Air filtration guidelines for operating rooms are determined by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) using a standard known as Minimum Efficiency Reporting Value (MERV). MERV is determined based on the size of particles successfully removed from the air and is used to classify the efficiency of HEPA filters. Ratings range from 1-16 and efficiency increases as the rating increases. [1] ASHRAE groups surgeries into three categories: minor surgical procedures (A); minor or major surgical procedures performed with minor sedation (B); and major surgical procedures performed with general anesthesia or regional block anesthesia (C). Each surgical category is given a minimum MERV rating it must comply with. [2]
Air filtration standards differ between the U.S. and other countries. The American ASHRAE rating system does not account for changes in filtration efficiency due to electrostatic charge. These MERV ratings do not account for a decrease in efficiency over the first few weeks of use due to a drop in static charge. The air filtration rating system from the International Standardization Organization (ISO) does account for this loss in filtration efficiency. [6] ISO standards are widely used in Europe and other countries.[ citation needed]
Laminar airflow ventilation consists of air flowing a single direction, as opposed to turbulent ventilation. [3] Current research shows mixed results as whether laminar airflow in an operating room decreases surgical site infections. [7] [8] [9] Laminar airflow ventilation is more frequently used in operating rooms in Europe and is considered best practice for operating rooms to prevent surgical site infections. The Centers for Disease Control and Prevention (CDC) in the United States does not find the use of laminar airflow in operating rooms beneficial.[ citation needed]
Air filtration guidelines for operating rooms are determined by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) using a standard known as Minimum Efficiency Reporting Value (MERV). MERV is determined based on the size of particles successfully removed from the air and is used to classify the efficiency of HEPA filters. Ratings range from 1-16 and efficiency increases as the rating increases. [1] ASHRAE groups surgeries into three categories: minor surgical procedures (A); minor or major surgical procedures performed with minor sedation (B); and major surgical procedures performed with general anesthesia or regional block anesthesia (C). Each surgical category is given a minimum MERV rating it must comply with. [2]
Air filtration standards differ between the U.S. and other countries. The American ASHRAE rating system does not account for changes in filtration efficiency due to electrostatic charge. These MERV ratings do not account for a decrease in efficiency over the first few weeks of use due to a drop in static charge. The air filtration rating system from the International Standardization Organization (ISO) does account for this loss in filtration efficiency. [6] ISO standards are widely used in Europe and other countries.[ citation needed]
Laminar airflow ventilation consists of air flowing a single direction, as opposed to turbulent ventilation. [3] Current research shows mixed results as whether laminar airflow in an operating room decreases surgical site infections. [7] [8] [9] Laminar airflow ventilation is more frequently used in operating rooms in Europe and is considered best practice for operating rooms to prevent surgical site infections. The Centers for Disease Control and Prevention (CDC) in the United States does not find the use of laminar airflow in operating rooms beneficial.[ citation needed]