Infektiologische Bedeutung von Raumlufttechnischen Anlagen (RLTA) in Operations- und Eingriffsräumen

Abstract

Surgical teams need to breathe air that is conducive to their health. An adequate exchange of air ensures oxygen supply, the ventilation of humidity, smells, toxic substances, especially narcotic gases and surgical smoke, pathogens and particles. With regard to the infection risk, DIN 1946 / 4 -differentiates between operation theaters with the highest demand for clean air (operation room class I a), operation theatres with a high demand (operation room class I b) and rooms within the operation theatres without special requirements, meaning that the microbial load in the air is close to or equal to that of normal in-room air quality (room class II). For an operation room class I a, ventilation that displaces the used air is necessary, while a regular ventilation is sufficient for operation room class I b. Because of ambiguous -results in previous studies, the necessity to define a -class I a for operation rooms is being questioned. Therefore, this review focuses on the analysis of the existing publications with respect to this -question. The result of this analysis indicates that so far there is only one surgical procedure, the -implantation of hip endoprosthetics, for which a preventive effect on SSI of a class I a ventilation (displacement of the used air) is documented. One recent study, reviewed critically here, -showed opposite results, but lacks methodological clarity. Thus, it is concluded that evidence for the requirement of operation room classes can only be derived from risk assessment (infection risk by surgical intervention, extent of possible damages), but not from epidemiological studies. Risk assessment must be based on the following criteria: size and depth of the operation field, -duration of the procedure, vascular perfusion of the wound, implantation of alloplastic material and general risk of the patient for an infection. From an infection preventive point of view, no class I a "displacement ventilation" is necessary for small surgical procedures for which the RKI recommends only a procedure room, and for surgical procedures for which a risk evaluation indicates that the air in the operation theater can be equal to normal air.

Laminar Airflow Ceiling Size: No Impact on Infection Rates Following Hip and Knee Prosthesis

“…However, this study generated a lot of debate, at least in Germany. [9][10][11] One of the major discussion points was the hypothesis that only ceiling distribution systems with a size of 2 or larger 3.2 m # 3.2 m work appropriately and that we did not consider the size of the LAF ceilings. 9,10 Therefore, we decided to investigate the association between SSI rates and the availability of LAF in the operating rooms again for the next 5-year period, with a special focus on ceiling size.…”

Hygiene guideline for the planning, installation, and operation of ventilation and air-conditioning systems in health-care settings – Guideline of the German Society for Hospital Hygiene (DGKH)

“…New, albeit retrospective non-controlled studies showed no protective influence in comparison to TML (mixed flow ventilation) [ 13 ], [ 14 ], [ 15 ], [ 16 ], [ 17 ]. All studies are marked by a number of limitations [ 18 ], [ 19 ], and thus do not lead to conclusive evidence at this point in time [ 20 ].…”

Baustelle OP

“…Allerdings spielt insgesamt betrachtet die Raumluft bei den meisten operativen Eingriffen als eigenständiges Erregerreservoir keine wesentliche Rolle, und selbst bei orthopädischen Implantationsoperationen kann sie nicht als Haupterregerreservoir betrachtet werden 3 ( 7,8,9,10,11 ). Auch die KRINKO kommentiert, dass aufgrund des infektionsprophylaktischen Effekts eine Differenzierung in Raumklasse Ia und Ib nicht gerechtfertigt ist 2 .…”