Sound Intensity and Noise Evaluation in a Critical Care Unit

Abstract

Background Sound levels in intensive care units can be high. Unfortunately, high levels of sound tend to result in poor sleep quality, which leads to slower healing, poorer immune response, and decreased cognitive function. Objectives To measure sound levels to which patients in intensive care units are typically exposed. Methods Peak sound pressure levels of alarms on medical devices set at different output levels were measured. Additionally, ambient sound pressure levels for durations of 10 to 24 hours were measured on 12 occasions in patients' rooms in the intensive care unit. Results Peak levels of equipment alarms measured inside a patient's room were high, and increased as the setting of the alarm level increased. The levels of these alarms when measured in an adjacent room did not increase with alarm output level. Mean sound levels inside the patient's room were generally less than 45 dB(A), but peak levels were often greater than 85 dB(C). Closing the door of the adjacent room did not decrease these peak levels. Peak and mean levels did not differ systematically during 24 hours of measurement. Conclusions High-intensity equipment alarms disturb patients' sleep but are critical in a medical emergency. However, nurses should not assume that raising the alarm output level will ensure that the alarm is audible from an adjacent room. Ambient noise measurements indicate high peak levels during both day and night. (American Journal of Critical Care. 2010;19:e88-e99)

Determination of Factors that Cause Noise in Intensive Care Unit Environment

“…3 In another study it was reported that daily noise level changed 41 dBA and 61 dBA at hospital environment. 8 In the study Khademi et al was reported daily noise level was reached 94 dBA and mean daily noise intensity was 60.2 dBA.…”

“…12,13 In an other study conducted by Lawson et al, it was stated that 56% of the noise source was alarms resulting from the devices at the ICU. 3 In another study, medical devices were indicated as a source of noise, especially ventilation system, bedside infusion pumps and monitor were reported noise sources. 14 In our study, we found that major cause of the noise was monitor alarms, 36 of total 50 patients (72%) were uncomfortable due to noise of these devices and the noise intensity was measured as 101.7.…”

“…2 Uncontrollable noise in ICU effects patients negatively both physically and psychologically and also may retard the healing process. 3 On the other hand in the recent studies effects of noise was detected on sleep and cardiovascular system. 3 Nurses play a key role on reducing physical, psychological and social stress where patients exposure at intensive care units and presenting health care integrated with progressive technology.…”

“…3 On the other hand in the recent studies effects of noise was detected on sleep and cardiovascular system. 3 Nurses play a key role on reducing physical, psychological and social stress where patients exposure at intensive care units and presenting health care integrated with progressive technology. ICN theme was ''Positive Practice Environments'' (Quality Workplaces=Quality Patient Care) in 2007.…”

“…4 Development of holistic health care and presenting in accordance with patient needs, reduction of other factors that cause stress especially like noise and avoiding destruction will speed up the healing processes. 3 In this study, severity and causes of the noises were investigated in a cardiovascular surgery (CVS) ICU. It was demonstrated to reveal the current situation and create a base for similar works.…”