A Pilot Study on Delirium in the Intensive Care Unit

Abstract

Delirium continues to be a major issue in intensive care units (ICUs). Sedation and lack of rapid eye movement (REM) sleep could be important factors in the development of delirium. Improper sedation may interfere with a patient's sleep pattern, specifically time spent in REM sleep, and could be a contributor to the development of delirium. The research team has discovered through this pilot study that there is a possible correlation between sedation, disruptions, and sleep. The goal of our research was to determine the relationship between these variables using a sleep monitor to capture actual sleep activity compared with patient characteristics and real-time activity in the ICU environment. This was a pilot study of 7 new patients, aged 65 years or older, who were intubated and sedated. Data on patient sleep cycles were collected using a wireless sleep monitor. A time sheet was placed outside each room to record time and type of interruption during nighttime hours (9 PM-6 AM). The patients were observed for 1 to 7 nights dependent on their length of stay in the ICU. Preliminary results demonstrated that, on average, between 9 PM and 6 AM, 48% remained awake (range, 8%-88%), 30% were in light sleep (range, 2%-50%), 18.5% were in REM (range, 2%-60%), and 3.4% were in a deep sleep (range, 0%-9%). Subject 1 remained awake 52% to 88% of the time during the entire admission of 7 days, had an Intensive Care Delirium Screening Checklist score of 5, and had a self-extubation; sedation ordered was Versed as needed. Subject 5 had no interventions done between 12 midnight and 4:50 AM, with the exception of turning once, and had an REM recorded of 60% on 1 night, which equals to 4 hours 49 minutes of rest. All patients with the exception of 1 were on fentanyl and Versed drips with varying dose adjustments throughout their admission. Preliminary results show that there is a relationship between lack of REM sleep and delirium. The pilot study was a useful model to demonstrate the need for further investigation in a larger population.