The role of clean air in wound infection acquired during operation.

A wound isolator was used to perform 109 total arthroplasties of the hip, while 108 similar operations were done in a plenum ventilated operating room. Extensive bacteriologic studies of all patients were carried out before, during and after operation. Despite sterility of the air around the wound in the isolator group of patients, two major wound infections occurred in each of the two groups. Five minor wound infections occurred in the isolator and three in the nonisolator group of patients. All wound infections appeared to be secondarily acquired. No evidence was obtained to indicate that primary wound infection occurred during operation. The need for ultraclean air in operating rooms is deemed to be less urgent than the need to prevent secondary infection after operation.