Selected Abstracts from the 31th International Vicenza Course on Critical Care Nephrology. Vicenza, June 11-14, 2013
Abstracts are available online only, free of charge, at www.karger.com/Background: Urine alkalinisation with sodium bicarbonate decreases renal oxidative stress and might attenuate sepsis-associated acute kidney injury (s-AKI). Its safety and feasibility in patients at risk of s-AKI has never been tested. Methods: We randomly assigned patients at risk of s-AKI [systemic inflammatory response syndrome (SIRS), oliguria and elevated (≥150 μg/l) serum neutrophil gelatinase-associated lipocalin
... ated lipocalin (NGAL) concentration] to receive a 0.5 mmol/kg bolus followed by a 0.2 mmol/kg/hr infusion of either sodium bicarbonate (treatment group) or sodium chloride (placebo group). Results: Among 50 patients with SIRS and oliguria, 25 (50%) had an elevated serum NGAL concentration. Of these, 13 were randomized to receive sodium bicarbonate and 12 to receive sodium chloride infusion. Study drugs were infused on average for a period of 25.9 ± 10.0 hours. Severe electrolyte abnormalities occurred in seven (28.0%) patients [four (30.8%) in treatment group vs. three (25%) in placebo group]. These abnormalities resulted in early protocol cessation in six (24.0%) patients and study drug suspension in one (4.0%). This adverse event rate was judged to be unacceptable and the study terminated early. There was no difference between the two groups in NGAL concentration over time, occurrence of AKI, requirement for renal replacement therapy, hospital length of stay and mortality. Conclusion: Administration of sodium bicarbonate and sodium chloride solutions in patients risk of s-AKI was associated with frequent major electrolyte abnormalities and early protocol cessation. The tested protocol does not appear safe or feasible. Introduction: Contrast-enhanced ultrasound (CEUS) is a new technique that might enable portable and non-invasive organ perfusion quantification at the bedside. However, it has not yet been tested in critically ill patients. We sought to establish CEUS's feasibility, safety, reproducibility and potential diagnostic value in the assessment of renal cortical perfusion in the peri-operative period in cardiac surgery patients. Methods: We recruited twelve patients deemed at risk of acute kidney injury planned for elective cardiac surgery. We performed renal CEUS with destruction-replenishment sequences before the operation, on intensive care unit (ICU) arrival and the day following the admission. Enhancement was obtained with Sonovue ® (Bracco, Milano, Italy) at an infusion rate of 1 ml/min. We collected hemodynamic parameters before, during and after contrast agent infusion. At each study time, we obtained five video sequences, which were analysed using dedicated software by two independent radiologists blinded to patient and time. The main output was a perfusion index (PI), corresponding to the ratio of relative blood volume (RBV) over mean transit time (mTT). Results: All 36 renal CEUS studies, including 24 in the immediate post-operative period could be performed and were well tolerated. Correlation between readers for PI was excellent (R 2 = 0.96, p < 0.0001). Compared with baseline, there was no overall difference in median PI's on ICU admission. However, the day after surgery, median PI's had decreased by 50% (p < 0.01) [22% decrease in RBV (p = 0.09); 48% increase in mTT (p = 0.04), both suggestive of decreased perfusion]. These differences persisted after correction for haemoglobin; vasopressors use and mean arterial pressure. Four patients developed AKI in the post-operative period. There was no correlation between post-operative changes in creatinine levels and changes in PI's. Conclusions: CEUS appears feasible and well tolerated in patients undergoing cardiac surgery even immediately after ICU admission. CEUS derived-parameters suggest a decrease in renal perfusion occurring within 24 hours of surgery. Abstracts Objectives: To establish the validity and reliability of measuring weight in critically ill patients with electronic weighing beds. Design: Prospective observational trial. Setting: Private intensive care unit (ICU) affiliated to university hospital. Patients: All patients admitted to ICU after cardiac surgery with an intended length of stay >48 hours. Interventions: None Measurements and Main Results: We weighed all eligible patients on ICU admission whenever possible and then twice daily (1200 and 2400 hrs) using electronic weighing beds (Hill-Rom TM , Batesville, USA). For each measurement, non-removable items were recorded and an average value deducted from the measured weight. We compared differences in body weights (BW) between two consecutive twelve hours periods with the corresponding fluid balance (FB). Additionally, we compared weights obtained with electronic-weighing beds to those obtained with a regular calibrated scale on ICU discharge. We obtained data in 103 consecutive patients for 414/548 (75.5%) of all possible BW measurements. On average, we identified a total of 3.5 kg (SD 1.4) of non-removable items on patients' beds at time of weighing. The correlation between 12 hourly changes in BW and FB was weak (r = 0.28, 95% CI 0.17-0.39), even after correction for insensible fluid losses (r = 0.27, 95% CI 0.15-0.38) and when only values obtained in intubated patients were taken into account (r = 0.34, 95% CI 0.16-0.49). Similarly, limits of agreements were wide (95% CI: -3.3 to 3.5 kg). There was also poor agreement between weights obtained on electronic beds and those obtained on the regular scale on ICU discharge (95% CI: -7.6 to 7.6 kg). Conclusion: Body weight measured by electronic weighing beds does not seem sufficiently robust or accurate to replace daily fluid balance in ICU. The clinical value of equipping ICU's with such beds remains uncertain.