***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: The effect of a single , oral bedtime dose of the benzodiazepine hypnotics flunitrazepam ( FR ; 2 mg ) , flurazepam ( FR ; 30 mg ) , and triazolam ( TR ; 0.5 mg ) on the sleep stages and the sleep EEG was investigated in eight healthy , young subjects . In comparison to the placebo night , all drugs reduced the percentage of stage 1 and REM sleep , increased stage 2 , and decreased the number of stage shifts . For FN and FR , some of these changes persisted in the postdrug night . All-night spectral analysis of the EEG showed a reduction of low-frequency activity ( 0.25 - 10.0 Hz ) in stages 2 , 3 + 4 and REM sleep , changes that persisted for all three drugs in the post-drug night . In the drug nights , activity in the spindle frequency range ( 11 - 14 Hz ) was enhanced particularly in stage 2 and 3 + 4 , activity in the high frequency range ( 17 - 25 Hz ) particularly in REM sleep and stage 1 . In the first third of the drug night , the depression of low-frequency activity in stage 2 was either absent ( FR ) or less prominent ( FN , TR ) than in the following part of the night . The results demonstrate that benzodiazepine hypnotics induce specific changes in the EEG spectra which reflect the immediate and residual drug effects more sensitively than conventional sleep scores We have evaluated the perioperative effects of melatonin with those of midazolam in 75 women in a prospect i ve , r and omized , double-blind , placebo-controlled study . Patients were given sublingual midazolam 15 mg , melatonin 5 mg or placebo , approximately 100 min before a st and ard anaesthetic . Sedation , anxiety and orientation were quantified before , and 10 , 30 , 60 and 90 min after premedication , and 15 , 30 , 60 and 90 min after admission to the recovery room . Psychomotor performance was evaluated at these times also , using the digit-symbol substitution test ( DSST ) and the Trieger dot test ( TDT ) . Patients who received premedication with either midazolam or melatonin had a significant decrease in anxiety levels and increase in levels of sedation before operation compared with controls . Midazolam produced the highest scores for sedation at 30 and 60 min after administration and significant psychomotor impairment in the preoperative period compared with melatonin or placebo . After operation , patients who received midazolam or melatonin premedication had increased levels of sedation at 30 min and impairment in performance on the DSST at 15 , 30 and 90 min compared with controls . There were no significant differences between the three groups for anxiety levels or TDT performance after operation . Amnesia was notable only in the midazolam group for one preoperative event ( entry into the operating room ) . Patient satisfaction was noted in the midazolam and melatonin groups only . We have demonstrated that melatonin can be used effectively for premedication of adult patients Postoperative pain can have a significant effect on patient recovery . An underst and ing of patient attitudes and concerns about postoperative pain is important for identifying ways health care professionals can improve postoperative care . To assess patients ’ postoperative pain experience and the status of acute pain management , we conducted a national study by using telephone question naires . A r and om sample of 250 adults who had undergone surgical procedures recently in the United States was obtained from National Family Opinion . Patients were asked about the  severity of postsurgical pain , treatment , satisfaction with pain medication , patient education , and perceptions about postoperative pain and pain medications .  Approximately 80 % of patients experienced acute pain after surgery . Of these patients , 86 % had moderate , severe , or extreme pain , with more patients experiencing pain after discharge than before discharge . Experiencing postoperative pain was the most common concern ( 59 % ) of patients . Almost 25 % of patients who received pain medications experienced adverse effects ; however , almost 90 % of them were satisfied with their pain medications . Approximately two thirds of patients reported that a health care professional talked with them about their pain . Despite an increased focus on pain management programs and the development of new st and ards for pain management , many patients continue to experience intense pain after surgery . Additional efforts are required to improve patients ’ postoperative pain experience The objective of the present study was to assess the toxicology of melatonin ( 10 mg ) , administered for 28 days to 40 volunteers r and omly assigned to groups receiving either melatonin ( N = 30 ) or placebo  ( N = 10 ) in a double-blind fashion . The following measurements were performed : polysomnography ( PSG ) , laboratory examinations , including complete blood count , urinalysis , sodium , potassium and calcium levels , total protein levels , albumin , blood glucose , triglycerides , total cholesterol , high-density lipoprotein ( HDL ) , low-density lipoprotein ( LDL ) , and very low-density lipoprotein ( VLDL ) , urea , creatinine , uric acid , glutamic-oxalacetic transaminase ( GOT ) , glutamic-pyruvate transaminase ( GPT ) , bilirubin , alkaline phosphatase , gama-glutamic transaminase ( GGT ) , T3 , T4 , TSH , LH/FSH , cortisol , and melatonin serum concentrations . In addition , the Epworth Somnolence Scale ( ESS ) and a sleep diary ( SD ) were also applied to the volunteers 1 wk before each PSG . In addition , the volunteers were asked about possible side effects ( SE ) that appeared during the treatment . The study was carried out according to the following timetable : Visit 0 , filling out the term of consent and inclusion criteria ; Visit 1 , PSG , laboratory examinations , ESS , SD ,  melatonin serum concentrations ; Visit 2 , SD ,  melatonin serum concentrations , SE ; Visit 3 ,  melatonin serum concentrations , PSG , ESS , SE ; Visit 4 , laboratory examinations , SE , melatonin serum concentrations , SD ; and Visit 5 , PSG , ESS , SE . Analysis of the PSG showed a statistically significant reduction of stage 1 of sleep in the melatonin group . No other differences between the placebo and melatonin groups were obtained . In the present study we did not observe , according to the parameters analyzed , any toxicological effect that might compromise the use of melatonin at a dose of 10 mg for the period of time utilized in this study BACKGROUND : The effect of melatonin on the intraoperative requirements for IV anesthetics has not been documented . We studied the effect of melatonin premedication on the propofol and thiopental dose – response curves for abolition of responses to verbal comm and s and eyelash stimulation . METHODS : This prospect i ve , r and omized , double-blind study included 200 adults with ASA physical status I. Patients received either 0.2 mg/kg melatonin or a placebo orally for premedication ( n = 100 per group ) . Approximately 50 min later , subgroups of 10 melatonin and 10 placebo patients were administered various doses of propofol ( 0.5 , 1.0 , 1.5 , 2.0 , or 2.4 mg/kg ) or thiopental ( 2.0 , 3.0 , 4.0 , 5.0 , or 6.0 mg/kg ) for anesthetic induction . The ability of each patient to respond to the comm and , “ open your eyes , ” and the disappearance of the eyelash reflex were assessed 60 s after the end of the injection of propofol or thiopental . Dose – response curves were determined by probit analysis . RESULTS : Melatonin premedication decreased thiopental ED50 values for loss of response to verbal comm and and eyelash reflex from 3.4 mg/kg ( 95%confidence interval , 3.2–3.5 mg/kg ) and 3.7 mg/kg ( 3.5–3.9 mg/kg ) to 2.7 mg/kg ( 2.6–2.9 mg/kg ) and 2.6 mg/kg ( 2.5–2.7 mg/kg ) , respectively ( P < 0.05 ) . Corresponding propofol ED50 values decreased from 1.5 mg/kg ( 1.4–1.6 mg/kg ) and 1.6 mg/kg ( 1.5–1.7 mg/kg ) to 0.9 mg/kg ( 0.8–0.96 mg/kg ) and 0.9 mg/kg ( 0.8–0.95 mg/kg ) , respectively ( P < 0.05 ) . CONCLUSIONS : Melatonin premedication significantly decreased the doses of both propofol and thiopental required to induce anesthesia BACKGROUND Iletrospective studies fail to identify predictors of postoperative nausea and vomiting ( PONV ) . The authors prospect ively studied 17,638 consecutive out patients who had surgery to identify predictors . METHODS Data on medical conditions , anesthesia , surgery , and PONV were collected in the post-anesthesia care unit , in the ambulatory surgical unit , and in telephone interviews conducted 24 h after surgery . Multiple logistic regression with backward stepwise elimination was used to develop a predictive model An independent set of patients was used to vali date the model RESULTS Age ( younger or older ) , sex ( female or male ) , smoking status ( nonsmokers or smokers ) , previous PONV , type of anesthesia ( general or other ) , duration of anesthesia ( longer or shorter ) , and type of surgery ( plastic , orthopedic shoulder , or other ) were independent predictors of PONV . A 10-yr increase in age decreased the likelihood of PONV by 13 % . The risk for men was one third that for women . A 30-min increase in the duration of anesthesia increased the likelihood of PONV by 59 % . General anesthesia increased the likelihood of PONV 11 times compared with other types of anesthesia . Patients with plastic and orthopedic shoulder surgery had a sixfold increase in the risk for PONV . The model predicted PONV accurately and yielded an area under the receiver operating characteristic curve of 0.785+/-0.011 using an independent validation set . CONCLUSIONS A vali date d mathematical model is provided to calculate the risk of PONV in out patients having surgery . Knowing the factors that predict PONV will help anesthesiologists determine which patients will need antiemetic therapy Melatonin has been reported to reduce preoperative anxiety . We performed this study to compare preoperative anxiety in elderly patients receiving melatonin ( M ) or placebo ( P ) .  Anxiety was measured in patients aged > 65 yr by a numerical rating scale ( range , 0–10 ) . Each patient was r and omized to receive M 10 mg or P orally : 71 patients were in group P and 67 in group M. The median ( quartiles ) anxiety level was 5 ( 2–8 ) before and 3 ( 1–7 ) 90 min after premedication in group M and 5 ( 3–6 ) and 3 ( 1–5 ) in group P , respectively . M and P reduce anxiety in elderly patients to a similar degree Midazolam ( 15 mg p.o . ) was compared with placebo and oxazepam ( 15 mg ) in 12 healthy volunteers and in seven patients suffering from sleep disorders in a single-blind cross-over study . Each treatment period lasted for seven days . The last two nights were spent in a sleep laboratory to evaluate the efficacy of the three compounds . The drugs were given to the patients every day and to the volunteers only on the recorded nights immediately before going to bed . The subjects rated their quality of sleep every morning after administration . Midazolam shortened ( P = 0.025 ) the sleep latency to first stage 2 ( t2 = 29 min ) compared with placebo ( t2 = 58.7 ) min and oxazepam ( t2 = 55.4 min ) in the group of patients ; in the group of volunteers t2 was shortened ( P = 0.05 ) only by midazolam ( t2 = 17.2 min ) compared with placebo ( t2 = 24.6 min ) . REM suppression was not found in the group of patients , while sleep stages 3 + 4 were slightly reduced . However , a suppression of REM by midazolam ( P = 0.025 ) and oxazepam ( P = 0.01 ) was observed in the volunteers compared with placebo . The effects of midazolam seemed to be related to its pharmacokinetics . The drug increased the amount of stage 3 + 4 ( P = 0.01 ) and suppressed REM ( P = 0.005 ) compared with oxazepam and placebo , only during the first 3 h , when it was measurable in plasma . Midazolam was rated by the patients more favourably than oxazepam ( P = 0.025 ) and placebo ( P = 0.05 ) . The volunteers noted no difference amongst the three treatments , but reported hangover effects after oxazepam BACKGROUND : Melatonin has anxiolytic and potential analgesic effects . In this study , we assessed the effects of melatonin premedication on pain , anxiety , intraocular pressure ( IOP ) , and operative conditions during cataract surgery under topical analgesia . METHODS : Forty patients undergoing cataract surgery under topical anesthesia were r and omly assigned 
    Output:
    
Thus , melatonin premedication is effective in ameliorating preoperative anxiety in adults , but its analgesic effects remain controversial in the perioperative period .