|Year : 2017 | Volume
| Issue : 1 | Page : 49-50
Air laminar flow ventilation is no better, case closed
Consultant Engineer, Director of Safety Dept, Saudi MOH, CBAHI Mentor Surveyor, Central Board for Accreditation of Healthcare Institutions, Jeddah, Saudi Arabia
|Date of Web Publication||23-Jun-2017|
Central Board for Accreditation of Healthcare Institutions, Jeddah
Source of Support: None, Conflict of Interest: None
Ventilation in critical care areas is crucial in minimizing surgical site infection, this article review the two ventilation modules used in operating rooms and based on previous studies conclude that hospitals should continue using the classical ventilation.
Keywords: Air laminar, ventilation, operating rooms, surgical site infection
|How to cite this article:|
Alzaid A. Air laminar flow ventilation is no better, case closed. Saudi Crit Care J 2017;1:49-50
| Introduction|| |
Since the current concept of operating rooms (ORs) was developed in the late 1800's, proper mechanical ventilation was established as a critical factor in reducing aerosols and particles within the surgery settings. This is done through continues dilution and mixing of existing OR air with outside fresh air. Most of the current air-conditioning and high-velocity air-conditioning (HVAC) codes and standards across the world require twenty air changes in ORs per hour. Although you need only 4–6 air changes per hour to achieve the comfort zone for the patient and staff, the high rate of the air changes is needed to dilute the air and minimize the chance for the particles and microorganisms “settling” on the OR surfaces, and more critically on the wound.
[Figure 1] shows the traditional HVAC air movements in the OR, also called the turbulent module, so to ensure the air mixing and removal of the particles from the OR. The supply air is a mix between fresh air and recirculating air from different areas. All air goes through high-efficiency particulate air filters before usage in OR.
In 1961, the world renowned orthopedic surgeon Sir Charnley, the hip replacement guru, advised new air circulation system to minimize the surgical site infection (SSI) associated with the long surgical procedure of hip replacement. His system – called the air laminar flow – is based on directing high-speed air supply inflow toward the operating table, creating an air curtain around the patient. [Figure 2] shows the schematic of air flow movement within the OR. Both the initial cost and operating cost of laminar air flow are much higher than the traditional turbulent system.
More than 30 years of the air laminar flow ventilation wide usage, all research amounts in one direction, no significant findings correlating the air flow ventilation to the reduction of SSI rates., Research review by the WHO in global guidelines for the prevention of SSI  adopted the same conclusion. Enormous researches have proven the air laminar flow ventilation in reducing the bacterial and containments in the OR environment but failed short in proven significant result in reducing SSI rates.,, The just published literature review (Bischoff et al.). sealed the fate of using air laminar flow ventilation in OR.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
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Bischoff P, Kubilay NZ, Allegranzi B, Egger M, Gastmeier P. Effect of laminar airflow ventilation on surgical site infections: A systematic review and meta-analysis. Lancet Infect Dis 2017;17:553-61.
[Figure 1], [Figure 2]