Emily P Fan1, Sabra M Abbott1, Kathryn J Reid1, Phyllis C Zee1, Matthew B Maas2. 1. Department of Neurology and the Center for Circadian and Sleep Medicine, Northwestern University, Chicago, IL, United States. 2. Department of Neurology and the Center for Circadian and Sleep Medicine, Northwestern University, Chicago, IL, United States. Electronic address: mbmaas@northwestern.edu.
Abstract
PURPOSE: We sought to characterize ambient light exposure in the intensive care unit (ICU) environment to identify patterns of light exposure relevant to circadian regulation. METHODS: A light monitor was affixed to subjects' bed at eye level in a modern intensive care unit and continuously recorded illuminescence for at least 24h per subject. Blood was sampled hourly and measured for plasma melatonin. Subjects underwent hourly vital sign and bedside neurologic assessments. Care protocols and the ICU environment were not modified for the study. RESULTS: A total of 67,324 30-second epochs of light data were collected from 17 subjects. Light intensity peaked in the late morning, median 64.1 (interquartile range 19.7-138.7) lux. The 75th percentile of light intensity exceeded 100lx only between 9AM and noon, and never exceeded 150lx. There was no correlation between melatonin amplitude and daytime, nighttime or total light exposure (Spearman's correlation coefficients all <0.2 and p>0.5). CONCLUSIONS: Patients' environmental light exposure in the intensive care unit is consistently low and follows a diurnal pattern. No effect of nighttime light exposure was observed on melatonin secretion. Inadequate daytime light exposure in the ICU may contribute to abnormal circadian rhythms.
PURPOSE: We sought to characterize ambient light exposure in the intensive care unit (ICU) environment to identify patterns of light exposure relevant to circadian regulation. METHODS: A light monitor was affixed to subjects' bed at eye level in a modern intensive care unit and continuously recorded illuminescence for at least 24h per subject. Blood was sampled hourly and measured for plasma melatonin. Subjects underwent hourly vital sign and bedside neurologic assessments. Care protocols and the ICU environment were not modified for the study. RESULTS: A total of 67,324 30-second epochs of light data were collected from 17 subjects. Light intensity peaked in the late morning, median 64.1 (interquartile range 19.7-138.7) lux. The 75th percentile of light intensity exceeded 100lx only between 9AM and noon, and never exceeded 150lx. There was no correlation between melatonin amplitude and daytime, nighttime or total light exposure (Spearman's correlation coefficients all <0.2 and p>0.5). CONCLUSIONS:Patients' environmental light exposure in the intensive care unit is consistently low and follows a diurnal pattern. No effect of nighttime light exposure was observed on melatonin secretion. Inadequate daytime light exposure in the ICU may contribute to abnormal circadian rhythms.
Authors: Ming-Cheng Chan; Peter M Spieth; Kieran Quinn; Matteo Parotto; Haibo Zhang; Arthur S Slutsky Journal: Crit Care Med Date: 2012-01 Impact factor: 7.598
Authors: Margaret A Pisani; Randall S Friese; Brian K Gehlbach; Richard J Schwab; Gerald L Weinhouse; Shirley F Jones Journal: Am J Respir Crit Care Med Date: 2015-04-01 Impact factor: 21.405
Authors: Robert T Dauchy; Melissa A Wren-Dail; Aaron E Hoffman; John P Hanifin; Benjamin Warfield; George C Brainard; Steven M Hill; Victoria P Belancio; Erin M Dauchy; David E Blask Journal: Comp Med Date: 2016 Impact factor: 0.982
Authors: Christina M Dennis; Robert Lee; Elizabeth Knowles Woodard; Jeffery J Szalaj; Catrice A Walker Journal: J Neurosci Nurs Date: 2010-08 Impact factor: 1.230
Authors: Matthew B Maas; Neil F Rosenberg; Adam R Kosteva; Rebecca M Bauer; James C Guth; Eric M Liotta; Shyam Prabhakaran; Andrew M Naidech Journal: Neurology Date: 2013-06-05 Impact factor: 9.910
Authors: Matthew B Maas; Bryan D Lizza; Sabra M Abbott; Eric M Liotta; Maged Gendy; John Eed; Andrew M Naidech; Kathryn J Reid; Phyllis C Zee Journal: Crit Care Med Date: 2020-06 Impact factor: 7.598
Authors: Matthew B Maas; Bryan D Lizza; Minjee Kim; Sabra M Abbott; Maged Gendy; Kathryn J Reid; Phyllis C Zee Journal: Crit Care Med Date: 2020-06 Impact factor: 7.598
Authors: Katarzyna Kotfis; Irene van Diem-Zaal; Shawniqua Williams Roberson; Mark van den Boogaard; Yahya Shehabi; E Wesley Ely; Marek Sietnicki Journal: Crit Care Date: 2022-07-05 Impact factor: 19.334
Authors: Jennifer J Dorsch; Jennifer L Martin; Atul Malhotra; Robert L Owens; Biren B Kamdar Journal: Semin Respir Crit Care Med Date: 2019-12-11 Impact factor: 3.119