| dc.description.abstract | Studies show that ventilation systems take an important role to reduce surgical site infection in hospitals. However, the ventilation system itself might not be enough. Staff's movement around the room, positioning of the surgical lamps, and even the clothing worn by the surgeons can interfere with the airflow, spreading contaminating particles around the operating room. These bacteria-carrying particles emitted by personnel can be transported through thermal plumes (TP) that have the ability to influence the distribution of air in the microenvironment area of the operating room.
The objective of this study is to characterise the thermal plume of a patient under two examined ventilation systems, laminar airflow (LAF) and turbulent mixed ventilation (MV) with a variable room temperature of 21 °C and 23 °C. Two operating rooms (ORs) at St. Olavs Hospital were used as study cases to compare the patient's thermal plumes. During the measurements, room temperature, relative humidity, velocity, temperature, and turbulence intensity of the thermal plume were determined.
As well as the experimental collection of data, theoretical calculations of the thermal plume and air distribution in the OR were assessed to understand the phenomenon and provide a thorough explanation in the discussion section.
The results show that most Indoor Air Quality (IAQ) parameters are within European standards except for the low humidity.
Regarding the measurement data, the risk of SSI increases at 23 °C rather than at 21 °C for both ventilation systems. This is due to increased turbulence intensity and a reduction in the thermal plume's velocity for the MV and for LAF, the thermal plume is suppressed at 5 cm at 21 °C while reaching a height of 10 cm at 23 °C.
This master thesis is a continuation of the specialisation project submitted in December 2022 that found that thermal plumes had an important role in dominating the airflow in the critical zone and thus, having the potential to prevent SSI. | |
