Compound A, formaldehyde and methanol concentrations during low-flow sevoflurane anaesthesia: comparison of three carbon dioxide absorbers.

AIM: To determine compound A, formaldehyde and methanol concentrations in low-flow anaesthesia using different carbon dioxide absorbers. METHODS: Fifteen patients scheduled for general or urological surgery were exposed to low-flow (500 ml/min) anaesthesia with sevoflurane. The patients were randomly allocated to three groups: soda lime, DrägerSorb Free or Amsorb Plus. The concentrations of compound A, formaldehyde and methanol were sampled and analysed from the limbs of the anaesthesia circuit at T30 (30 min after the start of low-flow sevoflurane anaesthesia), T90 (90 min) and T150 (150 min). The temperatures of the absorbers were measured at the same time. RESULTS: Statistically significant differences (P < 0.05) were found in the production of compound A from soda lime (with the highest values), DrägerSorb Free and Amsorb Plus at each measurement time. Only traces of methanol (ranging from < 0.131 to 3.799 mg/m(3)) were measured, higher with Amsorb Plus (statistically significant differences were found only at T90). The formaldehyde values (ranging from < 0.1227 to 17.79 mcg/m(3) p.p.b.) were higher with soda lime, and the difference was statistically significant at T150 and, in the inspiratory limb only, at T90. The temperatures of the absorbers were higher for soda lime and lower for Amsorb Plus; the difference was statistically significant at T0 in the upper canister and at T30 in both canisters. CONCLUSION: The concentrations of harmful products in the circuit were negligible and were lower using the new-generation absorbers. Using Amsorb Plus, the temperatures in the canisters were lower than with the other two absorbers.

[Part-time work at a hospital: study of atypical workers]. / Il part time in un'Azienda Ospedaliera: studio sui lavoratori atipici.

According to act 626/1994, employers have the duty to inform and train workers and their representatives. The implementation of training activities requires the following points: planning the training progra according to the needs of the target population, use of the methods aimed at promoting learning and the adoption of safe behaviour, setting-up of evaluation tools. The disciplines of risk perception and communication and adult training may provide useful contribution in this frame. At the light of the preliminary experiences in this field, the importance of the following items for workers, workers representatives and employers is emphasized: probabilistic causality models, role of cognitive and emotional factors in the learning process, definition of carcinogenic according to national and internationals organisation, meaning of TLV with respect to carcinogenic exposure, interaction between carcinogens in the case of multiple exposition, risk evaluation, preventive measures, transfer of carcinogen risk from workplace to domestic environment, due to lack of compliance with basic hygienic rules such proper use of work clothes.

Sevoflurane low-flow anaesthesia: best strategy to reduce Compound A concentration.

BACKGROUND: To define the best strategy to reduce Compound A production in Sevoflurane low-flow anaesthesia by experiments in vitro and in vivo of different absorbers and different anaesthesia machines. METHODS: In vitro Compound A has been measured at 45 degrees C in vitro following Sevoflurane interactions with potassium hydroxide, sodium hydroxide, soda lime, Dragersorb 800 Plus and Amsorb, a new absorber that does not contain sodium or potassium hydroxide. In vivo Compound A concentration in the anaesthesia circuit (inspiratory branch) has been measured using an indirect sampling method through absorber vials (SKC) with active coal granules, during low flows (500 ml/min) general anaesthesia using soda lime, Dragersorb 800 Plus or Amsorb as absorber. Compound A was also measured during low flows (500 ml/min) general anaesthesia using as carbon dioxide absorber soda lime with different anaesthesia machines. RESULTS: In vitro at 45 degrees C Compound A concentration with soda lime and Dragersorb 800 Plus was about 10 times higher than with Amsorb. In vivo the Compound A concentrations in the inspiratory branch of the circuit were lower in the group with Amsorb. CONCLUSION: The Compound A production is minimal with Amsorb as carbon dioxide absorber.

[Toxic polyneuropathy in shoe-industry workers. A longitudinal electromyographic study (author's transl)]. / Polineuropatia tossica in operai dell'industria calzaturiera. Studio elettromiografico longitudinale

A longitudinal electromyographic study was carried out on fifteen shoe-industry workers (one man and fourteen women) affected with toxic polyneuropathy. The mean values of age, duration of exposure and lenght of the follow-up period were 23.2 years, 4.2 years and 12.2 months, respectively. Twelve subjects (80%) had a sensory-motor involvement of both upper and lower limbs; in the remainder, only the latter were affected. From a clinical standpoint, the polyneuropathy was classified as mild in seven subjects (46.6%), moderate in four (26.7%) and severe in four. On the basis of electromyographic criteria (maximal motor nerve conduction velocity; features of voluntary contraction tracings; existence of spontaneous activity recorded in different points of the same muscle), the polyneuropathy could be defined as mild in two patients (13.3%), moderate in three (20%) and severe in 10 (66.7%). In eight subjects (53.3%) the electromyographic abnormalities disappeared completely, through a gradual improvement in six and alternative phases of improvement and worsening in two. As for the remainder patients (7, viz. 46.6%), improvement and worsening in two. As for the remainder patients (7, viz. 46.6%), four showed a reduction of their electromyographic abnormalities, whereas no significant changes occurred in the last three. The obtained results are discussed and the following conclusions drawn: 1. the lower limbs are mostly affected, both clinically and electromyographically; 2. the clinical symptoms do not parallel the electromyographic findings; 3. the course of the disease appears to be independent of the initial electromyographic pattern; 4. recovery appears to occur in most instances within approximately eighteen months since the onset of symptoms, generally without significant residual deficit. Finally, the role of electromyography in the diagnosis and the follow-up study of the observed toxic polyneuropathy is underlined.

[Arteriography findings in vibration vascular disease of upper limbs ("vibration angiopahty") (author's transl)]. / Reperti arteriografici nella patologia vascolare da vibrazioni degli arti superiori ("angiopatia da vibrazioni")

A bilateral angiographic study of the upper limbs was carried out under general anaesthesia in a group of 81 subjects--mostly (91.3%) miners--using vibrating tools. The patients' age ranged from 30 to 57 years; the time they worked as vibrating tool operators varied from 5 to 36 years; the duration of symptoms ranged from 3 months to 10 years. The mean values were 46.1, 20.9 and 3.7 years, respectively. Seventy-four subjects (91.3%) complained of Raynaud's-like phenomenon, which in 36 (44.4%) of them was elicited too, although partially, by provocative tests (cold exposure). Angiography was carried out under general anaesthesia maintained with halothane. Bilateral angiograms were available in 61 instances; in the remainder, only either right or left angiograms could be obtained. In all the subjects examined arteriographic lesions were found, mainly represented by organic stenoses and occlusions. The prevalance of such lesions was minimal at the level of the forearm arteries, and maximal at the level of the digital arteries. The 2nd finger, bilaterally, was the most frequently involved; the index finger on either side and the middle one on the right side were the most involved as to severity and extent of lesions. The 1st finger, however, was quite frequently involved too. No definite relationship between prevalance, severity and extent of arterial lesions, on one hand, and some history, clinical and functional parameters (such as age, vibrating tool usage time, smoking habit, hand arterial pattern, pulmonary silicosis, instrumental findings and Raynaud's-like phenomenon), on the other hand, could be established. As to Raynaud's-like phenomenon, it is hypothesized that such a finding could be, at least in part of cases, subsequent to the previous development of organic lesions in the digital arteries.