How does the ICU environment affect patient sleep?

Study design: Prospective observational study. Study plan / participants and recruitment: Environmental sensors will be placed in three bed-spaces for a minimum 3-week period. These 3 bed spaces have been chosen as they are a sample of the different types of bed-spaces in the TPCH ICU. One is a single patient room, one is an open plan bedspace with natural light and one is an open plan bedspace without natural light. Environmental factors will be measured concurrently for this period. All consented patients will be assessed for delirium, and a minimum of 5 patients with / without delirium will be included. The results for these two cohorts will be compared to evaluate whether there are any differences in sleep patterns and quality between delirious and non-delirious patients. Patients will be admitted to ICU and allocated a bedspace as per current routine clinical practice and procedures. The patients that are admitted to the 3 bed-spaces listed above will be approached to participate in the study and provide consent for a 24 hour sleep investigation study concurrent with the environmental measurements. Consent: The treating clinical team will notify the researchers of potential candidates. Identified potential participants will then be screened for suitability by an investigator, in consultation with the treating medical officer. Patients will be informed of the purpose and aims of the study and informed consent will be obtained prior to commencing the study. Participants will frequently be incapable of consent in which case consent will be obtained from surrogates making decisions for eligible patients. Study plan: Consented patients will have their sleep monitored for 24 hours. They will be monitored overnight between 18.00 & 08.00 via a validated portable sleep monitor. Also, activity will be recorded for a 24-hour period via a validated activity monitor. For the period where the patients are not monitored via a sleep monitor (08.00 - 18.00), the patients' sleep will be monitored by bedside nurse assessments, and recorded in 15-minute blocks. A blood test (5ml) will be taken in the evening before the patient goes to sleep, to determine the melatonin and stress biomarker levels. Patients will also be asked to complete two questionnaires about the quality and quantity of sleep. Perceived sleep quality will be measured in the morning after completing the sleep investigation using the "Richards-Campbell Sleep Questionnaire (RCSQ)" if the patient is deemed to be cognitively able to complete the questionnaire. The patient’s ability to complete the questionnaire will be determined by the researcher after a discussion with the treating medical team. If the patient is unable to complete the survey, the night shift nurse will complete it. Also, patients will be asked to complete the "sleep in the ICU questionnaire" on discharge from ICU. Equipment: Sleep will be measured and analysed using the Somtê polysomnography (PSG) recorder. PSG refers to the application of sensors and electrodes for the continuous monitoring of physiological variables during sleep. The Somtê is a small, portable PSG, that is worn as a belt across the patient’s thorax. Nine sensors are attached to the patient; 2 under the chin, 1 next to each eye, and 5 on the scalp. These sensors will be attached to the patient’s skin using a water-based glue. The sensors will measure and monitor muscle tone changes using electromyogram (EMG), eye movements using electroocculogram (EOG) and electrical activity in the brain using electroencephalogram (EEG). The equipment also has an inbuilt oximeter to measure pulse oximetry and can also measure patient body position as well as background light and sound. Patient activity will be monitored and measured using the ActiwatchTM actigraphy monitor. This is worn on the wrist, and records physical motion and light intensity. It will be worn on the arm with the minimum number of lines and cannulae, to ensure that arm movements are not limited by the patient attachments. Periods of interrupted or poor-quality sleep and sleep arousals identified will be investigated to determine any alignment with environmental disturbances during the monitoring periods. Data will be obtained from environmental measurements and graphed to determine if there are any correlations between environmental factors and sleep quality or disturbance. These will then be investigated further, with the aim to determine the primary contributors to the sleep disturbance. Also, clinical notes will be reviewed to see if there were any assessments or clinical interventions that could contribute to these sleep disturbance events.