Abstract
An assessment has been made regarding the postoperative infections, especially MRSA infections, in aged patients. Six hundred and fourty-four cases undergoing digestive tract surgery, except appendicitis, in our section for the recent 3 years were studied by dividing. They were into 3 groups: group A (aged 20-64), group B (aged 65-74) and group C (aged over 75). The incidence of postoperative infection increased with aging, namely it was 9.1% in group A, 18.3% in group B, or 22.9% in group C. As to the affected sites, respiratory tract and catheter infections were significantly predominant in group C. Among the isolates, MRSA was most frequently isolated in aged group C (56.9%) with a significant difference, followed by group B (26.0%) and group A (23.5%). MRSA infection in group C was commonly found in patients having postoperative insufficiency or some underlying diseases in the respiratory tract. On the other hand, many of the patients in group A and B were treated with the first or second generation of cephem families of antibiotics for postoperative prophylactic use, but the patient in group C were administrated with the third generation of cephem families of antibiotics (in 31.8%) or combined use of cephems and aminoglycosides (in 45.5%), with a significant difference. From these facts, it is presumed that the selection of antibiotics made consciously of decrease of self defence ability in aged patients induced selection of MRSA conversely, causing increased incidence of MRSA infections. It is considered that the choice of antibiotics for postoperative prophylactic use in aged patients showed be based on the level of contamination and on the contaminated bacteria.
