[Predictive factors of surgical infection in heart surgery]

Deep infection of the surgical site in cardiac surgery may lead to very severe complications. There is controversy as to the importance which different factors may have in the incidence of this complication. The aim of this study was to determine the importance of determined factors on the risk of deep infection of the surgical site.

A retrospective study of 1,127 patients submitted to cardiac surgery from 1989 to 1991 was performed. The factors associated to the development of deep surgical infection were determined by univariant analysis. A multiple logistic regression model was designed to identify the factors independently associated to the risk of infection. The morbidity of surgical infection attributable to prolonged preoperative stay was calculated.

Of the numerous factors associated to risk of surgical site infection on univariant analysis, only five were independently associated to risk of infection on multivariant analysis: prolonged preoperative stay (OR = 2.4 [1.1-5.5]), dirty surgery (OR = 3.2 [1.0-9.9]), length of the intervention (OR [every hour] = 1.5 [1.2-2.0]), diabetes mellitus or chronic obstructive pulmonary disease (OR = 2.6 [1.2-5.6]) and functional grade according to the New York Heart Association (OR = 3.4 [1.5-7.7]). The proportion of deep infection attributable to prolonged preoperative stay was 41.8% (4.0-58.2).

The incidence of deep surgical infection may be decreased with a reduction, whenever possible, of the length of surgical intervention and preoperative stay.