A bacteriological evaluation of laminar-flow systems for orthopaedic surgery.

An evaluation has been undertaken of the efficiency of laminar-flow ventilation in operating-rooms in which conventional operating-room clothing was used. It has been demonstrated that velocities in the region of 0.3-0.4 m./sec. will give maximum returns for effort in both down-flow and cross-flow systems. At this velocity the laminar-flow system, in terms of airborne bacteria measured at the wound site, was about 11 times more efficient using horizontal air-flow and 35-90 times more efficient using vertical air-flow than a plenum-ventilated operating-room.