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.