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 3 periods 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 3 periods, 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.