Subcutaneous emphysema is the local tissue swelling caused by the gas entering the subcutaneous tissue through the tissue gap. Although subcutaneous emphysema is usually a nonfatal and self-limited disease, in severe cases, the gas may spread to the neck, mediastinum and chest, resulting in mediastinal emphysema and other serious complications. This article reviews the etiology, pathogenesis, clinical manifestations, diagnosis, differential diagnosis of subcutaneous emphysema related to dental therapy,and operations that may cause subcutaneous emphysema in stomatology department,as well as the treatment and prognosis of subcutaneous emphysema, with a view to providing some references for dentists.
Humans ; Diagnosis, Differential ; Mediastinal Emphysema/pathology* ; Subcutaneous Emphysema/therapy* ; Neck/pathology* ; Face

Placental transmogrification of the lung (PTL) is a very rare benign lung lesion. There are only about 40 cases reported in the literature. The imaging and histological features of PTL cases in the publication are various, most of which are cystic and a few of which are solid. Being extremely rare, the solid PTL is unknown to major pathologists and surgeons. We reported a case of solid PTL in the anterior mediastinum. The patient was a 52-year-old male with no history of smoking and without symptoms. During physical examination, chest CT revealed a circular low-density lesion with a maximum diameter of 2.9 cm beside the spine in the posterior basal segment of the left lower lobe of the lung. The wedge resection was performed by video-assisted thoracoscopy. Grossly, a round nodule was located underneath the visceral pleura. It was about 3.0 cm×3.0 cm×1.6 cm and the cut surface was grey-red, soft and spongy. Microscopically, the nodule was constituted of papillare, which resembled placental villi at low magnification. The axis of papillae was edema, in which some mild round cells with clear cytoplasm and CD10 positive staining aggregated and transitioned to immature adipocytes and amorphous pink materials deposited with a few of inflammatory cells infiltration. The surface of papillae was covered with disconti-nuous alveolar epithelium. Combined with the typical morphology and immunohistochemical characteristics of CD10 positive, the diagnosis was PTL. The patient was followed up for 1 year without recurrence and discomfort. So far, the pathogenesis of PTL is unclear. The major hypotheses include hamartoma, variant of emphysema and clonal hyperplasia of stromal cells. Based on the study of our case and publication, we speculate that the hyperplasia of stromal cells located in the alveolar septa might be the first step to form the solid PTL. With the progression of the disease, a typical unilateral cystic nodule develops as a result of secondary cystic degeneration due to the occlusive valve effect. Surgery is the only option for diagnosis and treatment of PTL. The clinician should make an individualized operation plan according to the clinical manifestations, location and scope of the lesion, and preserve the surrounding normal lung tissue as much as possible while completely removing the lesion. There is a favorable prognosis.
Male ; Humans ; Female ; Pregnancy ; Middle Aged ; Hyperplasia/pathology* ; Placenta/pathology* ; Lung/pathology* ; Pulmonary Emphysema/surgery* ; Tomography, X-Ray Computed/methods*

Lung volume reduction loop uses bronchoscopic lung volume reduction(BLVR) technology to compress and collapse the necrotic emphysema tissue and exhaust the internal gas to achieve the purpose of lung volume reduction to treat emphysema. After the lung volume reduction loop is implanted into the human body, the compressed part of the lung tissue tends to expand with breathing, which makes the lung volume reduction loop expand into a linear trend periodically. Fatigue resistance is one of the most important performance indexes of the lung volume reduction loop. In the paper, Z-direction vibration fatigue machine was used to simulate the changes of human respiratory cycle movement to test the fatigue performance of lung volume reduction loop, which can provide some reference for the test method of in vitro fatigue performance of lung volume reduction related products in the future.
Bronchoscopy/methods* ; Emphysema/surgery* ; Humans ; Lung ; Pneumonectomy/methods* ; Pulmonary Emphysema/surgery* ; Treatment Outcome

Objective: To examine the modalities of treatment and clinical outcomes of emphysematous pyelonephritis (EPN), in order to improve the survival rate of EPN patients. Methods: Totally 14 patients diagnosed as EPN between October 2011 and November 2020 at Department of Urology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine were included in this article. Data collection including patient demographics, clinical manifestations, management and clinical outcomes were conducted by retrospective charts review, after receiving the institutional review board's approval. There were 11 females and 3 males with a median age of 59 years (range: 52 to 73 years). The lesions were located on the left side in 10 patients and right side in 4 patients. All the 14 patients suffered from fever, and present with severe sepsis or septic shock. The median time from symptom onset to admission to hospital was 3 days(range: 2 to 5 days). All cases had diabetes mellitus. Escherichia coli was the most common organism been cultured (11 cases), while Klebsiella pneumonia was the second (3 cases). CT scan showed bubbly or located gas in the renal parenchyma in 5 cases and presence of steaky or mottled gas in the renal parenchyma in 9 cases. All patients had been admitted to ICU for anti-septic shock therapy. Three patients had undergone percutaneous catheter drainage along with broad-spectrum antibiotics therapy while 3 patients had immediate nephrectomy, the other 8 cases had a combination of an initial percutaneous catheter drainage and second stage nephrectomy. Results: In this case series, 3 patients were died from EPN while the other 11 were survived. The median ICU stay time was 6 days (range: 3 to 11 days). Of the 3 patients died from EPN, 2 had undergone percutaneous catheter drainage along and 1 had received immediate nephrectomy. Among the 11 patients who were survived, only 1 had received percutaneous catheter drainage while the other 10 received nephrectomy (8 patients had staged nephrectomy). Follow-up was performed 6 months after discharge. Of the 11 surviving patients, 2 were lost to follow-up, and the remaining 9 patients had an creatine level of (118.4±29.4) μmol/L (range: 89 to 176 μmol/L). Conclusions: For patients coupled with diabetes who were initially diagnosed as acute pyelonephritis, the possibility of EPN should be considered when the disease progressed rapidly especially septic shock occurred. On the basis of empirical broad-spectrum antibiotics therapy and standardized anti-septic shock treatment, a combination of an initial percutaneous catheter drainage and second stage nephrectomy could be efficacious.
Aged ; Emphysema/therapy* ; Escherichia coli Infections ; Female ; Humans ; Male ; Middle Aged ; Pyelonephritis/therapy* ; Retrospective Studies ; Treatment Outcome

Humans ; Pilot Projects ; Prospective Studies ; Pulmonary Emphysema/surgery* ; Lung/surgery* ; Emphysema ; Perfusion ; Tomography, Emission-Computed ; Tomography ; Tomography, Emission-Computed, Single-Photon ; Pneumonectomy ; Bronchoscopy/methods*

Subcutaneous emphysema is commonly associated with infection caused by gas-producing organisms. In this case report, we describe a rare instance of traumatic subcutaneous emphysema of the hand and forearm caused by a puncture injury to the first web space of the hand. Our objective is to increase awareness of the potential for seemingly minor trauma to cause entrapment of significant air in subcutaneous tissues, thereby decreasing the likelihood that a clinically benign-appearing patient will be started down an unnecessarily aggressive treatment pathway. A 16-year-old, otherwise healthy white female, presented to the pediatric emergency room with an impressive amount of subcutaneous emphysema that developed over a 12-h period after sustaining an accidental laceration to the first web space of her right hand. She appeared nontoxic and had a clinically benign presentation. A comprehensive work-up was performed. She was splinted by the orthopedic surgery resident on call, and was admitted to the Pediatric Intensive Care Unit for overnight monitoring. She received tetanus vaccination and broad-spectrum antibiotics. The patient was discharged 2 days after admittance, with a splint applied to her right hand and forearm. She undertook home-based physical and occupational therapy. She had a pain-free range-of-motion in the right wrist, elbow and shoulder. The swelling in the right hand subsided completely. Although initially alarming, traumatic subcutaneous emphysema in an otherwise healthy patient from minor wounds (as featured in this case) does not necessarily mean one ought to proceed down an aggressive treatment algorithm. Careful evaluation of the patient's history, clinical examination findings, and determination of the Laboratory Risk Indicator for Necrotizing Fasciitis score can help guide physicians in the management of traumatic subcutaneous emphysema and potentially avoid unnecessary and costly interventions.
Humans ; Child ; Female ; Adolescent ; Forearm ; Subcutaneous Emphysema/diagnosis* ; Upper Extremity ; Anti-Bacterial Agents/therapeutic use* ; Wounds, Penetrating/surgery*

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characteristic of small airway inflammation, obstruction, and emphysema. It is well known that spirometry alone cannot differentiate each separate component. Computed tomography (CT) is widely used to determine the extent of emphysema and small airway involvement in COPD. Compared with the pulmonary function test, small airway CT phenotypes can accurately reflect disease severity in patients with COPD, which is conducive to improving the prognosis of this disease. CT measurement of central airway morphology has been applied in clinical, epidemiologic, and genetic investigations as an inference of the presence and severity of small airway disease. This review will focus on presenting the current knowledge and methodologies in chest CT that aid in identifying discrete COPD phenotypes.
Airway Obstruction ; Humans ; Phenotype ; Pulmonary Disease, Chronic Obstructive/diagnostic imaging* ; Pulmonary Emphysema/diagnostic imaging* ; Tomography, X-Ray Computed

Humans ; Mediastinal Emphysema ; Subcutaneous Emphysema ; Thyroidectomy/adverse effects*

BACKGROUND: We previously demonstrated that continuous exposure to nitrous acid gas (HONO) for 4 weeks, at a concentration of 3.6 parts per million (ppm), induced pulmonary emphysema-like alterations in guinea pigs. In addition, we found that HONO affected asthma symptoms, based on the measurement of respiratory function in rats exposed to 5.8 ppm HONO. This study aimed to investigate the dose-response effects of HONO exposure on the histopathological alterations in the respiratory tract of guinea pigs to determine the lowest observed adverse effect level (LOAEL) of HONO. METHODS: We continuously exposed male Hartley guinea pigs (n = 5) to four different concentrations of HONO (0.0, 0.1, 0.4, and 1.7 ppm) for 4 weeks (24 h/day). We performed histopathological analysis by observing lung tissue samples. We examined samples from three guinea pigs in each group under a light microscope and measured the alveolar mean linear intercept (Lm) and the thickness of the bronchial smooth muscle layer. We further examined samples from two guinea pigs in each group under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). RESULTS: We observed the following dose-dependent changes: pulmonary emphysema-like alterations in the centriacinar regions of alveolar ducts, significant increase in Lm in the 1.7 ppm HONO-exposure group, tendency for hyperplasia and pseudostratification of bronchial epithelial cells, and extension of the bronchial epithelial cells and smooth muscle cells in the alveolar duct regions. CONCLUSIONS These histopathological findings suggest that the LOAEL of HONO is < 0.1 ppm.
Alveolar Epithelial Cells ; drug effects ; Animals ; Bronchi ; drug effects ; Dose-Response Relationship, Drug ; Emphysema ; chemically induced ; Epithelial Cells ; drug effects ; Guinea Pigs ; Hyperplasia ; chemically induced ; Inhalation Exposure ; adverse effects ; Lung ; drug effects ; pathology ; ultrastructure ; Male ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Myocytes, Smooth Muscle ; drug effects ; Nitrous Acid ; toxicity

OBJECTIVE: To determine the predictive factors for treatment responsiveness in patients with chronic obstructive pulmonary disease (COPD) at 1-year follow-up by performing quantitative analyses of baseline CT scans. MATERIALS AND METHODS: COPD patients (n = 226; 212 men, 14 women) were recruited from the Korean Obstructive Lung Disease cohort. Patients received a combination of inhaled long-acting beta-agonists and corticosteroids twice daily for 3 months and subsequently received medications according to the practicing clinician's decision. The emphysema index, air-trapping indices, and airway parameter (Pi10), calculated using both full-width-half-maximum and integral-based half-band (IBHB) methods, were obtained with baseline CT scans. Clinically meaningful treatment response was defined as an absolute increase of ≥ 0.225 L in the forced expiratory volume in 1 second (FEV1) at the one-year follow-up. Multivariate logistic regression analysis was performed to investigate the predictors of an increase in FEV1, and receiver operating characteristic (ROC) analysis was performed to evaluate the performance of the suggested models. RESULTS: Treatment response was noted in 47 patients (20.8%). The mean FEV1 increase in responders was 0.36 ± 0.10 L. On univariate analysis, the air-trapping index (ATI) obtained by the subtraction method, ATI of the emphysematous area, and IBHB-measured Pi10 parameter differed significantly between treatment responders and non-responders (p = 0.048, 0.042, and 0.002, respectively). Multivariate analysis revealed that the IBHB-measured Pi10 was the only independent variable predictive of an FEV1 increase (p = 0.003). The adjusted odds ratio was 1.787 (95% confidence interval: 1.220–2.619). The area under the ROC curve was 0.641. CONCLUSION: Measurement of standardized airway dimensions on baseline CT by using a recently validated quantification method can predict treatment responsiveness in COPD patients.
Adrenal Cortex Hormones ; Cohort Studies ; Emphysema ; Follow-Up Studies ; Forced Expiratory Volume ; Humans ; Logistic Models ; Lung Diseases, Obstructive ; Male ; Methods ; Multivariate Analysis ; Odds Ratio ; Pulmonary Disease, Chronic Obstructive ; ROC Curve ; Tomography, X-Ray Computed