RADON INHALATION EXPERIMENTS TO TEST RADON EXHALATION KINETICS.

Three experiments were conducted with a volunteer to test the kinetics of the 222Rn exhalation after a short-time exposure to an elevated 222Rn air concentration. Radon concentration in an exhaled air was measured, complemented by whole body counting of 222Rn decay products in a body. Exhaled activities are compared with the prediction of the recent ICRP biokinetic model for radon. While a rapid equilibration of the exhaled radon activity concentration with that in the air inhaled corresponded with the model, the measured 222Rn exhalation rate was significantly less than modelled. Five hours after termination of the inhalation phase, the radon concentration in the exhaled air decreased to levels expected for non-elevated indoor radon activity concentration. Whole body activities of the 222Rn decay products were found higher than expected. Inhalation of the unattached fraction or residual activity of decay products in the air inhaled may be the explanation.

RESULTS OF CZECH NATIONAL STUDY OF RADIATION EXPOSURE FROM RADIOTHERAPY OF NON-MALIGNANT DISEASES, IN PARTICULAR OF HEEL SPURS.

About 26 000 patients are treated per year with radiotherapy for non-malignant diseases in the Czech Republic. Approximately 75% of them are treated on X-ray therapy units and most of these patients undergo radiotherapy of heel spurs. The evaluation of radiation exposure of these patients was based on measured organ doses and on data from clinical practice. Collective effective doses for particular diagnoses were calculated in order to compare doses resulting from different diagnoses treated on X-ray therapy units. The collective effective dose from radiotherapy of heel spurs in the Czech Republic in 2013 was evaluated to 77 manSv. It represents 25.6% of the total collective effective dose for all diagnoses of radiotherapy for non-malignant diseases treated on X-ray therapy units.

International intercomparison of measuring instruments for radon/thoron gas and radon short-lived daughter products in the NRPI Prague.

During the 7th European Conference on Protection Against Radon at Home and at Work held in the autumn of 2013 in Prague, the second intercomparison of measuring instruments for radon and its short-lived decay products and the first intercomparison of radon/thoron gas discriminative passive detectors in mix field of radon/thoron were organised by and held at the Natural Radiation Division of the National Radiation Protection Institute (NRPI) in Prague. In total, 14 laboratories from 11 different countries took part in the 2013 NRPI intercomparison. They submitted both continuous monitors for the measurement of radon gas and equivalent equilibrium radon concentration in a big NRPI chamber (48 m3) and sets of passive detectors including radon/thoron discriminative for the measurement of radon gas in the big chamber and thoron gas in a small thoron chamber (150 dm3).

[Criteria for perioperative risk evaluation--non-cardiac surgery]. / Predoperacní vysetrení u nemocných pred nekardiálním chirurgickým výkonem.

The paper presents criteria used to evaluate surgical risks associated with non-cardiac surgical procedures.

[The decrease in morbidity and mortality of patients with chronic forms of ischemic heart disease is the result of conservative treatment]. / Snízení morbidity a mortality nemocných s chronickými formami ischemické choroby srdecní je výsledkem konzervativní lécby.

Article presents actual comparison of therapeutic methods for patients with chronic coronary artery disease and their influence on morbidity and mortality. It calls attention to the insufficiently presented fact, that invasive methods, like percutaneous and surgical revascularization, despite great expectations, have not proved to lower morbidity and mortality in large randomized studies. In contrary several groups of drugs proved their efficiency many times. Paradoxically, the cheapest approach, life style intervention, seems to be the most efficient method for prognosis improvement of patients with chronic coronary artery disease.

Characteristic of patients surviving over a long-term period after intra-aortic balloon counterpulsation treatment.

Control examination of 21 patients after cardiac surgery which required the application of intra-aortic balloon counterpulsation in order to terminate extracorporeal circulation showed that, in spite of the serious postoperative course, the prognosis and quality of their life is a good one. Objective signs of left ventricular function show rather a moderate deterioration. Patients after myocardial revascularization have at the same time a demonstrable ischaemic disease of the lower extremities. Changes of more serious nature on the arteries of the lower extremities in connection with the earlier application of intra-aortic balloon counterpulsation could not be documented.

Intraaortic balloon counterpulsation.

The authors summarize their experience with intraaortic balloon counterpulsation (IABC) at the Institute for Clinical and Experimental Medicine between 1978-1984. A total of 756 cardiac surgery procedures were performed for ischaemic heart disease (IHD), and 266 procedures for rheumatic heart disease (RHD). Of patients operated on for IDH, IABC was used in 38 (5%) and, of those undergoing surgery for RHD, in 38 cases (14%). Overall, IABC was employed in 76 patients, i.e., 7%. Ventricular assistance using IABC was successful in 55% of patients. The technique was significantly more successful in IHD (68%) than in RHD (42%) patients. IABC was less successful in IHD patients suffering myocardial infarction intraoperatively. Moreover, the success of IABC depended on its early initiation. Eleven patients (14%) developed complications associated with IABC. The data do not differ from results reported by world's leading centres.

Clinical and haemodynamic findings in potential heart transplant recipients.

Based on an analysis of data from the literature and our own clinical, x-ray, electrocardiographic, biochemical, haemodynamic and angiographic findings, the article attempts to identify criteria for the selection of would-be heart transplant recipients in a clinical setting.

Haemodynamic changes immediately following myocardial revascularization.

The haemodynamic values before and immediately after direct myocardial revascularization were compared in 14 patients with ischaemic heart disease. Within the first hours after surgery cardiac output decreased to 50% of the preoperative value owing to a decrease in stroke volume, wedge pressure was increased, and systemic pressure was maintained at preoperative values by a rise in peripheral resistance. After the initial decrease cardiac output again increased to preoperative values (after 7 h) and above these values (19 h after surgery). Systemic blood pressure decreased owing to rapidly decreasing peripheral resistance. Knowledge of the pattern of haemodynamics in the early postoperative period facilitates the diagnosis of untoward circulatory episodes and permits to distinguish the effect of therapy from the haemodynamic changes normally occurring during this period.