Risk assessment of aggression toward emergency health care workers.

BACKGROUND: Health care and social service workers face a significant risk of job-related violence. AIMS: To develop a method for quantitative evaluation of the risk of violence, as required by Italian and European regulations, against extra-hospital emergency health care workers employed by the Regional Emergency Healthcare Service (ARES 118) in the Lazio Region in Italy. METHODS: Violence to the ARES 118 workers during working hours was examined by analysing injuries reported by them between 2005 and 2007. The assessment method proposed should give a numerical indicator of the risk of violence for each homogeneous group. The quantitative risk was evaluated on the basis of variables such as the days off work for each episode, the total number of aggressive attacks, the type of health intervention involved, etc. RESULTS: The rate of accidents related to aggression during working hours at the ARES unit was 6.3%, which is significantly higher than the figure of 2% reported for the entire health care sector. CONCLUSIONS: The present evaluation is largely based on analysis of the Injury Register. To increase the sensitivity of the method so that it closely reflects active reporting of events, it would be necessary to implement a procedure for reporting events in a 'company register of acts of violence' and to make workers more aware of the need to report all such episodes.

[Techniques of communication and information-formation of the workers]. / Tecniche della comunicazione e informazione-formazione dei lavoratori.

Communication has always had a very important role among human activities. Communication is: a Source sending a Message to an Addressee within a Context through a Contact thanks to a Code. In 1965 Umberto Eco developed the concept of Aberrant Decoding that is the wrong decoding of the message by the addressee. As to communication D.Lgs81/08 e s.m.i. fixes the following rules. Information of workers (Art. 36/1)--The employer is responsible for the workers to have the right information about risks for health and safety in their specific workplaces, etc. Formation of workers (Art 37/1)--The employer is responsible for the workers to have adequate and proper formation as to health and safety with regard to linguistic knowledge. Therefore it is really important for a Company to establish real communication between management and workers and among workers, to have a frequent feedback and to let information circulate in order to have all safety regulations followed properly.

Colloidal dispersions of oxide nanoparticles in ionic liquids: elucidating the key parameters.

The combination of ionic liquid and nanoparticle properties is highly appealing for a number of applications. However, thus far there has been limited systematic exploration of colloidal stabilisation in these solvents, which provides an initial direction towards their employment. Here, we present a new and comprehensive study of the key parameters affecting the colloidal stability in dispersions of oxide nanoparticles in ionic liquids. Twelve diverse and representative ionic liquids are used to disperse iron oxide nanoparticles. The liquid interface of these nanoparticles has been carefully tuned in a molecular solvent before transferring into an ionic liquid, without passing through the powder state. Multiscale-characterisation is applied, on both the micro and the nano scale, incorporating both small angle X-ray scattering and dynamic light scattering. The results show the surface charge of the nanoparticles to be a crucial parameter, controlling the layering of the surrounding ionic liquid, and hence producing repulsion allowing efficient counterbalancing of the attractive interactions. For intermediate charges the strength of the repulsion depends on the specific system causing varying levels of aggregation or even none at all. Several samples consist of sufficiently repulsive systems leading to single dispersed nanoparticles, stable in the long term. Thanks to the magnetic properties of the chosen iron oxide nanoparticles, true ferrofluids are produced, appropriate for applications using magnetic fields. The strength and breadth of the observed trends suggests that the key parameters identified here can be generalised to most ionic liquids.

[The occupational and active research, diagnosis and reporting of occupational diseases]. / Il Medico Competente e la ricerca attiva, diagnosi e denuncia delle malattie professionali.

The Occupational Doctor plays a key role on the protection of workers safety and prevention of occupational and work-related disease. His training and his need of updating, due to the constant transformation of work, the evolution of technology and the medical progress, set him in the center of all activities carried out to protect health in workplaces. The Occupational Doctor should devote special attention to the working anamnesis as well as to the pathological anamnesis both close and remote. He should also pay attention to semeiotics. Another important element is the relationship between the Occupational Doctor and the Doctor of General Medicine (MMG); this synergy is of vital importance in protecting health and in investigating diseases whether occupational or not. D.Lgs. 81/08 emphasizes this synergy, in fact name and phone number of Doctor of General Medicine is compulsory in Case History. Major source of information for all form of prevention is the survey of occupational disease which is a tool for epidemiological control. The use of a systematic collection of data, of protocols, of guidelines and of scientific evidence is the basis for identifying occupational diseases, their diagnosis and subsequent denunciations. This is the line suggested in MAL PROF informative system, made for registration of work-related diseases, and which is important, with other instruments, in realizing an integrated informative system for prevention in workplace. The Covenant for the Protection of Health and Prevention in Workplaces (DPCM 17/12/2007) indicates the strategic objectives of the National Health System for the consolidation and development of the existing system and of the programs promoting health and safety. These include the growth of the culture of prevention and of the epidemiological control of occupational diseases. The Occupational Doctor has an important role because he can identify the early onset of diseases during the working age and start all forms of prevention and health promotion. In the case of diagnosis of a suspected professional disease the Occupational Doctor has three distinct obligations. The first is to report to the legal authority (C.P.P. art. 365). The second requirement is the declaration of the occupational disease (D.P.R. 1124/65 art. 139) and the third is to issue the first certificate of occupational disease for compensation insurance (D.P.R. 1124/65 artt. 53, 251).

[Virus C hepatitis: successful therapy in a health care worker]. / Epatite C: la vittoria della terapia sul virus in un operatore sanitario.

Hepatitis C viral is a problem of population health. The World Health Organization considers Hepatitis C an epidemic, a "silent" epidemic because a patient living with Hepatitis C can be infected for decades before being discovered. Recent data show an estimated number of 170 million patients infected with hepatitis C virus in the world. Number of new infections per year has declined from an average of 240,000 in the 1980s to about 26,000 in 2004. The incidence of HCV infected patients is estimated to 500-600 new cases in a year in Italy. Chronic infection is present in 55%-85% of infected persons. Approximately one third of the patients develop cirrhosis over a number of years, which can lead to liver failure and other serious complications. There is no vaccine and no completely effective treatment. Recent data show PEG-IFN-RBV combination therapy is most effective. We describe one HCV infected individual case report with HCV genotype 1b who received combination therapy for 4 weeks. Levels of HCV RNA became undetectable after an mouth of treatment.

[Brugada syndrome and work place: two case report]. / Sindrome di Brugada e lavoro: due casi clinici.

Brugada Syndrome (BS) is a primary electrical disease of the heart that causes sudden cardiac death or life-threatening ventricular arrhythmias. This disease is hereditary syndrome genetically determined. The pattern of transmission is autosomic dominant. Several mutations linked to this syndrome affecting the gene SCN5A which encodes for the cardiac sodium channel have been described. Recent studies showed the disease is responsible for 4 to 50% of sudden deaths. A typical electrocardiographic (ECG) finding consists of the ST-segment elevation in the right precordial leads. These ECG patterns, which appears permanently or intermittently in patients, are unmasked by antiarrhythmic agents. This syndrome has a very poor prognosis when left untreated: one third of patients having suffered from syncopal episodes or resuscitated from near-sudden death develops a new episode of ventricular tachycardia within 2 years. The only available treatment is the implantable cardioverter-defibrillator. We report two cases of probable BS in workers exposed to occupational risks. These case reports demonstrate the importance of surveillance, particularly of cardiac examination for identifying patients at risk of ventricular arrhythmogenic events.

On-line optical imaging of the human brain with 160-ms temporal resolution.

We have developed an instrument for non-invasive optical imaging of the human brain that produces on-line images with a temporal resolution of 160 ms. The imaged quantities are the temporal changes in cerebral oxy-hemoglobin and deoxy-hemoglobin concentrations. We report real-time videos of the arterial pulsation and motor activation recorded on a 4 x 9 cm 2 area of the cerebral cortex in a healthy human subject. This approach to optical brain imaging is a powerful tool for the investigation of the spatial and temporal features of the optical signals collected on the brain.

Non-invasive optical mapping of the piglet brain in real time.

We have performed non-invasive, real-time optical mapping of the piglet brain during a subcortical injection of autologous blood. The time resolution of the optical maps is 192 ms, thus allowing us to generate a real-time video of the growing subcortical hematoma. The increased absorption at the site of blood injection is accompanied by a decreased absorption at the contralateral brain side. This contralateral decrease in the optical absorption and the corresponding time traces of the cerebral hemoglobin parameters are consistent with a reduced cerebral blood flow caused by the increased intracranial pressure.

Blood flow and oxygen consumption with near-infrared spectroscopy and venous occlusion: spatial maps and the effect of time and pressure of inflation.

We have measured the local blood flow (BF) and oxygen consumption (OC) in the human calf muscle using near-infrared spectroscopy during venous occlusion. Venous occlusion was achieved by inflating a pneumatic cuff around the thigh of the subject. We have investigated the influence of the inflation time and cuff pressure on the recovered values of BF and OC. We have found that if the cuff pressure is increased from a threshold pressure (approximately 30 mm Hg) to a critical pressure (approximately 45 mm Hg) in less than about 6 s, one measures the same values of BF and OC independent of the total inflation time and final cuff pressure. We also report nine-pixel spatial maps of BF and OC to show that this technique can lead to spatially resolved measurements of blood flow and oxygen consumption in tissues.

Contrast features of breast cancer in frequency-domain laser scanning mammography.

Frequency-domain optical mammography has been advocated to improve contrast and thus cancer detectability in breast transillumination. To the best of our knowledge, this report provides the first systematic clinical results of a frequency-domain laser scanning mammograph (FLM). The instrument provides monochromatic light at 690 and 810 nm, whose intensity is modulated at 110.0010 and 110.0008 MHz, respectively. The breast is scanned by stepwise positioning of source and detector, and amplitude and phase for both wavelengths are measured by a photomultiplier tube using heterodyne detection. Images are formed representing amplitude or phase data on linear gray scales. Furthermore, various algorithms carrying on more than one signal (amplitude ratio, phase difference, µa,µs',N) were essayed. Twenty visible cancers out of 25 cancers in the first 59 investigations were analyzed for their quantitative contrast with respect to the whole breast or to defined reference areas. Contrast definitions refer to the signal itself (definition 1), to the signal noise (definition 2), or were based on nonparametric comparison (definition 3). The amplitude signal provides better contrast than the phase signal. Ratio images between red and infrared amplitudes gave variable results; in some cases the tumor contrast was canceled. The algorithms to determine µa and µs' from amplitude and phase data did not significantly improve upon objective contrast. The N algorithm, using the phase signal to flatten the amplitude signal did significantly improve upon contrast according to contrast definitions 1 and 2, however, did not improve upon nonparametric contrast. Thus, with the current instrumentation, the phase signal is helpful to correct for the complex and variable geometry of the breast. However, an independent informational content for tumor differentiation could not be determined. The flat field algorithm did greatly enhance optical contrast in comparison with amplitude or amplitude ratio images. Further evaluation of FLM will have to be based on the N-algorithm images. © 1998 Society of Photo-Optical Instrumentation Engineers.

Near-infrared study of fluctuations in cerebral hemodynamics during rest and motor stimulation: temporal analysis and spatial mapping.

We have noninvasively studied the motor cortex hemodynamics in human subjects under rest and motor stimulation conditions using a multichannel near-infrared tissue spectrometer. Our instrument measures optical maps of the cerebral cortex at two wavelengths (758 and 830 nm), with an acquisition time of 160 ms per map. We obtained optical maps of oxy- and deoxy-hemoglobin concentration changes in terms of amplitudes of folding average, power spectrum and coherence at the stimulation repetition frequency, and the phase synchronization index. Under periodic motor stimulation conditions, we observed coherence and frequency or phase synchronization of the local hemodynamic changes with stimulation. Our main findings are the following: (1) The amplitude of the hemodynamic response to the motor stimulation is comparable to the amplitude of the fluctuations at rest. (2) The spatial patterns of the oxy- and deoxy-hemoglobin responses to the stimulation are different. (3) The hemodynamic response to stimulation shows a spatial localization and a level of phase synchronization with the motor stimulation that depends on the stimulation period.

Frequency-domain optical mammography: edge effect corrections.

We have investigated the problem of edge effects in laser-beam transillumination scanning of the human breast. Edge effects arise from tissue thickness variability along the scanned area, and from lateral photon losses through the sides of the breast. Edge effects can be effectively corrected in frequency-domain measurements by employing a two-step procedure: (1) use of the phase information to calculate an effective tissue thickness for each pixel location; (2) application of the knowledge of tissue thickness to calculate an edge-corrected optical image from the ac signal image. The measurements were conducted with a light mammography apparatus (LIMA) designed for feasibility tests in the clinical environment. Operating in the frequency-domain (110 MHz), this instrument performs a transillumination optical scan at two wavelengths (685 and 825 nm). We applied the proposed two-step procedure to data from breast phantoms and from human breasts. The processed images provide higher contrast and detectability in optical mammography with respect to raw data breast images.

Non-invasive and quantitative near-infrared haemoglobin spectrometry in the piglet brain during hypoxic stress, using a frequency-domain multidistance instrument.

The frequency-domain multiple-distance (FDMD) method is capable of measuring the absolute absorption and reduced scattering coefficients of optically turbid media. Absolute measurement of absorption at two near-infrared (NIR) wavelengths makes possible the quantitation of tissue haemoglobin concentration and tissue haemoglobin oxygen-saturation (StO2). However, errors are introduced by the uncertainties of background absorption and the dissimilarities between real tissues and the simplified mathematical model on which these measurements are based. An FDMD-based tissue instrument has been used for the monitoring of tissue haemoglobin concentration and oxygenation in the brain of newborn piglets during periods of hypoxia and hyperoxia. These tissue haemoglobin saturation values were compared with arterial saturation (SaO2) and venous saturation (SvO2) measured by blood gas analyses. A linear correlation was observed between StO2 and the average of SaO2 and SvO2. However, StO2 is not equal to any fixed weighted average of SaO2 and SvO2 unless we introduce an effective background tissue absorption. The magnitude of the background absorption was about 0.08 cm(-1) at 758 nm and 0.06 cm(-1) at 830 nm, and it was nearly consistent between piglets. The origin of this 'effective' background absorption may be real, an artefact caused by the application of a simplified model to a complex sample, or a combination of factors.

Non-invasive optical monitoring of the newborn piglet brain using continuous-wave and frequency-domain spectroscopy.

We have used continuous-wave (CW) and frequency-domain spectroscopy to investigate the optical properties of the newborn piglet brain in vivo and non-invasively. Three anaesthetized, intubated, ventilated and instrumented newborn piglets were placed into a stereotaxic instrument for optimal experimental stability, reproducible probe-to-scalp optical contact and 3D adjustment of the optical probe. By measuring the absolute values of the brain absorption and reduced scattering coefficients at two wavelengths (758 and 830 nm), frequency-domain spectroscopy provided absolute readings (in contrast to the relative readings of CW spectroscopy) of cerebral haemoglobin concentration and saturation during experimentally induced perturbations in cerebral haemodynamics and oxygenation. Such perturbations included a modulation of the inspired oxygen concentration, transient brain asphyxia, carotid artery occlusion and terminal brain asphyxia. The baseline cerebral haemoglobin saturation and concentration, measured with frequency-domain spectroscopy, were about 60% and 42 microM respectively. The cerebral saturation values ranged from a minimum of 17% (during transient brain asphyxia) to a maximum of 80% (during recovery from transient brain asphyxia). To analyse the CW optical data, we have (a) derived a mathematical relationship between the cerebral optical properties and the differential pathlength factor and (b) introduced a method based on the spatial dependence of the detected intensity (dc slope method). The analysis of the cerebral optical signals associated with the arterial pulse and with respiration demonstrates that motion artefacts can significantly affect the intensity recorded from a single optode pair. Motion artefacts can be strongly reduced by combining data from multiple optodes to provide relative readings in the dc slope method. We also report significant biphasic changes (initial decrease and successive increase) in the reduced scattering coefficient measured in the brain after the piglet had been sacrificed.

Cerebral and muscle oxygen saturation measurement by frequency-domain near-infra-red spectrometer.

Tissue oxygen saturation quantification was obtained using a frequency-domain multi-source method based on two wavelength light-emitting diodes. Brain saturation was 60.3 +/- 1.1% (n = 12). Brachioradial muscle saturation declined during forearm ischaemia and maximal voluntary contraction from 73.7 +/- 1.8 and 74.7 +/- 1.8% at rest to 44.2 +/- 3.3 and 61.4 +/- 2.9%, respectively.

Application of near-infrared tissue oxymetry to the diagnosis of peripheral vascular disease.

Near-infrared spectroscopy (NIRS) is a noninvasive technique to measure the tissue oxygenation in real time. This optical method has many advantages over the invasive analysis currently used for clinical tests. Among the possible applications of near-infrared oxymetry, we report three protocols (exercise, venous occlusion and tilting table) in conjunction with NIRS, and discuss their applicability in the diagnosis of peripheral vascular disease (PVD).

Hypertension and chronic exposure to noise.

The effects of noise on various cardiovascular parameters are conflicting and uncertain. In the current study, the authors studied 52 workers who were employed in a bedframe factory who were chronically exposed to noise and who had poor hearing. An additional group of 65 workers who had jobs in the light-metal sector and another group of 64 office workers served as two control groups; none of the controls were exposed to noise, and none had hearing defects. Blood pressure was measured for each person in the supine and standing positions, and an electrocardiogram was also performed. Sound-level measurements were taken in the workplaces. Mean systolic and diastolic blood pressures and diastolic blood pressure distributions were significantly higher in the noise-exposed group than in both control groups. Among the three groups, there were significantly different frequencies of hypertension, drops in blood pressure, and electrocardiogram anomalies. Within the group of bedframe workers, those exposed to a personal daily level of exposure (i.e., equivalent continuous noise level for exposure to noise for each individual workers in an 8-hr shift) that exceeded 90 dBA had a higher mean diastolic blood pressure and a higher frequency of diastolic hypertension than workers exposed to a personal daily level of exposure of < 90 dBA. The findings suggested that (a) work performed by the bedframe group had some effects on the cardiovascular system, (b) noise is a cardiovascular risk factor, and (c) cardiovascular effects are relative to intensity and type of exposure. Vascular damage often accompanies auditory damage, but--depending on individual susceptibility--the cardiovascular system can respond in various ways.

[Chronic noise exposure and the cardiovascular system in aircraft pilots]. / Esposizione cronica a rumore e apparato cardiovascolare in piloti di aeromobili.

The aim of this study was to assess whether pilots are exposed to any risk of effects on the cardiovascular apparatus, whether chronic exposure to noise can be a risk factor for this occupation, the importance of intensity, length and type of exposure to noise, and if any relationship exists between audiometric deficits and cardiovascular effects. The study comprised 416 pilots subdivided into two groups according to the different levels of chronic exposure to noise, and a group of 150 control subjects not exposed to noise. The results showed: a) a higher prevalence of hypertension, nearly always diastolic, and of ECG abnormalities in the group of pilots of turboprop aircraft compared to jet plane pilots and to controls (p < 0.005 and p < 0.01 respectively); b) a higher prevalence of orthostatic hypotension in the two groups of pilots than in the controls (p < 0.05); c) a higher prevalence of hypertension with audiometric deficit compared to hypertension without audiometric deficit both in the more heavily and in the less heavily exposed to noise (p < 0.05), and a higher prevalence of hypertension with audiometric deficit in subjects exposed to higher levels of noise compared to hypertension with deficit but in subjects with lower levels of exposure (p < 0.05); d) a higher prevalence of abnormalities of basal, maximum effort and recovery ECG in pilots exposed to higher noise intensity (p < 0.05); e) improved hypertensive response to ergometric test in pilots with basal hypertension; f) subjects with a maximal load up to 120 W belonged prevalently to the group exposed to more intense noise (p < 0.001), while those with maximal load up to 210 W (p < 0.001) belonged to the group exposed to less intense noise. Considering that pilots are comparable for traditional cardiovascular risk factors, including age, both within the group and with the controls, the results confirm 1) that pilots could be exposed to the risk of effects on the cardiovascular apparatus, 2) that noise could be one of the risk factors and that cardiovascular effects could be related to intensity, type and length of exposure, age being the same, 3) that vascular damage is often accompanied by hearing loss even if the response of the auditory apparatus is different from the response of the cardiovascular apparatus, 4) that the postural diminution of arterial blood pressure might be a sign of a cardiovascular effect of noise. Lastly, a higher hypertensive response in hypertensive pilots suggests that basal hypertension is not reversible. Also a longer exposure to noise seems to influence the cardiovascular apparatus, causing a decrease in the response to work loads due to a lower sympathetic adaptability. The altered response of sympathetic activity to the postural modifications in the more exposed subjects and the response to lower work loads in pilots exposed to more intense noise, suggests a hypothesis of catecholamine depletion and alteration of baroceptor sensitivity as a consequence of chronic sympathetic activation due to chronic exposure to noise.

Effective source term in the diffusion equation for photon transport in turbid media.

The Green's function for the diffusion equation is widely used to describe photon transport in turbid media. We have performed aseries of spectroscopy experiments on a number of uniform turbid media with different optical properties (absorption coefficient in the range 0.03-0.14 cm(-1), reduced scattering coefficient in the range 5-22 cm(-1)). Our experiments have been conducted in the frequency domain, where the measured parameters are the dc intensity (I(dc)), ac amplitude (I(ac)), and phase (?) of the light intensity wave. In an infinite medium, the Green's function predicts a linear dependence of ln(rI(dc)) and ? on the source-detector separation r. Our measurements show that the intercepts of these straight lines predicted by the Green's function do not agree with the experimental results. To reproduce the experimental results, we have introduced an effective photon source whose spatial extent and source strength depend on the optical properties of the medium. This effective source term has no effect on the slopes of the straight lines predicted by the Green'sfunction at large values of r.