In cirrhotic patients with hyperdynamic circulation, the Vigileo system showed a degree of error and unreliability higher than that considered acceptable for clinical purposes.

The new software (version 3.02) provided substantial improvements over the previous versions with better overall precision and trending ability. Further algorithm refinements will increase this technology's reliability to be extensively used in the highly complex setting of cirrhotic patients undergoing liver transplantation.

To verify whether cystatin C may be of some use as a renal function marker immediately after orthotopic liver transplantation (OLT), we compared serum cystatin C (S Cyst ), serum creatinine (S cr ), and creatinine clearance (C cr ) levels with the glomerular filtration rate (GFR). On postoperative days 1, 3, 5, and 7, S Cyst and S cr was measured in simultaneously drawn blood samples, whereas C cr was calculated using a complete 24-hour urine collection. The GFR was determined on the same days by means of iohexol plasma clearance (I-GFR). The correlation between 1/S Cyst and I-GFR was stronger than that of 1/S cr or C cr (P < 0.01). In the case of moderate reductions in I-GFR (80-60 mL/minute/1.73 m 2 ), S cr remained within the normal range, whereas the increase in S cyst was beyond its upper limit; for I-GFR reductions to lower levels (59-40 mL/minute/1.73 m 2 ), S cr increased slightly, whereas S cyst was twice its upper normal limit. When we isolated all of the I-GFR values on days 3, 5, and 7 that were >30% lower than that recorded on the first postoperative day, S Cyst (P < 0.0001) and S cr (P < 0.01) levels were increased, whereas C cr remained unchanged (P ‫؍‬ 0.09). Receiver operating characteristic (ROC) area-under-the-curve analysis showed that the diagnostic accuracy of S cyst was better than that of S cr and C cr . S cyst levels of 1.4, 1.7, and 2.2 mg/L respectively predicted I-GFR levels of 80, 60, and 40 mL/minute/1.73 m 2 . In conclusion, cystatin C is a reliable marker of renal function during the immediate post-OLT period, especially when the goal is to identify moderate changes in GFR. It has been widely demonstrated that acute renal failure can severely affect the postoperative course of a complex procedure such as orthotopic liver transplantation (OLT). 1,2 As renal function can be threatened for different reasons in the period immediately following OLT (i.e., hemodynamic disturbances, drug nephrotoxicity, acute surgical or infectious complications), it is very important for clinicians to have access to sensitive and reliable markers that can promptly identify renal dysfunction from its initial stage in order to allow them to adopt the necessary preventive and supportive measures for avoiding or containing the development of renal damage.Although commonly used, the measurement of serum creatinine (S cr ) and the calculation of creatinine clearance (C cr ) are not very reliable in cirrhotic patients undergoing OLT because some of the peculiarities of the liver disease (reduced muscle mass, decreased creatinine biosynthesis, high blood bilirubin levels) can lead to false results. [3][4][5] Furthermore, it has been reported that making routine S cr measurements is an insensitive way of assessing renal function in patients adminis-