The microbiologic risk of invasive haemodynamic monitoring in open-heart patients requiring prolonged ICU treatment.

The microbiologic risk of invasive haemodynamic monitoring and support was prospectively studied in 48 patients undergoing open-heart surgery under antibiotic prophylaxis and requiring intensive care for longer than 4 days. A total of 420 catheter tips were cultured of which 12 (2.9%) were positive. The incidence of positive catheter tip cultures was as follows: intravenous 1.8%, central venous 1.2%, arterial 1.8%, pulmonary arterial 5.9%, direct right atrial 2.4%, direct left atrial 0% and intra-aortic balloon pump catheters 7.7%. The rate of positive tip cultures was not significantly different for percutaneously and surgically inserted catheters (3.1% and 1.7% respectively). One (0.2%) catheter was associated with bacteraemia. Although the overall positive catheter tip culture rate was low, 21% of the patients had one or more positive catheter tip cultures. Complicated surgical procedures, a cardiopulmonary bypass time longer than 3.5 h, mechanical ventilation for more than 7 days, intensive care stay longer than 10 days, positive blood cultures and the use of more than 20 catheters were all individually associated with a significantly higher incidence of patients with positive tip cultures. Nevertheless, no patient developed endocarditis nor major morbidity related to the positive catheter tip cultures. Invasive haemodynamic monitoring does not seem to be an important microbiologic risk in open-heart patients requiring intensive care for longer than 4 days.