Infection control in cardiac surgery.

This report relates the results of a multifaceted, 4 year program directed toward reduction of infection in patients undergoing cardiac operations and extracorporeal circulation in a large teaching hospital. Retrospective analysis of all superficial and deep wound infections and prosthetic valve infections for the period of 1966 to 1970 and a prospective study of the period of 1970 to 1974 were made. The multifaceted program begun in 1970 consisted of (1) renovation of a cardiac operating room with incorporation of a high flow, vertical unidirectional ventilation system, (2) change in the gown and draping material for improvement of barriers to bacteriologic shedding, (3) frequent steam sterilization of prosthetic valves, (4) routine use of an antistaphylococcal agent in patients receiving valve replacement, and (5) an unannounced bacteriologic monitoring program of the cardiac operating room personnel. Studies of airborne particulates and bacteria and adequacy of skin preparation and hair removal also were conducted. The studies showed that (1) a high-flow HEPA filtered vertical ventilation system and altered operating room clothing reduced the concentration of airborne particles and the concentration of bacteria at the wound by a factor of 10 compared to conventional operating rooms, (2) the incidence of markedly contaminated scrubbed and unscrubbed hands decreased, (3) shedders and carriers were identified, and (4) current patient skin preparation and hair removal practices were satisfactory. The results of the program were a reduction of the deep wound infection rate from 2.9 to 0.6 percent (p less than 0.01) and a concomitant total wound infection decrease from 6.6 to 3.3 percent. Prosthetic valve infection rates decreased fourfold, from 5.6 to 1.4 percent. It is concluded that careful attention to possible endogenous sources of infection from the patient and a multifaceted program directed to exogenous sources of infection can lower infection rates in cardiac surgical patients.