in the control of pulmonary circulation, both under physiological and pathophysiological conditions. In addition, we review the evidence that the L-arginine-NO-cyclic guanosine monophosphate pathway is a major pharmacological target in the treatment of pulmonary vascular diseases.

Keywords: Nitric oxide; Arginine; Nitric oxide synthase; Cyclic GMP; Pulmonary circulation.

Objectives: Pulmonary endarterectomy (PEA) is the gold standard treatment for chronic thromboembolic pulmonary hypertension (CTEPH). This study aimed at reporting outcomes of CTEPH patients undergoing PEA within 10 years, focusing on advances in anesthetic and surgical techniques. Methods: We evaluated 102 patients who underwent PEA between January 2007 and May 2016 at the Instituto do Coração do Hospital das Clínicas da Universidade de São Paulo. Changes in techniques included longer cardiopulmonary bypass, heating, and cooling times and mean time of deep hypothermic circulatory arrest and shortened reperfusion time. Patients were stratified according to temporal changes in anesthetic and surgical techniques: group 1 (January 2007-December 2012), group 2 (January 2013-March 2015), and group 3 (April 2015-May 2016). Clinical outcomes were any occurrence of complications during hospitalization. Results: Groups 1, 2, and 3 included 38, 35, and 29 patients, respectively. Overall, 62.8% were women (mean age, 49.1 years), and 65.7% were in New York Heart Association functional class III-IV. Postoperative complications were less frequent in group 3 than in groups 1 and 2: surgical complications (10.3% vs. 34.2% vs. 31.4%, p=0.035), bleeding (10.3% vs. 31.5% vs. 25.7%, p=0.047), and stroke (0 vs. 13.2% vs. 0, p=0.01). Between 3 and 6 months post-discharge, 85% were in NYHA class I-II. Conclusion: Improvements in anesthetic and surgical procedures were associated with better outcomes in CTEPH patients undergoing PEA during the 10-year period.

Keywords: Pulmonary embolism; Pulmonary hypertension; Endarterectomy; Hospital mortality; Survival analysis; Postoperative complications.

Abstract Objective: To compare four laboratory methods in the diagnosis of pulmonary tuberculosis. Methods: Respiratory secretion specimens were collected from 160 patients suspected of having pulmonary tuberculosis. Direct testing for Mycobacterium tuberculosis was carried out using Ziehl-Neelsen staining, auramine staining, culture on Löwenstein-Jensen (LJ) medium and polymerase chain reaction (PCR). The strains isolated were identified by means of a radiometric method using p-nitro-alpha-acetylamino-beta-hydroxypropiophenone (NAP) and classical methods. The sensitivity of the methods was compared to the gold standard for the diagnosis of pulmonary tuberculosis, based on clinical, radiological and microbiological criteria. Results: Of the 160 patients, 142 were diagnosed with pulmonary tuberculosis according to the gold standard. The sensitivity of Ziehl-Neelsen staining, auramine staining, culture on LJ medium and PCR was 54.2%, 58.4%, 67.6% and 77.5%, respectively, when compared with the diagnostic criterion adopted. All four methods presented 100% specificity. In the identification of mycobacteria, there was high (96.8%) concordance between PCR and the radiometric method using NAP. The sensitivity of PCR was 50.8% in samples with negative sputum smear microscopy results and 98.8% in those with positive results. The sensitivity of PCR was lower in specimens with negative results in sputum smear microscopy and culture than in those with positive results (25.6% and 99.0%, respectively). Conclusions: We found PCR to be a promising method for the diagnosis of pulmonary tuberculosis, even in paucibacillary specimens. Simultaneous identification and faster results are additional advantages of this method.

Keywords: Tuberculosis, pulmonary/diagnosis; Culture media; Polymerase chain reaction; Sputum/microbiology.

Background: The nucleoside adenosine is a potent vasodilator. Although its effect on the pulmonary arteries is well known, its influence on capillaries and veins has yet to be described. Objective: To evaluate the pre- and post-administration effects of adenosine on arterial and venous resistance in the pulmonary circulation of patients with primary pulmonary hypertension. Method: The study involved 7 patients with primary pulmonary hypertension and presenting a positive response to adenosine on the acute test. Before and after adenosine administration, arterial and venous resistances were determined by estimating pulmonary capillary pressure through analysis of pulmonary artery pressure decay curves. Results: Following adenosine administration, there was an increase in the cardiac index (from 1.71 ± 0.23 to 2.72 ± 0.74 L/min-1/m-2) and a decrease in pulmonary vascular resistance (from 2924 ± 1060 to 1975 ± 764 dynes/s/cm-5/m-2) with no significant variations in mean pulmonary artery pressure (pre: 75.6 ± 16.8 mmHg; post: 78.1 ± 18.8 mmHg), pulmonary wedge pressure (pre: 15.3 ± 1.5 mmHg; post: 15.4 ± 1.9 mmHg) and pulmonary capillary pressure (pre: 43.8 ± 5.8 mmHg; post: 44.5 ± 4.9 mmHg). The ratio between arterial resistance and total pulmonary vascular resistance also presented a less than significant variation (pre: 50 ± 15%; post: 49 ± 17%). These findings suggest that adenosine affects the capillaries and veins as well as the arteries. Conclusion: We can conclude that the adenosine mechanism is not restricted to the arterial aspect of the pulmonary circulation, and that analysis of pulmonary capillary pressure could prove useful in the study of various drugs that affect the pulmonary circulation.

Keywords: Key Words: Adenosine/pharmacocinetic. Adenosine/uso terapêutico. Blood pressure. Hypertension pulmonary.

Objective: To identify incorrect inhaler techniques employed by patients with respiratory diseases in southern Brazil and to profile the individuals who make such errors. Methods: This was a population-based, cross-sectional study involving subjects ≥ 10 years of age using metered dose inhalers (MDIs) or dry powder inhalers (DPIs) in 1,722 households in the city of Pelotas, Brazil. Results: We included 110 subjects, who collectively used 94 MDIs and 49 DPIs. The most common errors in the use of MDIs and DPIs were not exhaling prior to inhalation (66% and 47%, respectively), not performing a breath-hold after inhalation (29% and 25%), and not shaking the MDI prior to use (21%). Individuals ≥ 60 years of age more often made such errors. Among the demonstrations of the use of MDIs and DPIs, at least one error was made in 72% and 51%, respectively. Overall, there were errors made in all steps in 11% of the demonstrations, whereas there were no errors made in 13%.Among the individuals who made at least one error, the proportion of those with a low level of education was significantly greater than was that of those with a higher level of education, for MDIs (85% vs. 60%; p = 0.018) and for DPIs (81% vs. 35%; p = 0.010).Conclusions: In this sample, the most common errors in the use of inhalers were not exhaling prior to inhalation, not performing a breath-hold after inhalation, and not shaking the MDI prior to use. Special attention should be given to education regarding inhaler techniques for patients of lower socioeconomic status and with less formal education, as well as for those of advanced age, because those populations are at a greater risk of committing errors in their use of inhalers.

Keywords: Asthma; Pulmonary disease, chronic obstructive; Dry powder inhalers; Metered dose inhalers.

Bronchoscopy with bronchoalveolar lavage, bronchial brush, and transbronchial biopsy are useful methods for the diagnosis of pulmonary diseases in patients infected with the human immunodeficiency virus (HIV). However, data on the accuracy of these techniques are conflicting. In order to estimate the sensitivity of the bronchoalveolar lavage, bronchial and transbronchial biopsy in pulmonary disease diagnosis in patients infected with HIV, the authors studied 71 consecutive patients, most of them with respiratory symptoms up to 15 days (58%) and radiologic signs of interstitial infiltrates (62%). The sensitivity was calculated taking as reference a constructed gold-standard, represented by the sum of all three techniques combined. Sensitivities for bronchoalveolar lavage, transbronchial biopsy, and bronchial brush were 86%, 43% and 5%, respectively. The association of bronchoalveolar lavage and transbronchial biopsy reached the sensitivity to 100%, reflecting how the gold-standard was constructed. The complication rate of the procedures was 3%. These results suggest that, in this population: (1) bronchoscopy with bronchoalveolar lavage, bronchial brush, and transbronchial biopsy are secure procedures with good diagnostic performance; (2) bronchoalveolar lavage alone has reached the highest sensitivity, whereas both bronchoalveolar lavage and transbronchial biopsy can be considered complementary techniques; (3) the association of bronchoalveolar lavage and transbronchial biopsy performed better than bronchoalveolar lavage alone; and (4) the use of bronchial brush in the sequence used in this protocol did not have any influence on the performance of diagnosis.

Keywords: Human immunodeficiency virus. Lung diseases. Diagnostic techniques. HIV. Lung infections.

The role of immunohistochemistry is to recognize antigens and, consequently, to identify and classify specific cells within a cell population whose morphology is heterogenous or apparently homogenous. The visualization of the antigen-antibody complex is made possible through the addition of either a fluorochrome conjugate or an enzyme to the antibody, which is then viewed under microscopy. Immunohistochemistry can be used in the routine diagnosis of lung cancer, in order to identify biological markers (diagnostic and prognostic). The essential immunohistochemistry panels will be discussed in this review.

Keywords: Immunohistochemistry; Tumor markers, biological; Lung neoplasms.

The diagnosis of acute pulmonary thromboembolism is based on the clinical probability, use of D-dimer (when available) and imaging. The main imaging modalities used in the diagnosis are ventilation-perfusion (V/Q), angiography, and computed tomography (CT). In the last decade several studies have demonstrated that spiral CT has a high sensitivity and specificity in the diagnosis of acute pulmonary thromboembolism. The evaluation of the pulmonary arteries has further improved with the recent introduction of multidetector spiral CT scanners. Various investigators have suggested that spiral CT pulmonary angiography should replace scintigraphy in the assessment of patients whose symptoms are suggestive of acute PE. This article discusses the role of the various imaging modalities in the diagnosis of acute pulmonary thromboembolism with emphasis on the role of spiral CT.

Keywords: Diagnostic imaging. Pulmonary embolism./diagnosis. Angiography. Lung diseases/radionuclide imaging. Tomography, emission-computed single-photon/methods.