Search

Summary To assess the effects of napping + bright light on shift work drivers sleepiness at the wheel, we performed a pilot study on nine shift workers on three shifts (morning, afternoon, night), driving on a private road circuit. Sleepiness at the wheel was measured by ambulatory polysomnography and assessed using 30-s segments of recordings with a percentage of theta electroencephalogram of at least 50% (15 s) of the period recorded. Sleepiness was also assessed by the Stanford Sleepiness Scale (SSS). Participants drove the same car on two similar 24-h periods of work, with three drivers in each shift (morning, afternoon, night), separated by 3 weeks. During the baseline period, the subjects were told to manage their rest as usual. During the second experimental period, they had to rest lying in a dark room with two naps of 20 min and then exposed to bright light (5000 lux) for 10 min. Subjects showed a significantly decreased sleepiness at the wheel with an average of 10.7 ± 6.7 episodes of theta sleep during the baseline (766 ± 425 s) versus 1.0 ± 1.0 episode lasting 166 ± 96 s during the second period (P = 0.016; P = 0.0109). The percentage of driving asleep was also significantly reduced (3.7% ± 1.9% versus 0.9% ± 0.6%, P = 0.0077). The average SSS score in the group decreased from 2.76 ± 1.27 to 2.28 ± 0.74 (P = 0.09). In this pilot and preliminary study, a combination of napping and bright light pulses was powerful in decreasing sleepiness at the wheel of shift work drivers.

BACKGROUND Severity of occupational asthma at diagnosis is an important prognostic factor. The aim of this study was to determine which factors affect the severity of occupational asthma with a latency period at diagnosis. METHODS The study population consisted of 229 consecutive subjects with occupational asthma with a latency period recruited by four occupational health departments and divided into two groups according to the severity of the disease at diagnosis. The moderate-severe (FEV(1) /=70% predicted and PD(20) methacholine >300 microg, n = 128) groups were compared in terms of clinical and demographic parameters. Multivariate analysis using logistic regressions was performed to examine factors associated with asthma severity. RESULTS Duration of symptoms before diagnosis was significantly longer in the moderate-severe group (mean +/- SD: 6.3 +/- 6.8 years vs 3.4 +/- 4.4 years, P < 0.001). Sex ratio, age, atopy, smoking habits, duration of exposure before symptoms, and molecular weight of the causal agent were not significantly different between the two groups. On multivariate analysis, only duration of symptoms before diagnosis was associated with asthma severity (aOR = 1.12, 95% CI 1.05-1.18, P < 0.001). CONCLUSIONS Severity of occupational asthma with a latency period at diagnosis was associated with duration of symptoms before diagnosis, but not with the type of causal agent. This finding emphasizes the need for early diagnosis and avoidance of exposure.

Background: Our aims were to compare the doses of wheat and rye flour that induce early bronchial responses in occupationally exposed asthmatic subjects and to assess the effects of the dose of inhaled flour, the duration of exposure and the dose rate. Methods: Ten patients underwent tests with lactose, wheat flour and rye flour. We compared the decrease in forced expiratory volume in 1 s (FEV1) observed during the challenge with flour and with lactose. We also calculated the amount of flour that was instantaneously active. Results: Seven subjects had significantly decreased FEV1 values following exposure to wheat and rye flour and two subjects only did so for rye flour. The provocative dose (PD, dose required to reduce FEV1 by 15%) of rye was lower than that of wheat flour (geometric mean; PD15 rye: 95 μg; wheat: 368 μg). The calculated doses of rye and wheat flour were better correlated with the change in FEV1 than were the cumulative doses. Conclusion: The bronchial response was greater with rye than with wheat flour. The response was related to the dose of allergen inhaled and to the dose rate.