RESUMO
Microbiological analyses were conducted on wild eels from the L'Albufera Lake (Spain). A total of 174 individuals were collected in two surveys (i.e. year 2008 and autumn-winter 2014) among those caught by local fishermen into the lagoon. The prevalence of Shewanella putrefaciens group was 1.7% in 2008 and rose above 32% in 2014. It was due to an outbreak of shewanellosis that presented a morbidity rate of 64%. S. putrefaciens group strains were isolated as pure cultures from the sick eels that showed white ulcers surrounded by a reddish inflammation, damage of the mouth, extensive skin discoloration, exophthalmia, ascites and bad odour. The S. putrefaciens group was recovered from freshwater samples taken at the L'Albufera system, along autumn-winter 2015. Its counts significantly increased in freshwater parallel to hypoxia and temperature rising. Shewanellae strains were identified as S. putrefaciens and S. xiamenensis by 16S rRNA gene sequencing. These isolates recovered from sick eels or freshwater were virulent for European eel by IP challenge (LD50 106 CFU g-1 body weight). They also caused 30-38% cumulative mortality, in European eels challenged by a 2-h bath (107 CFU mL-1 ). These results suggest that shewanellosis could be transmitted through water highlighting the fact that hypoxic conditions increase this bacterium levels in water.
Assuntos
Anguilla , Surtos de Doenças , Doenças dos Peixes/epidemiologia , Infecções por Bactérias Gram-Negativas/veterinária , Shewanella putrefaciens/fisiologia , Anaerobiose , Animais , Doenças dos Peixes/microbiologia , Água Doce , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Estações do Ano , Espanha/epidemiologiaRESUMO
OBJECTIVES: To determine mortality and long-term survival factors in patients with systemic autoimmune diseases (SAD) admitted to the intensive care unit (ICU). METHODS: Retrospective observational study including all consecutive patients with a diagnosis of any systemic autoimmune disease admitted to the medical ICU in a tertiary hospital between 1999 and 2007. Factors associated with reduced survival were identified by means of log rank test and backward stepwise Cox regression. RESULTS: Thirty-seven patients (26 females) were included with median age being 44.3 years (interquartilic range [IQR]: 31.3). Sixteen (43.2%) patients had systemic lupus erythematosus, 9 (24.3%) had systemic vasculitis, 4 (10.8%) had systemic sclerosis and 4 (10.8%) had primary antiphospholipid syndrome. The main reason for ICU admission was autoimmune disease flare-up in 20 (54.0%) patients, followed by infections in 12 (32.4%). Median APACHE II at admission was 17 (IQR 7). At the end of follow-up, 15 (40.5%) patients died, 10 (27%) during hospitalisation (7 in the ICU) and 5 after hospital discharge. Factors associated with reduced long-term survival were: APACHE II score ≥18 (HR 6.02, 95% CI 1.76-20.62), age <45 years (HR 6.54, 95% CI 1.84-23.29), presence of any previous chronic disease (HR 18.20, 95% CI 3.72-88.96), and increase of corticosteroid therapy during ICU stay (HR 22.87, 95% CI 4.31-121.30). CONCLUSIONS: The long-term survival of patients with systemic autoimmune diseases admitted to the ICU was related with age, higher APACHE II score, previous chronic diseases, and an increase in corticosteroids dose when comparing with previous ICU admissions.
Assuntos
Doenças Autoimunes/mortalidade , Doenças Autoimunes/terapia , Cuidados Críticos/estatística & dados numéricos , Unidades de Terapia Intensiva/estatística & dados numéricos , Sobreviventes/estatística & dados numéricos , Adulto , Síndrome Antifosfolipídica/mortalidade , Síndrome Antifosfolipídica/terapia , Dermatomiosite/mortalidade , Dermatomiosite/terapia , Feminino , Seguimentos , Humanos , Lúpus Eritematoso Sistêmico/mortalidade , Lúpus Eritematoso Sistêmico/terapia , Masculino , Prognóstico , Estudos Retrospectivos , Escleroderma Sistêmico/mortalidade , Escleroderma Sistêmico/terapia , Síndrome de Sjogren/mortalidade , Síndrome de Sjogren/terapia , Vasculite/mortalidade , Vasculite/terapiaRESUMO
Pulmonary sequestration is a rare malformation of the respiratory tract that accounts for 0.15-6.4% of all congenital lung anomalies. Treatment requires resection of the lesion, provided that there is no technical contraindication. The lesion should first be evaluated using video thoracoscopy and then resected whenever possible by video-assisted thoracic surgery (VATS). We report a case of extralobar pulmonary sequestration in a 48-year-old woman. She underwent lobectomy by VATS and achieved an excellent outcome.
Assuntos
Sequestro Broncopulmonar/cirurgia , Pneumonectomia/métodos , Cirurgia Torácica Vídeoassistida , Sequestro Broncopulmonar/complicações , Feminino , Hemoptise/etiologia , Humanos , Pessoa de Meia-Idade , Pneumonia/etiologia , RecidivaRESUMO
OBJECTIVE: To outline the usefulness of videothoracoscopic and videoassisted surgery in the final staging, resectability evaluation and treatment of lung cancer, and its possible advantages over thoracotomy. PATIENTS AND METHOD: Videothoracoscopy was performed on 296 patients suffering from lung cancer. Patient selection criteria are described, as well as techniques for the different kinds of resections. Postoperative care and patient follow-up is also detailed. RESULTS: Of the 296 patients 189 were operated on by open surgery after final staging and resectability evaluation. A total of 30 were considered unresectable by videothoracoscopic exploration, five cases needed exploratory thoracotomy to determine the resectability and in the remaining 72 cases the pulmonary resection was performed by videoassisted surgery: 21 pneumonectomies, five bilobectomies and 46 lobectomies. Three patients were rescued for surgery, after it was proven by intrapericardical videothoracoscopic exploration that the pulmonary artery was free at this level. The mean hospital stay was 48 h for the videothoracoscopic exploration and 6.8 days for the major lung resections. There were ten patients with complications (14%). The perioperatory mortality (30 days) was three cases (4.2%). The outcome (3-40 months follow-up) at the end of the study period was 62% patients alive and free of disease. DISCUSSION: The applications of videothoracoscopic and videoassisted surgery in the treatment of lung cancer are considered: final staging, resectability evaluation, nodule biopsy and major resections with mediastinal lymphadenectomy. Their advantages include minimized pain, better cosmetic results, a shorter hospital stay and fewer complications.
Assuntos
Neoplasias Pulmonares/cirurgia , Excisão de Linfonodo/métodos , Pneumonectomia/métodos , Gravação em Vídeo , Adulto , Idoso , Idoso de 80 Anos ou mais , Tomada de Decisões , Estudos de Avaliação como Assunto , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Retrospectivos , Taxa de Sobrevida , Toracoscopia , Resultado do TratamentoRESUMO
We describe our experience using exploratory video-assisted thoracoscopy (EVT) to definitively evaluate resectability in patients with lung cancer who are candidates for surgical resection. In a single procedure we performed full visual and surgical exploration of the pleural cavity, lung, mediastinum, as well as of the pericardial cavity when required. The technique was used in 151 patients. Resection was judged non viable in 18 (11.9%) and performance of exploratory thoracotomy was deemed unnecessary. In 3 cases thoracotomy proved necessary for exploration. Nineteen patients were treated by video-assisted surgery; standard thoracotomy was used to resect 111. Morbidity and mortality were null in the group undergoing EVT in whom resection was judged viable. We conclude that EVT should be used in all patients with lung cancer who are being considered for surgery before a thoracotomy is performed. EVT can be performed as part of the same surgical act, as it supposes a savings in exploratory thoracotomies (amounting to 11.9% in our series).
Assuntos
Neoplasias Pulmonares/diagnóstico , Toracoscopia/métodos , Gravação em Vídeo/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Excisão de Linfonodo , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Pneumonectomia , ToracotomiaRESUMO
Solitary fibrous tumors of the pleura are rare, with unpredictable clinical manifestations. By the time of diagnosis, the size and consistency of the tumor usually preclude the use of minimally invasive surgical techniques. We present a case of a 34-year-old male with a solitary fibrous tumor of the visceral pleura masquerading as a mediastinal tumor. The tumor was removed by video-assisted thoracic surgery.
Assuntos
Fibroma/cirurgia , Neoplasias Pleurais/cirurgia , Cirurgia Torácica Vídeoassistida , Adulto , Biomarcadores Tumorais/análise , Fibroma/química , Fibroma/diagnóstico , Humanos , Masculino , Neoplasias do Mediastino/diagnóstico , Neoplasias Pleurais/química , Neoplasias Pleurais/diagnóstico , FumarRESUMO
Forty-eight patients over the age of 70 with spontaneous pneumothorax (SP) are analyzed. The severity of the clinical picture is conditioned by the presence of earlier lung lesions, particularly related to emphysema, and by the degree of respiratory failure prior to SP. Treatment guidelines are listed. Pleural drainage/aspiration, applied in all cases, was of no avail in 69%. Tetracycline was injected into the pleural space of 23 patients, with failure recorded in 35%. Talc was applied by thoroscopy in 5 patients, to no avail. Video-assisted endoscopic surgery was carried out in 4 patients, with good results in 3. Surgery with access by lateral thoracotomy was carried out in 20 patients, with a single failure that was explained by the patient's condition.
Assuntos
Pneumotórax/terapia , Idoso , Idoso de 80 Anos ou mais , HumanosRESUMO
OBJECTIVE: Traditionally, thymectomy for myasthenia gravis has been performed using either a transcervical approach or a median sternotomy. However, excision of the thymic tissue by video-assisted thoracoscopic surgery is less aggressive and recovery is faster. The aim of this study was to evaluate the usefulness and outcomes of video-assisted thoracoscopic thymectomy. PATIENTS AND METHODS: Over the past 10 years, we have performed 25 video-assisted thoracoscopic thymectomies on patients with myasthenia gravis at our unit. This study included 16 women and 9 men, with a mean age of 48.1 years (range, 14-74 years). Right-side (22 cases) or left-side (3 cases) thoracoscopic surgery was performed, with a mean intervention time of 110 minutes (range, 60-193 minutes). RESULTS: No patient required assisted ventilation for more than 4 hours and the maximum stay in intensive care was less than 24 hours. Complications from surgery included 3 cases of contralateral pneumothorax, 1 pleural effusion, and 2 intraoperative hemorrhages from the thymic vein, all of which were resolved by video-assisted thoracoscopy. Likewise, 3 cases required conversion (due to hemorrhaging in 2 patients and technical difficulties in 1) and 2 required a second thoracoscopic intervention. No deaths occurred and clinical outcome was excellent in 11 cases (medical treatment no longer required), good in 10 (reduced medical treatment), and poor in 4 (no changes). CONCLUSIONS: Video-assisted thoracoscopic thymectomy is effective in the treatment of myasthenia gravis and improves patient recovery. In addition, the excellent surgical view allows the thymectomy to be performed with absolute safety.
Assuntos
Miastenia Gravis/cirurgia , Cirurgia Torácica Vídeoassistida , Timectomia , Adolescente , Adulto , Idoso , Feminino , Humanos , Unidades de Terapia Intensiva , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Reoperação , Segurança , Fatores de Tempo , Resultado do TratamentoRESUMO
OBJECTIVE: Primary palmar hyperhidrosis is a socially and occupationally debilitating disorder characterized by excessive sweating. The purpose of this study was to evaluate the results, complications, and degree of satisfaction among patients who underwent video-assisted bilateral thoracoscopic sympathectomy of the second and third ganglia (T2-T3) to treat primary palmar hyperhidrosis at the Department of General and Thoracic Surgery of the Hospital Universitario Virgen Macarena in Seville, Spain. MATERIAL AND METHOD: A study of 226 thoracoscopic sympathectomies was undertaken based on case histories and a prospective pre- and postoperative questionnaire survey. The sample was composed of 113 patients (47 males and 66 females), ranging in age from 14 to 50 years, with primary palmar and axillary hyperhidrosis, in some cases severe. Bilateral video-assisted thoracoscopic T2-T3 sympathectomy was performed under general anesthesia in all cases. Follow up included a questionnaire on pre- and postoperative quality of life and degree of satisfaction. Descriptive statistics on the surgical procedure, quality of life, and postoperative changes were compiled and frequency analyzed. A nonparametric Wilcoxon test for paired variables was performed to contrast significant differences between pre- and postoperative quality of life related to hyperhidrosis and its complications. RESULTS: The therapeutic success rate was 100%. Complications were seen in 14.2% of the cases and included hemothorax in two, hemopneumothorax in three, pleural hemorrhage in two, and minimal apical airspace in nine. Of the 106 patients who were monitored over a period of 6 to 12 months through follow-up interviews and questionnaires, 67% developed compensatory sweating, 95% reported improvement in quality of life, and 4% experienced no change in quality of life, mainly because of the emergence of compensatory sweating. Of the patients interviewed, 97.2% said that they would undergo the operation again. CONCLUSION: Video-assisted thoracoscopic sympathectomy for the treatment of primary palmar hyperhidrosis is effective, with low rates of morbidity and no mortality. Despite the appearance of postoperative changes such as compensatory sweating, patient satisfaction with the procedure is high and their quality of life improves.
Assuntos
Hiperidrose/cirurgia , Simpatectomia/métodos , Cirurgia Torácica Vídeoassistida/métodos , Adolescente , Adulto , Feminino , Humanos , Hiperidrose/etiologia , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Complicações Pós-Operatórias , Qualidade de Vida , Inquéritos e Questionários , Toracoscopia , Resultado do TratamentoRESUMO
OBJECTIVES: To demonstrate the usefulness of intrapericardial inspection of pulmonary vessels by video assisted thoracoscopy (VAT), for determining whether suspicion indicated by computed axial tomography (CAT) or magnetic resonance (MR) scanning is justified or not. PATIENTS AND METHOD: Since 1993 we have used exploratory VAT for final staging and assessment of lung cancer resectability. Intrapericardial vascular exploration (IVE) is a complementary method of assessing resectability in cT4 cases. We have performed 20 IVE among 460 VAT when intrapericardial involvement of pulmonary vessels has been suspected (19 men, 1 woman, mean age 64.6 years, range 50-77). VAT demonstrated invasion for 11 patients with previous suspicion based on hilar and vascular invasion shown by CAT scan; in 9 others such involvement was found during IVE for assessing resectability. VAT-IVE was performed through three or sometimes four entrance approaches, from which intrapericardial vessels were explored easily. RESULTS: Five cases were non-resectable: four due to invasion of the pulmonary artery to its point of origin and one due to extensive invasion of pulmonary veins and the left auricle. The remaining 15 cases were resectable and lesions were removed by posterolateral thoracotomy with intrapericardial dissection and ligature of the vessels. Five had been considered non-resectable by teams at other hospitals where they were classified as advanced cT4 cancers after imaging. The mean duration of IVE was 23 minutes (range 16 to 33); mean postprocedural stay was 48 h in non-resected patients, who were sent for neoadjuvant therapy on the third day. These patients, who underwent only IVE, had no complications and there were no deaths, with five unnecessary thoracotomies avoided. CONCLUSIONS: IVE allows correct staging of the T parameter in patients for whom T4 classification is suspected, avoiding unnecessary thoracotomies in non-resectable cases and allowing for surgical removal in cases where CAT or MR imaging results are unclear.
Assuntos
Neoplasias Pulmonares/cirurgia , Pericárdio , Neoplasias Vasculares/secundário , Idoso , Endoscopia , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Gravação em VídeoRESUMO
Blockade of the celiac plexus and the splanchnic nerves to combat abdominal pain can be achieved by percutaneous injection of local anesthetics or alcohol, or by thoracotomy. We describe the technique for performing splanchnicectomy with video-thoracoscopy in palliative surgery for cancer of the esophagogastric union, discussing the excellent results obtained immediately in 2 patients.
Assuntos
Plexo Celíaco , Neoplasias Esofágicas/fisiopatologia , Junção Esofagogástrica , Bloqueio Nervoso/métodos , Manejo da Dor , Nervos Esplâncnicos/cirurgia , Toracoscopia , Idoso , Neoplasias Esofágicas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Gravação em VídeoRESUMO
OBJECTIVES: Various approaches are used for the diagnosis and treatment of solitary pulmonary nodules (SPN) of unknown origin. New imaging techniques and nuclear medicine have provided more information about SPN, but surgical removal is still the most sensitive and specific way to obtain a correct analysis of the lesion. With video-assisted thoracic surgery (VATS), a histological diagnosis can be obtained without resorting to thoracotomy. In the present study we describe our experience with the diagnosis and treatment of SPN using VATS. MATERIAL AND METHODS: From July 1992 through April 2001, 182 patients were operated on for SPN in our department. DESIGN: Retrospective study. Mean age: 59.2 years (12-78). Sex: 39 women and 143 men. Localization: Visual or instrumental exploration in 102 patients, with palpation in 52 cases and using a hookwire guided by preoperative computed tomography in 25 (with failure in 4 of those cases). Tissue was biopsied during surgery and when the lesion was malignant, oncological excision was performed during the same operation. RESULTS: A firm diagnosis was obtained by VATS for 178 patients (98.3%). For three other patients the surgeon had to take a needle biopsy (Tru-cut) during surgery, and in one case conversion to open surgery was necessary. Histopathology: hamartoma: 11; fibrous nodule: 10; bronchiolitis obliterans: 1; pneumoconiosis: 1; mesenchymal tumor: 3; inflammatory pseudotumor: 14; mucormycosis: 1; tuberculoma:17; lymphoma: 1; carcinoid tumor: 6; metastasis: 22; bronchogenic carcinoma: 95. Mortality was 0.55%, with 1 patient dying from massive pulmonary thromboembolism. Morbidity was 5%, from 9 minor complications. CONCLUSIONS: VATS is an effective approach, with low morbidity and mortality. We consider it to be the technique of choice for the diagnosis of all SPN and for the treatment of some, such as benign nodules and solitary metastases.
Assuntos
Nódulo Pulmonar Solitário/diagnóstico , Cirurgia Torácica Vídeoassistida , Adolescente , Adulto , Idoso , Biópsia/instrumentação , Biópsia/métodos , Biópsia por Agulha , Carcinoma/diagnóstico , Carcinoma/epidemiologia , Carcinoma/secundário , Carcinoma/cirurgia , Criança , Feminino , Secções Congeladas , Hamartoma/diagnóstico , Hamartoma/epidemiologia , Hamartoma/patologia , Humanos , Pneumopatias/diagnóstico , Pneumopatias/epidemiologia , Pneumopatias/patologia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Pneumonectomia/métodos , Estudos Retrospectivos , Sensibilidade e Especificidade , Nódulo Pulmonar Solitário/epidemiologia , Nódulo Pulmonar Solitário/patologia , Nódulo Pulmonar Solitário/cirurgia , Espanha/epidemiologia , Cirurgia Torácica Vídeoassistida/estatística & dados numéricos , Tomografia Computadorizada por Raios X/instrumentação , Tomografia Computadorizada por Raios X/métodosRESUMO
The primary role of thymectomy for the treatment of myasthenia gravis is currently undisputed. Traditionally, the approach of choice has been sternotomy, although a transcervical route has also been advocated because of its lower rate of associated morbidity. Our department performed thymectomy using a video-assisted thoracoscopic technique in 7 patients (2 men and 5 women) between March 1993 and October 1995. The patients' mean age was 43.4 years (range 20 to 66 years). Complications were few, consisting of 2 cases of pneumothorax due to contralateral opening of the pleura, resolved by pleural drainage. No deaths occurred. Clinical results over periods of observation ranging from 14 to 44 months were excellent in 2 cases of complete remission; good in 3 patients with considerable reduction in drug requirements; and fair in 2 patients who continued to need the same doses of medication throughout the 14 months after thymectomy. The technique we propose is less aggressive than mid-sternotomy, offering incontrovertible advantages and leading to faster. No patient required assisted ventilation for longer than 4 hours and the maximum time spent in the intensive care unit was 24 hours. We therefore suggest that thymectomy to treat myasthenia gravis be performed by thoracoscopy.
Assuntos
Miastenia Gravis/cirurgia , Toracoscopia/métodos , Timectomia/métodos , Adulto , Idoso , Endoscopia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/diagnóstico , Cuidados Pré-Operatórios , Resultado do Tratamento , Gravação em VídeoRESUMO
Congenital cystic adenomatoid malformation involving the lung is a rare hamartomatous condition that is usually diagnosed in the neonatal period. The presentation of this malformation in older patients is exceptional and usually manifests in a series of recurrent lung infections affecting a single lobe or segment. The treatment of choice is complete surgical exeresis. This report of 3 cases of late presentation focuses on the surgical approach used and the unusual manifestation of recurrent spontaneous pneumothoraces in 1 patient. The patients were females aged 15, 16, and 25 years with histories of various respiratory diseases (extrinsic asthma, recurrent pneumonias, and pneumothoraces). The patients were referred to us for surgery with suspected diagnoses that were different from the final diagnoses in all cases. All underwent diagnostic video-assisted thoracoscopy to explore the affected hemothorax, and definitive treatment was possible during the procedure for 2 patients (a lobectomy and an atypical segmentectomy) by video-assisted surgery. The third patient underwent lobectomy by lateral thoracotomy after exploratory video-assisted thoracoscopy. Short- and long-term outcomes were excellent for all 3 patients.
Assuntos
Malformação Adenomatoide Cística Congênita do Pulmão/cirurgia , Pneumonectomia/métodos , Cirurgia Torácica Vídeoassistida , Adolescente , Adulto , Feminino , HumanosRESUMO
15 aged patients with clinical and laboratory evidence of cerebrovascular insufficiency and/or myocardial sclerosis were given suloctidil (Locton) at the daily dose of 200 mg X 3, for 180 days, under the conditions of an open trial. Blood and plasma viscosity, red cell deformability, total lipids, cholesterol, triglycerides, fibrinolysis (plasminogen, antiplasmin, euglobulins with and without activator, fibrinogen), and capillaroscopic parameters in the small conjunctival vessels (artery, vein, and capillary diameter, appearance of collaterals, red cell aggregation and flow homogeneity) were evaluated. After 30 days of treatment and particularly at the end of the trial a significant improvement of almost all these parameters was observed. Tolerance was always excellent.
Assuntos
Arteriosclerose/tratamento farmacológico , Propanolaminas/uso terapêutico , Suloctidil/uso terapêutico , Idoso , Viscosidade Sanguínea/efeitos dos fármacos , Transtornos Cerebrovasculares/tratamento farmacológico , Ensaios Clínicos como Assunto , Deformação Eritrocítica/efeitos dos fármacos , Feminino , Fibrinólise/efeitos dos fármacos , Humanos , Lipídeos/sangue , Masculino , Microcirculação/efeitos dos fármacos , Pessoa de Meia-Idade , Suloctidil/efeitos adversos , Fatores de TempoRESUMO
BACKGROUND: Since May 1992 we have used video-assisted thoracic surgery (VATS) for the treatment of the spontaneous pneumothorax. In this study we review the results obtained with this technique and we compare them with those obtained by conventional surgery (1976-1992). METHODS: 110 patients (98 males and 12 females, age 15-83 years) were operated by VATS, and 627 patients (567 males and 60 females, age 14-89 years) by conventional surgery. The surgical technique and the complications are compared. No one died. RESULTS: Although the number of complications was greater in the first group than in the second one (29.5% vs 15.1%), this is attributed to the lack of experience among surgeons in the first cases; which complications nearly disappeared in the last 60 patients. Less pain, better recovery, and shorter hospital stay resulted. CONCLUSIONS: For us VATS is the ideal technique with which to treat spontaneous pneumothorax.