International Journal of Mechanical And Production Engineering, ISSN: 2320-2092, Volume- 5, Issue-10, Oct.-2017 http://iraj.in Real-time Measurements of Relative Humidity and Temperature in Hospital Operating Room 92 REAL-TIME MEASUREMENTS OF RELATIVE HUMIDITY AND TEMPERATURE IN HOSPITAL OPERATING ROOM 1 KENG YINN WONG, 2 HASLINDA MOHAMED KAMAR, 3 NAZRI KAMSAH, 4 HUIYI TAN, 5 MUHD SUHAIMI DERIS 1,2,3,5 Faculty of Mechanical Engineering, 4 Faculty of Biosciences and Medical Engineering University Technology Malaysia, Johor, Malaysia. Email: 2 haslinda@mail.fkm.utm.my Abstract - This paper investigates a series of real-time measurements of relative humidity and temperature in an operating room at a private hospital located in Selangor, Malaysia. The measurements were logged for 24 hours, at 5 minute intervals, under the actual operating conditions. The time-averaged temperature and relative humidity during the surgical procedures were recorded to be 20.5 °C and 73.9 % respectively. The air temperature fulfilled the ASHRAE Standard 170 requirements, but the humidity level slightly fell out of the proposed range. The door openings and heavy traffic were found to disrupt the stability of the air temperature and humidity distributions in the operating room. The cleaning and disinfecting procedures significantly increased the humidity level by 14 %; whereas the frequent opening of the door elevated the air temperature by 2.5 °C. These two scenarios can potentially increase the growth and activities of bacteria, which may in turn increase the risk of patients suffering from surgical site infections. Keywords - Onsite Measurement, Operating Room, Relative Humidity, Temperature I. INTRODUCTION Maintaining a proper temperature and humidity distribution in the operating room, a healthcare facility for surgical procedures, could enhance infection control and the occupant’s comfort [1]. However, it has been reported that engineers struggle to fulfil indoor environmental conditions which satisfy occupants [2]. In general, a low-temperature distribution could result in health risks for the patient. To avoid hypothermia in patients, a temperature between 24 °C to 26 °C is preferable [3]. However, a temperature above 23 °C is hardly supportable by surgeons [4]. Surgeons demand the temperature to be in the range of 17 °C to 18 °C, while anesthesiologists and nurses prefer warmer conditions [1, 2]. In Romania, the supply air temperature usually falls within the range of 18 °C to 24 °C [3]. The Spanish and Turkish norms recommended a higher temperature range, from 22 °C to 26 °C; and 19 °C to 26 °C respectively [5]. In the UK, the proposed range is significantly wider, from 18 °C to 28 °C [3]. However, during paediatric surgery, the temperature can reach 27 °C [3]. For cardiac surgery, the air temperature should be maintained at 17 °C [6]. For special situations such as patients with polyarticular rheumatism or are highly burned, the air temperature should be kept between 30 °C to 32 °C. Yang et al. [7] and Forstot [8] reported that up to 50 % to 70 % of surgical patients developed mild hypothermia in the perioperative period. Table 1 tabulated the humidity level and temperature as recommended by the three international standards for the practice in the operating room. The overall humidity level should be maintained at an acceptable range. Low humidity levels favour blood coagulation and will cause problems associated with static electricity on medical equipment and surfaces [6]. A high moisture content promotes the growth and transfer of bacteria that can easily become airborne on water molecules and cause thermal discomfort [6]. In terms of European operating room practice, the humidity level should below 50 % [3]. ASHRAE and AIA standards, however, limit the humidity level to fall within 30 % to 60 %. For a patient with a certain health condition, such as polyarticular rheumatism, the humidity level of 30 % to 35 % is preferable. Nevertheless, a 60 % to 85 % moisture level is recommended for a highly burned patient. Table 1: Air temperature and humidity for operating room In recent years, similar studies have been reported by Uścinowicz et al. [11], Kamar et al. [12], and Tan et al. [13]. Their measurement studies, however, focused on the unoccupied and steady state conditions. The field measurement of humidity and temperature under the utilised scenario has not been investigated so far. The objective of the present study is to assess the humidity level and temperature condition under both actual usage and rest conditions. II. METHODOLOGY A. Operating Room Description The operating room is located in a private hospital in Selangor, Malaysia, and was categorised as an ISO Class 7 cleanroom . The room was mainly used for general and orthopaedic surgeries. The dimensions of the room are 8.5 m (W) × 3.0 m (H) ×4.2 m (L).