[Postoperative wound infections. II. Risk factors related to surgery].

UNLABELLED: Postoperative wound infection is the most frequent complication of surgical treatment. The occurrence of infection depends on many factors, but the most important is bacterial contamination of wound according to the site of operation. The aim of this study was to establish wound infection rate and to determine the relationship between site of operation, wound contamination and the other surgery related factors and postoperative wound infection risk. The material was 1527 surgically treated patients in the 3rd Surgical Department of the Collegium Medicum of the Jagiellonian University during one year. From the study population were excluded 66 patients with wounds of the head and 7 patients who died within three days after surgery without wound infection signs. The healing of each wound was observed during the patient's hospitalisation and 30 days after discharge from hospital, and in orthopedic patients 6 months after discharge. The total number of 132 infected wounds was identified. The population of 1352 wounds healed without any complications was a control group. Data were recorded in a Wound Infection Register Card and were collected in the computer database. The data were statistically analysed. Relations between single factor and postoperative wound infection were evaluated using chi2 statistics and in the small group Fisher's exact probability test. Odds ratios and corresponding 95% confidence intervals were computed for all variables. The overall wound infection rate was 8.9%. The significant factors (p < 0.05) were gastrointestinal operation, reoperation, intraoperative X-ray examination, haematoma of the wound after operation, skeletal traction prior to surgery and implantation of prosthetic material in clean wounds.

CONCLUSIONS: 1. Wound contamination, site of operation (GI tract), open drainage, reoperation, intraoperative X-ray examination and postoperative haematoma of the wound are statistically significant risk factors which influence postoperative wound infection rate. 2. Postoperative haematoma of wound is the most important local risk factor of wound infection after surgery.