***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Introduction Many intensive care patients experience sleep disruption potentially related tonoise , light and treatment interventions . The purpose of this study was tocharacterise , in terms of quantity and quality , the sleep of intensive care patients , taking into account the impact of environmental factors . Methods This observational study was conducted in the adult ICU of a tertiary referralhospital in Australia , enrolling 57 patients .  Polysomnography ( PSG ) was performedover a 24-hour period to assess the quantity ( total sleep time : hh : mm ) and quality ( percentage per stage , duration of sleep episode ) of patients ' sleep while in ICU.Rechtschaffen and Kales criteria were used to categorise sleep . Interrater checkswere performed . Sound pressure and illuminance levels and care events weresimultaneously recorded . Patients reported on their sleep quality in ICU using theRichards Campbell Sleep Question naire and the Sleep in Intensive Care Question naire . Data were summarised using frequencies and proportions or measures of central tendency and dispersion as appropriate and Cohen 's Kappa statistic wasused for interrater reliability of the sleep data analysis . Results Patients ' median total sleep time was 05:00 ( IQR : 02:52 to 07:14 ) . The majority ofsleep was stage 1 and 2 ( medians : 19 and 73 % ) with scant slow wave and REM sleep . The median duration of sleep without waking was 00:03 . Sound levels were high(mean Leq 53.95 dB(A ) during the day and 50.20 dB(A ) at night ) and illuminancelevels were appropriate at night ( median < 2 lux ) but low during the day(median : 74.20 lux ) . There was a median 1.7 care events/h . Patients ' meanself-reported sleep quality was poor . Interrater reliability of sleep staging washighest for slow wave sleep and lowest for stage 1 sleep . Conclusions The quantity and quality of sleep in intensive care patients are poor and may berelated to noise , critical illness itself and treatment events that disturb sleep . The study highlights the challenge of quantifying sleep in the critical care setting and the need for alternative methods of measuring sleep . The results suggest that a sound reduction program is required and other interventions toimprove clinical practice s to promote sleep in intensive care patients .Trial registration Australian New Zeal and clinical trial registry(http://www.anzctr.org.au/ ) : ACTRN12610000688088 Objective To assess survival , morbidity ( physical and psychological ) , quality of life ( QOL ) , and employment status of intensive care survivors up to 12 months after discharge from the intensive care unit ( ICU ) . Design Prospect i ve study . Setting University hospital adult ICU . Patients Between August 1 , 1995 , and July 31 , 1996 , 370 patients were admitted . Of these patients , 29 % died in the ICU . Three months after discharge from the ICU , 227 patients were alive , and 143 agreed to participate .  Cumulative mortality was calculated using the original complete cohort . Measurements and Main Results Demographic data , severity of acute illness ( Acute Physiology and Chronic Health Evaluation [ APACHE ] II ) , admitting specialty , primary diagnosis , and length of stay were recorded . Physical and ICU-related psychological morbidity ( Hospital Anxiety and Depression scale score ) were recorded . Health-related QOL was assessed using the Short-Form 36 . All the question naires were completed in the clinic at 3 months . Assessment of physical morbidity and employment status at 6 and 12 months were conducted by telephone . The cumulative mortality was 39 % at 3 months , 41 % at 6 months , and 43 % at 12 months . Deaths after 3 months occurred in the group who refused follow-up . The median age for the follow-up group was 51 yrs ; the gender split was 68 women and 75 men ; the mean admission APACHE II score was 18.79 ( sd 6.15 ) ; and the median length of ICU stay was 3.8 days . At 3 months , ∼80 % of all patients interviewed were satisfied with their QOL . Older men ( > 65 yrs ) and younger women ( < 65 yrs ) demonstrated significantly better health with respect to some subdomains of the Short-Form 36 compared with their counterparts . The prevalence of psychological distress ( Hospital Anxiety and Depression scale score , ≥8 ) was low : 11.9 % had heightened anxiety , and 9.8 % were depressed . There were high levels of fatigue , poor concentration , and sleep disturbance ; the latter was more marked in women ( p = .022 ) . Improvement in all three symptoms occurred during the next 9 months . Significantly more women reported loss of hair ( p < .0001 ) . Men were slower to return to employment ; 75 % of women had returned by 6 months compared with only 65 % of men at 1 yr . Conclusion Assessment of outcome after ICU stay must include QOL measurements . Three months after discharge , there is a low incidence of ICU-related psychological or psychiatric illness and the majority of patients are satisfied . Differences in the incidence and nature of morbidity exist between the genders Background Delirium is an acute state of brain dysfunction characterised by fluctuating inattention and cognitive disturbances , usually due to illness . It occurs commonly in the intensive care unit ( ICU ) , and it is associated with greater morbidity and mortality . It is likely that disturbances of sleep and of the day-night cycle play a significant role . Melatonin is a naturally occurring , safe and cheap hormone that can be administered to improve sleep . The main aim of this trial will be to determine whether prophylactic melatonin administered to critically ill adults , when compared with placebo , decreases the rate of delirium . Methods This trial will be a multi-centre , r and omised , placebo-controlled study conducted in closed ICUs in Australia . Our aim is to enrol 850 adult patients with an expected ICU length of stay ( LOS ) of 72 h or more . Eligible patients for whom there is consent will be r and omised to receive melatonin 4 mg enterally or placebo in a 1:1 ratio according to a computer-generated r and omisation list , stratified by site . The study drug will be indistinguishable from placebo . Patients , doctors , nurses , investigators and statisticians will be blinded . Melatonin or placebo will be administered once per day at 21:00 until ICU discharge or 14 days after enrolment , whichever occurs first . Trained staff will assess patients twice daily to determine the presence or absence of delirium using the Confusion Assessment Method for the ICU score . Data will also be collected on demographics , the overall prevalence of delirium , duration and severity of delirium , sleep quality , participation in physiotherapy sessions , ICU and hospital LOS , morbidity and mortality , and healthcare costs .  A subgroup of 100 patients will undergo polysomnographic testing to further evaluate the quality of sleep . Discussion Delirium is a significant issue in ICU because of its frequency and associated poorer outcomes . This trial will be the largest evaluation of melatonin as a prophylactic agent to prevent delirium in the critically ill population . This study will also provide one of the largest series of polysomnographic testing done in ICU.Trial registration Australian New Zeal and Clinical Trial Registry ( ANZCTR ) number : ACTRN12616000436471 . Registered on 20 December 2015 The  Bispectral Index ( BIS )  is a system used to measure sedation levels . Some investigators recently analyzed changes in the BIS during natural sleep in adults and found that the BIS diminished considerably as sleep became deeper . No such studies have been undertaken to investigate changes in the BIS in sleeping children . The aim of this work was to assess the trend of the BIS in the various stages of sleep in a group of children , performing a descriptive analysis on a limited number of cases . We evaluated 15 children with negative clinical findings and a normal electroencephalogram ( EEG ) as part of their follow-up for prior episodes of epilepsy , recording the BIS and  EEG  in a waking state , in the various stages of sleep and on reawaking . For each stage , the mean value , the st and ard deviation , and the range of BIS values were calculated . The results showed that the BIS decreased progressively as sleep became deeper . The correlation between the stage of sleep and the BIS was significant . On reawaking , a slow increase was apparent in the BIS In this study , the aim was to test the biochemical effects of melatonin supplementation in Intensive Care Unit ( ICU ) patients , since their blood levels are decreased . Sixty-four patients were enrolled in the study . From the evening of the 3rd ICU day , patients were r and omized to receive oral melatonin ( 3 mg , group M ) or placebo ( group P ) twice daily , at 20:00 and 24:00 , until discharged . Blood was taken ( at 00:00 and 14:00 ) , on the 3rd ICU day to assess basal nocturnal melatonin values , and then during the treatment period on the 4th and 8th ICU days . Melatonin , total antioxidant capacity , and oxidative stress were evaluated in serum . Melatonin circadian rhythm before treatment was similar in the two groups , with a partial preservation of the cycle . Four hours from the 1st administration ( 4th ICU day , 00:00 ) , melatonin levels increased to 2514 ( 982.3 ; 7148 ) pg·mL−1 in group M vs. 20.3 ( 14.7 ; 62.3 ) pg·mL−1 in group P ( p < 0.001 ) . After five treatment days ( 8th ICU day ) , melatonin absorption showed a repetitive trend in group M , while in group P nocturnal secretion ( 00:00 ) was impaired : 20 ( 11.5 ; 34.5 ) pg·mL−1 vs. 33.8 ( 25.0 ; 62.2 ) on the 3rd day ( p = 0.029 ) . Immediately from the beginning of treatment , the total antioxidant capacity was significantly higher in melatonin treated subjects at 00:00 ; a significant correlation was found between total antioxidant capacity and blood melatonin values ( ρ = 0.328 ; p < 0.001 ) . The proposed enteral administration protocol was adequate , even in the early phase , to enhance melatonin blood levels and to protect the patients from oxidative stress . The antioxidant effect of melatonin could play a meaningful role in the care and well-being of these patients Background Sleep deprivation is common in critically ill patients in intensive care units ( ICU ) . It can result in delirium , difficulty weaning , repeated nosocomial infections , prolonged ICU length of stay and increased ICU mortality .  Melatonin , a physiological sleep regulator , is well known to benefit sleep quality in certain people , but evidence for the effectiveness in ICU sleep disturbance is limited . Methods / Design This study has a prospect i ve , r and omized , double-blind , controlled , parallel-group design . Eligible patients are r and omly assigned to one of the two treatment study groups , labelled the ‘ melatonin group ’ or the ‘ placebo group ’ . A dose of 3 mg of oral melatonin or placebo is administered at 9:00 pm on four consecutive days . Earplugs and eye masks are made available to every participant . We plan to enrol 198 patients . The primary outcome is the objective sleep quality measured by the 24-hour polysomnography . The secondary outcomes are the subjective sleep quality assessed by the Richards Campbell Sleep Question naire , the anxiety level evaluated by the Visual Analogue Scale-Anxiety , the number of delirium-free days in 8 and 28 days , the number of ventilation-free days in 28 days , the number of antibiotic-free days , ICU length of stay , the overall ICU mortality in 28 days and the incidence and severity of the side effects of melatonin  in ICU patients . Additionally , the body stress levels , oxidative stress levels and inflammation levels are obtained via measuring the plasma melatonin , cortisone , norepinephrine , malonaldehyde(MDA ) , superoxide dismutase(SOD ) , interleukin-6 ( IL-6 ) and interleukin-8 (IL-8)concentrations . Discussion The proposed study will be the first r and omized controlled study to use the polysomnography , which is the gold st and ard of assessing sleep quality , to evaluate the effect of melatonin on the sleep quality and circadian rhythms of ICU patients . The results may recommend a new treatment for ICU patients with sleep deprivation that is safe , effective and easily implementable in daily practice .Trial registration This study was registered with Clinical Trials ( NCT ; registration number : ChiCTR-TRC-14004319 ) on 4 March 2013 BACKGROUND AND AIM Patients in the intensive care unit often suffer from lack of sleep at night . We hypothesised that nocturnal melatonin may increase observed nocturnal sleep in tracheostomised patients . DESIGN Double-blind , r and omised , placebo-controlled pilot study . SETTING ICU of a tertiary hospital . PARTICIPANTS Thirty-two ICU patients with tracheostomy who were not receiving continuous sedation . METHODS We administered either oral melatonin ( 3 mg ) or placebo at 20:00 . We collected pre- and post-dosage blood sample s on Days 1 and 3 to confirm drug delivery . Primary outcome measure was number of hours of observed sleep at night , assessed by the 
    Output:
    
We found insufficient evidence to determine whether administration of melatonin would improve the quality and quantity of sleep in ICU patients .