OPPOSITE-HANDED PATIENT ROOM: Decibel Comparison @ 500 Hz.

OPPOSITE-HANDED PATIENT ROOM: Decibel Comparison @ 500 Hz.

SAME-HANDED PATIENT ROOM: Decibel Comparison @ 500 Hz.

SAME-HANDED PATIENT ROOM: Decibel Comparison @ 500 Hz.

It's already well-established that noise can be a problem in healthcare environments. Studies show that noise from mechanical devices, patients and their visitors, and staff can compromise a patient's ability to keep private matters confidential, to sleep, and to heal.

“Sound management is very important in a healing environment,” says Lisbeth Gierman, senior vice-president and administrator at WakeMed Cary Hospital, a 114-bed community hospital located in Cary, North Carolina. “More relaxed and better rested patients tend to have less pain and discomfort.” They also tend to spend less time in the hospital. According to Press Ganey Associates, Inc., which measures performance and improvement in U.S. hospitals, complaints about noise outnumber all others by a ratio of two to one.

No wonder, then, that healthcare organizations are cracking down on noise. The World Health Organization now recommends decibel levels of 35 in patient rooms (which seems especially low when you consider that the average conversation is 60 decibels). The American Institute of Architects also is cracking down on noise with stricter guidelines for patient rooms (see sidebar).

WakeMed Cary Hospital is working to create an environment that is “sound aware,” Gierman says. To that end, the hospital plans to institute white-noise machines in patient rooms, a new nighttime-quiet program, and a new design. That design includes smaller communication desks for staff, special quiet zones, and same-handed rooms.

Same-handed advantages

Same-handed rooms, which feature an identical, repeated layout as opposed to mirror-image configuration, recently have been the buzz in the healthcare architecture and engineering communities. Based on the principles of lean manufacturing, same-handed rooms are believed to encourage seamless and intuitive processes in patient care, which experts say can decrease stress on staff and cut errors. “Same-handed rooms allow the providers to focus on the patient rather than the distractions of room configurations,” Gierman says.

Same-handed rooms also tend to limit noise. It's a fact that has been reported less frequently than other beneficial aspects of this configuration, but noise reduction may be one of same-handed rooms’ greatest advantages.

Why is that? It all comes down to the headwall. In same-handed rooms, headwalls—and the equipment and systems built into them—face the same direction in each room. This means in every room there's a solid, monolithic wall on the other side of each headwall. This monolithic wall's construction is unbroken, meaning noise can't penetrate it—it is, in effect, a “quiet wall.” Contrast this to mirror-image configurations, in which there's a patient on the other side of each headwall—and that headwall has been penetrated with up to 30 holes. The result is obvious: More noise on both sides of the wall (figures 1 and 2).

Note the pathways for noise through each hole in the wall in a mirror-image configuration (A), where headwalls are back to back. Contrast this with a same-handed configuration (B), where noise stops at the wall. Key: E = electrical; O = oxygen; V = vacuum; M = medical air

Compare the mirror-image (A) and same-handed (B) configurations; the potential for sound leakage in the mirror-image configuration is clear when the rooms are viewed from above

A leaky wall

Every hole, no matter how small, allows sound to escape or enter a room. Unfortunately, the headwalls of patient rooms must have multiple penetrations to accommodate systems and equipment. Here's a short list of the items required for just one headwall:

  • Medical gas station outlets

  • Electrical power outlets

  • Overbed lights

  • Night lights

  • Vacuum bottle slide

  • Switches

  • Nurse call equipment

  • Code blue equipment

  • Monitoring equipment

  • Telephone provisions

  • Data jacks

  • Clock/timer units

These items are standard for hospital headwalls, and each item requires at least one penetration in the wall. Each penetration increases sound leakage exponentially. For example, a one-square-inch hole through a wall with a sound transmission class of 40 (the class for a standard stud wall) will transmit as much acoustical energy as almost 100 square feet of the wall, according to Lyle Yerges in his seminal book Sound, Noise, and Vibration Control (figure 3). That means that headwalls with multiple penetrations let so much noise get through, you might as well have no wall at all.

This chart shows how noise levels increase exponentially with each uncaulked opening. An STC Value rates the sound-insulating value of a wall, floor, or ceiling. The higher the STC rating, the less sound will be transmitted. One square-inch hole through an STC 40 wall will transmit as much acoustical energy as almost 100 square feet of the wall. Note: This illustration is a simple reference; obtaining actual transmission loss values is an order of magnitude higher and needs to be connected with frequency Hz. Source: Sound, Noise, and Vibration Control by Lyle F. Yerges, 1985, page 121. Used with permission of Robert E. Kreiger Publishing Co

Room for a change

Switching to same-handed configuration can be a big change. And inspiring such a dramatic conversion throughout a healthcare system can take extra planning—and some persuasion.

At WakeMed Cary Hospital, we were able to show our client the advantages of same-handed rooms before construction began. We did this by constructing two mockup patient rooms in same-handed configuration in an unfinished area of the hospital.

The cost to create one mock-up room can range from $25,000 to $50,000—an expense that often is redeemed when you avoid your first change order. Constructing a mockup room also has the advantage of inspiring the understanding and buy-in of your client's healthcare team. Seeing and touching the room gives them a chance to experience the new configuration in three dimensions, and the whole idea of same-handed rooms instantly becomes clear.

Gierman says the mock-up rooms made a big difference: “The mockup rooms were a key to our planning process. They allowed all of our staff—nursing, respiratory, pharmacy, environmental services, facilities, etc.—to simulate activities within the room, so we could make adjustments where needed.” The mock-up rooms did such a great job of making staff part of the design process, Gierman says she'd “never build a patient care area without them.”

With the move to same-handed configuration, the facility is hoping to reduce noise in patient rooms dramatically. In fact, the hospital's new same-handed design will cut the number of wall penetrations by 50%. The plan is to use the same model on all new patient rooms throughout the growing WakeMed healthcare system.

Soundproof design

Changing room configuration may not be an option for every hospital, but there are other practical ways to prevent leaks from existing holes and to help control the transmission of noise. Here's a sampling of techniques, many of which were adapted at WakeMed Cary Hospital:

Caulking. Placing drywall with double sides and at least six beads of caulk on the track top and bottom—a simple step that generally is not happening in the industry—can reduce noise. At WakeMed Cary Hospital, we plan to caulk under and on top of each room's metal track to create a good seal. Little gaps can mean a lot of noise.

Full-height walls. If you stop a wall from reaching full height, the ceiling becomes a pathway for noise. Walls should extend to the deck—the bottom of the next floor.

All-concrete flooring systems. We often choose this structure in part because concrete has the mass to absorb vibration and reduce noise transition through the floor system.

Ceiling tiles. Sound-absorbing ceiling tiles, which are two to three times thicker than typical ceiling tiles, can dramatically cut noise. Ceiling tiles with high acoustical value tiles are often twice as expensive as regular ceiling tiles, so it's wise to use them judiciously. At WakeMed Cary Hospital, we used them in patient rooms but not in hallways.

Doorways. Always seal around doorways—the largest opening in the room.

Hallways. Consider the materials used in halls and whether they provide good acoustics. Look at how nursing stations are positioned and whether a better hallway design could reduce noise. To minimize hallway noise at WakeMed Cary Hospital, we developed a hallway design that specifies that no doorways be across from each other.

Televisions. In same-handed rooms, a television placed against a monolithic wall across the room is directly behind another patient's headwall. Usually that TV is silent, since the TV itself has no speaker. The speaker is usually part of a pillow speaker placed near the patient's bedside. Be sure this is the case when installing televisions in patient rooms.

The bottom line

Estimates put the cost of same-handed rooms at about $3,500 more per room than mirror-image configurations. In an 80-room hospital, that means the cost of same-handed configuration is about $240,000. When you consider that a new hospital can cost up to $600 million, and that medical errors cost the United States healthcare system $24 billion per year, you see how quickly the initial investment pays off through increased patient satisfaction and safety. HD

Doug Fick, PE, LEED AP, is a principal at BSA LifeStructures and handles engineering design for complex projects, including surgery expansions, patient tower renovations and chilled water facilities. He has championed the issue of reducing noise levels in hospitals for decades. Gary Vance, AIA, ACHA, LEED AP, a principal at BSA LifeStructures, specializes in space planning and design of healthcare facilities. A registered architect and board-certified member of the American College of Healthcare Architects, he is a leader in developing metrics and facility-related research.

For more information, visit http://www.bsalifestructures.com.