The severity of respiratory distress occurring prior to loss of posture during exposure to: 20, 30, 40, 50, 60, 70, 80 or 90 per cent carbon dioxide in air; 2 or 5 per cent residual oxygen in argon; 30 per cent carbon dioxide in argon with either 2 or 5 per cent residual oxygen; or 40 per cent carbon dioxide in argon with either 2 or 5 per cent residual oxygen, was subjectively determined in pigs from their behaviour. The results indicated that exposure to 2 per cent oxygen in argon (anoxia) induced minimal respiratory distress, 30 per cent carbon dioxide in argon with 2 per cent residual oxygen induced a moderate distress and exposure to all the concentrations of carbon dioxide in air induced severe respiratory distress in the pigs. From the animal welfare point of view, using 2 per cent oxygen in argon (anoxia) appears to be the optimum choice for gas stunning pigs. Secondly, a mixture of 30 per cent carbon dioxide in argon with 2 per cent residual oxygen is preferred to 90 per cent carbon dioxide in air.

The aversive effects of 90 per cent argon in air, 30 per cent carbon dioxide in air or 90 per cent carbon dioxide in air were investigated in slaughter weight pigs. Aversion was assessed from their reluctance to enter the three gaseous atmospheres to obtain a reward (apples). The pigs did not show any aversion to the inhalation of 90 per cent argon in air. The majority of the pigs did not show aversion to the presence of 30 per cent carbon dioxide in air. By contrast, the inhalation of 90 per cent carbon dioxide was aversive to the majority of the pigs. Fasting them for up to 24h prior to testing did not overcome the pigs ‘ reluctance to enter an atmosphere containing 90 per cent carbon dioxide.

Experiments were undertaken to determine the toxicity in the lung of dust generated by opencast coal mining. Since it was impractical to collect the large mass of actual opencast respirable dust required for the toxicity experiment, a surrogate dust with the same size distribution was manufactured (PSW). This surrogate dust had the same basic mineralogical composition as mineralogically characterized airborne dust collected from the welsh coal opencast pit at Park Slip West. Diesel exhaust particles (DEP), generated from mining vehicular and mechanical activity, contribute towards opencast particulate matter. Therefore, a second dust comprising of a 50/50 by weight mixture of the surrogate mineral dust and diesel soot was also examined (PSW + DEP). These dusts and DEP (weak biological reactivity) and a-quartz (high biological reactivity) were instilled into the lungs of healthy rats. The animals were sacrificed at 1, 6 and 11 weeks. Assessments of potential toxicity included lung to body weight ratios, acellular protein in lung lavage (markers of lung permeability) and total free cells (marker of inflammation). The surrogate opencast dust with or without DEP caused no significant increases in any of the parameters studied and as such was very similar to the weak biological effects of DEP alone. These effects contrasted sharply with those observed for the bioreactive mineral, quartz that induced rapid increases in permeability and a progressive inflammation. The use of a surrogate is less desirable then the real opencast mine dust, however, if as believed, the surrogate material is a representative mixture of the actual airborne dust around this opencast site, then these particles should show little or no short-term lung toxicity following inhalation.

A widely produced chemical, chlorine is used in various industries including automotive, electronics, disinfectants, metal production, and many others. Chlorine is usually produced and transported as a pressurized liquid; however, as a gas it is a significant pulmonary irritant. Thousands of people are exposed to chlorine gas every year, and while large-scale exposures are uncommon, they are not rare. Symptoms are usually related to the concentration and length of exposure, and although treatment is largely supportive, certain specific therapies have yet to be validated with randomized controlled trials. The majority of those exposed completely recover with supportive care; however, studies have shown the potential for persistent inflammation and chronic hyperreactivity. This case report describes an incident that occurred in Graniteville, South Carolina, when a train derailment exposed hundreds of people to chlorine gas. This report reviews the events of January 6, 2005, and the current treatment options for chlorine gas exposure.(Disaster Med Public Health Preparedness. 2014;0:1-6)

Un nouvel outil a été développé pour optimiser l’efficacité des traitements par le DTPA après blessure, sur la base d’une réduction de la dose efficace engagée. Les simulations montrent, notamment, que pour du 239Pu modérément soluble (type M), des traitements précoces (24 i.v.) étalées sur 4 mois permettent une réduction d’un tiers de la dose, alors que leur prolongement sur 5 ans, avec un intervalle de 2 semaines, peut diminuer la dose d’un facteur 5. En revanche, pour des composés peu solubles (type S), l’efficacité des traitements précoces est négligeable et un gain dosimétrique d’un facteur 3 n’est atteint que pour des traitements effectués 2 fois par mois durant 50 ans. Certaines des hypothèses retenues pour la modélisation ont été validées par les résultats d’expérimentations animales récemment publiés. Enfin, la structure d’un nouveau modèle applicable à la fois au Pu et à l’Am est rapportée, structure tenant compte de la décorporation urinaire et fécale de ces actinides et qui pourrait être adapté à différentes posologies et formes galéniques de DTPA.

L’objectif de ce document est de proposer aux médecins du travail des INB, des recommandations pour la rédaction de protocoles de traitement par le Ca-DTPA des contaminations internes par le plutonium et l’américium. Ces recommandations s’appuient sur le bilan des injections réalisées dans les centres CEA et AREVA en France. Elles ont été réalisées par un groupe de travail de médecins du CEA, d’AREVA et du Service de protection radiologique des Armées. Cet article concerne principalement le Ca-DTPA administré par voie intraveineuse (IV). Les autres formes galéniques, voies d’administration ainsi que les traitements adjuvants sont également évoqués. Pour les plaies contaminées et les inhalations, les indications du traitement par le Ca-DTPA sont précisés ; en particulier son initialisation, sa posologie, sa durée, sa fréquence d’administration, les critères d’arrêt, son efficacité et le gain dosimétrique. Une aide décisionnelle est proposée pour la prescription du suivi radiotoxicologique nécessaire à la conduite du traitement et à l’évaluation dosimétrique.

Dust particles generated in the ITER Tokamak may include some tritium. The coefficients derived to evaluate the doses resulting from the inhalation of the usual forms of tritium (gaseous, tritiated water, organic form) are not adequate for tritiated dust. This paper is a short literature study about the assessment of tritiated dust dose coefficients and their significance in worker, population and environmental protection for ITER

Dans l’industrie nucléaire française, les doses engagées après inhalation de radionucléides sont généralement évaluées à partir de mesures biologiques dont l’analyse peut permettre de remonter (démarche ascendante) à l’incorporation initiale puis à la dose par application de la dose par unité d’exposition (DPUI). Une valeur spécifique de la DPUI peut être attribuée à chaque contamination. Cet article présente une synthèse des données de la littérature et de résultats de recherches en cours concernant les incertitudes sur l’estimation de l’incorporation, de la biocinétique des radionucléides et sur les doses après une exposition à des aérosols renfermant des actinides. Une comparaison des incertitudes a été réalisée après une application ascendante et descendante des modèles. Dans ce dernier cas, la contamination interne est évaluée à partir de prélèvements atmosphériques effectués au poste de travail. Les incertitudes les plus élevées sont calculées après une application descendante des modèles. L’interprétation des différents résultats qui sont ici rapportés souligne l’intérêt de la connaissance des incertitudes pour évaluer de manière réaliste l’impact dosimétrique d’une contamination accidentelle. Par ailleurs, différents exemples illustrent les limites de l’application de certainsmodèles de la Commission internationale de protection radiologique (CIPR) qui sont utilisés en radioprotection. Au-delà, cette synthèse souligne les difficultés de l’estimation du risque de cancer à partir d’un calcul de doses, notamment, du fait de l’hétérogénéité de leur distribution au sein des différentes régions cible du tractus respiratoire.

For dose assessment following chronic or accidental inhalation of radioactive aerosols, the dosimetric models of the International Commission on Radiological Protection (ICRP) provide dose coefficients, retention and excretion functions. Unknown date or dates of intake is the major source of uncertainty in dose assessment during routine monitoring of nuclear workers. The two assumptions commonly made in dose assessment from an unknown time pattern of intake have been tested experimentally with a model of repeated inhalation by rats. The hypothetical intake derived from lung measurement was relatively reliable under the two hypotheses. The hypothetical intake derived from excreta measurement depended on the choice of hypothesis and on the real time pattern of intake.

Background and objective: The study was designed to compare the costs of propofol versus sevoflurane for the maintenance of the hypnotic component of anaesthesia during general anaesthesia, guided by the bispectral index, for gynaecological laparoscopic surgery.

Methods: Forty ASA Grade I—II female patients scheduled for gynaecological laparoscopy were randomly allocated to two groups. All patients received a continuous infusion of remifentanil (0.25 µg kg−1 min−1) for 2 min. Then anaesthesia was induced with propofol 1% at 300 mL h−1 until loss of consciousness. To guide the bispectral index between 40 and 60, Group 1 patients received propofol 10 mg kg−1 h−1 initially, which was increased or decreased by 2 mg kg−1 h−1 steps; Group 2 patients received sevoflurane, initially set at 2 vol.% and adjusted with steps of 0.2–0.4%. The time and quality of anaesthesia and recovery were assessed in two postoperative standardized interviews.

Results: Patient characteristics, the propofol induction dose, the bispectral index and the haemodynamic profiles during induction of anaesthesia, and its duration, were similar between the groups. In Group 1, 7.55 ± 1.75 mg kg−1 h−1 propofol and in Group 2, 0.20 ± 0.09 mL kg−1 h−1 liquid sevoflurane were used for maintenance. The cost for maintenance, including wasted drugs, was higher when using propofol (€25.14 ± 10.69) than sevoflurane (€12.80 ± 2.67). Postoperatively, recovery profiles tended to be better with propofol; however, the day after discharge no differences were found.

Conclusions: When applying the bispectral index to guide the administration of hypnotic anaesthetic drugs, propofol-based maintenance of anaesthesia was associated with the highest cost. A trend towards a better recovery profile was obtained with propofol. However, on the day after discharge, no differences in quality were observed.

Background and objective: Isoflurane is a chiral, volatile anaesthetic with low metabolic rate (0.17%) that is routinely administered in its racemic form. Knowledge about the distribution of the enantiomers in human beings may give some important information about the understanding of the mechanisms of volatile anaesthetics.

Methods: Blood samples were drawn immediately after tracheal extubation and daily up to 8 days postoperatively from patients undergoing general anaesthesia with isoflurane racemate. The enantiomer enrichment of isoflurane was determined by headspace gas chromatography-mass spectrometry.

Results: At all time points, there was a statistically significant accumulation of the S(+) enantiomer in blood, especially at days 2 (52.01%) and 7 (52.1%). Separate analysis of obese patients or in a small group of patients with co-existing lung disease did not show any difference to the total population. In addition, duration of anaesthesia did not influence the enantiomer concentrations.

Conclusions: We suggest that a slower association and dissociation rate is responsible for the S(+) enrichment.

Background and objective: Although the MAC>tetanus(minimum alveolar concentration that prevents movetetanus ment in response to electrical tetanus stimulation in 50% of patients) of isoflurane decreases during anaesthesia and surgery, it is not known whether this occurs to the same extent with other inhalational anaesthetics. We determined the MACtetanus of sevoflurane before and after surgery.

Methods: Eleven patients who underwent arthroscopy of the shoulder underwent inhalational induction of anaesthesia with sevoflurane and tracheal intubation by succinylcholine. MACtetanus was determined in each patient by testing the response to a 10 s, 50 Hz, 80 mA transcutaneous tetanic electrical stimulus to the ulnar nerve at varying concentrations of sevoflurane. The end-tidal concentration of sevoflurane was kept constant for 15 min before each stimulus and the concentration of sevoflurane varied in increments of 0.1% until a sequence of three alternate responses (move, not move, move) or (not move, move, not move) was obtained. After arthroscopy of the shoulder, individual MAC were measured as described above.

Results: The mean MACtetanus decreased from 2.22 ± 0.29% before arthroscopy to 1.82 ± 0.26% after arthroscopy (P < 0.01).

Conclusions: It is concluded that the MACtetanus of sevoflurane decreases during anaesthesia and surgery.

Background and objective: In this randomized, double-blind study, we aimed to investigate the effect of aminophylline on recovery from sevoflurane.

Methods: One-hundred ASA I–II patients scheduled for elective surgery were randomly divided into two groups receiving either NaCl 0.9% (Group 1, n = 50) or aminophylline 5 mg kg−1 (Group 2, n = 50). All patients were premedicated with atropine 0.01 mg kg−1 and midazolam 0.06 mg kg−1 intramuscularly. Anaesthesia was induced with propofol 2 mg kg−1 for muscle relaxation, and atracurium 0.5 mg kg−1 was maintained with sevoflurane 2% in 50% oxygen and nitrous oxide. Further atracurium (0.1 mg kg−1 was given when needed. Aminophylline or saline was given after sevoflurane was discontinued. Heart rate, mean arterial pressure, peripheral oxygen saturation, the duration of anaesthesia and recovery times (eye opening, verbal response, extubation and successful performance of arithmetical calculations) were recorded.

Results: There were no statistically significant differences in mean arterial pressure, peripheral oxygen saturation and anaesthesia time between the two groups. Heart rate increased significantly (P < 0.05) after aminophylline and was also higher than in the placebo group. Recovery times were significantly shorter (P < 0.001) in the patients receiving aminophylline.

Conclusions: Aminophylline speeded recovery after sevoflurane anaesthesia and it may have some advantage in anaesthesia practice for patients.

Background and objective: To compare the conditions for insertion of the laryngeal mask airway using sevoflurane or propofol plus fentanyl. We evaluated the haemodynamic changes and cost of induction of anaesthesia in both groups.

Methods: Sixty patients were equally and randomly divided into two groups. Both groups received fentanyl 1 μg kg−1. Patients in the sevoflurane group were induced with 8% sevoflurane and those in the propofol group with propofol 2.5 mg kg−1. Conditions for insertion were graded on a three-point scale using six variables. Overall, conditions were assessed as excellent, satisfactory or poor based on the total score in each group. Systolic and diastolic arterial pressure and heart rate were recorded for 6 min after mask insertion. The financial cost of induction in both groups was calculated.

Results: The mean (±SD) time taken from induction to successful laryngeal mask insertion was significantly shorter with propofol (68.70 ± 22.60 s) compared with sevoflurane (149.83 ± 55.25 s). Excellent or satisfactory conditions were observed in 30 (100%) patients in the propofol group and in 29 (96.66%) in the sevoflurane group. Systolic and diastolic arterial pressures were significantly lower in the propofol group. The cost of sevoflurane used was €3.95 ± 1.48 (Rs 216.23 ± 64.66) (P < 0.05) compared with that of propofol, which was €3.23 ± 0.65 (Rs 141.00 ± 28.20).

Conclusions: Although there was a faster induction with propofol-fentanyl, conditions for insertion of the laryngeal mask airway were similar in both groups. Haemodynamic stability was better with sevoflurane-fentanyl. The propofol-fentanyl combination was more cost-effective.