The hustle and bustle of hospitals can sometime mean a lot of noise, even in the intensive care unit (ICU). While the World Health Organization recommends the noise in specialty wards stay below 35 decibels (dBA) — the level of sound you can get away with in a library — new research presented during Euroanaesthesia 2016 finds that it always exceeds the limit.

Noise levels aren’t just a nuisance to ICU patients and staff, but they can also have a negative impact on patients' well-being. Past research has found that noise exposure can slow down patients’ recovery, cause sleep disturbances, and raise blood pressure. Put it another way: peace and quiet is essential for these patients’ recovery. Unfortunately, the new study suggests ICU noise rests at 45 dBA, while it's 52 dBA half of the time. That's just six points lower than the volume of a dishwasher or clothes dryer.

Researchers set out to assess a potential noise problem in one ward of the Jessa Ziekenhuis Hospital in Belgium. They placed a sound level meter on the side of each bed in a two-bedroom room, as well as in the nursing station. The bedside meters read 52.8 dBA during the night and 54.6 dBA during the day on average, with 14 readings exceeding 80 dBA — the level of sound a blow-dryer or kitchen blender makes. The most noise recorded by patients' beds was as loud as a hand drill at 101.1 dBA. Tthe readings recorded at the nursing station were similar: 52.6 dBA during the day and 53.9 dBA at night, plus 11 peaks above 80 dBA.

With that said, researchers acknowledged equipment noise, alarms, medical staff activity, as well as hospital machinery all factored into the overall noise measurements. In fact, researchers believe electronics are responsible for the above-average noise peaks they have recorded since “electronic sounds are more arousing than human voices.”

"The sound levels in our ICU clearly exceeded the WHO recommendations but are comparable with sound levels in other ICUs,” said researcher Dr. Eveline Claes, in a statement. “Those elevated sound levels as well as frequent sound level peaks can be responsible for the subjective feeling of noise pollution experienced by patients, nurses and doctors. In our department, measures should be taken to reduce the average sound level and the incidence and magnitude of sound level peaks."

And while it is true noise affects patients’ general wellbeing, researchers note that it may be close to impossible to reduce noise in ICUs because they need the alarms to warn nurses and clinicians about emergencies. In the meantime, a 2012 study suggests patients in the ICU use earplugs to block out unusually high levels of noise in order to get some rest.

"Various programs of staff education, task scheduling, equipment repositioning, and alarm threshold review have not lowered sound levels to within WHO-recommended levels,” Claes explained. “The practical solution at present seems to be earplugs or other ear defender devices for patients, although there may be opportunities in the future to modulate alerts through the use of smart alarm systems and to develop equipment that produces less noise."

Source: Claes E. Euroanaesthesia 2016. 2016.