Sleep quality in Intensive Care Unit

Abstract

Introduction Critically-ill patients who require hospitalization are admitted to the Intensive Care Unit (ICU). Although sleep quality could be an important factor in the recovery of these patients, the ICU environment is not conducive to sleep (1). Since few studies have evaluated this matter, the objective of this study was to assess the quantity and quality of sleep in ICU patients. Materials and methods Polysomnography for consecutive hours (from 10 p.m. to 8 a.m) were performed in conscious adult patients connected to artificial ventilation by an orotracheal tube or tracheostomy. All patients were not receiving sedation from 24 h prior to the study. Light and noise levels were measured. Results are presented as medians and percentiles (25th and 75th). Results To date, 13 polysomnography studies have been performed. Three studies were interrupted due to clinical deterioration of the patient. Of the remaining 10 patients, 4 tracings (40%) could not be scored by standard AASM criteria because characteristic graphoelements to define sleep staging were absent. In the other 6 patients, total sleep time was 182 min (130–228) with a sleep efficiency of 31% (22–38). Sleep time was as follows: N1, 56 min (39–75); N2, 112 min (68–132); and N3, 6 min (1–34). Only two patients presented REM sleep. During the 10-hour study, median light and noise levels were 19 lux (17–22) and 49 decibels (48–50), respectively. Conclusion In a non-negligible percentage of patients admitted to an ICU, polysomnography data did not fulfill the standard criteria for scoring. In those patients where standard criteria could be applied, quantity and quality of sleep were highly abnormal, with short N3 and REM sleep stages. The present results fall in the line with previous studies which suggest the need of a new classification for sleep analysis in critically ill patients (2, 3). Moreover, further studies are necessary in order to evaluate the consequences of these sleep findings on patient outcomes. Acknowledgements Drouot X, Cabello B, d’Ortho MP, Brochard L. Sleep in the intensive care unit. Sleep Med Rev. 2008 Oct;12(5):391–403. Drouot X, Roche-Campo F, Thille AW, Cabello B, Galia F, Margarit L, d’Ortho MP, Brochard L. A new classification for sleep analysis in critically ill patients. Sleep Med. 2012 Jan;13(1):7–14. Watson PL, Pandharipande P, Gehlbach B et al., Atypical Sleep in Ventilated Patients: Empirical Electroencephalography Findings and the Path Toward Revised ICU Sleep Scoring Criteria. Critical Care Medicine 2013 August; 14(8):1–1.