Noise levels around the intensive care units (ICUs) exceed the WHO recommendations by more than 20 decibel (dB), says a European study.

Researchers from the Universities of Gothenburg and Boras, monitored sound levels around a group of seriously ill patients at the ICU of the Sodra Alvsborg Hospital over a 24-hour period.

The sound levels around the seriously ill were on average between 51 and 55 dB. This is comparable with a busy road, the report said.

For the greater part of the 24 hours, between 70 and 90 per cent of the time, the sound level was above 55 dB in addition, there were a number of short sound bursts above 100 dB, the journal Intensive and Critical Care Nursing reports.

When the patients were interviewed about their experiences of the surrounding sounds, they recalled both positive and negative experiences. Positive experiences included, for example, the sound of the staff talking quietly between themselves or providing information on ongoing treatment, according to a Gothenburg statement.

“Sounds perceived as frightening were uncontrollable sounds from, for example, alarms, and sounds from seriously ill fellow patients, and treatments and examinations. One patient also described how the sounds around him had entered into his dreams and hallucinations,” said Lotta Johansson, researcher at the Sahlgrenska Academy.

The sound levels found by the study are slightly lower than those measured by previous studies, but still significantly higher than the 30 dB recommended by the WHO for patient rooms in hospitals.

“The interesting thing is that what the patients considered most disturbing was unknown and uncontrollable sounds rather than the generally high sound level.

“This shows that we must take further measures to create healing care environments with better conditions for sleep and recovery for seriously ill patients,” said Johansson in a statement.