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Purpose:  This study was carried out to investigate the impact of abdominal dynamic four-dimensional CT angiography (4D-CTA) for guiding transarterial chemoembolization (TACE) on the amount of contrast material used, operator radiation exposure, catheter consumption, and diagnostic confidence., Materials and Methods:  Written consent was waived for this IRB-approved retrospective study. 29 patients (20 men; mean age: 65.7 ± 11.5 years) with malignant liver lesions underwent 4D-CTA, prior to initial TACE. Time-resolved volume-rendering technique (VRT), maximum-intensity projection (MIP), and multiplanar reconstruction (MPR) series were reconstructed, enabling a direct selective catheterization of the tumor-supplying artery without prior conventional digital subtraction angiography (DSA). 29 patients (16 men; mean age: 69.4 ± 13.9) who underwent traditional TACE served as the control group. The amount of administered contrast media, operator radiation exposure, and catheter consumption during TACE were compared. Two radiologists assessed diagnostic confidence in the exclusion of portal vein thrombosis., Results:  4D-CTA TACE resulted in a significant reduction in the amount of contrast media used, compared to traditional TACE (-61.0 ml/ -66.3 % intra-arterial, -12.8 ml/ -13.8 % overall; P < 0.001). The dose-area product indicating operator radiation exposure during intervention was reduced by 50.5 % (P < 0.001), and 0.7 fewer catheters on average were used (P = 0.063), while 4D-CTA data was available to guide TACE. Diagnostic confidence in the exclusion of portal vein thrombosis was significantly enhanced by 4D-CTA, compared to traditional DSA images (scores, 3.9 and 2.4, respectively; P < 0.001)., Conclusion:  Dynamic 4D-CTA enables TACE with a substantially reduced amount of contrast material, decreases operator radiation exposure, and increases diagnostic confidence in the exclusion of portal vein thrombosis., Key Points:   · 4D-CTA prior to TACE decreases the amount of utilized contrast material.. · The intra-arterial fraction of contrast media can be reduced by two-thirds.. · The risk of CIN may be decreased by means of 4D-CTA TACE.. · Operator radiation exposure is lower using 4D-CTA for guiding TACE.. · 4D-CTA portography allows for a higher diagnostic confidence than conventional DSA images.., Citation Format: · Albrecht MH, Vogl TJ, Wichmann JL et al. Dynamic 4D-CT Angiography for Guiding Transarterial Chemoembolization: Impact on the Reduction of Contrast Material, Operator Radiation Exposure, Catheter Consumption, and Diagnostic Confidence. Fortschr Röntgenstr 2018; 190: 513 - 520., Competing Interests: 'Moritz H. Albrecht received a speaker fee from Siemens. Julian L. Wichmann received speaker fees from Siemens and General Electric. Ralf W. Bauer received speaker fees from and was a consultant for Siemens.', (© Georg Thieme Verlag KG Stuttgart · New York.)

Objective: Although no dose-response relationship exists for the health risks associated with the occupational exposure to inhaled anaesthetics, public health authorities recommend threshold values. The aim of the present study was to assess whether and to what extent these threshold values are exceeded in surgeons and circulating nurses of an Eastern European university hospital, before and after measures had been taken to reduce occupational exposure., Methods: At nine workplaces, occupational exposure to nitrous oxide and the volatile anaesthetic used (halothane or isoflurane) was measured within the breathing zones of surgeons and circulating nurses by means of photoacoustic infrared spectrometry. The measurements were carried out in 1996 and were repeated in 1997 after the installation of active scavenging devices at five workplaces, and an air-conditioning system at one workplace., Results: Occupational exposure to nitrous oxide and halothane or isoflurane was lower in 1997 compared with that of 1996. In 1996, 89% of the nitrous oxide values were above the European threshold value of 100 ppm, whereas in 1997 approximately 50% were above this limit. In 1996 the majority of the measurements for the volatile anaesthetics were already below 5 ppm halothane and 10 ppm isoflurane and the number of measurements exceeding these limits was further reduced in 1997., Conclusion: The measures taken were effective in reducing waste gas exposure. Nevertheless, further efforts are necessary, especially for nitrous oxide, to reach Western European standards and to minimise possible health risks. These efforts comprise the installation of (active) scavenging devices, air-conditioning systems and new anaesthesia machines at all workplaces, the use of low-flow anaesthesia, the replacement of inhaled anaesthetics by intravenous anaesthetics and an appropriate working technique.

Unlabelled: To minimize the possible health risks posed by waste anesthetic gases, the National Institute of Occupational Safety and Health (NIOSH) recommends exposure limits. We investigated the genotoxicity of a previously established occupational exposure exceeding these limits (high-level exposure) and of one within these limits (low-level exposure). Genotoxicity was assessed by the formation of micronucleated lymphocytes in 25 anesthetists and anesthetic nurses of an Eastern European (High-Level Exposure Group) and a German (Low-Level Exposure Group) university hospital. Each exposed group was compared with a group of nonexposed personnel of the same hospital. Compared with its Control Group, there was an increased fraction of micronucleated lymphocytes per 1000 binucleated cells in the High-Level Exposure Group (median 14.0, range 9.0-26.7 vs median 11.3, range 3.2-19.4; P < 0.05) but not in the Low-Level Exposure Group (median 9.8, range 4.2-20.0 vs median 10.5, range 5.0-20.5). We conclude that a high-level exposure to inhaled anesthetics is associated with an increase in chromosome damage, and measures are recommended to decrease exposure levels. As evidenced by the formation of micronucleated lymphocytes, the threshold values recommended by NIOSH appear to be safe., Implications: A high level of occupational exposure to inhaled anesthetics is associated with genotoxicity (as defined by formation of micronucleated lymphocytes), whereas a low-level exposure (within National Institute of Occupational Safety and Health limits) is not.

Background: Although no dose-response relationship for the health risks associated with the occupational exposure to inhaled anaesthetics exists, public health authorities recommend threshold values. The aim of the present study was to assess if and to what extent these threshold values are exceeded in an eastern European university hospital before and after measures had been taken to reduce occupational exposure., Methods: At nine workplaces occupational exposure of anaesthetists to nitrous oxide and halothane or isoflurane was measured by means of photoacoustic infrared spectrometry. The measurements were carried out in 1996 and were repeated in 1997 after the installation of active scavenging devices at five workplaces and an air-conditioning system at one workplace., Results: Occupational exposure to nitrous oxide and halothane or isoflurane was lower in 1997 compared to 1996. In 1997 most of the nitrous oxide values still exceeded the threshold value of 100 ppm, whereas most of the halothane and isoflurane values were already below the threshold values of 5 ppm and 10 ppm in 1996., Conclusion: The measures taken were effective in reducing waste gas exposure. Nevertheless, further efforts are necessary, especially for nitrous oxide, to reach western European standards. These efforts comprise structural measures such as active scavenging devices and air-conditioning systems at all workplaces, the use of total intravenous anaesthesia, low-flow anaesthesia and an appropriate working technique.

Genotoxicity related to waste anaesthetic gas exposure is controversial. We have investigated the frequency of sister chromatid exchanges in peripheral lymphocytes of operating room personnel exposed to trace concentrations of isoflurane and nitrous oxide. Occupational exposure was recorded using a direct reading instrument. Frequencies of sister chromatid exchanges were measured in lymphocyte cultures of 27 non-smokers working in the operating room and 27 non-smoking controls. Personnel were exposed to an 8-h time-weighted average of nitrous oxide 11.8 ppm and isoflurane 0.5 ppm. After exposure, sister chromatid exchange frequency was increased significantly (mean 9.0 (SD 1.3) vs 8.0 (1.4) in exposed and control personnel, respectively) (P < 0.05). We conclude that exposure to even trace concentrations of waste anaesthetic gases may cause genetic damage comparable with smoking 11-20 cigarettes per day.

We have compared occupational exposure to isoflurane and desflurane during cardiopulmonary bypass, with and without a scavenging system at the membrane oxygenator outlet. Trace concentrations of volatile anaesthetics were measured by a direct reading instrument in 40 elective heart surgery procedures. Measurements were obtained in the breathing zones of the anaesthetist and perfusionist. When a scavenging system was used, median desflurane values were less than 0.3 ppm and isoflurane values less than 0.2 ppm. Without a scavenging system values were, in general, three- (isoflurane) to five- (desflurane) fold higher. We conclude that the use of a scavenging system at the membrane oxygenator outlet can reduce occupational exposure to volatile anaesthetics. We therefore recommend routine use of scavenging devices during cardiopulmonary bypass.

We report the findings of a study on exposure of operating room staff to sevoflurane, halothane and nitrous oxide during induction and maintenance of anaesthesia in children. Concentrations of anaesthetic agents in the operating theatre were measured directly by highly sensitive, photoacoustic infrared spectrometer during 20 anaesthetics. Samples were taken from the breathing zones of the anaesthetist and the circulating nurse. The operating theatre was of modern design with an air conditioning system providing 20 changes of air each hour. The threshold values of 100 ppm N2O, 50 ppm isoflurane and 10 ppm halothane recommended by the United Kingdom Committee for Occupational Safety and Health (COSH) were exceeded in several cases for a short time during mask induction. After tracheal intubation, trace concentrations of sevoflurane, halothane and N2O were mostly under the recommended levels and comparable to levels measured during adult anaesthesia.