Neutrophil gelatinase-associated lipocalin as emerging biomarker of acute renal failure in renal transplant patient after coronary artery bypass surgery.

Acute renal injury (AKI) is a serious complication, which increases the risk of death after cardiac surgery. Although serum Cre is typically used for diagnosis of AKI, there are disadvantages in its use as renal marker. Neutrophil gelatinase-associated lipocalin (NGAL) is a protein of the lipocalin family and is expressed by neutrophils and other epithelial cells including segments of proximal collecting tubule (PCT). It is introduced as an excellent renal biomarker, for the early diagnosis of AKI in children and adults undergoing renal transplantation and cardiac surgery. According to literature data NGAL is detected in the very first urine sample within two hours following ischemia. It is one of the earliest and most robustly induced proteins in kidneys following ischemic and nephrotoxic insults. We present an interesting case of renal transplant patient under long-term immunosuppressive therapy. He had already renal impairment of the transplant kidney (GFR 29.3 mL/min/1.73 m(2)). He suffered from coronary artery disease without history of myocardial infraction and underwent elective coronary artery bypass grafting (CABG). Renal function was monitored also with NAGL, in order to avoid potential renal graft failure postoperatively.

"Learning curves" of cardiac surgery in relation to risk stratification and hospital location.

AIM: The purpose of this study was to determine any significant differences in "learning curves" between private and public hospitals when the same senior surgeon was responsible during the initial phases of open-heart surgery programs development, in relation to risk stratification and hospital location. METHODS: A prospective review of 610 patients records was performed at a newly-opened cardiothoracic program in a public University Hospital (PUH) in the periphery of Greece, and a private institution (PI) with an experienced intensive care unit (ICU) in the capital city of Athens. Preoperative risk stratification, mortality and postoperative length of stay (LOS) were analysed between 1999 to 2001. RESULTS: At PUH 298 patients were operated and 312 patients at PI. There were 136 low risk (EuroSCORE 0-2) and 474 medium and high-risk patients (EuroSCORE > or =3). There was no significantly elevated mortality or learning curve in low risk surgery either at PUH (57 patients with 1 death) or PI (79 patients and 1 death). In medium and high-risk surgery at PI there was no mortality in 68 patients operated by the senior surgeon and no learning curve in all 233 such patients. In 240 medium and high-risk patients at PUH there was a learning curve despite the involvement of the same senior surgeon. In 1999 and 2000 the observed mortality (OM) in 150 patients was 15.33%, EuroSCORE 5.98, and in 2001 in 91 patients OM 3.29%, EuroSCORE 5.95 with p=0.00.8 when "experienced" ICU staff was employed. LOS was significantly reduced in 97 patients in 2001 at PUH (8.7 d +/- 2.81 vs 11.07 days +/- 7.9 in 1999 and 2000, p=0.046) confirming the existence of a learning curve at the PUH. No such change was observed at PI (8.2 days vs 7.8, p=0.45). CONCLUSION: No mortality differences or learning curve characteristics were detected for low risk operations either at PUH or PI. For medium and high risk surgery there appears to be a learning curve in PUH but not in PI despite senior surgeon involvement in both. The presence of an experienced ICU appears to play a critical role in the outcome of operations in newly opened cardiothoracic programs.