Fumigation in Operation Theatres

April 4, 2018 | Author: Utkarsh Rai | Category: Disinfectant, Hvac, Air Conditioning, Chemistry, Wellness


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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 – 400 016 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?  Air should flow from the ceiling & be exhausted near the floor .97%) Positive pressure Requirement of 15-20 air changes /hour with a minimum of 3 air changes of fresh air (20%).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. 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) . Temperature of 20.220C. remove contaminated air & minimize the risk of transmission of airborne microorganisms  Consists of air inlets.Heating Ventilation Air Conditioning (HVAC) Systems  HVAC system maintain indoor air temp. fan ducts & air exhausts . humidity modification mechanisms. heating & cooling equipment. & humidity. control odours. filter beds.  Fumigation is no longer used in the Western Literature as they have all the modern critical parameters required for OT . there are extreme situations in operation theater (OT) facilities. 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?? . ranging from rooms with fans. window air conditioning. to the more sophisticated laminar airflow systems More than 60-80% of OTs.Indian Scenario  In India. The origin of fogging can be traced to the 19th century when Lister aerosolized carbolic acid to improve antisepsis in operative practice .Fogging  Nebulization of a disinfectant to decontaminate rooms vacated by patients with communicable diseases. The room would then be sealed & opened 12-24 hours later.What Is Fumigation?  Fumigation consisted of a mixture of formalin (280 ml) and potassium permanganate (150 gm) being placed in a bowl. Later on this changed formalin being sprayed with humidification by a spraying device or automist. Temperature 180C & Humidity should be maintained to 600C . Self defeating – OT fumigated with Formaldehyde needs to be force de-aired with unclean air d. Carboxyl acid & fumigation with Formaldehyde Advantages – Established age old technique Cost effective Disadvantages – a. Carboxylic acid has efficacy as scouring and disinfecting agent b.Different Methods 1. Unsafe Formaldehyde is carcinogenic . min 24 hrs turn around time c. Time consuming. 2. Aldehyde based germicides Glutaraldehyde & formaldehyde (200 ml in 10 liters of water i.Formaldehyde has been identified as a carcinogen . Self defeating – OT fumigated with Formaldehyde needs to be force de-aired with unclean air c. AdvantagesEffective Disadvantages – a. Leaves sticky residue because of surfactant base b. Unsafe.e 2%) through fogging machine is the commonly used procedure. Fungi and spore forming organisms . Viruses. Has no known resistant strains c. Has deep penetrating capability b. Silver (Ag) and Hydrogen Peroxide (H2O2) Advantages – a. Amoeba. Mycobacteria. Effective against Bacteria.3. A fogging system Droplets~7microns thrust by a motor running at 20.01% dilute sliver nitrate .000 RPM to a distance of 15 m Solution Ecoshield – 11% Hydrogen Peroxide and 0. 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)   . 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) . Fogging hastens the process of setting of airborne microorganisms. Mist. Air sampler . 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    .  No studies to demonstrate that fogging actually reduces the incidence of nosocomial infection. 1971: isuued May 1972) . 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. Third Quarter. aureus or E. coli. even in areas in completely saturated with residual disinfectant* *CDC: National Nosocomial Infections Study Quaterly Report. good & safe hospital practices. 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 . studies have not compared standard cleaning practices with fumigation/fogging.check up of human default . .to improve the standard of hospital hygiene & asepsis  .favourable psychological effect on staff & patients . In India.litigation . 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 . Jan 2002)  .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 airconditioners 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.
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