Anesthetic management for placement of tracheobronchial stents in patients with airway stenosis

We report the anesthetic management for stents placement in patients with tracheobronchial stenosis. The subjects were 6 patients with lung cancer and one patient with tracheal invasion of esophageal cancer. Anesthesia was induced with propofol, fentanyl and vecuronium, and maintained with propofol and vecuronium. After intubation, tracheostomy was performed. The patients were kept apnic during insertion of stents. Three patients had dynamic stents inserted from tracheostomy site and one orally. Three patients had Dumon stents inserted orally, but the procedure in one patient was cancelled because her stent could not be placed at appropriate position. We recommend the anesthetic management through the tracheostomy site for the placement of Dumon tubes or dynamic stents.     

Subepicardial Aneurysm: Echocardiographic Evaluation and Evolution

Subepicardial aneurysms (SEA) are an infrequent and serious form of subacute cardiac rupture complicating myocardial infarction. An early diagnosis and surgical repair may be life saving. SEA comprise an abrupt interruption of the myocardium, with a narrow neck and thin wall containing only the epicardium. It may progress to fatal cardiorrhexis. We describe the echocardiographic evolution of this type of cardiac rupture and the contribution of contrast-enhanced echocardiography. A possible pathophysiological mechanism is proposed.     

Quantitative evaluation of the pulmonary microdistribution of TiO2 nanoparticles using X‐ray fluorescence microscopy after intratracheal administration with a microsprayer in rats

The unevenness of pulmonary nanoparticle (NP) distribution, which hinders the establishment of an absolute dose–response relationship, has been described as one of the limitations of intratracheal administration techniques for toxicological assessment of inhaled NPs. Quantification of the NP microdistribution would facilitate the establishment of a concentration–response relationship in localized regions of the lung; however, such quantitative methods have not been reported. Here, we established a quantitative method for evaluating pulmonary TiO₂ NP microdistribution in rats using X‐ray fluorescence microscopy. Ti intensity in lung sections from rats intratracheally administered 10 mg kg^–1 TiO₂ NPs with a microsprayer was measured using X‐ray fluorescence with a 100 µm beam size. Ti reference samples were prepared by dropping different concentrations of Ti solutions on glass slide or lung sections of untreated rat. Ti intensity increased linearly with Ti content in the reference samples on both substrates. The detection limit of TiO₂ was estimated to be 6.3 ng mm^–2. The reproducibility was confirmed for measurements done in the short‐ (2 weeks) and long‐term (6 months). The quantitative results of TiO₂ NP microdistribution suggested that more TiO₂ NPs were distributed in the right caudal and accessory lobes, which are located downstream of the administration direction of the NP suspension, and the lower portion of each lobe. The detection rates of TiO₂ NPs were 16.6–25.0%, 5.19–15.6%, 28.6–39.2%, 21.4–38.7% and 10.6–23.2% for lung sections from the right cranial, middle, caudal, accessory and left lobes, respectively. Copyright © 2015 John Wiley & Sons, Ltd.     

Heparin concentration and hemostatic alterations with low systemic heparinization during CPB using heparin-coated circuits

Extracorporeal circulation with heparin coated circuits allows reduction of systemic heparin. The authors investigated the effects of this method on the hemostatic and fibrinolytic systems and heparin concentration simultaneously. Ten patients undergoing coronary artery bypass surgery were studied. The dose of heparin was 100 IU.kg-1, and the target activated clotting time (ACT) was more than 300 seconds. Blood samples were obtained at the following times; before and after giving heparin, 10 and 40 minutes after the start of extracorporeal circulation, after cross-clamp release, and after giving protamine, and heparin concentration, ACT, thrombin-antithrombin complex (TAT), plasmin alpha 2 plasmin inhibition complex (PIC), and D-dimer were measured. ACT was kept over 300 seconds without additional heparin administration. Heparin concentration was maintained at 1.0 IU.ml-1. However, after release of the aortic cross-clamp, TAT, PIC, D-dimer increased significantly. Despite reduced systemic heparinization, heparin concentration was maintained adequately. Thrombin generation and fibrinolytic activity showed no significant increase until the release of the aortic cross-clamp.     

Quantitative identification of sources of dioxin-like polychlorinated biphenyls in sediments by a factor analysis model and a chemical mass balance model combined with Monte Carlo techniques

The major sources of dioxin-like polychlorinated biphenyls (PCBs) in two sediment cores from Tokyo Bay and Lake Shinji (both in Japan) were identified and their source contributions estimated using two receptor models. The first was a nonnegative constrained factor analysis (FA) model, and the second was a nonnegative constrained chemical mass balance model combined with Monte Carlo techniques (CMB-MC) to take into account the variability and uncertainty in both PCB congener profiles of sources and environmental samples. According to the FA model, variations in the concentrations of dioxin-like PCBs in each sediment core were accounted for almost entirely by two factors, which were considered to correspond to Kanechlors (KCs; Japanese PCB products) and incineration. The CMB-MC model investigated the trends of the burdens from four types of KCs and incineration to the concentrations of dioxin-like PCBs in each sediment core. The results for both sediment cores obtained by both models indicated that the burden from KCs increased gradually beginning in the 1950s, peaked around 1970, and declined thereafter, whereas the burden from incineration increased gradually from the 1950s to the early 1990s. The estimated contribution from incineration to the toxic equivalent concentration of dioxin-like PCBs was comparable to that from KCs.