Lowering the relative humidity levels in an operating room can have an effect on sterile supplies and electro-medical equipment in the OR. A recent joint communication from several professional organizations, including the Ambulatory Surgery Center Association, the American Hospital Association and the Association of periOperative Registered Nurses, among many others, aims to educate healthcare providers on those effects.
In 2010, the American Society of Heating, Refrigeration and Air Conditioning Engineers changed the lower end of the acceptable humidity in the OR from 30 percent to 20 percent. Primarily, this change was made to accommodate areas of the country, like Denver, where humidity levels change rapidly and the HVAC systems cannot keep up.
"It takes the system awhile to catch up," says Ramona Conner, RN, editor-in-chief, Guidelines for Perioperative Practice, with AORN. "Allowing the parameter to shift to 20 percent before you take action is an effort to recognize seasonal variation in humidity…and now people won't be cited when the lower humidity drops to 20 percent," she explains.
While it is now acceptable to have humidity in the OR below 30 percent, that does not mean that hospitals should lower their humidity to those low levels for long periods of time.
"In truth, people are most comfortable in the 30 to 60 percent range," Ms. Conner says. When humidity drops below 30 percent for long periods of time, skin starts to dry out. "It's just not comfortable for people."
But the main concern is not skin moisture levels; it is equipment safety in the OR. When humidity levels are too low for long periods of time, people can more easily become "charged" and create a shock when coming in contact with medical equipment. Additionally, some electro-medical equipment, especially older pieces, can malfunction unexpectedly in low humidity levels.
The point of the joint communication, Ms. Conner says, is to provide guidance for hospitals that have ORs susceptible to seasonal humidity changes. It provides a risk assessment for organizations to prepare for lower OR humidity levels.
"When your humidity drops, pay attention to what's going on in the environment, pay attention to how thorough your cleaning measures are and don't be alarmed if your humidity drops below 30 percent for a short period of time," Ms. Conner urges. "But also be aware of what supplies and equipment you're using in the OR and…take measures to protect them."