Factors affecting sleep quality in Intensive Care Units.

Objective: To report sleep quality and identify related factors.

Design: A descriptive cross-sectional study was made with a convenience sample of 129 patients. The differences between 3periods were evaluated using the Wilcoxon test and Spearman correlation r. Multiple regression analyses were performed to relate independent variables to sleep quality.

Setting: The Department of Intensive Care Medicine of a tertiary hospital.

Participants: Patients admitted between February 2016 and December 2017.

Interventions: Questionnaire administration.

Variables: Items of the modified Freedman questionnaire, and demographic and clinical variables.

Results: External factors interfering with sleep quality were noise and constant light exposure in the 3periods, with significant differences between these periods in nursing care (P=0.005) and nursing activities (P=0.019). The other factors affecting sleep quality and identified by the multivariate regression model were age (P=0.012), daily alcohol intake (P=0.023), benzodiazepine use during admission to the ICU (P=0.01) and comorbidities (P=0.005). There were significant differences in sleepiness between discharge and the first day (P≤0.029) and between discharge and half stay (P=0.001).

Conclusions: Noise and light were the most annoying factors, but statistical significance was only reached for nursing activities and care. Age, alcohol intake, benzodiazepine use in the ICU and a higher comorbidity index had a negative impact upon sleep. Sleepiness was reduced at the end of stay.