Introduction
delirium, PTE, insomnia, CTEPH
CHRONIC THROMBOEMBOLIC PULMONARY HYPERTENSION
Individuals receiving care in the intensive care unit (ICU) suffer from extremely poor sleepRamelteon is a synthetic, melatonin-receptor (types 1 and 2) agonist that is FDA-approved for the treatment of insomnia. In the outpatient setting, studies have shown that ramelteon increases total sleep time (magnitude of effect approximately 7 min) and sleep efficiency and decreases subjective sleep latency (magnitude of effect approximately 4 min)As part of a randomized clinical trial (RCT) testing ramelteon versus placebo effect on delirium in patients recovering in the ICU who underwent elective pulmonary thromboendarterectomy (PTE) surgery, a major cardiothoracic surgery used for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH), we collected objective measures of sleepHere we explore the hypothesis that ramelteon would improve actigraphy-based sleep metrics in this cohort, which was a pre-specified outcome in the original study. We further examined basic activity and circadian rest-activity parameters between drug groups to evaluate for differences. Finally, we examined sleep, activity, and circadian rest-activity differences between individuals who developed delirium versus those who did not to address the hypothesis that individuals with delirium would have reduced circadian rest-activity rhythmicity (i.e., objectively measured loss of day-night activity pattern) compared to those who did not develop delirium.