Depth of Pleural Effusion in Thoracentesis: Comparison of Lateral, Posterolateral and Posterior Approaches in the Supine Position.

BACKGROUND: In patients who have difficulty sitting, thoracentesis is attempted in a supine position via lateral approach. Recently, a new table has been designed for supine thoracentesis. This table has gaps that allow access to the posterolateral and posterior hemithorax. OBJECTIVES: To compare important safety-related parameters between lateral, posterolateral, and posterior approaches in supine thoracentesis. MATERIALS AND METHODS: First, two cadavers were placed supine on a table featuring gaps allowing access to the posterolateral and posterior hemithorax. Water was administered with sonographic measurement of the depth of pleural effusion (DPE) at the mid-axillary and posterior axillary line. Second, CT images were analyzed in 25 consecutive patients (32 free-shifting, moderate-to-large effusions; mean, 668 (146 - 2020 mL). DPE, craniocaudal distance that effusion can be visualized (CCD), and presence of passive atelectasis at each of the lateral, posterolateral, and posterior routes was assessed. RESULTS: In each cadaver, DPE in the posterolateral route was greater than that in the lateral route (P = 0.002, P < 0.001). The amount of pleural fluid enough to spread DPE to higher than 1 cm at the posterior axillary line was less than half the amount at the mid-axillary line (500 mL vs. 1,100 mL; 800 mL vs. 1700 mL). CT showed that the DPEs and CCDs of posterolateral and posterior routes were greater than those of the lateral route (P < 0.001). In thirteen effusions (40.6%), DPE was greater than 1 cm in both posterolateral and posterior routes but less than 1 cm in the lateral route. Frequencies of passive atelectasis in posterolateral and posterior routes (81.3% and 90.6%) were higher (P < 0.001) than that in the lateral route (28.1%). CONCLUSION: Safety-related parameters of posterolateral and posterior approaches in supine thoracentesis are far better than that of the conventional lateral approach.

Novel supine thoracentesis bed enabling thoracentesis via the posterior axillary line.

PURPOSE: This study describes on supine thoracentesis bed (STB), which helps thoracentesis of supine patient by enabling unlimited access to the posterolateral surface of a hemithorax. MATERIALS AND METHODS: Records of 15 patients who had received US-guided supine thoracentesis on STB were reviewed. We investigated the lateral or posterolateral approaches selected by the operators. We reviewed pre-procedural CT scans (obtained within 1 day) to examine if the approach of the operators could be justified in terms of depth of effusion and overlying chest wall thickness. RESULTS: The most common rationale for the use of the supine position was back or leg pain in 6 patients and hemi-or quadriplegia in 4. The operators chose the posterolateral approach in all 15 patients. On 6 concurrent CT scans, the mean depth of effusion was significantly (p < 0.004) greater in the posterolateral approach (3.0 ± 2.2 vs. 1.5 ± 1.9 cm). There was no significant difference in the thickness of the chest wall between the two approaches (1.6 ± 0.3 vs. 1.8 ± 1.0 cm, p = 0.61). CONCLUSIONS: By using STB, supine thoracentesis can be done via the posterolateral approach, which was associated with greater depth of effusion in our study, and may be superior to the conventional lateral approach.

Thermoelastic characteristics of thermal barrier coatings with layer thickness and edge conditions through mathematical analysis.

The thermoelastic behaviors of such as temperature distribution, displacements, and stresses in thermal barrier coatings (TBCs) are seriously influenced by top coat thickness and edge conditions, which were investigated based on the thermal and mechanical properties of plasma-sprayed TBCs. A couple of governing partial differential equations were derived based on the thermoelastic theory. Since the governing equations are too involved to solve analytically, a finite volume method was developed to obtain approximations. The thermoelastic characteristics of TBCs with the various thicknesses and microstructures were estimated through mathematical approaches with different edge conditions. The results demonstrated that the top coat thickness and the edge condition in theoretical analysis are crucial factors to be considered in controlling the thermoelastic characteristics of plasma-sprayed TBCs.

Mathematical analysis of thermoelastic characteristics in plasma-sprayed thermal barrier coatings.

The thermoelastic characteristics of plasma-sprayed thermal barrier coatings (TBCs) have been analyzed using mathematical modeling. Two types of TBC model, cylinder and circular disk which are commercial plasma-sprayed TBCs, subjecting to symmetric temperature distribution to the radial and longitudinal directions, respectively, were taken into consideration. Based on the thermoelastic theories, a second order ordinary differential equation was derived for the cylinder model and a pair of partial differential equations were set up for the circular disk model. The analytic solution was obtained from the ordinary differential equation, while a finite volume method was developed for numerical solutions to the pair of partial differential equations due to the complexity of governing equations. The thermoelastic characteristics of TBC models, such as temperature distributions, displacements, and stresses, were displayed according to the obtained solutions. The rate of heat conduction in the section of the top coat is relatively slow in comparison with the substrate, and no profound difference appears in the temperature distribution between two TBC models. The highest longitudinal tensile stress is expressed at the bond coat of both models, and the substrate is under the compressive stresses to the circumferential direction. While the cylinder expands to the positive longitudinal direction only, the expansion in the circular disk occurs to both the positive and negative longitudinal directions. Relatively large displacement and stresses exhibit in the cylinder as compared with the circular disk. In the circular disk, the stresses to the radial direction undulate at each section, and the displacement profile displays that the width of the circular disk is slightly narrowed. The results demonstrate that the mechanical and thermal properties of the top and bond coats are the crucial factors to be considered in controlling the thermoelastic characteristics of plasma-sprayed TBCs.

B cell-activating factor is a novel diagnosis parameter for asthma.

BACKGROUND: Asthma is a life-threatening immediate-type allergic disease. B cell-activating factor (BAFF) is a key regulator of B lymphocyte development and is required to generate and maintain the mature B cell pool. OBJECTIVES: To investigate the level of BAFF in the serum of asthma patients and the role of BAFF on T cells. METHODS: The BAFF level was measured by enzyme-linked immunosorbent assay. Peripheral blood mononuclear cells (PBMC) from asthma patients were analyzed by flow cytometry. T8.1 cells were used to test the role of BAFF on T cell-antigen-presenting cell (APC) conjugate formation. RESULTS: The BAFF level in patient serum was elevated relative to normal serum. Immunoglobulin E (IgE) concentration and the percentage of CD3+ T and CD19+ B cells vary according to the serum BAFF level. Patients with high BAFF and high IgE (group II) and those with high BAFF and low IgE (group III) show a high ratio of CD3+ T to CD19+ B cells, and the opposite is seen for patients with low BAFF and high IgE (group I) and those with low BAFF and low IgE (group IV). The addition of BAFF increased PBMC proliferation and T cell-APC conjugate formation. BAFF concentration in serum decreased after treatment with antiasthmatic drugs including glucocorticoids and immunosuppressants. CONCLUSION: These findings suggest that the serum BAFF level is high in both IgE-mediated asthma and non-IgE-mediated asthma and extend our knowledge about the fact that BAFF may play a stimulatory role on the proliferation of T cells. Thus, BAFF could be a parameter to monitor the severity of asthma symptoms.

Clinical characteristics of acute pulmonary thromboembolism in Korea.

BACKGROUND: Acute pulmonary thromboembolism (APTE) remains an important cause of morbidity and mortality in Western countries. In Korea, both the incidence and the mortality rate of APTE were thought to be low compared to Western countries. We performed the present study to investigate the current status of APTE in Korea. METHODS: Eight hundred and eight registry patients with APTE were analyzed with respect to clinical symptoms and signs, the presence of underlying diseases or predisposing factors, diagnostic methods, treatment and clinical course. RESULTS: The most common risk factors were prolonged immobilization (22.9%), deep venous thrombosis (22.0%), a recent operation (19.2%), and cancer (15.8%). The most common symptoms were dyspnea (78.6%), and chest pain (26.9%). The most common abnormality on chest radiography was effusion. The overall mortality rate at 3 months was 11.0%. Multivariate logistic regression analysis demonstrated that increased mortality risk was independently associated with the following baseline factors: onset in hospital (OR 1.88; 95% CI 1.03-3.42; p=0.03), lung cancer (OR 9.20; 95% CI 1.96-43.27; p=0.005), tachycardia (OR 3.50; 95% CI 1.86-6.60; p=0.0001), cardiogenic shock (OR 6.74; 95% CI 2.73-16.64; p=0.0001), and cyanosis (OR 3.45; 95% CI 1.27-9.44; p=0.01). CONCLUSIONS: Some differences did exist for the risk factors, symptoms, chest X-ray findings, mortality rate and prognostic factors as compared with those for Western patients. These results can prove especially helpful in the diagnosis as well as for the treatment of patients with APTE.