Hu Rong-Fang, Hegadoren Kathleen M, Wang Xiao-Yan, Jiang Xiao-Ying
School of Nursing, Fujian Medical University, China.
Faculty of Nursing, University of Alberta, Canada.
Aust Crit Care. 2016 May;29(2):62-7. doi: 10.1016/j.aucc.2015.08.001. Epub 2015 Aug 23.
The intensive care units' (ICU) environment is considered clinically relevant sources of stress for patients.
To measure 24-h sound and light levels in 7 ICUs in China [four medical (MICU), two surgical (SICU) and one coronary (CCU) ICUs] and to identify the main sources related to increased sound levels.
Sound pressure and light levels were monitored for specific times over a 24-h period using a digital sound level meter and a light detector in 7 ICUs. Sound pressure levels were measured for 20min every hour. The main events at the time of peak noise levels were recorded. Light levels were measured every 2h at three locations for each ICU: near a window, in the centre of the room, at eye level of a patient receiving assisted ventilation.
The mean value of 24-h sound pressure levels exceeded 50dB(A) in all ICUs, ranging from 56.5 to 70.1dB(A). The SICUs and CCU had higher sound pressure readings from 0700h to 1600h, compared to the MICUs where the sound pressure readings reflected less variability across the 24-h period. Marked differences were observed in luminance levels among various ICUs and also across the 24-h period for all three locations. The mean highest level of nocturnal luminance at eye level of patients receiving assisted ventilation ranged from 15 to 489lx before midnight (1800-2400h) and 10 to 239lx after midnight (2401-0759h).
High sound pressure levels are prevalent throughout 24h in the ICUs, especially in the SICU. Many of the readings exceeded international standards. Peak sound pressure levels were related primarily to staff activities and the alarm sounds of machines. ICU patients are exposed to high levels of artificial light continuously throughout the day and night.
重症监护病房（ICU）的环境被认为是患者临床上相关的压力源。
测量中国7个ICU（4个内科重症监护病房、2个外科重症监护病房和1个冠心病重症监护病房）内24小时的声光水平，并确定与声级升高相关的主要来源。
使用数字声级计和光探测器在7个ICU中，于24小时内的特定时间监测声压和光照水平。每小时测量20分钟的声压水平。记录噪声峰值水平时的主要事件。每个ICU在三个位置每2小时测量一次光照水平：靠近窗户处、房间中央、接受辅助通气患者的眼部高度。
所有ICU中24小时声压水平的平均值均超过50dB(A)，范围在56.5至70.1dB(A)之间。与内科重症监护病房相比，外科重症监护病房和冠心病重症监护病房在07:00至16:00的声压读数更高，内科重症监护病房的声压读数在24小时内变化较小。不同ICU之间以及所有三个位置在24小时内的亮度水平均观察到显著差异。接受辅助通气患者眼部高度的夜间平均最高亮度水平在午夜前（18:00至24:00）为15至489勒克斯，午夜后（00:01至07:59）为10至239勒克斯。
ICU内24小时声压水平普遍较高，尤其是在外科重症监护病房。许多读数超过了国际标准。声压峰值水平主要与工作人员活动和机器警报声有关。ICU患者日夜持续暴露在高强度的人工光下。
