Keep it quiet, please! Noise hurts everyone
October 1, 1998 4 minutes read
Keep it quiet, please! Noise hurts everyone
Behavior modification can cut noise by 28%
How well could you rest if beepers, alarms, and speakers constantly emitted peeps, beeps, squawks, and squeaks from around and beside your bed - not to mention, blaring televisions and loud conversation?
A series of three studies from a team of physicians at Rhode Island Hospital in Providence shows patients in most intensive care units aren't sleeping too soundly, either. (See suggested reading, p. 114.)
"Unless ICU staff make a special effort to reduce noise levels, it can reach 80 decibels - the equivalent of a loud subway ride or blaring rock music," says co-author Richard P. Millman, MD, FCCP, professor of medicine in the division of Pulmonary, Sleep and Critical Care Medicine at Brown University School of Medicine, and director of the sleep disorder clinic at Life Span Hospital, both in Providence.
The Environmental Protection Agency standard for noise levels at inpatient facilities is 45 decibels in the daytime and 35 decibels at night.
Such noise pollution has several negative consequences, explains Millman. "For the patients on ventilators, sleep deprivation can make weaning more difficult because it affects respiratory muscle function. It is also causes symptoms of ICU 'psychosis,'" he says. Critical care nurses also suffer from working in a loud environment. "Noise has been implicated in contributing to nurse burnout."
In the most recent study, which was conducted from August 1995 to August 1997, Millman and five associates first examined the causes of noise pollution in the medical intensive care units. "Then we wanted to find out if behavior modification could have an effect on noise levels in the ICU," he says. The team selected this setting because an earlier study had shown it to have the highest noise levels among the inpatient settings, he says.
In the first portion of the study, the team used a sound-level meter with internal storage capabilities. "We placed it next to the patient's head because we wanted to get the most accurate estimate of what the patient would be hearing," Millman says.
In addition to a sound meter, human hearing was also enlisted in the study. "On 16 separate occasions, a resident sat next to the head of the patient's bed and sounds in 15 second intervals for 10 consecutive minutes," he says. "The task was to monitor [on all four shifts] the loudest noises perceived by the human ear during each 15-second interval." After analyzing both sets of data, the team identified 12 noises that contributed to high peak sound levels, ranging from 74.8 decibels to 84.6 decibels. "Television and conversation were the biggest culprits," Millman says. (See chart on major sources of noise, inserted in this issue.)
The team then separated the causes of noise into two categories: those that could be easily lowered if staff changed their behavior and those that needed other solutions.
"About 51% of the noise - television, talking beepers, and intercom - could be reduced through behavior modification," he says. The rest of the noise came from ICU equipment that had preset volume controls such as alarms on ventilators.
To create a quieter atmosphere, the team next developed a comprehensive educational program aimed at all the staff, including nurses, physicians, secretaries, and respiratory therapists.
Through inservices and morning report, the team discussed noise pollution and its impact on patients and the work environment. "We also highlighted the types of noise that occurred and outlined what could be done about it," Millman says.
The team's suggestions included:
r turning off large central televisions in patient rooms;
r placing beepers on the vibrate mode;
r decreasing the use of the intercom;
r turning down the volume on overhead speakers;
r adhering strictly to visiting hours and to the number of bedside visitors;
r decreasing or eliminating loud or unnecessary conversation at the bedside.
For three weeks, the resident measured the noise levels while staff practiced these behavior modifications. "We set up a contest between shifts - the one that had the biggest reduction would get pizza," Millman says.
The most difficult behavior to change was turning down - or off - the televisions. "Switching to the [beepers'] vibrate mode was no big deal; neither was turning down the overhead speaker. But the biggest struggle came with television," he explains.
When the television is blasting, staff and visitors have to speak above it, so noise levels from conversation escalate. "Yet we heard some of the nurses insist, 'I want to watch my show.'" says Millman, who recommend individual television ear plugs for patients. "The televisions are there to stimulate the patients, not the staff."
The behavior modification did work, he says. "We reduced peak noise levels in all time periods except 12 a.m. to 6 a.m.," he says. (See chart, inserted in this issue.) For example, the afternoon shift reduced its noise levels from 82.7 to 78.5. "Although that may not seem like a significant decrease, it is. What's important to note is that for every increase of 10 decibels, the sound is doubled," he explains.
Why did the night shift's noise level increase instead of decrease? "We speculate that those hours are inherently the quietest time in the hospital setting so there isn't much behavior to be modified," he explains.
Suggested reading
1. Kahn DM, Cook T, Carlisle C, Nelson DL, Kramer NR, Millman RP. Identification and modification of environmental noise in an ICU setting. Chest 1998; 114:535-540.
2. Aaron J, Carlisle C, Carsdadon M, Myers TJ, Hill NS, Millman RP. Environmental noise as a cause of sleep disruption in an intermediate respiratory care unit. Sleep 1996: 19:707-710.
3. Meyer TJ, Eveloff SE, Bauer MS, Schwartz WA, Hill N, Millman RP. Adverse environmental conditions in the respiratory and medical ICU settings. Chest 1994; 105:1,211-1,216.
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