Reducing Infection in Ultra Clean Air Operating Theatres

The use of ultra clean air operating theatres was pioneered in the UK by Professor Sir John Charnley during the development of total hip replacement. When conventional operating theatres were replaced with ultra clean theatres there were dramatic reductions in infection rates. Although much has changed in the subsequent 50 years the basic conclusion that prevention of infection is better than cure remains valid.

We have and taken detailed 3-D and anemometry measurements of airflow in an ultra clean theatre and, working with the Department of Chemical Engineering, University of Birmingham and other international collaborators we have produced an highly detailed Computational Fluid Dynamic model of one of the theatres at the Royal Orthopaedic Hospital, Birmingham. This model enables particle tracking experiments to be carried out, which have identified what best practice looks like in this type of theatre.

In the present environment reducing energy consumption and avoiding waste of materials is of vital importance, however changes in practice need to be supported by robust evidence that microbiological safety will be maintained. The human cost of infected joint replacements, the energy cost and financial costs will be discussed. The potential problems of replacing single use plastics with reusable items will be reviewed.

Methods of measuring infection rates in joint replacements using the National Joint Registry and the UKHSA infection surveillance systems are both valuable, but there are inconsistencies in their outcomes. In the UK and elsewhere it is not routine to test the microbiology of operating theatres whilst they are in use. This stands in sharp contrast to pharmaceutical production facilities where millions of microbiology plates are used every year to monitor the environment. This approach is now changing with pilot studies and an ongoing national audit, which are designed to produce quality improvements in this area.