All quiet in intensive care? No, it’s louder than a revving motorbike: Noise caused by life-support machine alarms and staff rushing about can hamper patients’ recovery.
- Noise levels in intensive care units can be as loud as a revving motorbike
- But critically ill patients admitted to wards from casualty need quietness
- Racket can lead to sleep deprivation – hampering patients’ recovery
PUBLISHED: 18:49 EST, 29 May 2016 | UPDATED: 13:34 EST, 30 May 2016
It is the hospital ward where the critically ill are most in need of peace and quiet as doctors and nurses battle to save their lives.
But noise levels in intensive care units can hit 101 decibels – as loud as a revving motorbike, heavy lorry or a loud action scene in a Hollywood blockbuster.
Guidelines say that intensive care units [ICUs] should be just 35 decibels – the hushed tones of a traditional library.
Critically ill patients admitted to wards from casualty need quietness while staff need low noise levels to help them concentrate and work efficiently.
Instead many patients in intensive care have to endure a deafening racket from life support machine alarms, beeping equipment and the din of staff going about their business, which can lead to sleep deprivation – hampering patients’ recovery.
On average, the Belgian study found average sound levels by the bedside were 52.8 decibels [dBA] during the night and 54.6 dBA during the day – the sound of a loaded dishwasher.
But noise pollution in the ward meant there were 14 peaks above 80 dBA over a 24 hour period.
This is a similar level to a noisy restaurant, a busy street or lawn mower or a shouted conversation.
The highest peak was 101.1 dBA – louder than a motorbike, heavy lorry about seven metres away, a hand drill or action scenes in films.
At the nursing station, average sound levels of 52.6 dBA at night time and 53.9 dBA at day time were recorded. There were 11 peaks above 80 dBA with a maximum sound peak of 90.6 dBA.
The World Health Organisatin recommends average sound levels for hospital wards below 35 decibels (dBA) with a maximum of 40 dBA at night time.
A whisper in a quiet library heard from six feet away measures 30dB while normal conversation heard from three foot away measures 60 to 65dB.
By comparison loud rock concerts reach 115dB while a chainsaw measures between 115 to 120dB.
Following complaints from both patients and staff about the noise, researchers from Jessa Ziekenhuis Hospital in Hasselt, Belgium (pictured) measured noise levels in one 12 bed intensive care ward
Previous studies have found sound levels in ICUs are significantly higher with average sound levels always exceeding 45 dBA and for half of the time exceeding 52 dBA.
Sound monitors were placed at the bedside of a two bed unit as well as at the nursing station recording 24 hours two weeks apart.
Dr Eveline Claes said: ‘Since electronic sounds are more arousing than human voices, so it is highly likely that the peaks we measured are alarm activity.
‘The sound levels in our ICU clearly exceeded the WHO recommendations but are comparable with sound levels in other ICUs.
‘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.
On average, the Belgian study found average sound levels by the bedside were 52.8 decibels [dBA] during the night and 54.6 dBA during the day – the sound of a loaded dishwasher (file image)
‘In our department, measures should be taken to reduce the average sound level and the incidence and magnitude of sound level peaks.’
However, she adds: ‘It is not easy to create an ICU without noise. We need the alarms to warn us about emergencies.
‘Various programmes of staff education, task scheduling, equipment repositioning and alarm threshold review have not lowered sound levels to within WHO-recommended levels.
‘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.’
The study was presented at Euroanaesthesia 2016 in London.