title: Ambient light levels and critical care outcomes.
abstract: OBJECTIVE
  Guidelines for the construction of critical care units require windows in room design to ensure a contribution of natural sunlight to ambient lighting. However, few studies have been published with evidence assessing this recommendation. We investigated the association of ambient light levels with clinical outcomes and sedative/analgesic/neuroleptic use in a medical intensive care unit (MICU).
  
  
  METHODS
  This is a retrospective, observational study at a tertiary care facility with a 29-bed MICU. First/single MICU admissions between April 19, 2006, and June 30, 2009 (N = 3577), were analyzed with respect to clinical outcomes and sedation use according to MICU room orientation and corresponding light levels.
  
  
  RESULTS
  Light levels were low but varied among the 4 room orientations. There were no significant differences in MICU mortality (north, 14.0%; east, 13.5%; west, 16.2%; south, 15.6%; P = .451), hospital mortality (20.8%, 20.9%, 22.2%, 22.3%; P = .796), 28-day intensive care unit-free days (17.6 ± 10.2, 18.0 ± 10.1, 17.7 ± 10.5, 17.2 ± 10.4; P = .555), 28-day ventilator-free days (16.3 ± 11.1, 16.5 ± 11.1, 15.5 ± 11.5, 15.4 ± 11.4; P = .273). No clinically significant differences in intravenous sedative/analgesic use occurred across room orientations.
  
  
  CONCLUSIONS
  Despite differing ambient light, room orientation was not associated with critical care outcomes or differences in sedative/analgesic/neuroleptic use. Current guidelines positing that windows alone are necessary or sufficient for MICU room light management may require further investigation and consideration.
authors: Division of Pulmonary and Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA. Avercele@medicine.umaryland.edu
authors: Avelino C
authors: AC
authors: Verceles
authors: Xinggang
authors: X
authors: Liu
authors: Michael L
authors: ML
authors: Terrin
authors: Steven M
authors: SM
authors: Scharf
authors: Carl
authors: C
authors: Shanholtz
authors: Anthony
authors: A
authors: Harris
authors: Babajide
authors: B
authors: Ayanleye
authors: Ann
authors: A
authors: Parker
authors: Giora
authors: G
authors: Netzer
mesh_terms: D000700:Analgesics; D014150:Antipsychotic Agents; D003422:Critical Care; D004363:Drug Utilization; D005260:Female; D006749:Hospital Design and Construction; D017052:Hospital Mortality; D006801:Humans; D006993:Hypnotics and Sedatives; D007362:Intensive Care Units; D007902:Length of Stay; D008029:Lighting; D016015:Logistic Models; D008297:Male; D008396:Maryland; D008875:Middle Aged; D010362:Patients' Rooms; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012189:Retrospective Studies; D013472:Sunlight; D016896:Treatment Outcome
chemical_list: D000700:Analgesics; D014150:Antipsychotic Agents; D006993:Hypnotics and Sedatives