Noise levels in intensive care units can go well above recommended levels, disturbing both patients and the healthcare professionals that care for them, suggest Belgian researchers.
They suggested that earplugs might be a practical solution to improve the wellbeing of patients.
“The practical solution at present seems to be earplugs or other ear defender devices for patients”
The World Health Organization’s guidelines recommend average sound levels for hospital wards below 35 decibels (dBA) with a maximum of 40 dBA at night time.
Reported sound levels in ICUs are significantly higher, with average sound levels always exceeding 45 dBA and for 50% of the time exceeding 52 dBA, said the study authors. After several patient complaints and remarks from the nursing staff about noise, the study authors measured sound levels in one 12-bed ward of their hospital’s ICU.
A sound level meter was placed bedside in a two-bed room as well as at the nursing station of the ward. Measurements were performed after a two-week adjustment period to avoid potential bias from people being aware noise was being observed. Sound levels were continuously recorded for 24 hours at each location.
Bedside, average sound levels were 52.8 dBA during the night and 54.6 dBA during the day. A total of 14 sound peaks above 80 dBA were recorded with the highest peak at 101.1 dBA.
At the nursing station, average sound levels of 52.6 dBA at night time and 53.9 dBA at day time were recorded. Here, there were 11 peaks above 80 dBA with a maximum sound peak of 90.6 dBA.
The researchers noted that the measurements were significantly above the WHO recommendations of 35 dBA average and 40 dBA peaks, but comparable with other ICU recordings.
Equipment noise, alarms, hospital machinery and staff activity could all have contributed to the noise, suggested the study authors.
Lead author Dr Eveline Claes, from Jessa Ziekenhuis Hospital in Hasselt, said: “Since electronic sounds are more arousing than human voices, so it is highly likely that the peaks we measured are alarm activity.
Warning over high levels of noise in critical care units
“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,” she said.
However, Dr Claes added that it was “not easy to create an ICU without noise”, noting that alarms were necessary and staff education, task scheduling, equipment repositioning had little effect.
“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,” she said.