1. Indian Operation Theatres??
Do We Need Fumigation In Our
Indian Operation Theatres??
- Dr. Ajita Mehta
President HIS-I
Consultant Microbiologist
P. D. Hinduja National Hospital & MRC
Veer Savarkar Marg, Mahim (West)
Mumbai –

2. Points to be discussed …………
Critical Parameters for ideal Operation Theatre (OT)
Indian Scenario about OT
What is Fumigation / Fogging
Do we need fumigation in India?
What will be the Take Home Message?

3. Critical parameters for OT
Filter air through 2 layer beds in series
(efficiency of the 1st filter bed being >30% & that of the 2nd
filter bed being >90%)
HEPA filters (to remove > 0.3 m with an efficiency of 99.97%)
Positive pressure
Requirement of air changes /hour with a
minimum of 3 air changes of fresh air (20%).
Air should flow from the ceiling & be exhausted
near the floor

4. Temperature of 20- 220C, is comfortable & inhibits
bacterial growth
Relative humidity 30-60% to slow down bacterial
growth
Laminar airflow (ultra – clean air) & UV radiation
have been suggested as additional measures in
certain situations (orthopedic operations)

5. Heating Ventilation Air Conditioning (HVAC) Systems
HVAC system maintain indoor air temp. & humidity,
control odours, remove contaminated air & minimize
the risk of transmission of airborne microorganisms
Consists of air inlets, filter beds, humidity modification
mechanisms, heating & cooling equipment, fan ducts
& air exhausts

6. Fumigation is no longer used in the Western Literature
as they have all the modern critical parameters required
for OT

7. Indian Scenario In India, there are extreme situations in operation
theater (OT) facilities, ranging from rooms with fans,
window air conditioning, to the more sophisticated
laminar airflow systems
More than 60-80% of OTs, donot have air handling
unit (AHU) & other modern facilities with critical
parameters
In hospitals that lack heat ventilation air conditioning
(HVAC) systems the quality of air in the OT cannot
be guaranteed
What can we do in such circumstances??

8. Fogging Nebulization of a disinfectant to decontaminate rooms
vacated by patients with communicable diseases.
The origin of fogging can be traced to the 19th century when Lister aerosolized carbolic acid to improve antisepsis in operative practice

9. Fumigation consisted of a mixture of formalin (280
What Is Fumigation?
Fumigation consisted of a mixture of formalin (280
ml) and potassium permanganate (150 gm) being
placed in a bowl. The room would then be sealed
& opened hours later. Later on this changed
formalin being sprayed with humidification by a
spraying device or automist.
Temperature 180C & Humidity should be maintained to 600C

10. Different Methods 1. Carboxyl acid & fumigation with Formaldehyde
Advantages – Established age old technique
Cost effective
Disadvantages – a. Carboxylic acid has efficacy as
scouring and disinfecting agent
b. Time consuming, min 24 hrs turn
around time
c. Self defeating – OT fumigated with
Formaldehyde needs to be force
de-aired with unclean air
d. Unsafe Formaldehyde is carcinogenic

11. 2. Aldehyde based germicides
Glutaraldehyde & formaldehyde (200 ml in 10 liters of water i.e 2%) through fogging machine is the commonly used procedure.
Advantages Effective
Disadvantages – a. Leaves sticky residue because of
surfactant base
b. Self defeating – OT fumigated
with Formaldehyde needs to be
force de-aired with unclean air
c. Unsafe- Formaldehyde has been
identified as a carcinogen

12. Silver (Ag) and Hydrogen Peroxide (H2O2)
Advantages – a. Has deep penetrating capability
b. Has no known resistant strains
c. Effective against Bacteria, Viruses,
Mycobacteria, Amoeba, Fungi and
spore forming organisms

13. A fogging system
Droplets~7microns thrust by a motor running at 20,000 RPM to a distance of 15 m
Solution
Ecoshield – 11% Hydrogen
Peroxide and 0.01% dilute
sliver nitrate

14. Efficacy of Fumigation / Fogging method
Viable bacteria may fail to grow when cultured in the
presence of disinfectants
Neutralization of disinfectant (ammonia vapours or water)
is must before collecting air samples or swabs
Lecithin & Tween – 80 in appropriate concentrations
are suitable neutralizing agents
Environmental contaminants are generally associated
with organic residues that bind & deactivate most
disinfectants, (least likely to be benefit in those areas contaminated
with organic materials such as blood, feces or pus)

15. Fogging hastens the process of setting of airborne
microorganisms. Mist, generated by a disinfectant or
water would achieve the same process
Air sampling is useful to detect aerosols or particles of
microorganisms. (requires particle counter & practical method for
evaluating efficiency of filters)

16. Air sampler

17. The Unresolved issues of microbiologic sampling are:
Lack of standards
Lack of Standard protocols for testing
Sensitivity of sampler used
Such sampling should largely be reserved for
epidemiological investigations during outbreaks

18. No studies to demonstrate that fogging actually reduces
the incidence of nosocomial infection. The role of
contaminated environmental surfaces in causing
nosocomial infection remains to be elucidated*
Controlled studies at CDC have demonstrated that
quaternary ammonium fog does not produce a significant
(one log )reduction in bacterial counts of S. aureus or
E. coli, even in areas in completely saturated with residual
disinfectant*
*CDC: National Nosocomial Infections Study Quaterly Report, Third Quarter. 1971: isuued May 1972)

19. In India, studies have not compared standard cleaning
practices with fumigation/fogging.
No substitute for vigorous scrubbing, washing of surfaces
& removing the organic matter
Safety of repeated exposure of humans to disinfectant
& fog has not been established
Inspite of these drawbacks it is the best alternative for
- litigation
- good & safe hospital practices,
- check up of human default
- favourable psychological effect on staff & patients
- to improve the standard of hospital hygiene & asepsis

20. Points to support
Significant reduction in the number of bacteria in the
ambient air
Effective decontamination of exposed environmental
surfaces
Decreased risk of infection for housekeeping personnel
engaged in terminal cleaning
Decreased housekeeping costs
Secondary psychological benefits for hospital personnel

21. Take Home Message……
Fumigation is the only alternative however following
precautions should be taken
Replace formalin with a safer agent like a H2O2 stabilized
with a silver salt
It has no role in OTs with modern day HAVCs
For litigation after fogging do the air sampling & keep the
record
This is not an alternative to mechanical cleaning of surfaces
If surgeries are being performed with window air-
conditioners fogging would be required on a daily basis
not on weekends alone as is practiced (WHO guidelines on
prevention & control of Hospital Associated infections SEA-HLM-343. Jan 2002)

22. THANK YOU!