engleski

Neopterin kinetics after cardiac surgery with or without cardiopulmonary bypass

INTRODUCTION Cardiac surgery (CS) with cardiopulmonary bypass (CPB) induces systemic inflammatory response by activating plasma proteins and blood cells. Activated monocytes/macrophages produce inflammatory marker neopterin (NP) which is helpful for follow-up pathological states associated with the activation of cell-mediated immunity. Therefore, the main focus of this study was to explore the NP kinetics in first 24 hours after cardiac surgery according to the use of CPB. The secondary aim was to test hypothesis that NP can be used as an important factor for monitoring patient's postoperative status. MATERIALS AND METHODS Two patient groups undergoing CS were studied: 42 patients without the CPB use (off-pump group) and 36 patients with the CPB use (on-pump group) (Table 1). Blood samples were taken one day before the surgery and 12, 24 and 72 hrs after the surgery. NP levels were measured by commercial ELISA kit in duplicates. RESULTS Significant difference between groups were found for NP levels 12 and 24 hrs after CS, being higher in on-pump group (Figure 1). Strong association was found between NP levels 12 hrs after CS and the length of ICU stay for on-pump group (r=0.744 ; p<0.001). Patients were additionally compared on the basis of NP cut-off value, set to 10 nmol/L. There were 7 patients (17%) in off-pump group and 12 patients (34%) in on-pump group with elevated preoperative NP levels. Strong association was found between preoperative NP levels and the length of ICU stay for those on-pump patients with elevated preoperative NP (r=0.855 ; p=0.001 ; linear regression equation y=0.50x-5.14 ; p<0.001) (Figure 2). DISCUSSION Our study was the first to describe NP kinetics within first 24 hours after cardiac surgery, with respect to the use of CPB. Limitations of our study include small sample size and wide age range (39-77 years). Since preoperative NP levels were age dependent, it is necessary to analyze relationship between NP and the length of ICU stay in more specifically designed patient groups. Additionally, this study was not designed to study clinical endpoints and, therefore, future studies are necessary to determine exact postoperative complications associated with higher preoperative NP levels. CONCLUSIONS CPB was found to increase early postoperative NP levels more than off-pump surgery. Preoperative NP levels higher than 10 nmol/L in on-pump group could predict prolonged ICU stay and outpoint patients at higher risk for developing postoperative complications and, therefore, help to determine the necessary therapeutic interventions.

cardiopulmonary bypass; systemic inflammatory response; neopterin

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