Apr 01, 2012
By Laura Eggertson

Hospital Noise

Increasingly, it hinders communication and puts patients at risk.

As a new nurse in the labour and delivery unit in a busy Toronto-area community hospital, Shirley Alvares was constantly alert, listening for the beeping, humming and pulsing of monitors that warned her of changes in a baby’s or a mother’s condition. Her anxiety about responding to those alarms was so acute that it didn’t end when she got home.

“I used to hear them, as clear as day, in my sleep,” says Alvares, an RN who worked in hospitals for 32 years before moving into academia.

Unfortunately, neither the sounds of monitor alarms nor the voices of colleagues relaying critical information are as clear as day to nurses anymore. According to a growing body of research, including that of acoustical expert Ilene Busch-Vishniac, noise levels in hospitals have progressively increased over the last 50 years. They now routinely surpass the level the World Health Organization recommends and have entered territory that can promote hearing loss under some conditions in certain areas of the hospital.

The average daytime sound levels in hospitals around the world have risen to 72 decibels, from 57 decibels in 1960. Nighttime sound levels have also grown, over the same time period, to an average of 60 decibels, up from 42. Decibel levels in patients’ rooms should not exceed 35, according to WHO guidelines. (Levels of 80 decibels or more can cause hearing loss.)

“If you ask patients, staff and visitors to rank the top problem in hospitals, noise always, for each group, comes out in the top three,” says Busch-Vishniac, a mechanical engineer and the provost at McMaster University in Hamilton, Ont. “Excessive noise has been known to be a problem for decades, and there are no signs of it getting better.”

More than 150 years ago, Florence Nightingale identified noise as a barrier to healing in her Notes on Nursing: What It Is, and What It Is Not: “Unnecessary noise, then, is the most cruel absence of care which can be inflicted either on sick or well.” Today, the sheer variety and ubiquity of background noise and disruptive sounds render sleep a virtual impossibility for many patients.

The cacophony in hospitals comes from a blend of mechanical and human sources, bounced off hard surfaces that reflect sound. Heating and ventilation units hum, blast and switch on and off. People talk, moan, snore, scream, laugh and cry. Huge cleaning machines swish down corridors. Stretchers roll down hallways, crashing into walls or carts, jarring instruments. Overhead paging systems blare. Phones ring, iPods blast music, televisions chatter. Kettles whistle, microwaves beep and fridges hum. Ambulance sirens pulse and helicopter rotors thump. Through it all, the alarms ring, buzz, and beep, competing with all the other sounds.

For nurses, the din makes it difficult to hear, harder to focus and tough to be understood, says Busch-Vishniac, who conducted a seminal noise reduction study at Johns Hopkins University from 2003 to 2005.

In the operating suite, as one example, the conversations of surgeons and other members of the health-care team and the asides of the residents as they come and go combined with the squeal of power instruments and medical devices disturb nurses’ concentration, says one Ottawa surgical nurse. Edna — who asked that her real name not be used because she is critical of how her hospital has dealt with this issue — finds the noises people make are a greater distraction than the sounds of machinery: “I have stood in the middle of the OR and said, ‘Would everybody please shut up!’” The more people that are in the theatre, the noisier it is, she adds, “and you just want to scream.”

Effective noise-reduction strategies at work

Here are two examples of staff projects in hospitals in the U.S. that led to the implementation of low-tech, inexpensive solutions.

At St. Luke’s University Hospital in Bethlehem, Pa., the professional practice council of the inpatient neuroscience unit introduced the following strategies:

  • installed sound metres in nursing stations to increase awareness of noise levels
  • provided patients with earplugs
  • installed soft door closers
  • removed rubber transitions between carpets and tile floors in doorways
  • turned down the volume on televisions and phones
  • set up report areas that were not near patients’ rooms
  • coordinated care activities to reduce disruptions to patients
  • implemented quiet times
  • conducted random surveys of patients in their rooms, to assess their perceptions of noise levels.

At Stanford Hospital & Clinics in Palo Alto, Calif., the medical nursing unit came up with similar strategies to those being used by the St. Luke’s group along with the following:

  • hung signs at nursing stations and on doors to patient units, with reminders to be quiet
  • recommended investing in more expensive pulse-oximeter probes, like those used in intensive care units, that don’t slide off fingers easily
  • encouraged nurses to call the maintenance department to adjust door-closing mechanisms
  • proposed appointing a champion on each nursing unit to customize strategies
  • suggested a bedtime routine involving dimmed hall lights, closed patient room doors and fewer hallway conversations.

Despite the urgings of the nursing staff that the hospital invest in iPods or similar devices to play soothing background music, it has been left up to individual surgeons to decide whether they will bring in something to play their own music on. Those surgeons who do are the ones OR nurses are most eager to assist, Edna says.

The health effects of noise on patients have also been documented. For one, they require more pain and sleep medication in noisier environments. One study has linked hospital noise to increases in hypertension and ischemic heart disease in patients.

“The number one thing patients say to you when they are admitted is ‘But I won’t sleep well,’” says Cathy Brown, an RN in diagnostic imaging at Edmonton’s Royal Alexandra Hospital. “And the reason is the noise.”

At Toronto’s Hospital for Sick Children, physicians in the emergency department measured sound levels because they were having trouble hearing conversations in the department and on the telephone. “We were really concerned that we might be missing important information,” says Dr. William Mounstephen, co-author of the results of a study published in Pediatric Emergency Care. “It was causing a lot of stress.”

The researchers discovered the average noise level over a 24-hour period was almost 69 decibels, with peaks of more than 80 decibels. The noise interfered with communication and teaching, Mounstephen and his colleagues concluded. After the study, the hospital, which was redesigning the emergency department, incorporated changes to reduce noise. For example, instead of one central nursing station where all staff gathered, the hospital set up four nursing stations in different sections of the department. Noise baffles were installed as well. The result, says Mounstephen, is a less noisy, less stressful and safer emergency department. “Now we can actually talk to each other at a normal conversational level,” he says.

The overall level of noise in hospitals also contributes to a phenomenon known as alarm fatigue. “It’s an enormous problem. We now have so many alarms going off so frequently that it is impossible for hospital staff to respond to each alarm as though it were urgent,” says Busch-Vishniac.

To cope, nurses perform a kind of auditory triage. They respond to the alarms they believe have the highest degree of urgency, ignoring those they think are triggered by common device failures, like a patient rolling over and dislodging a pulse oximeter. But sometimes, nurses guess wrong.

“Alarms go off constantly, but the literature suggests that well over 90 per cent of them result in no action being taken,” Busch-Vishniac says. “That’s why, unfortunately, it leads to some adverse events.”

The U.S. Food and Drug Administration (FDA) received 566 reports of alarm-related deaths from 2005 through 2008. Some of those events occurred after staff did not hear the alarms or did not react fast enough to their warnings. Hospital noise and alarm fatigue in particular are now receiving high profile in the U.S. from the FDA and organizations such as the Joint Commission (the major accreditation and certification body for health-care organizations) and the Association for the Advancement of Medical Instrumentation.

There are no comparable Canadian statistics that break down adverse events connected to alarm fatigue and medical devices, because Canadian hospitals only report such incidents on a voluntary basis. Busch-Vishniac believes alarm fatigue is equally dangerous for patients in Canada, because our hospitals are just as saturated with alarm noise from the same medical devices.

Some of the companies building and renovating hospitals are incorporating noise-reduction strategies. Meeting acoustical standards was a requirement of the tender the McGill University Health Centre issued for its new Glen Campus. Before construction began, contractor SNC-Lavalin measured outside sound levels produced by a nearby light rail transit system. The company based its exterior wall design on the need to reduce that sound, says Yves Gauthier, director of design for the project.

Acoustic ceiling tiles that absorb noise and silencers on heating and ventilation systems are among the features of the new campus, adds Jean-François Latour, the company’s acoustics expert. Consultation and planning rooms, for example, will also have adequate insulation to help preserve the confidentiality of conversations, he says. Single patient rooms, which will be the standard there, will also cut the noise and increase acoustic privacy. Latour has also been involved in the construction of several other health-care facilities in which noise control and sound insulation are important aspects of the design requirements.

In today’s climate of fiscal restraint, however, fewer hospitals are being constructed and renovation budgets are tight. That means large redesigns to reduce noise are less likely — a point Busch-Vishniac and another acoustical expert, Erica Ryherd, both acknowledge.

“More and more hospital owners and administrators are willing to spend money on good acoustic design, but it’s a long road,” says Ryherd, an assistant professor of mechanical engineering at the Georgia Institute of Technology in Atlanta. “The key is to educate not just those groups and the health-care professionals but also the architects,” she says. Ryherd favours architectural and noise-control solutions over what she calls “administrative” fixes, such as designating quiet zones in hospitals or giving patients earplugs.

Busch-Vishniac, however, got good results at Johns Hopkins Hospital when she and her research team introduced staff in the pediatric intensive care ward to personal communicator devices that allow administrators to signal individual staff members directly and quietly. That, in turn, allowed them to reduce the number of overhead pages. The devices were so popular that no one wanted to give them up when the research project ended.

The Johns Hopkins team also achieved a dramatic drop in noise levels on a cancer unit by attaching sound-absorbing materials to the ceiling and the upper part of the unit’s walls with industrial-strength Velcro. Within minutes, staff members were able to lower the volume on their telephones and the public address system, and the overall noise level dropped.

Busch-Vishniac believes that hospital administrators will make positive changes as better sound-absorbing materials become available, as medical device companies develop ways to coordinate and reduce alarm sounds and as awareness grows about the damage excessive noise does to staff and patients. “It is only in the last five years that there’s some understanding of how high the level of noise in hospitals is and that we are causing the deterioration of health in patients just by subjecting them to it,” she says.

Meanwhile, nurses like Edna will continue to climb into their cars at the end of a shift and sit for a few moments before turning on the engine — thankful for the silence.

Laura Eggertson is a freelance journalist in Ottawa, Ont.
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