The Relationship between Noise and Sleep Patterns in Intensive Care Units

소음과 수면양상에 관한 연구 - 중환자실을 중심으로 -

The environment in the ICU leads to negative changes in a patient's usual sleep pattern and so contributes negatively to the patient's health condition as compared to patients in general wards. Therefore, it is thought that an important nursing intervention would be to identify the relation between noise and sleep patterns which play an important role in illness recovery. The purpose of the present study was to explore the relationship between noise in the ICU and the sleep pattern of patients admitted to the ICU. A descriptive correlation design was used to examine the relationship. Thirty-four subjects were recruited from a Medical ICU (MICU), Surgical ICU (SICU) and Coronary Care Unit (CCU) at a large university hospital in Suwon. Data were collected from September 28 to October 31 in 1999. In the present study, noise was categorized into noise level and patients' perception of noise. The objective noise level was measured using the A-Weighted Sound Level Meter. The patients' preception of noise was measured using a self-reported questionnaire developed by the researcher. Sleep patterns in this study includes both quantity and quality of sleep. These were measured using open ended questionnaires and the 'Korean Sleep Scale A' developed by Oh, Song, Kim(1998). The data was analyzed using the SPSS-WIN to test the research question, Pearson product moment correlation coefficient was run. Ancillary analysis were conducted with demographic variables to determine their relation to the main study variables. For the ancillary analysis, t-test and one-way ANOVAs were performed. The results of the present study are summerized as follows : 1. The total mean of objective noise level (10pm-6am) was 56.2dB. The means for night time noise level in individual ICUs for the SICU, MICU and CCU, were 58.7dB, 58.6dB and 48.3dB, respectively. The total mean for patients' noise perception was 42.8 out of a maximum possible score of 76. For item means of noise perception, the one ranked highest was "conversations between doctors and nurses" (3.2). The one ranked lowest was "noise from the radio" (1.2). Regarding the degree of perception for each type of noise source, the one ranked highest was "equipment noise" (2.6), the second was "conversation between medical staff" (2.4), the third was "conversation between patients, caregivers and visitors" (2.3), and the one ranked lowest was "environment noise" (1.8). 2. Looking at quantity of sleep of ICU patients, the mean nocturnal sleep time was found to be 4.9 hours. The total mean of sleep quality for ICU patients was 21.0 out of a maximum possible score of 40. 3. The relationship between perception of noise and quantity of sleep was statistically significant(r= - .41, p<.05). The relationship between perception of noise and quality of sleep was also statistically significant(r= - .47, p<.01). The results of the study indicate that personal perception of noise is related to sleep patterns. Therefore, it is suggested that nursing interventions be developed to reduce the degree of personal perception of noise and, thus, decrease sleep pattern disturbances in patients in the ICU.