Sterilization of operation theaters Document Transcript
Sterilization of Operation Theatres Methods to Replace FumigationDr.T.V.Rao MD In spite of brief stay of patients in the operation theatre, the environment of operation theatre plays a great role in the onset and spread of infections, because of a multifactor causation of infections. It is usually necessary to study the epidemiology of infection as a multidisciplinary approach. In resource poor circumstances as in most developing countries, people work in isolation and few facilities to make any epidemiological surveys. Many believe that routine Microbiological monitoring is most essential but in reality it is not practicable. But every hospital should pay good attention in proper maintenance of air conditioning plants, ventilator systems, and to have greater control on mechanisms and personnel involved in disinfection and sterilization of materials used in the theatres in operative procedures. Sterilisation means eradicating germs completely, which is not 100% possible in an operation theatre. The sources of bacterial contamination are from air and the environment, infected body fluids, patients, articles, equipment etc. The following methods are practiced to keep the operation theatre (OT) bacteriologically safe and below accepted levels: 1. Special air flow pattern (the air flow pattern is such that filtered and purified air circulates and contaminated air is removed continuously). There is restriction of personnel traffic, closing of OT doors and a good ventilation system. 2. Standard cleaning, disinfection with appropriate chemical agents, good theatre practice, discipline, can provide a microbiologically safe environment. Fumigation Fumigation is an age old process of sterilisation, of the environment, may be a sick room or Operation theatres. It is done with formalin fumes. Formalin fumes are very pungent and harmful. So when a room is fumigated, it is tightly closed and sealed before fumigation. The room is opened after fumigation (12 -‐ 24 hours). The room can be used once all fumes are out. OSHA indicated that Formaldehyde should be handled in the workplace as potential carcinogen and set an employee exposure standard for Formaldehyde that limits an 8-‐hour time-‐ weighted average exposure concentration of 0.75ppm. Commercially available disinfectant Formaldehydes are the most commonly used agents for high level disinfection of the theatre environment. Formaldehyde is the commonly used agent. Formaldehyde gas is generated from liquid formalin utilizing potassium permanganate crystals. 40% formalin liquid is added to potassium permanganate crystals to generate gas. Alternately, formalin liquid can be dispersed by a sprayer like device in the theatre environment. After a contact time of at least 6-‐8 hours, the formaldehyde needs to be neutralized by using ammonia,
allowing at least 2 hours contact time for ammonia to neutralize the formaldehyde prior to the use of theatre. How the Fumigation was done 1 Seal the room with adhesive tapes round the edges of the doors / windows and ventilators and apertures. 2 For Each 1000 cu.ft of space place 500ml formaldehyde (40% solution) and 1000ml of water in an electric boiler. Switch on the boiler, leave the room and seal the door. 3. Seal the room for 24 hrs. 4. Then open the door and neutralize any residual formaldehyde with ammonia by exposing 250ml of S.G 880 ammonia/ 1Lt of formaldehyde used. (Ref -‐ Mackie and McCartney Practical Medical Microbiology 13th Edition) 5. Fumigation is obsolete in many developed nations in view of toxic nature of Formalin. Too frequent use and inhalation is hazardous 6 Several new safe chemicals are emerging but constrains of economy limit the use and several hours of closure of operation theatres can be curtailed as with Fumigation. Aldehydes are potentially carcinogenic and it is therefore recommended that other agents such as hydrogen peroxide, hydrogen peroxide with silver nitrate, peracitic acid and other chemical compounds of formaldehyde should be used in place of the currently prevalent practice of using formaldehyde. These agents are dispersed with the aid of a fogger-‐like device inside the theatre environment. The contact time is about an hour and the theatre can be used immediately after the contact time. THE FOLLOWING PRECAUTIONS HAVE GREATLY REDUCED THE RATES OF INFECTION 1. Every Hospital must constitute Infection control committee to monitor the events in the Hospital, on all matters related to control of Infections. 2. The entry of unnecessary personnel to be restricted into operation theatres as everyone contributes to Infection. 3. A thorough washing with warm water and good detergent can bring overall improvement than mere decontamination sterilization with other Chemicals or fumigation. 4. Frequent monitoring and training of medical and paramedical staff must carry high priority than mere mechanical and chemical methods.
5. Thorough washing and carbolisation if done every day after the surgeries will greatly enhance the safety standards and economize the repeated expenditure on fumigation Emerging Compounds in use for Sterilization of Operation theatres Bacillocid rasant A newer and effective compound in environmental decontamination with very good cost/benefit ratio, good material compatibility, excellent cleaning properties and virtually no residues. It has the advantage of being a Formaldehyde-‐free disinfectant cleaner with low use concentration. Active ingredients: Glutaral 100 mg/g, benzyl-‐C12-‐18-‐ alkyldimethylammonium chlorides 60 mg/ g, didecyldimethylammonium chloride 60 mg/g. Advantages -‐ Provides complete asepsis within 30 to 60 minutes. -‐ Cleaning with detergent or carbolic acid not required. -‐ Formalin fumigation not required. -‐ Shutdown of O.T. for 24 hrs. not required. : Provides complete asepsis within 30 to 60 mts. Cleaning with detergent or carbolic acid not required ® Formalin fumigation not required ® Shutdown of O.T. for 24 hours not required with Bacillocid ® Other Newer and Non Toxic compounds. A Chemical compound VIRKON gaining importance as non-‐Aldehyde compound. Virkon proved to be safe Virucidal Bactericidal, Fungicidal Mycobactericidal Newer and Non Toxic compounds. Virkon is a multi-‐purpose disinfectant. It contains oxone (potassium peroxymonosulphate), sodium dodecylbenzenesulfonate, sulphamic acid; and inorganic buffers. It is typically used for cleaning up hazardous spills, disinfecting surfaces and soaking equipment. The solution is used in many areas, including hospitals, laboratories, nursing homes, funeral homes, medical, dental and veterinary facilities, and anywhere else where control of pathogens is required. Virkon has a wide spectrum of activity against viruses, some fungi, and bacteria. However, it is less effective against spores and fungi than some alternative disinfectants. Several other compounds are emerging in the Market for safer use, may need better resources for utility and implementation. Operation theatres should be built with implementation of good civil Engineering standards. OPERATION THEATRE -‐ DISCIPLINE 1. Only people absolutely needed for an assigned work should be present in the Operation Theatres 2. People present in theatre should make minimal movements and curtail unnecessary movements in and out of theatres, which will greatly reduce bacterial count.
3. 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 4 Prompt disposal of Theatre waste out of the theatre is of top priority. Any spillage of Body fluids including Blood on the floors is highly hazardous and prompts the rapid multiplication of Nosocomial pathogens in particular Pseudomonas spp SURVEILLANCE OF OPERATION THEATRE 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 Air bore 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 we can do the Surveillance for Air borne 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. STERILISATION AND DISINFECTION OF OPERATION THEATRES AND CRITICAL CARE AREAS GENERAL INSTRUCTIONS 1. Keep the floor dry when in use. 2. Use only vacuum cleaners (booming to be forbidden as it will dispense the infected material all around and on the equipment’s. 3. 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. 4. 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 1. Only remove the dust with cloth wetted with clean water. (Mop theatre furniture lamps, sitting tables, trolley tops, operation tables, procedure tables, and Boyle’s apparatus) Note: Need not use chemicals/disinfectants unless contaminated with blood or body fluids Between the procedures Clean operation tables or contaminated surfaces with disinfectant solutions. 1. In case of spillages of blood/ body fluids decontaminate with bleaching solution/ chlorine solution (10% available chlorine) 2. All discard waste in plastic bags (do not accumulate around surgical sites)
3. Do not discard soiled linen and gowns in the operation theatre floor. At the end of the day 1 .Clean all the table tops, sinks, door handles with detergent followed by low level disinfectant. 2 .Clean the floors with detergents mixed with warm water. 3. Finally mop with disinfectant like phenol in the concentration of 1 in 10 (low concentrations of phenol will not serve the purpose). 4. Keep the operation theatre dry for the next days work TRAINING OF PARAMEDICAL STAFF/ RESIDENTS 1. The short solution to control infection lies with trained staff. 2. The principal and control of infection to all new comers and junior staff should be a goal of any good Institution. 3. Formulate guidelines update as per the changing situation in control the infection. 4. Institute should formulate ideas on infection control to the need of circumstances, as there are no fixed guidelines or formulae to control to suit all occasional. 5. Simple repeated hygienic hand wash is most cost effective method to reduce several infections in Hospitals, in particular operation theatres Dr.T.V.Rao MD Professor of Microbiology Bibliography 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 Disinfection, sterilization and operation theater guidelines for dermatosurgical practitioners in India Narendra Patwardhan1, Uday Kelkar2 Year : 2011 | Volume : 77 | Issue : 1 | Page : 83-‐93 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) 4 Assessment of in-‐vitro efficacy of 1% Virkon against bacteria, fungi, viruses and spores by means of AFNOR guidelines. Herńndez A, Martró E, Matas L, Martín M, Ausina V. PMID 11073729 [PubMed -‐ indexed for MEDLINE] 5 Evaluation of in vitro efficacy of the disinfectant Virkon. Gasparini R, Pozzi T, Magnelli R, Fatighenti D, Giotti E, Poliseno G, Pratelli M, Severini R, Bonanni P, De Feo Eur J Epidemiol. 1995 Apr; 11(2):193-‐7.
Correspondence Dr.T.V.Rao MD Professor of Microbiology Travancore Medical College Kollam Kerala Email email@example.com