An Impact of the Efficient Functioning of the Ventilation and Air-Conditioning System on Thermal Comfort of the Medical Staff in the Operating Room

Abstract

Ventilation and air conditioning systems are necessary for developing proper parameters of indoor environment in operating rooms. The main task of ventilation and air conditioning in those specific areas consists in creating desirable temperature, reducing the number of microorganisms and the concentrations of hazardous gases and substances in the air, as well as ensuring the proper direction of airflow. In Poland, indoor environment in operating rooms has to comply with the requirements set out in three regulations ( No. 31, item 158, as amended) and the document entitled "Guidelines for the design of general hospitals". Given insufficient accuracy of the abovementioned national documents, it is a common practice to use foreign standards, i.e. ASHRAE Standard 170-2013, DIN 1946-4: 2008 and FprCEN TR 16244: 2011. When considering the conditions for thermal comfort, it is important to bear in mind a close link between air flow velocity and air temperature. Air in the zone occupied by patients and medical staff must not cause the sensation of draft. Furthermore, air velocity should be sufficient to eliminate interference caused by the presence of people and other sources of heat. It should also reduce the turbulence level in the air in the operating room. Efficient functioning of ventilation and air conditioning was tested during treatments and operations carried out on three wards of a Warsaw hospital. Tests were performed with the participation of medical staff from various surgical units. They were asked to perform minor manual tasks to simulate work on the operating table, and to complete a questionnaire on subjective thermal sensation. The applied methodology is widely used during testing of general and local ventilation in public buildings. Air temperature, relative humidity, air flow supply and exhaust air from the operating room were determined on the basis of VelociCalc 8360 and Testo 435 anemometers with a 3-function probe and 3 vane probes with the diameter of 16 mm, 60 mm and 100 mm. Throughout the study, microclimate conditions in the operating rooms were controlled by the EHA MM101 microclimate meter. Test results showed that the microclimate parameters met the requirements of the aforementioned documents. However, individual thermal sensations reported by the medical staff pointed to the lack of thermal comfort and, in extreme cases, e.g. when using lead aprons during operations, perception of the thermal environment as 'very hot'. The efficiency and type of air distribution in operating rooms has a decisive effect on the results.

Factors Affecting the Thermal Comfort of Perioperative Personnel in the OR

“…In our study, the number of perioperative personnel who reported satisfaction with the thermal environment was significantly lower among those wearing additional clothing than among those who were not wearing it. Other studies have confirmed that the properties of surgical clothes and wearing additional protective clothing (eg, lead aprons) affect thermal comfort …”

“…Patients generally prefer warmer temperatures than health care personnel . The unique structure of an OR affects the thermal comfort levels of perioperative personnel …”

“…Satisfaction with the thermal environment involves a complex and subjective reaction to certain variables. 26 Personnel may need to adjust the indoor temperature with the changes in season because thermal comfort levels may vary according to the season. 27 The preferred temperature for thermal comfort in the health care setting also may vary according to the occupant and setting.…”

“…We developed the FATCS using existing literature as a guide . The survey included 18 questions about the demographics (eg, age, sex), occupational characteristics (eg, occupation, education, years of experience), and personal characteristics (eg, BMI, health status) of the participants.…”

“…We developed the FATCS using existing literature as a guide. 6,9,21,26,27 The survey included 18 questions about the demographics (eg, age, sex), occupational characteristics (eg, occupation, education, years of experience), and personal characteristics (eg, BMI, health status) of the participants. The survey also aimed to assess potential effects of thermal discomfort on personnel and asked participants for suggestions to improve thermal comfort conditions.…”