Reasons related to the operating room structure:
· Lack of a ventilating system
· Lack of / or inefficient anaesthetic gas evacuation system
· Lack of extractors in the operating room
Reasons related to the medical equipment:
· Anaesthetic machines without a gas evacuation system
· Loss of gas from anaesthetic machines due to lack of maintenance
· Gas loss or leakage from the anaesthetic circuit
· Loss or leakage of flow meter
· Loss in the vaporizer
· Evacuation valves Malfunctioning
· Loss or Leakage in the Canister CO2-absorber
· Loss or leakage in the ventilator
Reasons related to the anaesthetic techniques:
· Wrong mask sealing
· Flushing in the circuit
· Failure in the vaporizer filling
· Failure in the gas flow closure at the end of the process
· Leakage in the paediatric circuit
· Leakage in the uncuffed tracheal tube with gold standard for paediatric practices
Recommendations
In order to reduce chemical pollution and environmental exposure levels in the operating room, the anaesthetic concentration residues should be reduced as follows:
Using gas evacuation system:
A gas evacuation system should be used in all operating rooms where anaesthesia is administered. Besides, the air at this workplace should be changed 15 or 21 times per hour. It is recommended that the anaesthetic machines should have their own evacuation system.
Each medical institution should organize, define and implement not only a corrective and preventive plan but also an equipment maintenance plan that includes a gas evacuation system, central aspiration, air conditioning system and ventilation system.
These measures aim at achieving the concentration levels recommended by ruling agencies which established the maximum anaesthetic gas residue limit at workplace
Performing appropriate working practices:
· Use of low flow anaesthetic circuits
· Effective use of surgical mask with an adequate co-adaptation to avoid leakage
· Effective closure of the vaporizer when it is not used
· Use of fresh gas flow after anaesthetic induction
· Complete reservoir bag drainage from the evacuation system before discontinuing the anaesthesia
· Careful vaporizer filling to avoid environmental leakage
· Prudent avoidance of flushing in the circuit
· Control of the normal functioning of over flow valves
· Effective revision of the gold standard reusable tracheal tube to avoid leakage in the cuff
Monitoring anaesthetic gases residues in the operating room
Monitoring is not a formal and compulsory practice; however, those institutions that implement it as a regular practice will have accurate and precise information about gas leakage or loss in the system.
Establishing medical surveillance programs
Institutions should implement programs where anaesthesiologists and staff members working in the operating room are trained. These programs should include not only updated information about medical literature on the subject, in special those that put emphasis on the side effects of anaesthetic residue gases, but also information about the maintenance and revision of the equipment involved. Besides, each institution should provide workers with a report on side effects at his / her work produced by the gasses.
Conclusion
Depending on the gas concentration, the presence of residual anaesthetic gases at workplace and adjacent rooms has been widely proved. Acting on the above mentioned factors will allow reducing the gas concentration to low values.
From the technical point of view, two basic measures can be taken: Residue gas elimination from the source of emission by means of scavenging and general ventilation of the operating room by renovating or treating the air.
As regards side effects on human health, recent revisions show that there is not strong evidence suggesting that residue anaesthetic gas concentration poses a risk to humans; however there is not conclusive evidence that proves the contrary.
As regards repercussions of low intellectual or physical performance, there is not agreement among different authors, so it is reasonable to consider that there is not conclusive evidence that proves that anaesthetic agents in the quantity found in operating rooms without any ventilation system have an effect on the psychomotor behaviour of healthy workers at a laboratory.
In order to eliminate the residual gases, there are different procedures, most of which are based on vacuum exhaust gas management (Scavenging) , however a basic complement to the localized gas scavenging is a general ventilation of the place with total air renovation or air treatment. The combination of both systems together with a periodic circuit and respirator maintenance allows obtaining adequate environmental air quality without an excessive cost
Bibliography
1. CALABRESE GUSTAVO. Guía de Prevención y Protección de los Riesgos Profesionales del Anestesiólogo. Comisión de Riesgos Profesionales de La Confederación Latinoamericana de Sociedades de Anestesiología. C.L.A.S.A. 2003
2. Parietti Alfredo. Riesgo Profesional Hosp. De Enfermedades Infecciosas “Fco. J. Muñiz” Buenos Aires, Argentina
3. Guardino Solá Xavier, Rosell Farrás Mª Gracia. Exposición laboral a gases anestésicos. Centro nacional de Condiciones de trabajo. http://www.estrucplan.com.ar/Producciones/entrega.asp?IdEntrega=365
4. Ramón De Lille-Fuentes. Contaminación ambiental en sala de operaciones y sus consecuencias para el anestesiólogo y personal que labora en ellas. Centro Panamericano de Ingeniería sanitaria CEPIS/OPS 19-08-99
5. Dr. Pedro Barbieri Bioseguridad En Quirófano. REV ARG. ANEST. 1995; 53: 3: 147-160
6. Rodolfo Vega Ramos Riesgos profesionales del anestesiólogo y del personal de quirófano. PROGRAMA DE ACTUALIZACIÓN CONTINUA PARA ANESTESIÓLOGOS Tomo A-1 Pág. 65-69. 1997
Translation: Transworld, Language Solutions
http://www.portalesmedicos.com/traductores-medicina/transworld
