Download - M icrobiological surveillance of ots
Dr. SUMI NANDWANIAssociate Professor, Microbiology,
E.S.I.C.,PGIMSR, Basaidarapur, New Delhi
History of Hygiene
Greek Era : Aristotle recommends Boiling water to armies. Advises the Alexander
Semmelweis: Practices & emphasizes the importance of washing hands with chlorinated water in Obstetrics to reduce maternal mortality
Historical Aspects Changed the History 1867 –Dr.Joseph Lister
first identifies airborne bacteria and uses Carbolic acid spray in surgical areas
1880 – Johnson and Johnson introduce antiseptic surgical dressings.
Reduction of Hospital associated infections
Mortality reducedMorbidity reduced
Role of Microbiological Surveillance in OTs
Surgical site infections -a significant health risk to hospital patients.
Source of infection may be either endogenous or exogenous.
The O.T. environment plays a great role in the onset and spread of infection
Good infrastructures do not mean a safe environment
Factors affecting rate of post operative infection Effective sterilization
and disinfections procedures
Good surgical techniqueTheatre designBacterial contamination
of theatre airOT discipline - movement
of staff Appropriate use of
prophylactic antibioticsFlow of traffic from one
zone to another
MONITORING EFFECTIVE STERILIZATION AND DISINFECTIONMETHODS OF
STERILIZATION USED IN CSSD:
a)Moist Heat- Autoclaveb)Dry Heat – Hot Air Oven,
Infra Red Sterilizerc)Chemical-
ETO,formaldehyde,Glutaraldehyde, Peracetic acid
d)Plasma sterilizer - H2O2 in plasma state used
INDICATORS FOR EFFECTIVE STERILIZATION:
a) Physical- Graphs plotted based on temperature, pressure and humidity
b) Chemical- Chemical Indicators: can be found on medical packaging and autoclave tape ( BOWIE – DICK TEST), and these change color once the correct conditions have been met.
Biological indicatorsContain spores of a heat-
resistant bacterium, Bacillus stearothermophilus for autoclave and Bacillus subtilis for ETO in a strip kept in a 3M attest plastic vial.
Change of color of a pH-sensitive chemical.
IN USE TEST FOR DISINFECTANTSGrowth in more than 5 drops =
failure of DisinfectionA Chemical compound VIRKON
gaining importance as non Aldehyde compound
What is wrong with our PracticesDisinfectants used indiscrimately,Used unnecessarilyNot used when needed.Concentration not adequateEconomic consideration,Business promotions.Laboratory testing X Hospital
conditions may not correlate.
Air Surveillance of Operation theatre
Scope- To determine air bacterial count in OT and to detect pathogenic bacteria like staphylococcus aureus.
Factors influencing: Number of persons present. Body movements, Disturbances of clothing.Methods of Air surveillance:1 Settle plate method.2 Slit sampler method (from given volume)3 Particle counter ( non viable count )
Settle plate method A count of colonies yields a
relative estimate of no. of organisms
INTERPRETATION : Acceptable levels : In OT- 10 cfu/ ft3 / min In specialized OT/ burns
unit – 1 cfu/ ft3 / min
Even a single colony of a pathogen like S. aureus should
be taken as unsatisfactory.
Slit SamplerVery Effective / Highly sensitive
Fixed volume of air is sucked and bacterial counts are made
Note: doors must be kept closed and the theatre empty until sampling is complete.
Sampling volume needs to be greater than 0.25 m3 (250 L) . Usually 300 l/ min. Preset for 1 min
Acceptable counts:( Ayliffe et al) < 35 colony-forming units (cfu) / m 3 of air
for a conventional theatre During operation < 180 CFU/m 3 of air using
ultra clean laminar flow.Less than one CFU of Clostridium
perfringens or Staphylococcus aureus in 30 m 3 .
Basic care of Operation Theatres.Reduction of Microbial
counts is important.Paying great attention to
Floors Using too many chemicals not necessary
Keep the floor Clean and Dry - with Vacuum cleaner and Wet cleaning techniques
Keep the mops dry when not in use,
Frequent cleaning of Walls and Roof is not needed
Number of persons present and Movements they make, has direct relation to increase of bacterial counts
Prompt disposal of Theatre waste out of the theatre is of top priority
Handling of Air in Operation theatre.Critical parameters for air quality include ( WHO
Guidelines)(1) Maintenance / validation of efficacy of filters(2) Pressure gradient across the filter bed and in
the operation theatre(3) Air changes per hour (minimum 15 air
changes per hour)(4) Temperature and humidity should be
maintained between 20-22°C and 30-60%, Air pressure vented to the operation theatre. Direction of air flow should be from clean to less
clean areas. Environmental cleaning should be twice daily Proper design and ventilation of operating
theatres(HVAC) systems HEPA filters indicated in operating rooms designated
for orthopaedic implant procedures
Good Hand Washing Practices Save many Lives
1. Alcohol with Chlorhexidine.
2.Alchool without Chlorhexidine.
3 Chlorhexidine 2 %4 Chlorhexidine 4 %5 Povidone with Iodine
7.5 %6 Triclosan 1 % Or Anything
NEW
BEST HAND WASH IS
Fumigationa biohazard procedure ?To sterilize the operation theatre formaldehyde gas (bactericidal & sporicidal,viricidal) is widely employed as it is cheaper. In spite of the gas being hazardous continues to be used in several developing countries
Newer Chemical Agents in Hospital Useavailable but the Economic Limitation
Bacteriological surveillance testing at regular intervals is not warranted
But warranted when : modification of operation theaters are doneIn any unforeseen increase of incidence of
infection from any particular operation theatre.
Routine and regular testing for Anerobic spores is not essential except when there was suspected case of Tetanus or Gas Gangrene attributed
Culturing unnecessary surface areas causes confusion and meaningful interpretation is lost.
Use your Wisdom
Everyone
References Surveillance, Sterilization and Disinfection of Operation Theatres in the
Developing World by Dr.T.V.Rao MD – Dr.Chithra.VN MD July 17, 2010 By 4u Articles
Principles, And Practices of Disinfection, Preservation and Sterilization by A.D.Russel, W.B.Hugo & G.A.J Ayliffe.
www.cdc.gov/cdc.htm www.his.org.uk www.ific.narod.ru WHO : Prevention of Hospital aquired infections. A practical guide. 2nd ed.
2002. Geeta Mehta. Microbiological surveillance of operation theatre.
http://www.orthoteers.org/content/content.aspx?article=372 Colquhoun J, Partridge L. Computational Fluid Dynamics Applications in
Hospital Ventilation Design. The Australian Hospital Engineer 2003; 26(1):35-40.