RESUMO
HISTORY: A 58-year-old male patient with an active smoking status was admitted twice to the intensive care unit (ICU) of a tertiary referral thoracic center for severe hypercapnic acute respiratory failure and persistent bilateral chest radiograph opacities that were unchanged over the course of the two ICU admissions within a 3-month period. The patient had obesity (body mass index, 36), stage 3 vascular chronic renal insufficiency, and hebephrenic schizophrenia treated with haloperidol, carbamazepine, and cyamemazine. He reported chronic dyspnea on exertion, which worsened for 6 months. At the second ICU admission, the patient was afebrile, with a blood pressure of 160/72 mm Hg and pulse oximetry of 93% on 6 L/min oxygen therapy through a nonrebreathing mask. Physical examination showed signs of respiratory failure with wheezing and active abdominal expiration, and bilateral pulmonary crackles without chest pain, hemoptysis, clubbing, or signs of cardiac failure. The patient had no peripheral lymphadenopathy and no enlarged spleen. Blood gases (on 6 L/min oxygen) showed respiratory acidosis (pH, 7.15 [normal range, 7.38-7.42]; PaO2 level, 67 mm Hg [normal range, 80-100 mm Hg]; PaCO2 level, 102 mm Hg [normal range, 38-42 mm Hg]; bicarbonate [HCO3-], 29 mmol/L [normal range, 22-27 mmol/L]). Noninvasive ventilation was initiated. Imaging performed during the second ICU hospitalization included CT and MRI of the chest without contrast enhancement, and fluorine 18 (18F) fluorodeoxyglucose (FDG) PET/CT.
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Pneumonia Lipoide , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia Lipoide/diagnóstico por imagem , Pneumonia Lipoide/induzido quimicamente , Tomografia Computadorizada por Raios X/métodos , Diagnóstico Diferencial , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodosRESUMO
PURPOSE: To identify clinical, radiological, and angiographic characteristics associated with recurrent hemoptysis after bronchial artery embolization (BAE) in patients with lung cancer and severe hemoptysis admitted to the intensive care unit (ICU). MATERIALS AND METHODS: A total of 144 consecutive patients with lung cancer who underwent BAE for life-threatening hemoptysis admitted in the ICU between 2014 and 2022 were retrospectively included. Demographics, laboratory values, clinical course, and radiological/angiographic features were compared between those with and without recurrent hemoptysis within 1 month after embolization. RESULTS: Of the 144 patients (mean age, 60.2 years [SD ± 10.9]; females, 15.3%), 34.7% (50/144) experienced clinically relevant recurrent hemoptysis within 1 month; among them, 29 of 50 (58.0%) cases necessitated a second embolization. Massive hemoptysis was observed in 54.2%, with 16.7% receiving the vasopressin analog terlipressin. The mean volume of hemoptysis and simplified acute physiology score II (SAPS II) were 235 mL (SD ± 214.3) and 31.2 (SD ± 18.6), respectively. Computed tomography (CT) angiography revealed pulmonary artery (PA) injury (11.5%) and necrosis/cavitation (25.8%), and PA embolization was performed in 15.3% of cases. Technical success rate was 92%. SAPS II (P = .01), massive hemoptysis (P < .001), terlipressin use (P = .01), necrosis/cavitation (P = .01), and PA injury on CT angiography (P < .001) were associated with recurrent hemoptysis. Independent predictors on multivariate analysis were massive hemoptysis (P = .016) and PA injury on CT angiography (P = .001). CONCLUSIONS: In patients with lung cancer and life-threatening hemoptysis treated by BAE, massive hemoptysis and PA injury identified on CT angiography are independent predictors of recurrent hemoptysis.
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Artérias Brônquicas , Embolização Terapêutica , Hemoptise , Neoplasias Pulmonares , Recidiva , Humanos , Hemoptise/etiologia , Hemoptise/terapia , Hemoptise/diagnóstico por imagem , Feminino , Pessoa de Meia-Idade , Embolização Terapêutica/efeitos adversos , Masculino , Artérias Brônquicas/diagnóstico por imagem , Estudos Retrospectivos , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/terapia , Idoso , Fatores de Risco , Resultado do Tratamento , Fatores de Tempo , Angiografia por Tomografia Computadorizada , Valor Preditivo dos Testes , Medição de RiscoRESUMO
BACKGROUND: Immune checkpoint inhibitors (ICI) have revolutionized the management of cancer. They can induce immune-related adverse events (irAE) leading to intensive care unit (ICU) admission. We aimed to describe irAEs for ICU admissions in solid cancer patients treated with ICIs. METHODS: This prospective multicenter study was conducted in France and Belgium. Adult patients with solid tumor and treated with systemic ICIs within the last 6 months, requiring non-programmed ICU admission were included. Patients admitted for microbiologically documented sepsis were excluded. Imputability of irAEs in ICU admissions was described according to the WHO-UMC classification system at ICU admission and at ICU discharge. The use of immunosuppressant treatment was reported. RESULTS: 115 patients were eligible. Solid tumor was mainly lung cancer (n = 76, 66%) and melanoma (n = 18, 16%). They were mainly treated with an anti-PD-(L)1 alone (n = 110, 96%). Main ICU admission reasons were acute respiratory failure (n = 66, 57%), colitis (n = 14, 13%), and cardiovascular disease (n = 13, 11%). ICU admission was considered "likely" associated with irAE for 48% (n = 55) of patients. Factors independently associated with irAE were a good ECOG performance status (PS) (ECOG-PS of 0 or 1 vs. ECOG-PS of 2-3, odds ratio [OR] = 6.34, 95% confidence interval [95% CI] 2.13-18.90, and OR = 3.66, 95% CI 1.33-10.03, respectively), and a history of irAE (OR = 3.28, 95% CI 1.19-9.01). Steroids were prescribed for 41/55 (75%) patients with ICU admission "likely" related to irAE. Three patients were subsequently treated with immunosuppressants. CONCLUSION: IrAEs accounted for half of ICU admissions in cancer patients receiving ICIs. They could be treated with steroids. Identifying the imputability of irAEs in ICU admissions remains a challenge.
RESUMO
Background: The absence of diagnosis of acute respiratory distress syndrome (ARDS) concerns 20% of cancer patients and is associated with poorer outcomes. Diffuse pneumonic-type adenocarcinoma (P-ADC) is part of these difficult-to-diagnose ARDS, but only limited data are available regarding critically ill patients with diffuse P-ADC. We sought to describe the diagnosis process and the prognosis of P-ADC related ARDS patients admitted to the intensive care unit (ICU). Methods: Single-center observational case series study. All consecutive patients admitted to the ICU over a two-decade period presenting with (I) histologically or cytologically proven adenocarcinoma of the lung and (II) ARDS according to Berlin definition were included. Clinical, biological, radiological and cytological features of P-ADC were collected to identify diagnostic clues. Multivariate logistic regression analyses were performed to assess factors associated with ICU and hospital mortality. Results: Among the 24 patients included [70 (61-75) years old, 17 (71%) males], the cancer diagnosis was performed during the ICU stay in 19 (79%), and 17 (71%) required mechanical ventilation. The time between the first symptoms and the diagnosis of P-ADC was 210 days (92-246 days). A non-resolving pneumonia after 2 (2 to 3) antibiotics lines observed in 23 (96%) patients with a 34 mg/L (19 to 75 mg/L) plasma C-reactive protein level at ICU admission. Progressive dyspnea, bronchorrhea, salty expectoration, fissural bulging and compressed bronchi and vessels were present in 100%, 83%, 69%, 57% and 43% of cases. Cytological examination of sputum or broncho-alveolar lavage provided a 75% diagnostic yield. The ICU and hospital mortality rates were 25% and 63%, respectively. The time (in days) between first symptoms and diagnosis [odds ratio (OR) 1.02, 95% confidence interval (95% CI): 1.00-1.03, P=0.046] and the Simplified Acute Physiology Score II (OR 1.16, 95% CI: 1.01-1.33, P=0.040) were independently associated with ICU mortality. Conclusions: Non-resolving pneumonia after several antibiotics lines without inflammatory syndrome, associated with progressive dyspnea, salty bronchorrhea, and lobar swelling (i.e., fissural bulging, compressed bronchi and vessels) were suggestive of P-ADC. Delayed diagnosis of diffuse P-ADC seemed an independent prognostic predictor and disease timely recognition may contribute to prognosis improvement.
RESUMO
PURPOSE: To study prevalence of targeted therapy (TT)-related adverse events requiring ICU admission in solid tumor patients. METHODS: Retrospective multicenter study from the Nine-i research group. Adult patients who received TT for solid tumor within 3 months prior to ICU admission were included. Patients admitted for TT-related adverse event were compared to those admitted for other reasons. RESULTS: In total, 140 patients, median age of 63 (52-69) years were included. Primary cancer site was mostly digestive (n=27, 19%), kidney (n=27, 19%), breast (n=24, 17%), and lung (n=20, 14%). Targeted therapy was anti-VEGF/VEGFR for 27% (n=38) patients, anti-EGFR for 22% (n=31) patients, anti-HER2 for 14% (n=20) patients and anti-BRAF for 9% (n=5) patients. ICU admission was related to TT adverse events for 30 (21%) patients. The most frequent complications were interstitial pneumonia (n=7), cardiac failure (n=5), anaphylaxis (n=4) and bleeding (n=4). At ICU admission, no significant difference was found between patients admitted for a TT-related adverse event and the other patients. One-month survival rate was higher in patients admitted for TT adverse event (OR=5.733 [2.031-16.182] P<0.001). CONCLUSIONS: Adverse events related to targeted therapy accounted for 20% of ICU admission in our population and carried a 16% one-month mortality. Outcome was associated with admission for TT related to adverse event, breast cancer and good performance status.
Assuntos
Unidades de Terapia Intensiva , Neoplasias , Adulto , Idoso , Mortalidade Hospitalar , Hospitalização , Humanos , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Estudos Retrospectivos , Taxa de SobrevidaAssuntos
Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/patologia , COVID-19/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Adenocarcinoma/complicações , COVID-19/complicações , COVID-19/terapia , Feminino , Humanos , Neoplasias Pulmonares/complicações , Pessoa de Meia-IdadeRESUMO
BACKGROUND: The use of cyclophosphamide in patients with acute exacerbation of idiopathic pulmonary fibrosis (IPF) is unknown. Our study was designed to evaluate the efficacy and safety of four cyclophosphamide pulses in addition to high-dose methylprednisolone in this population. METHODS: In this double-blind, placebo-controlled trial done in 35 departments across 31 hospitals in France, adult patients (≥18 years) with acute exacerbation of IPF and those with suspected acute exacerbation of IPF were randomly assigned in a 1:1 ratio using a web-based system to receive either intravenous pulses of cyclophosphamide (600 mg/m2) plus uromitexan as haemorrhagic cystitis prophylaxis (200 mg/m2) at the time of cyclophosphamide administration and then again, 4 h later, or placebo at days 0, 15, 30, and 60. Random assignment was stratified according to the severity of IPF and was block-balanced with variable block sizes of four or six patients. Patients receiving mechanical ventilation, with active infection, with active cancer, or who were registered on the lung transplant waiting list were excluded. All patients received standardised high-dose glucocorticoids. The investigators, patients, and the sponsor were masked to the treatment assignments. The primary endpoint was 3-month all-cause mortality, analysed by a χ2 test adhering to an intention-to-treat principle. The trial is now complete and registered with ClinicalTrials.gov, NCT02460588. FINDINGS: Between Jan 22, 2016, and July 19, 2018, 183 patients were assessed for eligibility, of whom 120 patients were randomly assigned and 119 patients (62 [52%] with severe IPF) received at least one dose of cyclophosphamide (n=60) or placebo (n=59), all of whom were included in the intention-to-treat analysis. The 3-month all-cause mortality was 45% (27/60) in patients given cyclophosphamide compared with 31% (18/59) in the placebo group (difference 14·5% [95% CI -3·1 to 31·6]; p=0·10). Similar results were found after adjustment by IPF severity (odds ratio [OR] 1·89 [95% CI 0·89-4·04]). The risk of death at 3 months, independent of the treatment received, was higher with severe than non-severe IPF (OR 2·62 [1·12-6·12]) and was lower with the use of antifibrotic therapy (OR 0·33 [0·13-0·82]). Adverse events were similar between groups by 6 months (25 [42%] in the cyclophosphamide group vs 30 [51%] in the placebo group) and their proportion, including infections, did not differ. Overall infection was the main adverse event and occurred in 20 (33%) of 60 patients in the cyclophosphamide group versus 21 (36%) of 59 patients in the placebo group. INTERPRETATION: In patients with acute exacerbation of IPF, adding intravenous cyclophosphamide pulses to glucocorticoids increased 3-month mortality. These findings provide evidence against the use of intravenous cyclophosphamide in such patients. FUNDING: Programme Hospitalier de Recherche Clinique of the French Ministry of Health (PHRC 2014-502), Roche Pharmaceuticals.
Assuntos
Glucocorticoides , Fibrose Pulmonar Idiopática , Adulto , Ciclofosfamida/efeitos adversos , Método Duplo-Cego , Glucocorticoides/efeitos adversos , Humanos , Fibrose Pulmonar Idiopática/tratamento farmacológico , Resultado do TratamentoAssuntos
Adenocarcinoma de Pulmão/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Insuficiência Respiratória/terapia , Acrilamidas/uso terapêutico , Adenocarcinoma de Pulmão/complicações , Adenocarcinoma de Pulmão/genética , Adulto , Idoso , Compostos de Anilina/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/complicações , Carcinoma Pulmonar de Células não Pequenas/genética , Crizotinibe/uso terapêutico , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Cloridrato de Erlotinib/uso terapêutico , Feminino , Gefitinibe/uso terapêutico , Humanos , Unidades de Terapia Intensiva , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Ventilação não Invasiva , Oxigenoterapia , Respiração Artificial , Insuficiência Respiratória/etiologia , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
BACKGROUND: Non-invasive ventilation has never been compared with high-flow oxygen to determine whether it reduces the risk of severe hypoxaemia during intubation. We aimed to determine if preoxygenation with non-invasive ventilation was more efficient than high-flow oxygen in reducing the risk of severe hypoxaemia during intubation. METHODS: The FLORALI-2 multicentre, open-label trial was done in 28 intensive care units in France. Adult patients undergoing tracheal intubation for acute hypoxaemic respiratory failure (a partial pressure of arterial oxygen [PaO2] to fraction of inspired oxygen [FiO2] ratio of ≤300 mm Hg) were randomly assigned (1:1; block size, four participants) to non-invasive ventilation or high-flow oxygen during preoxygenation, with stratification by PaO2/FiO2 ratio (≤200 mm Hg vs >200 mm Hg). Key exclusion criteria were intubation for cardiac arrest, altered consciousness (defined as a Glasgow coma score of less than eight points), other contraindications to non-invasive ventilation (recent laryngeal, oesophageal, or gastric surgery, and substantial facial fractures), pulse oximetry not available, pregnant or breastfeeding women, and refusal to participate. The primary outcome was the occurrence of severe hypoxaemia (pulse oximetry <80%) during the procedure, assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT02668458. FINDINGS: Between April 15, 2016, and Jan 8, 2017, 2079 patients were intubated in the 28 participating units, and 322 were enrolled. We excluded five patients with no recorded data, two who withdrew consent or were under legal protection, one who was not intubated, and one who had a cardiac arrest. Of the 313 patients included in the intention-to-treat analysis, 142 were assigned to non-invasive ventilation and 171 to high-flow oxygen therapy. Severe hypoxaemia occurred in 33 (23%) of 142 patients after preoxygenation with non-invasive ventilation and 47 (27%) of 171 with high-flow oxygen (absolute difference -4·2%, 95% CI -13·7 to 5·5; p=0·39). In the 242 patients with moderate-to-severe hypoxaemia (PaO2/FiO2 ≤200 mm Hg), severe hypoxaemia occurred less frequently after preoxygenation with non-invasive ventilation than with high-flow oxygen (28 [24%] of 117 patients vs 44 [35%] of 125; adjusted odds ratio 0·56, 0·32 to 0·99, p=0·0459). Serious adverse events did not differ between treatment groups, with the most common immediate complications being systolic arterial hypotension (70 [49%] patients in the non-invasive ventilation group vs 86 [50%] patients in the high-flow oxygen group) and chest infiltrate on x-ray (28 [20%] vs 33 [19%]), and the most common late complications being death at day 28 (53 [37%] vs 58 [34%]) and ventilator-associated pneumonia during ICU stay (31 [22%] vs 35 [20%]). INTERPRETATION: In patients with acute hypoxaemic respiratory failure, preoxygenation with non-invasive ventilation or high-flow oxygen therapy did not change the risk of severe hypoxaemia. Future research should explore the effect of preoxygenation method in patients with moderate-to-severe hypoxaemia at baseline. FUNDING: French Ministry of Health.
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Ventilação não Invasiva , Oxigenoterapia , Insuficiência Respiratória/terapia , Doença Aguda , Cateterismo , Feminino , Humanos , Hipóxia/etiologia , Hipóxia/prevenção & controle , Intubação Intratraqueal , Masculino , Pessoa de Meia-Idade , Ventilação não Invasiva/métodos , Nariz , Oximetria , Oxigenoterapia/métodos , Respiração Artificial/métodosRESUMO
PURPOSE OF REVIEW: A prompt identification of the cause of acute respiratory failure (ARF)/acute respiratory distress syndrome (ARDS) is required in order to initiate a targeted treatment. Yet, almost 10% of ARDS patients have no identified ARDS risk factor at ARDS diagnosis. Numerous rare causes of ARF have been reported in this setting. The purpose of this review is to delineate the main rare causes of ARF/ARDS and to provide clinicians with a pragmatic diagnostic work-up. RECENT FINDINGS: Recent epidemiological data have proposed the identification of a subgroup of ARDS patients lacking exposure to common risk factors. These can be categorized as having immune, drug-induced, malignant and idiopathic diseases. A standardized diagnostic work-up including chest imaging, the objective assessment of left heart filling pressures, bronchoalveolar lavage fluid microbiological investigations and cytological analysis, immunological tests and search for pneumotoxic drugs may allow for identifying the cause of ARF in most cases. Open lung biopsy should be considered in other cases. SUMMARY: A prompt identification of the cause of ARF is required to initiate a targeted treatment. Patients with no identified ARDS risk factor should undergo a comprehensive and hierarchized diagnostic work-up.
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Unidades de Terapia Intensiva , Síndrome do Desconforto Respiratório , Biópsia , Humanos , Pulmão , Síndrome do Desconforto Respiratório/diagnóstico , Fatores de RiscoAssuntos
Artérias Brônquicas/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Embolização Terapêutica/métodos , Hemoptise/diagnóstico por imagem , Pneumonectomia/métodos , Doença Pulmonar Obstrutiva Crônica/complicações , Idoso , Artérias Brônquicas/patologia , Broncoscopia/métodos , Terapia Combinada/métodos , Estado Terminal , Seguimentos , Hemoptise/etiologia , Hemoptise/terapia , Humanos , Unidades de Terapia Intensiva , Masculino , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Radiografia Torácica/métodos , Recidiva , Medição de Risco , Resultado do TratamentoRESUMO
Hemoptysis is a life-threatening complication of Behcet's disease that is likely related to pulmonary artery aneurysm (PAA). Vascular interventional radiology may offer effective emergency therapeutic option, but has not been thoroughly investigated in this setting. A case series of a French referral center for hemoptysis combined with a literature review of case reports was conducted. Between 1995 and 2016, 12 patients were referred to our center for hemoptysis revealing or complicating the course of Behcet's disease. Pulmonary artery aneurysm (PAA) was the mechanism of hemoptysis in ten patients, nine of whom were treated by a transcatheter embolotherapy. Combining an additional 8 case reports from the literature, 17 patients treated by transcatheter embolotherapy for PAA were analyzed. The duration of the course of Behcet's disease was 22 months [IQR 3-45] at the time of PAA diagnosis. Transcatheter embolotherapy of PAA was successful for immediately controlling hemoptysis in all patients, without major complication except for one. Hemoptysis recurred in seven patients (41%) within 5 months [IQR 1-12]. The use of coils for transcatheter embolotherapy was associated with hemoptysis recurrence. A bronchosystemic hypervascularization related to the previously occluded PAA was the main mechanism of bleeding recurrence, leading to bronchosystemic artery embolization in four patients and surgery in two patients. Behcet's disease-related hemoptysis is mainly due to PAA. Transcatheter embolotherapy should be considered as the first-line emergency treatment for PAA-related hemoptysis, in association with the immunosuppressive regimen. Hemoptysis may recur in half of the cases, involving preferentially a bronchosystemic arterial mechanism.
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Aneurisma/terapia , Embolização Terapêutica/métodos , Adulto , Síndrome de Behçet/terapia , Tratamento de Emergência , Feminino , França , Hemoptise/etiologia , Humanos , Masculino , Estudos Prospectivos , Artéria Pulmonar/fisiopatologia , Centros de Cuidados de Saúde Secundários , Estatísticas não ParamétricasRESUMO
PURPOSE: Some patients presenting with acute respiratory failure and meeting the Berlin criteria for acute respiratory distress syndrome (ARDS) lack exposure to common risk factors (CRF). These so-called ARDS mimickers often lack histological diffuse alveolar damage. We aimed to describe such ARDS mimickers lacking CRF (ARDS CRF-) in comparison with others (ARDS CRF+). METHODS: Retrospective study including all patients receiving invasive mechanical ventilation for ARDS admitted to the intensive care units (ICUs) of two tertiary care centers from January 2003 to December 2012. RESULTS: The prevalence of ARDS CRF- was 7.5 % (95 % CI [5.5-9.5]; n = 50/665). On the basis of medical history, bronchoalveolar lavage fluid cytology, and chest CT scan patterns, four etiological categories were identified: immune (n = 18; 36 %), drug-induced (n = 13; 26 %), malignant (n = 7; 14 %), and idiopathic (n = 12; 24 %). Although the ARDS CRF- patients had a lower logistic organ dysfunction score (4 [3-8] vs. 10 [6-13]; p < 0.0001) and less often shock upon ICU admission (44 vs. 80 %; p < 0.0001) than their counterparts, their overall ICU mortality rate was very high (66 % [46-74]), and the absence of CRF remained associated with ICU mortality by multivariable logistic regression analysis (adjusted OR = 2.06; 95 % CI [1.02-4.18]; p = 0.044). Among ARDS CRF- patients, the presence of potentially reversible lung lesions with corticosteroids (aOR = 0.14; 95 % CI [0.03-0.62]) was associated with ICU survival. CONCLUSIONS: The absence of CRF among patients with ARDS is common and associated with a higher risk of mortality. For such atypical ARDS, a complete diagnostic workup, including bronchoalveolar lavage fluid cytology and chest CT scan patterns, should be performed to identify those patients who might benefit from specific therapies, including corticosteroids.
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Síndrome do Desconforto Respiratório/diagnóstico , Síndrome do Desconforto Respiratório/terapia , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , França/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Síndrome do Desconforto Respiratório/epidemiologia , Estudos Retrospectivos , Fatores de RiscoRESUMO
This review focuses on the epidemiological characteristics and etiologies of four primary systemic vasculitides with frequent lung involvement, namely Wegener granulomatosis (WG), microscopic polyangiitis (MPA), Churg-Strauss syndrome (CSS), and Goodpasture syndrome (GPS). Elucidation of the mechanisms underlying these vasculitides with frequent lung involvement is complicated by their rarity, which hampers the undertaking of large-scale studies; difficulties in classification; and their multifaceted clinical presentations, which infer the existence of several etiologic pathways. Notwithstanding, epidemiological research showed some evidence for international, interethnic, and temporal variations of the frequencies of these four vasculitides; led to the identification of several genetic and environmental risk factors; and provided insight on the extent to which genes and environment might contribute to their development. Available data support the concept that WG, MPA, CSS, and GPS have unique and shared risk determinants. Although the precise causes of these vasculitides are not yet fully understood and the development of prevention strategies is out of our reach at present, current knowledge enables the formulation of etiologic hypotheses to provide caregivers and their patients with valuable information on the nature of these rare entities.