Objective: Ventilator-associated pneumonia (VAP) is the leading type of hospital-acquired infection in ICU patients. The diagnosis of VAP is challenging, mostly due to limitations of the diagnostic methods available. The aim of this study was to determine whether antibody-coated bacteria (ACB) evaluation can improve the specificity of endotracheal aspirate (EA) culture in VAP diagnosis. Methods: We conducted a diagnostic case-control study, enrolling 45 patients undergoing mechanical ventilation. Samples of EA were obtained from patients with and without VAP (cases and controls, respectively), and we assessed the number of bacteria coated with FITC-conjugated monoclonal antibodies (IgA, IgM, or IgG) or an FITC-conjugated polyvalent antibody. Using immunofluorescence microscopy, we determined the proportion of ACB among a fixed number of 80 bacteria. Results: The median proportions of ACB were significantly higher among the cases (n = 22) than among the controls (n = 23)-IgA (60.6% vs. 22.5%), IgM (42.5% vs. 12.5%), IgG (50.6% vs. 17.5%), and polyvalent (75.6% vs. 33.8%)-p < 0.001 for all. The accuracy of the best cut-off points for VAP diagnosis regarding monoclonal and polyvalent ACBs was greater than 95.0% and 93.3%, respectively. Conclusions: The numbers of ACB in EA samples were higher among cases than among controls. Our findings indicate that evaluating ACB in EA is a promising tool to improve the specificity of VAP diagnosis. The technique could be cost-effective and therefore useful in low-resource settings, with the advantages of minimizing false-positive results and avoiding overtreatment.

Keywords: Pneumonia, ventilator-associated/diagnosis; Immunohistochemistry; Fluorescent antibody technique; Antibodies, bacterial/analysis; Trachea/microbiology; Intensive care units.

Hypersensitivity pneumonitis (HP), or extrinsic allergic alveolitis, is an immunologically mediated disease resulting from the inhalation of organic substances that trigger an inflammatory response in the alveolar wall, bronchioles, and interstitium in susceptible individuals. Although HP is predominantly an occupational disease, seen in adulthood, cases in children have been described. The diagnosis of HP requires a high degree of suspicion. The treatment consists in avoiding contact with the antigen, and, in some cases, systemic corticosteroids might be necessary in order to prevent its progression to pulmonary fibrosis. We report the clinical cases of three children with a history of contact with birds and a family history of HP. All three patients presented with cough and dyspnea on exertion. The disease was diagnosed on the basis of the clinical history and ancillary diagnostic test results consistent with the diagnosis, including a predominance of lymphocytes (> 60%, CD8+ T lymphocytes in particular) in bronchoalveolar lavage fluid and a ground-glass pattern seen on HRCT of the chest. Early diagnosis is crucial in order to prevent HP from progressing to pulmonary fibrosis. Hereditary factors seem to influence the onset of the disease.

Keywords: Alveolitis, extrinsic allergic; Bronchoalveolar lavage; Glucocorticoids.

Objective: To evaluate the efficacy of mitomycin C (MMC) in the endoscopic treatment of tracheal stenosis. Methods: Patients with laryngotracheal, tracheal, or tracheobronchial stenosis were treated with dilation and topical MMC. The inclusion criteria were as follows: being ineligible for surgery (for medical reasons) at the time of evaluation; membranous stenosis responding well to dilation; and postoperative stenosis at the anastomosis site. Etiology of stenosis and indication for treatment with MMC, as well as site, length, and percentage of stenosis, together with presence of tracheostomy and duration of follow-up, were analyzed. The outcomes evaluated were symptom-free interval ≥ 12 months, number of dilations with topical application of MMC, and complications. Results: Twenty-two patients (15 men and 7 women) were treated between 2003 and 2010. Stenosis was due to endotracheal intubation in 15 patients and surgery in 8. Pure tracheal stenosis was encountered in 13 patients, subglottic stenosis was encountered in 4, tracheobronchial stenosis was encountered in 3, and complex stenosis was encountered in 2. The length of stenosis ranged from 0.5 cm to 2.5 cm, and the percentage of stenosis ranged from 40% to 100%. Nine patients had undergone tracheostomy and had a Montgomery T-tube in situ. Treatment was successful in 14 patients, who remained free of symptoms for at least 12 months. The number of topical applications of MMC ranged from 1 to 5, and complications included fungal infection, keloid scarring, granuloma, and mediastinal emphysema. Conclusions: MMC appears to be effective in the endoscopic treatment of tracheal stenosis.

Keywords: Tracheal stenosis; Mitomycin; Endoscopy.

A significant percentage of pleural effusions remains without a diagnostic explanation. In such circumstances, the anatomical-pathological result of nonspecific chronic pleuritis should be revised. This is an important issue, not only for the pathologist, but mainly for the pneumologist, who usually makes the clinical-pathological correlation during the routine practice. Although the existence of established criteria is accepted, they are certainly subjective and make the communication by means of a common language difficult, mainly among pathologists. The authors recently studied 311 pleural biopsies with histo-pathological diagnoses of chronic nonspecific pleuritis. All specimens were reviewed and the histo-pathological parameters quantified by stereology. The patients were stratified according to the final diagnosis of their disease, including cases of chronic renal failure, vasculitis, pancreatitis, tuberculosis, cancer, and congestive cardiac failure, in this case considering the pleura as normal. This procedure allowed us to obtain a discriminating model, whose morphological subcriteria classified almost 90% of the nonspecific chronic pleuritis biopsies, according to their final clinical diagnoses, which included true nonspecific chronic pleuritis or tuberculosis pleuritis, paraneoplastic pleuritis, or even normal pleura. By adding to this model the biochemistry or differential cytology of the pleural liquid, its classificatory power reaches 99% of correctness. This study represents the result of the experience acquired over several years in the histo-pathological interpretation of pleural biopsies, based on the correlation between morphology and biochemistry and cytology of the pleural fluid.

Keywords: Biopsy, needle. Pleura/pathology. Pleura/cytology. Pleural effusion.

Lipoid pneumonia is a rare disease resulting from the micro-aspiration of lipid formulations. Making a diagnosis of lipoid pneumonia requires a high degree of clinical suspicion. Herein, we report the case of a female patient with a history of breast cancer, presenting progressive dyspnea and cough, together with radiological findings of bilateral pulmonary infiltrate. The working diagnosis of lymphangitic carcinomatosis, for which chemotherapy would be indicated, was called into question based on the high-resolution computed tomography findings and on the fact that the patient had a history of chronic ingestion of laxatives containing mineral oil. A lung biopsy confirmed a diagnosis of lipoid pneumonia, which should always be considered in patients with diffuse lung disease having been exposed to potential causative agents.

Keywords: Pneumonia, lipid; Tomography, X-Ray Computed; Mineral oil; Case Reports [Publication type]

Objective: In developing countries, sputum smear microscopy is the main tool for pulmonary tuberculosis case finding. The objective of the present study was to evaluate the diagnostic efficacy of Gabbett's staining (GS) and modified cold staining (MCS), both of which are two-step methods, in comparison with that of fluorescent staining (FS), which is a three-step method, for the detection of AFB in sputum smears. Methods: Our sample comprised 260 sputum samples collected from individuals suspected of having pulmonary tuberculosis at Kasturba Hospital, in Manipal, India. Smears were prepared in triplicate: one each for FS, MCS, and GS. The smears were randomly numbered so that the examiner was blinded to the sample identities. Results: Of the 260 samples, 16 (6.15%), 15 (5.77%), and 13 (5.00%) showed positive AFB results with FS, MCS, and GS, respectively. The sensitivity of GS and MCS, in comparison with that of FS, was 81.25% and 93.75%, respectively. The concordance of GS and MCS with FS was good (0.988 and 0.996, respectively), and no statistically significant differences were found. Conclusions: Although MCS and GS were found to be less sensitive than was FS, which is evaluated under fluorescence microscopy, the first two are promising methods for the diagnosis of tuberculosis.

Keywords: Tuberculosis, pulmonary; Diagnostic techniques and procedures; Microscopy, fluorescence; Sputum.

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.

Objective: To analyze the relationship between one-minute sit-to-stand test (1MSTST) parameters and a diagnosis of post COVID-19 condition in a cohort of patients who previously had COVID-19. Methods: This was a prospective cohort study of patients with post COVID-19 condition referred for body plethysmography at a tertiary university hospital. Post COVID-19 condition was defined in accordance with the current WHO criteria. Results: Fifty-three patients were analyzed. Of those, 25 (47.2%) met the clinical criteria for post COVID-19 condition. HR was lower in the patients with post COVID-19 condition than in those without it at 30 s after initiation of the 1MSTST (86.2 ± 14.3 bpm vs. 101.2 ± 14.7 bpm; p < 0.001) and at the end of the test (94.4 ± 18.2 bpm vs. 117.3 ± 15.3 bpm; p < 0.001). The ratio between HR at the end of the 1MSTST and age-predicted maximal HR (HRend/HRmax) was lower in the group of patients with post COVID-19 condition (p < 0.001). An HRend/HRmax of < 62.65% showed a sensitivity of 78.6% and a specificity of 82.0% for post COVID-19 condition. Mean SpO2 at the end of the 1MSTST was lower in the patients with post COVID-19 condition than in those without it (94.9 ± 3.6% vs. 96.8 ± 2.4%; p = 0.030). The former group of patients did fewer repetitions on the 1MSTST than did the latter (p = 0.020). Conclusions: Lower SpO2 and HR at the end of the 1MSTST, as well as lower HR at 30 s after initiation of the test, were associated with post COVID-19 condition. In the appropriate clinical setting, an HRend/HRmax of < 62.65% should raise awareness for the possibility of post COVID-19 condition.

Keywords: COVID-19; Post-acute COVID-19 syndrome; Heart rate; Respiratory function tests.

Objective: To evaluate the diagnostic performance of the rapid shallow breathing index (RSBI) in predicting extubation failure among adult patients in the intensive care unit and to determine the appropriateness of the classical RSBI cut-off value. Methods: This was a prospective study conducted in the adult intensive care unit of the Botucatu School of Medicine Hospital das Clínicas. The RSBI was evaluated in 73 consecutive patients considered clinically ready for extubation. Results: The classical RSBI cut-off value (105 breaths/min/L) presented a sensitivity of 20% and a specificity of 95% (sum = 115%). Analysis of the receiver operator characteristic (ROC) curve revealed a better cut-off value (76.5 breaths/min/L), which presented a sensitivity of 66% and a specificity of 74% (sum = 140%). The area under the ROC curve for the RSBI was 0.78. Conclusions: The classical RSBI cut-off value proved inappropriate, predicting only 20% of the cases of extubation failure in our sample. The new cut-off value provided substantial improvement in sensitivity, with an acceptable loss of specificity. The area under the ROC curve indicated that the discriminative power of the RSBI is satisfactory, which justifies the validation of this index for use.

Keywords: Adult; Intensive care; ROC curve; Ventilator weaning; Diagnosis; Respiration, artificial.

Setting: Considering the difficulty to establish diagnosis of tuberculosis in childhood, the authors studied three diagnostic criteria published in the literature in the last 20 years, evaluating their sensitivity, specificity, and accuracy. Material and methods: In a prospective study, 94 children at ages ranging from 0 to 15 years having contact with bacillary tuberculous adults were studied in the Municipal Health Center of Duque de Caxias, Rio de Janeiro. The following criteria were studied: Keneth Jones, described by Stegen et al.(1), World Health Organization(2) and Keith Edwards, described by Crofton et al.(3). Results: Among the criteria studied, those of Keith Edwards showed the best sensitivity and specificity, with 84% and 97%, respectively. WHO criterion showed a 100% specificity but zero sensitivity. Keneth Jones criterion showed 56% sensitivity and a 94% specificity. Conclusion: In poor areas, such as that of this study, where easy-to-handle operational methods are required, the criteria studied proved to be adequate to detect tuberculosis cases in children in contact with tuberculous adults. Those of Keith Edwards were the most useful although some changes are necessary for a better adaptation to Brazil.

Keywords: Tuberculosis, diagnosis. Child. Community health care centers.

Introduction: At present, chest radiography (CR) is the main instrument used in the diagnosis of silicosis, following the International Labor Organization (ILO) recommendations. In incipient cases, the interpretation of radiographs is difficult and disagreement may occur, even among experienced readers. Recently, the possibility of evaluating incipient cases by using high resolution computed tomography (HRCT) has been considered. Objective: To compare CR with HRCT results. Patients and methods: An original group of 135 ex-miners were evaluated by CR, according to ILO recommendations, examined by three readers, from November 1997 to December 1999. HRCT was indicated to 68 patients whose median profusion readings was 1/0 or below. HRCT results were examined by two readers and, in cases of disagreement, a third reader was consulted. HRCT results were classified according to micronodule profusion into categories 0 to 3. CR and HRCT results were compared using McNemar test, weighed Kappa coefficient and log-linear models. Results and conclusion: There was good agreement among the methods in category 0, so it was concluded that both methods are similar in excluding the diagnosis of silicosis. However, in category 1 or greater (diagnosis of the disease) a good agreement among the methods was not observed.

Keywords: Silicosis. Thoracic radiography. Tomography X-ray computed. Pneumoconiosis.

Objective: This study aimed to determine the serum levels of NACHT, Leucine-rich repeat (LRR), and Pyrin (PYD) domains-containing Protein 3 (NLRP3) and cathelicidin LL-37, and investigate their prognostic significance in community-acquired pneumonia (CAP). Methods: The sample of this prospective study was composed of 76 consecutive patients with CAP. Demographic data and clinical characteristics were collected. Serum levels of NLRP3 and LL-37 were determined by ELISA. Spearman's analysis was used to evaluate the correlation between NLRP3 and LL-37. Association of NLRP3 and LL 37 with 30-day survival and mortality rates was assessed using the Kaplan-Meier curve and logistic regression analysis. Results: Serum NLRP3 significantly increased whereas serum LL-37 significantly decreased in patients with severe CAP. Significant correlation was observed between serum NLRP3 and LL-37 in CAP patients. Patients with higher levels of NLRP3 and lower levels of LL-37 showed lower 30-day survival rate and higher mortality compared with those with lower NLRP3 and higher LL-37 levels. Conclusion: Severe CAP patients tend to present higher serum NLRP3 and lower serum LL-37, which might serve as potential biomarkers for CAP prognosis.

Keywords: Community-acquired pneumonia; Prognosis; Biomarkers; Prospective study.

We aimed to test a new model of self-expanding tracheal stent so that it might be made available for clinical use. Using direct laryngoscopy, we placed polyurethane-coated, nitinol stents into the middle third of the trachea in 25 New Zealand rabbits. After a mean observation period of 26 days, we evaluated stent migration, degree of expansion, attachment, adherence, formation of granulation tissue, presence of inflammatory infiltrate, parietal involvement, and epithelial lining. The results showed complete radial expansion, little adherence to the tracheal mucosa, and low tissue attachment, as well as high rates of granuloma formation and stent migration. This new model proved to be biocompatible and showed a behavior similar to that of other stents on the market.

Keywords: Prosthesis implantation; Tracheal stenosis; Rabbits; Stents.

Objective: To describe the development of a silicone stent and perform in vivo testing for biocompatibility/applicability in the normal canine trachea. Methods: Four different densities were tested in order to obtain the silicone prototypes. The pressure required for compression considering a contact area of 1 cm2, and a 30% reduction in diameter was calculated for each density. The best density was 70-75 Shore A hardness. Powdered barium sulfate was added to the silicone to make the stent radiopaque and easily identifiable in radiological imaging. This novel stent presents a corrugated external surface with discontinuous and protruding arcs resembling the tracheobronchial rings (for intercalation and fixation in the lumen of the lower airways), a highly polished inner surface and smooth extremities (to prevent friction-related damage). The prototype considered most appropriate in terms of rigidity and flexibility was bronchoscopically implanted in normal canine tracheas. After eight weeks, the animals were euthanized, and the tracheas were removed for anatomopathological analysis. Results: There were no postimplantation complications, and none had to be removed. After eight weeks, the devices were found to be well-positioned. Histopathology revealed a well-preserved epithelial basal membrane, foci of denuded epithelium, mild submucosal inflammatory infiltrate with scattered granulation tissue, vascular neoformation, and no microorganisms. Conclusions: The stent developed proved resistant to mechanical stress, biocompatible in the canine trachea and well-preserved at the study endpoint.

Keywords: Implants, experimental; Silicones; Biocompatible materials.

Background: Antimicrobial treatment of community-acquired respiratory tract infections (CARTI) is usually empiric and antibiotics are chosen on the basis of surveillance studies. The SENTRY Program was designed to monitor antimicrobial resistance via a worldwide surveillance network of sentinel laboratories. Three sites in Brazil participated in the 1997 and 1998 SENTRY Program. Methods: A total of 344 bacterial isolates, collected from patients with CARTI in 1997 and 1998, were tested against more than 20 antimicrobial agents by the broth microdilution method. Results: Among S. pneumoniae (176 isolates), 71.6% were susceptible to penicillin. High level resistance to penicillin and resistance to cefotaxime was found in 2.3 and 4.0%, respectively. The newer quinolones, levofloxacin, (MIC90 of 2 mg/mL) and gatifloxacin (MIC90 of 0.5 mg/mL) were active against 100% of the isolates tested. Among the other non-b-lactam drugs tested, the rank order of pneumococci activity was (% susceptible): chloramphenicol (97.5%) > clindamycin (94.0%) > azithromycin (90.3%) > clarithromycin (89.4%) > tetracycline (76.4%) > trimethoprim/sulfamethoxazole (60.2%). The percentage of Haemophilus influenzae (101 isolates) susceptible to amoxicillin was 90.1%, whereas among Moraxella catarrhalis (67 isolates) only 9.0% were susceptible. Clavulanic acid restored the activity of amoxicillin against both H. influenzae and M. catarrhalis. However, H. influenzae showed increased levels of resistance to trimethoprim/sulfametoxazole (55.1% susceptibility), clarithromycin (80.4% susceptibility), and cefaclor (88.2%) susceptibility). All H. influenzae and M. catarrhalis isolates were susceptible to levofloxacin (MIC90, < 0.5 mg/mL for both) and gatifloxacin (MIC90, < 0.06 mg/mL for both) with very low MICs. Conclusion: Results indicate that the rate of S. pneumoniae showing high-level penicillin resistance is still low in Brazil. However, intermediate resistance to penicillin associated with resistance to other classes of antimicrobial agents was relatively high. On the other hand, the new quinolones were highly active against 100% of the respiratory pathogens tested.

Keywords: Respiratory tract infections. Bacterial pneumonia. Microbial drug resistance. Program evaluation. Microbial sensibility tests.

Objective: Levels of procalcitonin, midregional pro-atrial natriuretic peptide (MR-proANP), C-terminal provasopressin (copeptin), and C-reactive protein (CRP), as well as Sequential Organ Failure Assessment (SOFA) scores, are associated with severity and described as predictors of outcome in ventilator-associated pneumonia (VAP). This study sought to compare the predictive value of these biomarkers for mortality in VAP. Methods: An observational study of 71 patients with VAP. Levels of procalcitonin, MR-proANP, copeptin, and CRP, together with SOFA scores, were determined at VAP onset, designated day 0 (D0), and on day 4 of treatment (D4). Patients received empirical antimicrobial therapy, with modifications based on culture results. Patients who died before D28 were classified as nonsurvivors. Results: Of the 71 patients evaluated, 45 were classified as survivors. Of the 45 survivors, 35 (77.8%) received appropriate antimicrobial therapy, compared with 18 (69.2%) of the 26 nonsurvivors (p = 0.57). On D0 and D4, the levels of all biomarkers (except CRP), as well as SOFA scores, were lower in eventual survivors than in eventual nonsurvivors. For D0 and D4, the area under the ROC curve was largest for procalcitonin. On D0, MR-proANP had the highest positive likelihood ratio (2.71) and positive predictive value (0.60), but procalcitonin had the highest negative predictive value (0.87). On D4, procalcitonin had the highest positive likelihood ratio (3.46), the highest positive predictive value (0.66), and the highest negative predictive value (0.93). Conclusions: The biomarkers procalcitonin, MR-proANP, and copeptin can predict mortality in VAP, as can the SOFA score. Procalcitonin alone has the greatest predictive power for such mortality.

Keywords: Pneumonia, ventilator-associated/mortality; Biological markers/analysis; Health Status Indicators.