ICU Patients' Perception of Sleep and Modifiable versus Non-Modifiable Factors That Affect It: A Prospective Observational Study.

: Good sleep quantity and quality are essential for patient recovery while in the intensive care unit (ICU). Patients commonly report poor sleep while in the ICU, and therefore, identifying the modifiable factors that patients perceive as impacting their sleep is important to improve sleep and recovery. This study also assessed night-time light and sound levels in an ICU in an effort to find modifiable factors.

The effect of high-dose, short-term caffeine intake on the renal clearance of calcium, sodium and creatinine in healthy adults.

The consumption of caffeine has been linked to osteoporosis, believed to be due to enhanced bone resorption as a result of increased calcium excretion in the urine. However, the amount of calcium in the urine may not necessarily reflect the true effect of caffeine on calcium clearance. This study therefore examined the impact of high-dose, short-term caffeine intake on renal clearance of calcium, sodium and creatinine in healthy adults.

Robustness of inter-individual differences in slow wave sleep for daytime sleep periods after total sleep deprivation with or without caffeine administration: potential implications for around-the-clock operations.

There are large inter-individual differences in slow wave sleep, which constitute a trait or phenotype. We investigated whether the manifestation of this trait is impacted by daytime sleeping after sleep deprivation, and to what extent it is robust to prior caffeine intake. N = 12 subjects underwent three 48 h periods of total sleep deprivation with different caffeine dosing regimens.

Feasibility of Online Haemodiafiltration in Sleep Apnoea: A Randomized Crossover Study.

Background: Sleep apnoea is prevalent in dialysis patients. Previous studies identified excessive inflammation in -patients with sleep apnoea. Online haemodiafiltration -(OL-HDF) may reduce systematic inflammation through better clearance of middle molecules.

Risk factors of sleep-disordered breathing in haemodialysis patients.

Background: Sleep-disordered breathing (SDB) is common in patients with kidney disease; but often underdiagnosed as it is infrequently assessed in clinical practice. The objective of this study was to assess the risk factors of SDB in haemodialysis patients, and to identify useful assessment tools to detect SDB in this population.

Methods: We used nocturnal oximetry, Epworth Sleepiness Scale (ESS) and STOPBANG questionnaire to screen for SDB in haemodialysis patients.

Cardiac autonomic activity during simulated shift work.

Shift work leads to adverse health outcomes including increased risk of cardiovascular disease. Heart rate (HR) and heart rate variability (HRV) are measures of cardiac autonomic activity and markers of cardiovascular disease and mortality. To investigate the effects of shift work on cardiac autonomic activity, we assessed the influence of simulated night work on HR and HRV, and dissociated the direct effects of circadian misalignment from those of sleep displacement and altered physical activity patterns.

The impact of caffeine consumption during 50 hr of extended wakefulness on glucose metabolism, self-reported hunger and mood state.

Caffeine is known for its capacity to mitigate performance decrements. The metabolic side-effects are less well understood. This study examined the impact of cumulative caffeine doses on glucose metabolism, self-reported hunger and mood state during 50 hr of wakefulness.

Effects of strategic early-morning caffeine gum administration on association between salivary alpha-amylase and neurobehavioural performance during 50 h of sleep deprivation.

Self-assessment is the most common method for monitoring performance and safety in the workplace. However, discrepancies between subjective and objective measures have increased interest in physiological assessment of performance. In a double-blind placebo-controlled study, 23 healthy adults were randomly assigned to either a placebo (n = 11; 5 F, 6 M) or caffeine condition (n = 12; 4 F, 8 M) while undergoing 50 h (i.

Sleep and cognitive performance of African-Americans and European-Americans before and during circadian misalignment produced by an abrupt 9-h delay in the sleep/wake schedule.

We conducted two studies of circadian misalignment in non-Hispanic African and European-Americans. In the first, the sleep/wake (light/dark) schedule was advanced 9 h, similar to flying east, and in the second these schedules were delayed 9 h, similar to flying west or sleeping during the day after night work. We confirmed that the free-running circadian period is shorter in African-Americans compared to European-Americans, and found differences in the magnitude and direction of circadian rhythm phase shifts which were related to the circadian period.

Advancing the sleep/wake schedule impacts the sleep of African-Americans more than European-Americans.

There are differences in sleep duration between Blacks/African-Americans and Whites/European-Americans. Recently, we found differences between these ancestry groups in the circadian system, such as circadian period and the magnitude of phase shifts. Here we document the role of ancestry on sleep and cognitive performance before and after a 9-h advance in the sleep/wake schedule similar to flying east or having a large advance in sleep times due to shiftwork, both of which produce extreme circadian misalignment.

Decreased salivary alpha-amylase levels are associated with performance deficits during sleep loss.

During sleep deprivation, neurobehavioral functions requiring sustained levels of attention and alertness are significantly impaired. Discrepancies between subjective measures of sleepiness and objective performance during sustained operations have led to interest in physiological monitoring of operator performance. Alertness, vigilance, and arousal are modulated by the wake-promoting actions of the central noradrenergic system.

Caffeine administration at night during extended wakefulness effectively mitigates performance impairment but not subjective assessments of fatigue and sleepiness.

The current study investigated the effects of repeated caffeine administration on performance and subjective reports of sleepiness and fatigue during 50h extended wakefulness. Twenty-four, non-smokers aged 22.5±2.

The influence of break timing on the sleep quantity and quality of fly-in, fly-out shiftworkers.

Although shift and break timing is known to affect the sleep of shiftworkers, this has not been demonstrated in Fly-in, Fly-out (FIFO) settings which, compared to residential based settings, may be favourable for sleep. This study investigated the sleep quantity and quality of shiftworkers working a FIFO operation comprising of shifts, and therefore breaks, across the 24-h day. The sleep of 24 males (50.

The relative contributions of the homeostatic and circadian processes to sleep regulation under conditions of severe sleep restriction.

Study Objectives: To investigate the relative contributions of the homeostatic and circadian processes on sleep regulation under conditions of severe sleep restriction.

Design: The 13-day laboratory based study consisted of 3 × 24-h baseline days (8 h sleep opportunity, 16 h wake) followed by 7 × 28-h forced desynchrony days (4.7 h sleep opportunity, 23.

The influence of circadian time and sleep dose on subjective fatigue ratings.

Subjective ratings of fatigue are increasingly being used as part of a suite of tools to assess fatigue-related risk on the road and in the workplace. There is some debate however, as to whether individuals can accurately gauge their own fatigue states, particularly under conditions of sleep restriction. It is also unclear which references are used by individuals to assess fatigue - for example prior sleep, time of day, workload, or previous ratings.

Performance on a simple response time task: Is sleep or work more important for miners?

The purpose of the current study was to investigate the impact of work- and sleep-related factors on an objective measure of response time in a field setting. Thirty-five mining operators working 12-h shift patterns completed daily sleep and work diaries, wore activity monitors continuously and completed palm-based psychomotor vigilance tests (palmPVT) at the start and end of each shift. Linear mixed models were used to test the main effects on response time of roster, timing of test, sleep history and prior wake.

Contribution of core body temperature, prior wake time, and sleep stages to cognitive throughput performance during forced desynchrony.

Shiftworkers are often required to sleep at inappropriate phases of their circadian timekeeping system, with implications for the dynamics of ultradian sleep stages. The independent effects of these changes on cognitive throughput performance are not well understood. This is because the effects of sleep on performance are usually confounded with circadian factors that cannot be controlled under normal day/night conditions.

The effects of different roster schedules on sleep in miners.

Shiftwork involving early morning starts and night work can affect both sleep and fatigue. This study aimed to assess the impact of different rostering schedules at an Australian mine site on sleep and subjective sleep quality. Participants worked one of four rosters; 4 x 4 (n = 14) 4D4O4N4O 7 x 4 (n = 10) 7D4O7N40 10 x 5 (n = 17) 5D5N50 14 x 7 (n = 12) 7D7N70.