Role of Microbiological Surveillance
The environments in the operation theatre are dynamic and subject to continuous change. Good infrastructures do not mean a safe environment as human make a greater difference in making the environment unsafe.
Microbiologists should be aware of organisms, sites and populations as surveillance cultures should be chosen carefully to allow meaningful interpretation of results. Microbiologists should be familiar with the clinical techniques as those normally used for culturing clinical specimens may not yield correct result when applied to environmental specimens. Sites and cultured reports should not be chosen as etiological sources in the present infections. Culturing unnecessary surface areas causes confusion and meaningful interpretation is lost.
AIR IS THE IMPORTANT SOURCE OF INFECTION
Bacterial counts in operation theatres are influenced by the number of individuals present, ventilation and air flow, the results should be interpreted taking the above facts into consideration.
Surveillance for Airborne Pathogens:
In resource poor hospitals, settle plates with blood agar are used and can detect pathogens, commensals and saprophytic bacteria. Multiple plates are kept and results are based on overall assessment rather than on a single plate study in the room. Microbiologists will clarify the acceptable counts at the different physical locations in multispecialty hospitals.
There is a sea change in analysis of bacterial counts in recent past with advances in medical technologies like Joint replacement surgeries dealing with critical patients. Slit sampler and Air centrifuge equipment for bacterial counts are replacing settle plates, the safe level of colony counts can be calculated as per the standards created with peer reviewed studies by the manufacturers.
How frequently should Surveillance be done for Airborne Microbes?
Yet there is no definite answer to this question!
Doing too frequent surveys are expensive and will not correlate the existing infection rate in the Hospital. But can indicate the circumstance we operate which can have bearing effect if the safety standards fall. Surveillance for Clostridia spores may be needed. The age old tradition of detection of anaerobic spores of C.tetani, and Gas gangrene producing organisms are losing ground with onset of more awareness on theatre sterilization. Routine testing for the anaerobes are not essential except when there were suspected cases of Tetanus or Gas gangrene attributed to operating in a particular operation theatre.
But it is ideal to survey the operation theatres for anaerobes when newly constructed or any remodelling or structural alterations are done. In such situations which will have trust worthy safety of the theatre.
General Instructions for sterilization and disinfection of Operation theatres
- Keep the floor dry when in use.
- Use only vacuum cleaners (booming to be forbidden as it will dispense the infected material all around and on the equipments.
- Chemical disinfection of an operation room floor is probably unnecessary. The bacteria carrying particles already on the floor are unlikely to reach an open wound in sufficient numbers to cause an infection.
- Cleaning alone followed by drying will considerably reduce bacterial population.
- Wall and Ceilings - Wall and ceiling are rarely contaminated. The numbers of bacteria do not appear to increase even if walls are not cleaned. Frequent cleaning is not necessary and has little influence on bacterial counts. Routine disinfection is therefore unnecessary, but only cleaned when dirty.
Environmental cleaning of Operation theatres:
At the Beginning of the Day
- Only remove the dust with cloth wet with clean water. (Mop theatre furniture lamps, sitting tables, trolley tops, operation tables, procedure tables, and Boyle’s apparatus). Note: Chemicals/disinfectants need not be used unless contaminated with blood or body fluids.
Between the procedures
- Clean operation tables or contaminated surfaces with disinfectant solutions.
- In case of spillages of blood/ body fluids decontaminate with bleach solution/ chlorine solution (10% available chlorine)
- Discard all waste in colour coded plastic bags (do not accumulate around surgical sites)
- Do not discard soiled linen and gowns in the operation theatre floor.
At the end of the day
- Clean all the table tops, sinks, door handles with detergent followed by low level disinfectant.
- Clean the floors with detergents mixed with warm water.
- Finally mop with disinfectant like phenol in the concentration of 1 in 10 (low concentrations of phenol will not serve the purpose).
- Keep the operation theatre dry for the next day's work.
Operation Theatre Discipline:
- Only people absolutely needed for an assigned work should be present in the Operation Theatres
- People present in theatre should make minimal movements and curtail unnecessary movements in and out of theatres, which will greatly reduce bacterial count.
- Air borne contamination is usually affected by type of surgery, quality of air which in fact depends on rate of air exchange.
- All the persons including the least cadre of employers are partners in infection control and should be aware to comply with infection control regulations.
- Prompt disposal of Theatre waste out of the theatre is of top priority. Any spillage of body fluids on the floors is highly hazardous and prompts the rapid multiplication of nosocomial pathogens.
- Prof.T.V.Rao MD
1 Principles and Practice of Disinfection, Preservation and Sterilization, 3rd edn. A. D. Russell, W. B. Hugo, G. A. J. Ayliffe, Eds. Blackwell Scientific Ltd., Oxford, 1999. ISBN 063 2041 43,
2 Patwardhan, Narendra, and Uday Kelkar. "Disinfection, sterilization and operation theater guidelines for dermatosurgical practitioners in India." Indian Journal of Dermatology, Venereology, and Leprology 77.1 (2011): 83.
3 Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008, William A. Rutala, Ph.D., M.P.H.1,2, David J. Weber, M.D., M.P.H.1,2, and the Healthcare Infection Control Practices Advisory Committee (HICPAC)3 (CDC 2008)
About the Author:
The author of this post is a Professor of Microbiology at Travancore Medical College, Kollam, Kerala, India. He can be reached at firstname.lastname@example.org.
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