Abstract & Commentary

Can Anything Really be Done to Make Intensive Care Units Less Noisy?

By Linda L. Chlan, RN, PhD, School of Nursing, University of Minnesota, is Associate Editor for Critical Care Alert.

Synopsis: Best practices that combine work setting noise reduction policies and engineering controls are needed to reduce noise levels in ICUs to the 45-dBA level recommended by the Environmental Protection Agency — roughly equivalent to sound levels in a normal work environment with casual conversation or from a radio playing in the background.

Source: Konkani A, Oakley B. Noise in hospital intensive care units — A critical review of a critical topic. J Crit Care 2011;Oct 25 [Epub ahead of print.]

This paper reports on the findings of a systematic literature review on noise and noise-reduction strategies in the intensive care unit (ICU). The goal of the literature review was to determine the best ways to ameliorate sound/noise in the ICU. A search on PubMed and the ISI Web of Knowledge of research articles written in English through May 2011, was conducted using the key words ICU, noise, and hospital. Citations were reviewed and those that examined sources of noise levels, current noise levels in the ICU, and methods to reduce noise were included in the review. Articles were excluded from the review if they measured noise in general hospital areas or overall hospital noise. The search yielded 29 articles, and 10 papers meeting the authors' inclusion criteria were included in the review.

The findings on sound/noise levels in the ICU, noise sources, effects of noise on staff performance, and patient perception of noise were presented in the review paper. Not surprisingly, since 1960, average daytime noise/sound levels in hospitals have increased from 57 dBA to 72 dBA. One of the most significant findings was that night-time noise levels have increased from 42 dBA to 60 dBA, which is about as loud as a noisy lawnmower. Peak sound levels have been measured at > 85 dBC, which is similar to a chainsaw heard 10 meters away. The major sources of ICU noise were staff and visitor conversations; equipment alarms; activities such as opening and closing storage drawers or equipment packages; telephones, pagers and television; and closing doors and falling objects. A full 34% of noise was deemed to be totally avoidable.

Two articles documented the effect of noise on staff, concluding that noise can contribute to nurses' stress, higher heart rates, feelings of irritation, and tension. However, there was no documented association between noise and work performance. Patients reported that mornings are the most annoying and that people talking was the source of noise they found most annoying. The Environmental Protection Agency (EPA) recommends sound levels not exceed 45 dBA, as anything higher than that causes persons to raise their voices when conversing. Unfortunately, none of the studies reviewed found ICU sound levels within this recommended level. The authors noted that there was no consistent measurement of noise among the studies reviewed, as some measured average sound levels at one point in time while others only reported peak sound levels. Some studies reported noise/sound levels at only one point in time whereas others measured sound/noise levels over a number of days. These measurement discrepancies made it a challenge for the authors to draw any meaningful conclusions from their review.

The authors concluded that there is no single solution to reduce noise levels in the ICU. Efforts need to fall into the category of "avoidable" noise levels, such as unnecessary staff conversations outside patient rooms. The authors commented that general behavior modification strategies like enforced "quiet time protocols" and simple low-cost environmental modifications on doors can be helpful in reducing noise in the ICU.


Given the high-tech, high-demand, 24/7 nature of the environment, it is not surprising that ICUs are noisy, which can be a source of annoyance for patients. Noisy environments can impede efficient work if crucial conversations cannot be heard due to excessive background sounds in the environment. Can a less noisy ICU environment be attained without sacrificing patient safety given the demands for care delivery in the sometimes chaotic environment? For the health of patients and staff, the response should be, "We need to try and reduce those avoidable sources of noise in the ICU."

Equipment and monitoring devices will need to alarm. The review by Konkani and Oakley provided several best practices that can be tailored by individual ICUs to reduce annoying sound levels on their respective units. Suggestions include simple, low-tech interventions such as staff education on the adverse effects of noise and those areas patients find the most annoying (i.e., unnecessary, loud staff conversations), quiet-time protocols tailored to individual ICUs, and fixing noisy doors and other pieces of equipment. While the EPA ideal sound limit may not be consistently achievable, there is room for improvement by all clinicians to reduce unnecessary noise in their work environments.