Paula K. Schweitzer

Effect of caffeine on physiological sleep tendency and ability to sustain wakefulness at night

Marked sleepiness occurs during typical night shift work hours and this reduced alertness is associated with marked performance deficits. The effect of caffeine (versus placebo) upon sleepiness at night was studied using objective measures of physiological sleep tendency and ability to sustain wakefulness. Both measures show caffeine to reduce sleepiness at a single dose roughly the equivalent of two to four cups of coffee. Despite impressive objective differences in alertness with caffeine, subjects did not consistently differentiate between drug conditions on subjective alertness assessments. The use of CNS stimulants to promote alertness during night shift hours should be considered, particularly for occupations for which alertness is critical.

Management of obstructive sleep apnea: Comparison of various treatment modalities†

From July, 1982 through March, 1986, 253 patients with moderate to severe sleep apnea (OSA) were treated and had polysomnographic assessment of treatment. The treatment modalities were: 1. uvulopalatopharyngoplasty (UPP), 2. nasal continuous positive airway pressure (CPAP), 3. tracheostomy, 4. medication (tricyclic antidepressants), 5. tongue retaining device (TRD), and 6. orthodontic device.

Countermeasures for night work performance deficits: The effect of napping or caffeine on continuous performance at night

Abstract Napping and caffeine consumption, two common strategies for improving alertness and performance on the night shift, were investigated in two separate studies. Performance was measured with a simulated assembly line task (SALT) during a single night work shift. Both strategies proved beneficial. Performance and subjective alertness were improved following either a 2.3-h evening nap or ingestion of caffeine (4 mg/kg) prior to the work shift. The effects were noted particularly at the trough of circadian alertness. Although neither napping nor caffeine countered the strong circadian influence on performance and alertness in the early morning hours, both strategies attenuated their sharp decline. Further research is required to determine the generalizability of these findings beyond a single night shift and in different populations of workers, such as older age groups, or chronic caffeine users.

Slow-wave sleep deprivation and waking function

SUMMARY  Slow‐wave sleep (SWS) has been theorized to be an intense form of nonREM sleep, but selective deprivation of SWS or Stage 4 sleep has not been shown to cause greater decrements in alertness or performance, compared to deprivation or disruption of the other stages of sleep. The present experiment examined the effects of marked SWS deprivation (SD) for two nights, a control sleep disruption (CD) condition in which minutes of SWS were preserved, and a no sleep disruption (ND) condition. Daytime sleepiness was assessed with the multiple sleep latency test (MSLT) and performance was evaluated with the simulated assembly line task (SALT), neither of which was used in previous studies of SWS or Stage 4 sleep deprivation. In agreement with prior studies, two nights of SD did not cause greater daytime sleepiness than did CD, although sleepiness in both conditions was increased compared to the ND condition. In addition, neither SD nor CD caused declines in performance or mood. However, post hoc analysis suggests an interaction between SWS and sleep duration, such that sufficient SWS may tend to prevent adverse effects of mild sleep loss on waking function.

Effects of lorazepam and its withdrawal on sleep, performance, and subjective state.

The effects of 3 mg lorazepam on polysomnographic recordings, performance, anxiety, and perceived sleep were examined. Six insomniac subjects slept in the sleep laboratory for 18 consecutive nights after having taken placebo or lorazepam. Polysomnographic data and subjective reports indicated hypnotic efficacy in terms of sleep initiation and maintenance. There was some evidence of rebound insomnia after drug withdrawal, although it was not evident from all measures. Clear performance decrements occurred during lorazepam use.