Effects of earplugs and eye masks on nocturnal sleep, melatonin and cortisol in a simulated intensive care unit environment

Table 1 Sleep architecture and study condition for subjects (n = 14)

Variable	Baseline	NL	NLEE	ANOVA P	Contrast P
Time in bed (min)	539.7 ± 1.7	536.0 ± 15.9	536.0 ± 13.7	0.48	----
Total sleep time (min)	456.0 ± 39.9	454.7 ± 41.8	475.1 ± 33.4	0.20	0.06
Sleep efficiency Index	0.8 ± 0.1	0.8 ± 0.1	0.9 ± 0.0	0.12	0.09
REM%	10.9 ± 5.9	9.3 ± 4.3	12.9 ± 4.3	0.03	0.005
S1%	21.8 ± 10.4	23.4 ± 11.9	22.5 ± 9.7	0.80	0.67
S2%	43.9 ± 10.2	45.6 ± 10.3	43.5 ± 6.9	0.57	0.20
S3%	14.0 ± 6.8	11.6 ± 6.5	13.9 ± 5.6	0.30	0.11
Sleep onset latency (min)	22.3 ± 13.1	23.4 ± 16.6	15.4 ± 16.4	0.46	0.055
REM latency (min)	121.8 ± 47.0	146.9 ± 56.2	105.7 ± 47.0	0.02	0.013
Arousals index	13.0 ± 4.7	15.1 ± 6.2	12.2 ± 6.5	0.03	0.04

ANOVA, repeated measures analysis of variance; Contrast, paired student's test or wilcoxon's rank sum test of simulated ICU environment with and without earplugs and eye masks; NL, recorded ICU noise and light exposure; NLEE, recorded ICU noise and light, subjects wore earplugs and eye masks; REM, rapid eye movement.

ISSN: 1364-8535