title: Sound level intensity severely disrupts sleep in ventilated ICU patients throughout a 24-h period: a preliminary 24-h study of sleep stages and associated sound levels.
abstract: BACKGROUND
  It is well recognized that sleep is severely disturbed in patients in intensive care units (ICU) and that this can compromise their rehabilitation potential. However, it is still difficult to objectively assess sleep quantity and quality and the determinants of sleep disturbance remain unclear. The aim of this study was therefore to evaluate carefully the impact of ICU sound intensity levels and their sources on ICU patients' sleep over a 24-h period.
  
  
  METHODS
  Sleep and sound levels were recorded in 11 ICU intubated patients who met the criteria. Sleep was recorded using a miniaturized multi-channel ambulatory recording device. Sound intensity levels and their sources were recorded with the Nox-T3 monitor. A 30-s epoch-by-epoch analysis of sleep stages and sound data was carried out. Multinomial and binomial logistic regressions were used to associate sleep stages, wakefulness and sleep-wake transitions with sound levels and their sources.
  
  
  RESULTS
  The subjects slept a median of 502.2 [283.2-718.9] min per 24 h; 356.9 [188.6-590.9] min at night (22.00-08.00) and 168.5 [142.5-243.3] during daytime (8 am-10 pm). Median sound intensity level reached 70.2 [65.1-80.3] dBC at night. Sound thresholds leading to disturbed sleep were 63 dBC during the day and 59 dBC during the night. With levels above 77 dBC, the incidence of arousals (OR 3.9, 95% CI 3.0-5.0) and sleep-to-wake transitions (OR 7.6, 95% CI 4.1-14) increased. The most disturbing noises sources were monitor alarms (OR 4.5, 95% CI 3.5-5.6) and ventilator alarms (OR 4.2, 95% CI 2.9-6.1).
  
  
  CONCLUSIONS
  We have shown, in a small group of 11 non-severe ICU patients, that sound level intensity, a major disturbance factor of sleep continuity, should be strictly controlled on a 24-h profile.
authors.affiliation: Centre du Sommeil et de la Vigilance, Hôtel-Dieu de Paris, APHP, Université Paris Descartes, Paris, France.|EA 7330 VIFASOM Sommeil-Vigilance-Fatigue et Santé Publique, Hôtel Dieu de Paris, Université Paris Descartes, 1 place du Parvis Notre Dame, 75004, Paris, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Elbaz
authors.affiliation: Centre du Sommeil et de la Vigilance, Hôtel-Dieu de Paris, APHP, Université Paris Descartes, Paris, France. damien.leger@aphp.fr.|EA 7330 VIFASOM Sommeil-Vigilance-Fatigue et Santé Publique, Hôtel Dieu de Paris, Université Paris Descartes, 1 place du Parvis Notre Dame, 75004, Paris, France. damien.leger@aphp.fr.
authors.forename: Damien
authors.initials: D
authors.lastname: Léger
authors.affiliation: EA 7330 VIFASOM Sommeil-Vigilance-Fatigue et Santé Publique, Hôtel Dieu de Paris, Université Paris Descartes, 1 place du Parvis Notre Dame, 75004, Paris, France.|Unité Fatigue et Vigilance, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Sauvet
authors.affiliation: Service de Réanimation médicale, Hôpital Cochin, APHP, Université Paris Descartes, Paris, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Champigneulle
authors.affiliation: Centre du Sommeil et de la Vigilance, Hôtel-Dieu de Paris, APHP, Université Paris Descartes, Paris, France.|EA 7330 VIFASOM Sommeil-Vigilance-Fatigue et Santé Publique, Hôtel Dieu de Paris, Université Paris Descartes, 1 place du Parvis Notre Dame, 75004, Paris, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Rio
authors.affiliation: Centre du Sommeil et de la Vigilance, Hôtel-Dieu de Paris, APHP, Université Paris Descartes, Paris, France.|Cognitive Neuroimaging Unit, U992, INSERM, Gif/Yvette, France.|NeuroSpin Center Institute of Bioimaging, Commissariat à l'Energie Atomique (CEA), Gif/Yvette, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Strauss
authors.affiliation: EA 7330 VIFASOM Sommeil-Vigilance-Fatigue et Santé Publique, Hôtel Dieu de Paris, Université Paris Descartes, 1 place du Parvis Notre Dame, 75004, Paris, France.|Unité Fatigue et Vigilance, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France.
authors.forename: Mounir
authors.initials: M
authors.lastname: Chennaoui
authors.affiliation: Stanford University Sleep Disorders Clinic, Palo Alto, CA, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Guilleminault
authors.affiliation: Service de Réanimation médicale, Hôpital Cochin, APHP, Université Paris Descartes, Paris, France.
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Mira
keywords: Intensive care unit; Monitoring; Sleep; Sound intensity; Weaning