Problem-Based Learning Discussion to Introduce Quality Improvement to Residents in the Perioperative Setting.

Introduction: Quality improvement (QI) is a growing and critical part of perioperative medical practice. However, there are few examples of educational tools to introduce new learners from anesthesiology to QI. This may contribute to a lack of enthusiasm to learn about and apply these concepts.

Effects of caffeine on the human circadian clock in vivo and in vitro.

Caffeine's wakefulness-promoting and sleep-disrupting effects are well established, yet whether caffeine affects human circadian timing is unknown. We show that evening caffeine consumption delays the human circadian melatonin rhythm in vivo and that chronic application of caffeine lengthens the circadian period of molecular oscillations in vitro, primarily with an adenosine receptor/cyclic adenosine monophosphate (AMP)-dependent mechanism. In a double-blind, placebo-controlled, ~49-day long, within-subject study, we found that consumption of a caffeine dose equivalent to that in a double espresso 3 hours before habitual bedtime induced a ~40-min phase delay of the circadian melatonin rhythm in humans.

Combination of light and melatonin time cues for phase advancing the human circadian clock.

Study Objectives: Photic and non-photic stimuli have been shown to shift the phase of the human circadian clock. We examined how photic and non-photic time cues may be combined by the human circadian system by assessing the phase advancing effects of one evening dose of exogenous melatonin, alone and in combination with one session of morning bright light exposure.

Design: Randomized placebo-controlled double-blind circadian protocol.

Effects of the melatonin MT-1/MT-2 agonist ramelteon on daytime body temperature and sleep.

Study Objectives: A reduction in core temperature and an increase in the distal-proximal skin gradient (DPG) are reported to be associated with shorter sleep onset latencies (SOL) and better sleep quality. Ramelteon is a melatonin MT-1/MT-2 agonist approved for the treatment of insomnia. At night, ramelteon has been reported to shorten SOL.