[Time trends of infections in orthopedic and traumatologic surgery].

Background: We have carried out a prospective study among 2,047 patients, operated in the Department of Traumatology of "La Paz" Hospital during two years in order to know the time trend of nosocomial infection.

Methods: All the operated patients have been included in the Study. Several variables have been collected (age, kind of surgery, infection, day of infection onset). Information was collected from the patient's clinical history and evolution and processed with the Sigma programme.

Results: The total percentage of infection was 10.06%; it was 7.63% in clean surgery and 26.79% in dirty surgery. Wound was the most frequent location of infection, followed in order of frequency by urine, respiratory system and sepsis. Since the patient is operated, there are two periods when infection increase significantly; those are between the 7-10 and 25-30 post operation days. This tendency is typical of wound and urine infections; but in septicaemia, infection appears about the third post operation day in dirty surgery and about the 14th day in clean surgery. When studying the moment of patients's infection in clean surgery, a quick increase of wound infection is obtained in the second week, going from 33% (the 7th day) to 78% (the 14th day); next the curve slope diminishes down to 100% (the 61st day). In dirty surgery, the initial increase of wound infection is greater (54% on infections appear the 7th day) and next it slows (64% of infections appear the 14th day and 100% are present the 45th day).

Conclusions: It is necessary to reduce the infection rate in clean surgery mainly by improving surgical prophylaxis. The risk of infection appears earlier in dirty surgery than in clean surgery; for this reason, we shall insist upon its treatment (not prophylaxis) at the moment of the operation. Surveillance of infection signs must be intensified at maximum during the first post-operation week for dirty surgery and in the second week for clean surgery.