title: The impacts of nitrous oxide gas on sleep quality during alcohol withdrawal.
abstract: BACKGROUND
  Poor quality of sleep among alcoholics and persons undergoing alcohol withdrawal has been described as a possible cause of alcohol relapse. It has been suggested earlier that nitrous oxide gas has a significant effect on the signs of alcohol withdrawal syndrome (AWS) and thus might be expected to reduce sleep disturbance during withdrawal. The aim of the present study was to investigate sleep quality during alcohol withdrawal, to evaluate the correlation between sleep quality and the severity of AWS and alcohol craving, and to determine if nitrous oxide treatment does counteract withdrawal's effects on the quality of sleep. Voluntary patients (n = 105) admitted to the A-Clinic detoxification center with AWS were included in the study. The AWS patients were randomly assigned to one of the following 45-minute gas treatments: (1) nitrous oxide/oxygen; (2) normal air/O2; and (3) medical (normal) air. The study was single-blind by design. Sleep quality was assessed after these treatments during the inpatient period; sleep time, sleep efficiency and the fragmentation of sleep were recorded by wrist-worn actigraphs. Severity of AWS was evaluated by the Clinical Institute Withdrawal Assessment of Alcohol Scale (CIWA-Ar) and that of alcohol dependence and craving by the Obsessive Compulsive Drinking Scale [OCDS] and the Severity of Alcohol Dependence Data (SADD) questionnaire.
  
  
  RESULTS
  The fragmentation index and the time awake while in bed were both much above the reference values for the Finnish population. These values reflect the restless and disturbed night sleep of the subjects. The only statistically significant effects between the treatment groups were found in the correlations of CIWA-Ar (severity of AWS) scores, OCDS-scores (alcohol craving) and coffee consumption, all of which were positively associated with movement time and negatively with total sleep time and sleep efficiency. The sleep quality of patients treated with nitrous oxide gas did not differ from the sleep quality of those treated with normal air.
  
  
  CONCLUSIONS
  The severity of AWS and coffee consumption had the most significant negative impact on sleep quality. According to our results, nitrous oxide gas does not differ from placebo in its effect on sleep quality during alcohol withdrawal.
authors.affiliation: Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland. tuuli.lahti@thl.fi.
authors.forename: Tuuli
authors.initials: T
authors.lastname: Lahti
authors.forename: Taina
authors.initials: T
authors.lastname: Methuen
authors.forename: Risto
authors.initials: R
authors.lastname: Roine
authors.forename: Kaija-Liisa
authors.initials: KL
authors.lastname: Seppä
authors.forename: David
authors.initials: D
authors.lastname: Sinclair
authors.forename: Markku
authors.initials: M
authors.lastname: Partinen
authors.forename: Hannu
authors.initials: H
authors.lastname: Alho