The fragile X mutation and fragile X syndrome are associated with hyperarousal, hyperactivity, aggression, and anxiety. These may be related to strong reactions to auditory, tactile, visual, and olfactory stimuli [Hagerman, 1996b; Hagerman and Cronister, 1996]. However, almost no data exist describing hyperarousal and sensory sensitivity in individuals with the fragile X mutation. This study establishes a reliable laboratory paradigm for examining reactions to sensory stimuli. We found the pattern of electrodermal responses (EDRs) to stimulation in one sensory modality predicted the pattern of EDRs in four other sensory systems. In addition, the EDR pattern of individuals with the fragile X mutation was related to their FMR-protein expression. Finally, EDRs in individuals with fragile X syndrome were significantly different from those of normal controls, demonstrating greater magnitude, more responses per stimulation, responses on a greater proportion of trials, and lower rates of habituation. The findings support the theory that individuals with fragile X syndrome have a physiologically based enhancement of reactions to sensations. Because electrodermal activity indexes sympathetic nervous system activity, the data suggest that the over-arousal to sensation may involve the sympathetic system.

No abstract

Background: Secondary inhalation of medical aerosols is a significant occupational hazard in both clinical and homecare settings. Exposure to fugitive emissions generated during aerosol therapy increases the risk of the unnecessary inhalation of medication, as well as toxic side effects. Methods: This study examines fugitively-emitted aerosol emissions when nebulising albuterol sulphate, as a tracer aerosol, using two commercially available nebulisers in combination with an open or valved facemask or using a mouthpiece with and without a filter on the exhalation port. Each combination was connected to a breathing simulator during simulated adult breathing. The inhaled dose and residual mass were quantified using UV spectrophotometry. Time-varying fugitively-emitted aerosol concentrations and size distributions during nebulisation were recorded using aerodynamic particle sizers at two distances relative to the simulated patient. Different aerosol concentrations and size distributions were observed depending on the interface. Results: Within each nebuliser, the facemask combination had the highest time-averaged fugitively-emitted aerosol concentration, and values up to 0.072 ± 0.001 mg m−3 were recorded. The placement of a filter on the exhalation port of the mouthpiece yielded the lowest recorded concentrations. The mass median aerodynamic diameter of the fugitively-emitted aerosol was recorded as 0.890 ± 0.044 µm, lower the initially generated medical aerosol in the range of 2–5 µm. Conclusions: The results highlight the potential secondary inhalation of exhaled aerosols from commercially available nebuliser facemask/mouthpiece combinations. The results will aid in developing approaches to inform policy and best practices for risk mitigation from fugitive emissions.

Background: Nebulised medical aerosols are designed to deliver drugs to the lungs to aid in the treatment of respiratory diseases. However, an unintended consequence is the potential for fugitive emissions during patient treatment, which may pose a risk factor in both clinical and homecare settings. Methods: The current study examined the potential for fugitive emissions, using albuterol sulphate as a tracer aerosol during high-flow therapy. A nasal cannula was connected to a head model or alternatively, a interface was connected to a tracheostomy tube in combination with a simulated adult and paediatric breathing profile. Two aerodynamic particle sizers (APS) recorded time-series aerosol concentrations and size distributions at two different distances relative to the simulated patient. Results: The results showed that the quantity and characteristics of the fugitive emissions were influenced by the interface type, patient type and supplemental gas-flow rate. There was a trend in the adult scenarios; as the flow rate increased, the fugitive emissions and the mass median aerodynamic diameter (MMAD) of the aerosol both decreased. The fugitive emissions were comparable when using the adult breathing profiles for the nasal cannula and tracheostomy interfaces; however, there was a noticeable distinction between the two interfaces when compared for the paediatric breathing profiles. The highest recorded aerosol concentration was 0.370 ± 0.046 mg m−3 from the tracheostomy interface during simulated paediatric breathing with a gas-flow rate of 20 L/min. The averaged MMAD across all combinations ranged from 1.248 to 1.793 µm by the APS at a distance of 0.8 m away from the patient interface. Conclusions: Overall, the results highlight the potential for secondary inhalation of fugitive emissions released during simulated aerosol treatment with concurrent high-flow therapy. The findings will help in developing policy and best practice for risk mitigation from fugitive emissions.