R.S. Silva

Sonolência excessiva Excessive daytime sleepiness

Sleepiness is a physiological function, and can be defined as increased propension to fall asleep. However, excessive sleepiness (ES) or hypersomnia refer to an abnormal increase in the probability to fall asleep, to take involuntary naps, or to have sleep atacks, when sleep is not desired. The main causes of excessive sleepiness is chronic sleep deprivation, sleep apnea syndrome, narcolepsy, movement disorders during sleep, circadian sleep disorders, use of drugs and medications, or idiopathic hypersomnia. Social, familial, work, and cognitive impairment are among the consequences of hypersomnia. Moreover, it has also been reported increased risk of accidents. The treatment of excessive sleepiness includes treating the primary cause, whenever identified. Sleep hygiene for sleep deprivation, positive pressure (CPAP) for sleep apnea, dopaminergic agents and exercises for sleep-related movement disorders, phototherapy and/or melatonin for circadian disorders, and use of stimulants are the treatment modalities of first choice.

Sleep Complaints and Polysomnographic Findings: A Study of Nuclear Power Plant Shift Workers

The literature widely recognizes that shift workers have more health complaints than the general population. The objective of this study was to describe the prevalence of sleep complaints and verify the polysomnographic (PSG) variables of shift workers in two Brazilian nuclear power plants. We carried out a subjective evaluation with a sleep questionnaire. Based on these results, the interviewees that reported sleep‐related complaints were referred for polysomnographic evaluation. Of the 327 volunteers initially evaluated by the sleep questionnaire, 113 (35%) reported sleep complaints; they were significantly older, had higher body mass index (BMI), and worked more years on shifts than those without sleep complaints. Of these 113, 90 met criteria for various sleep disorders: 30 (9%) showed obstructive sleep apnea (OSA), 18 (5.5%) showed limb movement, and 42 (13%) evidenced both sleep problems and had a significantly higher proportion of sleep stage 1 and arousals compared with the 23 shift workers that had no indices of sleep problems. The present study found that 90 (27.5%) of the evaluated participants met the PSG criteria of some type of clinical sleep disorder. This high proportion should be investigated for associations with other aspects of work, such as working hours, working schedule, years performing shift work, and access to health services. Due to the strong association between sleep disorders and the incidence of fatigue and sleepiness, the evaluation of the sleep patterns and complaints of shift workers is essential and should be considered to be one of the basic strategies of industry to prevent accidents.

Sleep, ageing and night work

Studies have shown that the frequency or worsening of sleep disorders tends to increase with age and that the ability to perform circadian adjustments tends to decrease in individuals who work the night shift. This condition can cause consequences such as excessive sleepiness, which are often a factor in accidents that occur at work. The present study investigated the effects of age on the daytime and nighttime sleep patterns using polysomnography (PSG) of long-haul bus drivers working fixed night or day shifts. A total of 124 drivers, free of sleep disorders and grouped according to age (<45 years, N = 85, and > or =45 years, N = 39) and PSG timing (daytime (D) PSG, N = 60; nighttime (N) PSG, N = 64) participated in the study. We observed a significant effect of bedtime (D vs N) and found that the length of daytime sleep was shorter [D: <45 years (336.10 +/- 73.75 min) vs N: <45 years (398 +/- 78.79 min) and D: > or =45 years (346.57 +/- 43.17 min) vs N: > or =45 years (386.44 +/- 52.92 min); P < or = 0.05]. Daytime sleep was less efficient compared to nighttime sleep [D: <45 years (78.86 +/- 13.30%) vs N: <45 years (86.45 +/- 9.77%) and D: > or =45 years (79.89 +/- 9.45%) and N: > or =45 years (83.13 +/- 9.13%); P < or = 0.05]. An effect of age was observed for rapid eye movement sleep [D: <45 years (18.05 +/- 6.12%) vs D: > or =45 years (15.48 +/- 7.11%) and N: <45 years (23.88 +/- 6.75%) vs N: > or =45 years (20.77 +/- 5.64%); P < or = 0.05], which was greater in younger drivers. These findings are inconsistent with the notion that older night workers are more adversely affected than younger night workers by the challenge of attempting to rest during the day.

Effect of smoking habits on sleep

To evaluate the effect of smoking habits on sleep, data from 1492 adults referred to the Sleep Institute were accessed and divided into 3 categories of smoking status: current, former and non-smokers. Categories of pack-years (<15 and > or =15) defined smoking severity. The association of smoking status and smoking severity with sleep was analyzed for sleep parameters, especially apnea and hypopnea index (AHI) > or =5, more than 5% of total sleep time (TST) spent with oxyhemoglobin saturation (SaO2) <90%, and arousal index. The arousal index was higher among current (21 +/- 17) and former smokers (20 +/- 17) than non-smokers (17 +/- 15; P < 0.04). Former smokers had a higher percent of TST at SaO2 <90% than non-smokers (9 +/- 18 vs 6 +/- 13; P < 0.04). Former smokers with pack-years > or =15 compared to <15 exhibited higher AHI (22 +/- 24 vs 16 +/- 21; P < 0.05) and arousal index (22 +/- 19 vs 18 +/- 15; P < 0.05). Current smokers with pack-years > or =15 compared to <15 exhibited higher arousal index (23 +/- 18 vs 18 +/- 16; P < 0.05) and percent of TST at SaO2 <90% (11 +/- 17 vs 6 +/- 13; P < 0.05). Smoking status and pack-years were not associated with AHI > or =5 on logistic regression analysis, but current smokers with pack-years > or =15 were 1.9 times more likely to spend more than 5% of TST at SaO2 <90% than non-smokers (95%CI = 1.21-2.97; P = 0.005). The variability of arousal index was influenced by gender, AHI and current smokers with pack-years > or =15 (all P < 0.01). Smoking habits seem to be associated with arousal and oxyhemoglobin desaturation during sleep, but not with AHI. The effect was more pronounced in current than former smokers.

Relationship between Brazilian airline pilot errors and time of day

Flight safety is one of the most important and frequently discussed issues in aviation. Recent accident inquiries have raised questions as to how the work of flight crews is organized and the extent to which these conditions may have been contributing factors to accidents. Fatigue is based on physiologic limitations, which are reflected in performance deficits. The purpose of the present study was to provide an analysis of the periods of the day in which pilots working for a commercial airline presented major errors. Errors made by 515 captains and 472 co-pilots were analyzed using data from flight operation quality assurance systems. To analyze the times of day (shifts) during which incidents occurred, we divided the light-dark cycle (24:00) in four periods: morning, afternoon, night, and early morning. The differences of risk during the day were reported as the ratio of morning to afternoon, morning to night and morning to early morning error rates. For the purposes of this research, level 3 events alone were taken into account, since these were the most serious in which company operational limits were exceeded or when established procedures were not followed. According to airline flight schedules, 35% of flights take place in the morning period, 32% in the afternoon, 26% at night, and 7% in the early morning. Data showed that the risk of errors increased by almost 50% in the early morning relative to the morning period (ratio of 1:1.46). For the period of the afternoon, the ratio was 1:1.04 and for the night a ratio of 1:1.05 was found. These results showed that the period of the early morning represented a greater risk of attention problems and fatigue.

Violência durante o sono

Cases of violent behavior during sleep have been reported in the literature. However, the incidence of violent behavior during sleep is not known. One epidemiological study showed that approximately 2% of the general population, predominantly males, presented violent behavior while asleep. In the present study, the authors describe clinical and medico-legal aspects involved in violent behavior investigation. Violent behavior refers to self-injury or injury to another during sleep. It happens most frequently following partial awakening in the context of arousal disorders (parasomnias). The most frequently diagnosed sleep disorders are REM behavior disorder and somnambulism. Violent behavior might be precipitated by stress, use of alcohol or drugs, sleep deprivation or fever.

Sleep Parameters in Patients Using Pacemakers with Sleep Rate Function on

Introduction: The cardiovascular system (CVS) is heavily influenced by the autonomic nervous system. Additionally, there is a functional alteration during the various stages of sleep. In nonrapid eye movement (NREM), a state of cardiovascular relaxation occurs during stages three and four. A large amount of rapid ocular movements is concentrated in rapid eye movement (REM) sleep. During this phase, fluctuations in arterial pressure (AP) and heart rate (HR) can be readily noted. Sleep disordered breathing (SDB) has been associated with cardiac rhythm disorders. Recently, cardiac rhythm disorder treatment with pacemaker (PM) highlighted a reduction in abnormal respiratory events during sleep.